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Soil acidification is an issue for agriculture that requires effective management, typically in the form of lime (calcium carbonate, CaCO3), application. Mid infrared (MIR) spectroscopy methods offer an alternative to conventional laboratory methods, that may enable cost-effective and improved measurement of soil acidity and responses to liming, including detection of small–scale heterogeneity through the profile. Properties of an acidic soil following lime application were measured using both MIR spectroscopy with Partial Least Squares Regression (MIR-PLSR) and laboratory measurements to (a) compare the ability of each method to detect lime treatment effects on acidic soil, and (b) assess effects of the different treatments on selected soil properties. Soil properties including soil pH (in H2O and CaCl2), Aluminium (Al, exchangeable and extractable), cation exchange capacity (CEC) and organic carbon (OC) were measured at a single field trial receiving lime treatments differing in rate, source and incorporation. Model performance of MIR-PLSR prediction of the soil properties ranged from R2 = 0.582, RMSE = 2.023, RPIQ = 2.921 for Al (extractable) to R2 = 0.881, RMSE = 0.192, RPIQ = 5.729 for OC. MIR-PLSR predictions for pH (in H2O and CaCl2) were R2 = 0.739, RMSE = 0.287, RPIQ = 2.230 and R2 = 0.788, RMSE = 0.311, RPIQ = 1.897 respectively, and could detect a similar treatment effect compared to laboratory measurements. Treatment effects were not detected for MIR-PLSR-predicted values of CEC and both exchangeable and extractable Al. Findings support MIR-PLSR as a method of measuring soil pH to monitor effects of liming treatments on acidic soil to help inform precision agricultural management strategies, but suggests that some nuance and important information about treatment effects of lime on CEC and Al may be lost. Improvements to prediction model performance should be made to realise the full potential of this approach. [ABSTRACT FROM AUTHOR]

Background: Soil acidity, low soil nutrient status and low nitrogen fixing inoculants as a result of poor soil fertility management practices are the major constraints in soybean production in Assosa Zone, particularly in Assosa and Bambassi districts. Hence, this experiment was conducted to evaluate the effect of bio-, organic and inorganic NPSB fertilizers and lime on soil physico-chemical properties. Methods: During the period 2019-2020 factorial combinations of two bio-fertilizer inoculants [without bio-fertilizer (B1) and SB12 plus MAR1495 bio-fertilizer at their recommended rates of 500 g ha-1 (B2); two organic fertilizers without fresh cattle manure (M1) and fresh cattle manure at 10 t ha-1 (M2); two lime rates without lime (L1) and lime at 5 t ha-1 (L2); two inorganic NPSB fertilizers NPSB at 9.5-23-3.5-0.05 (F1) and NPSB at 19-46-7-0.1 (F2) at their recommended rates for soybean] were laid out in a randomized complete block design with three replications. Bulk density, pH, total nitrogen, available phosphorus, organic carbon and cation exchange capacity were collected and analyzed using SAS software version 9.1.3 and significant mean differences were separated using Duncan's multiple range test (DMRT). Result: Bulk density, pH, total nitrogen, available phosphorus, organic carbon and cation exchange capacity were highly affected (P<0.01) by the interactions of bio-, organic and inorganic fertilizers and lime. Finally, the interaction of SB12+MAR1495, 10 t/ha fresh cattie manure, 5 t/ha lime and NPSB at 19-46-7-0.1 improved the bulk density, pH, total nitrogen, available phosphorus, organic carbon and cation exchange capacity at both districts. [ABSTRACT FROM AUTHOR]

Results of eleven survey rounds of arable soils performed from 1964 to 2022 in the southwestern part of the central chernozemic region in Belgorod oblast are analyzed. Ordinary chernozems predominate in the steppe zone of the region, and typical and leached chernozems predominate in the forest-steppe zone. During the eleventh survey round (2019–2022), the average application of mineral fertilizers was 114.4 kg a.i./ha; of organic fertilizers, 9.6 t/ha; the rate of liming of acid soils was 43 800 ha per year. As a result, the average yield of winter wheat increased to 5.09 t/ha, sugar beet up to 45.6 t/ha, and corn for grain up to 7.15 t/ha. At the same time, the maximum value of the weighted average content of organic matter (5.3%) was recorded in the soils of cropland for the entire observation period. The part of acid soils decreased to 28.6%, and the part of moderately acid soils decreased to 3.0%. The hydrolytic acidity decreased to 2.7 cmol(c)/kg. The weighted average content of available phosphorus (139 mg/kg) and potassium (161 mg/kg) was the highest in the central chernozemic region. Soils with the low content of available sulfur comprised 85.7% of surveyed soils, those with the low content of zinc, 97.2%; copper, 92.5%; cobalt, 98.8%, manganese, 40.1%; and molybdenum, 21.3%. In terms of the content of available boron, 98.2% of soils were classified as very rich. [ABSTRACT FROM AUTHOR]

Limestone needs to react with water to correct the soil acidity. Therefore, it is expected that soil water availability interferes with limestone reaction time. The objectives of the study were (1) verify whether soil water availability alters limestone reaction time and (2) to evaluate whether the period of less than 60 days between limestone incorporation and sowing is sufficient to correct soil acidity. Two trials were carried out in a greenhouse, in a completely randomized design, in a factorial scheme. In the first trial, the BRS RB331 Ipyporã grass was grown, and the soil was subjected to the combination between the number of times the soil was raised to the maximum water retention capacity (1, 2, 3 and 9 irrigation) and two base saturation (50% and 60%). In the second trial, the Panicum maximum cv. Mombasa was grown, and six treatments were adopted in a 3 × 2 factorial scheme, consisting of the combination of three levels of water availability (50%, 75% and 100% from maximum water-holding capacity) and two limestone reaction periods (30 and 60 days). Soil water availability significantly influenced the limestone reaction time. As a result, it is possible to implant Mombasa and BRS Ipyporã grasses after 30 days of limestone incorporation, provided that the water saturation in the soil is increased to 75%. [ABSTRACT FROM AUTHOR]

Ureolytic microbes are abundant in broiler litter (BL), and previous research indicates that microbially induced calcium carbonate precipitation via urea hydrolysis occurs in gypsum‐amended litters. Given that calcium carbonate (CaCO3) is used to correct soil acidity, we hypothesized that the soil‐liming potential of BL + gypsum is greater than that of unamended litter. First, an experiment was conducted to isolate ureolytic bacteria from BL and confirm their ability to precipitate CaCO3. To determine the effects of calcium on urea hydrolysis, six isolates were identified from screenings of 30 colonies collected from different BL sources. Calcium increased the ureolytic rate by 29%–160% and the precipitation of CaCO3 by ~1500% in solution. The 16S rRNA of the isolate with the greatest rate of urea hydrolysis was sequenced and belong to Lysinibacillus macroides. Broiler litter amended with gypsum was inoculated with L. macroides and found to precipitate significantly more CaCO3 than inoculated litter without gypsum. Finally, over the course of a 28‐day incubation, the pH and inorganic‐N of soil, soil + BL, and soil + BL + gypsum were measured. Surprisingly, soil + BL + gypsum was found to have a significantly lower pH than soil + BL for the first 21 days. We propose that the decreased liming ability of BL + gypsum is due to a combination of pH buffering mechanisms and increased nitrification. Although gypsum is a useful litter amendment, it cannot be used to increase the liming ability of litter, despite the fact that gypsum‐amended litter has more CaCO3. Core Ideas: Calcium ions increase the rate of urea hydrolysis by poultry litter‐derived ureolytic isolates.Inoculating gypsum‐amended litter with ureolytic bacteria increases the CaCO3 and NH4+ content of litter.The soil liming potential of gypsum‐amended litter is not greater than the liming potential of unamended litter, even though treated litter contains more CaCO3. [ABSTRACT FROM AUTHOR]

Modelling the lime requirement (LR) is a fast and efficient way to determine the amount of lime required to obtain a pH that can overcome the adverse effects caused by soil acidification. This study aimed to model the LR based on the properties of soil and lime. A total of 17 acidic soils and 39 lime samples underwent soil–lime incubation in the laboratory. The predictive equations for the LR (t ha−1) were modelled using ∆pH (the difference between the target pH and initial pH), the neutralizing value (NV, mmol kg−1) of lime, soil pH, soil clay content (%), soil bulk density (BD, g cm−3), and the depth of soil (h, cm) as the factors in an exponential equation. The generic predictive equation, L R = ∆ p H × e − 3.88 − 0.069 × N V + 0.51 × p H + 0.025 × C l a y × B D × h , was validated as the most reliable model under field conditions. Simplified predictive equations for different soil textures when limed with quicklime and limestone are also provided. Furthermore, the LR proportions provided by hydrated lime, quicklime, limestone, and dolomite in commercially available lime can be expressed as 0.58:0.64:0.97:1.00. This study provides a novel and robust model for predicting the amount of lime product containing components with different neutralizing abilities that are required to neutralize soils with a wide range of properties. It is of great significance to agronomic activities and soil remediation projects. [ABSTRACT FROM AUTHOR]

Background and Aims: Suitable N source supply is critical to improve plant growth and N uptake, but the importance of nitrate (NO3−) for rice (Oryza sativa L.) and microbiota is often neglected in acidic paddy soils where ammonium (NH4+) is dominant. This study aimed to explore the differential effects of NH4+ and NO3− on rice growth, fertilizer nitrogen recovery efficiency (FNRE), and rhizosphere bacterial community in acid soil. Methods: Two rice varieties, Kasalath (Al-sensitive indica) and Koshihikari (Al-tolerant japonica), were exposed to different N sources with or without lime in an acid soil. Results: Liming and NO3− application solely improved the growth and FNRE of the Al-sensitive rice, namely, by increasing soil pH and alleviating Al toxicity. Compared with liming and rice variety, N source had a more pronounced influence on rhizobacterial community composition. Of the two sources, NO3− had a stronger effect on the rhizobacterial community than NH4+. Remarkably, rice plants fed with NH4+ specifically recruited Desulfosporosinus and Desulfitobacterium associated with ferric NH4+ oxidation in the rhizosphere, whereas those exposed to NO3− recruited Alicyclobacillus with NO3−-reducing iron oxidation ability. Three keystone taxa were identified in a rhizobacterial co-occurrence network analysis: Alicyclobacillus, which was positively associated with rice growth and FNRE, and Acidobacteriales and WPS-2, both with negative associations. Conclusion: Compared with NH4+, NO3− enhances the growth and FNRE of Al-sensitive rice and exerts dominant effects on the rhizobacterial community, which indicates the importance of NO3− for rice and has instructive implications for N management in acid soil. [ABSTRACT FROM AUTHOR]

N2O contributes to increasing the greenhouse effect and is also involved in stratospheric ozone depletion. In soil and water, N2O reductase catalyses the reduction of N2O into the inert form N2. N2O reductase activity is known to be affected by acidic conditions and the application of liming materials to acidic soils is now proposed as a solution for mitigating soil N2O emissions. During a one-year laboratory experiment, we studied the functioning of N2O reductase after the application of calcium carbonates to an acidic soil with a very low capacity to reduce N2O. The functioning of N2O reductase was characterised through anaerobic incubations using the acetylene inhibition technique combined with a logistic model to determine the main enzyme functioning characteristics (latency, maximal rate). Both changes in soil pH and soil capacity to reduce N2O were rapidly observed after the application of lime materials. The activity of N2O reductase was observed to be efficient throughout the experiment even when the soil had returned to initial acidic conditions, revealing a hysteretic response of N2O reductase to pH variations. Nevertheless, some signs of lower N2O reductase activity over time were observed mainly after 200 days of applying lime materials. Altogether, these results suggest that, in this soil condition, the beneficial impact of the application of liming materials on N2O emissions could last longer than this on soil pH. [ABSTRACT FROM AUTHOR]

Acid soils cover about 30% of the total ice-free land area. Based on this, the study aimed to evaluate soil acidity correction, focusing on identifying studies on limestone recommendations and corrective measures in agricultural systems. To do so, a systematic literature review (SLR) was carried out, composed of: 1) a systematic literature mapping (SLM), which identifies studies using topic-specific keywords and database automatic search; 2) Snowballing, technique that expands the initial selection using references of the selected studies; and 3) a SLR to synthesize the selected papers. First, 169 scientific papers were selected, of which 116 by SLM, 26 by backward Snowballing, and 27 by forward Snowballing. Most of the papers were about lime requirement (LR) methods (43%) and liming effects on soil and plants (19%). A total of 26 LR methods were found in the papers, of which most were base saturation and Shoemaker-McLean-Pratt methods. Calcium and magnesium carbonates, as well as dolomite, were the main sources of soil acidity correction. In brief, the study provided a critical and constructive analysis of the existing literature on soil acidity correction; the findings showed that liming is the most used and effective method to neutralize soil acidity. [ABSTRACT FROM AUTHOR]

Detailed knowledge of a soil's lime requirement (LR) is a prerequisite for a demand-based lime fertilization to achieve the optimum soil pH and thus sustainably increasing soil fertility and crop yields. LR can be directly determined by the base neutralizing capacity (BNC) obtained by soil-base titration. For a site-specific soil acidity management, detailed information on the within-field variation of BNC is required. However, soil-base titrations for BNC determination are too laborious to be extensively applied in routine soil testing. In contrast, visible and near-infrared spectroscopy (visNIRS) is a time and cost-effective alternative that can analyze several soil characteristics within a single spectrum. VisNIRS was tested in the laboratory on 170 air-dried and sieved soil samples of nine agricultural fields of a quaternary landscape in North-east Germany predicting the soil's BNC and the corresponding lime requirement (LRBNC) at a target pH of 6.5. Seven spectral pre-processing methods were tested including a new technique based on normalized differences (ND). Furthermore, six multivariate regression methods were conducted including a new method combining a forward stagewise subset selection algorithm with PLSR (FS-PLSR). The models were validated using an independent sample set. The best regression model for most target variables was FS-PLSR combined with the second Savitzky-Golay derivation as pre-processing method achieving R2s from 0.68 to 0.82. Finally, the performance of the direct prediction of LRBNC (R2 = 0.68) was compared with an indirect prediction that was calculated by the predicted BNC parameters. This resulted in slightly higher correlation coefficients for the indirect method with R2 = 0.75. [ABSTRACT FROM AUTHOR]

Phosphorus (P) transformations and associated changes in soil chemistry following lime application in acidic soils are very determinant to enhance P use efficiency. Thus, this study was conducted to evaluate the effects of different rates of lime on soil P fractions and chemical properties in acidic Luvisols of southern Ethiopia. The lime rates were 0 t/ha (0%), 3.75 t/ha (50%), 7.5 t/ha (100%), and 11.25 t/ha (150%), and incubated for a month with three replications. The soil P fractions analyzed includes soluble P (P-sol), P associated with iron (Fe-P), aluminum (Al-P), calcium (Ca-P), organic part (Org-P) and residual (Res-P). The result indicated that liming significantly (p < 0.05) improved the release of P-sol, Ca-P, and Res-P, and reduced Fe-P, Al-P, and Org-P. The changes in soil chemical properties were also significant. For instance, increased rate of lime enhanced soil pH from 5.3 to 6.5, reduced exchangeable acidity from 1.47 to 0.15 cmol(+)/kg, and increased available P from 2.74 to 8.72 cmol(+)/kg. Yet, the amount of P-sol was found low for plant needs even at a 150% rate of lime. Thus, working on external P requirement to equilibrate the need for plants followed by crop response validation are suggested. [ABSTRACT FROM AUTHOR]

Soil acidity with associated low nutrient availability is one of the major constraints to soybean production in southwestern Ethiopia. Integrated use of lime and acid-tolerant crops is believed to reduce soil acidity and improve crop production. The experiment was conducted in the field condition of Mettu, southwestern Ethiopia during the 2017/18 main cropping season. The experiment comprised fifteen soybean genotypes and two soil amendment (lime and unlimed) treatments arranged in a split-plot design with three replications. For each treatment, four rows were planted per plot; data related to growth, root, nodule, and yield of the crop were collected at a necessary stage for each. Liming and genotype interaction had significantly (P = 0.01) affected all parameters considered except for hundred seed weight and root volume and were affected only by the main effects of genotypes and liming. A significant reduction for most parameters was found on lime-untreated soil than treated soil. Though some genotypes showed higher performance for root, growth parameters, and yield components under unlimed soils; however, gave higher yield and yield components, when grown on lime-untreated with an average yield reduction of 13.7%, due to soil acidity. The maximum grain yield of (1943.93 kg ha-1) was obtained under lime treated acid soil from PI567046A genotype; while the lowest (510.49 kg ha-1) were recorded from SCS-1genotype under the lime untreated acid soil. Genotype BRS268 showed higher yield (1319.83 kg ha-1) under lime untreated acid soil than lime treated acid soil (1143.47 kg ha-1) and showed less reduction percentage for a number of the nodules, root weight, and number of seeds per plant; while PI567046A showed high reduction percentage for yield, biomass, number of pod and seed per plant. A high difference was observed among the soybean genotypes for soil acidity tolerance, which might be further exploited by breeders for the genetic improvement of soybean. Genotype BRS268 had performed better than other tested genotypes under increased soil acidity. selection would be effective to improve soybean genotypes performance on acid soils and identify low Phosphorus tolerant genotype that helps smallholder farmers optimize soybean productivity on acid soils in the study area. HAWASSA-04 variety is the most tolerant among the tested materials. However, further study is required by considering additional genotypes to reach a conclusive recommendation [ABSTRACT FROM AUTHOR]

This study investigated phosphorous (P) sorption characteristics under lime rates, and validated them under field conditions. Soil samples from nitisols and luvisols were taken, mixed with lime(tha−1) at[0,0], [5.25, 3.75], [10.5, 7.5] and [15.75, 11.25], respectively, and incubated for 30 days. It was equilibrated with KH2PO4 at 0, 10, 20, 30, 40, and 50 mgPL−1. The data were tested with Freundlich and Langmuir models. External P requirement (EPR) and changes in chemical properties were evaluated. The field validation on wheat involved rates of P (0, 8.2, 16.4, 24.6, 32.9, and 41.1 kg ha−1) and lime (0, 650, and 1300 kgha−1) in a randomized complete block design with three replications. Freundlich was found the best-fitted model. Freundlich coefficient (Kf) ranged from 212 to 45 mgPkg−1 (nitisols) whereas it was 112.7 to 16.29 mgPkg−1 (luvisols). EPR (kgPha−1) without and the highest lime rate were: nitisols (142.5 and 52.32 kgPha−1) and luvisols (124.84 and 25.94 kgPha−1). Liming reduced EPR by 63.3% (nitisols) and 79.3% (luvisols). Liming increased soil pH from [4.55 to 6.60 in the nitisols, and 5.33 to 6.51 in luvisols]; exchangeable acidity (cmol(+)kg−1) 3.84 to 0.01 nitisols, and 0.72–0.05 luvisols, and available P (mg/kg) 3.2–6.32 nitisol, and 2.74–8.72 luvisols. Furthermore, applying 32.9 kgPha−1 x 1300 kgha−1 lime resulted in grain yield (4345.2 kgha−1) that was 449% more than the untreated crop (791.3 kgha−1). The validation result suggested higher P than blanket P recommendation. It also justifies that excess P or lime alone cannot be a complete solution for P management and increased yield. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of liming on soil fertility, growth, nutrition and production of red pitaya (Hylocereus monacanthus) plants cultivated in pot. The experiment was conducted in blocks, with five doses of limestone (0.0; 0.6; 1.2; 1.8; and 2.5 t ha−1) and four replicates. Corrective doses were established to achieve base saturation of 20 to 70%. Liming increased soil pH (4.5 to 6.7), Ca concentration (5.36 to 20.11 mmolc dm−3), Mg concentration (4.36 to 16.53 mmolc dm−3) and base saturation (23.69 to 72.61%) and reduced potential acidity (37.39 to 15.41 mmolc dm−3). Liming reduces nitrogen concentration and increased phosphorus, calcium and sulfur concentrations in the cladodes. There was an increase in phosphorus concentration and decrease in boron and iron concentrations in fruit peel according to the increase in limestone doses; in the pulp, there was an increase in boron concentration and decrease in iron and zinc concentrations, from the lowest to the highest dose of limestone. Based on the principal component analysis, the limestone dose of 1.8 t ha−1 increased base saturation to 59%, providing favorable chemical conditions for the growth and productivity of red pitaya. [ABSTRACT FROM AUTHOR]

• The potential of microorganisms in olive trees in southern Brazil is still a gap. • Beneficial microorganisms can improve seedling growth and resistance to stress. • Each species of microorganism had its beneficial potential affected by pH. • The inoculant species can be adjusted according to the soil condition. The benefits of plant growth-promoting microorganisms to increase productivity have been demonstrated in various crops. Little is known about their potential in olive orchards in southern Brazil, whose naturally acidic soils are intensively limed for olive production. The present study investigated the effect of four inoculations (no inoculation, inoculation of the bacterium Azospirillum brasilense , inoculation of the fungus Trichoderma harzianum and inoculation of the fungus Trichoderma virens) at different levels of soil liming on the development of olive seedlings. The results showed that the microorganisms T. virens, T harzianum, and A. brasilense, but especially T. virens , when applied to the soil, promoted increased growth in height, diameter, and total dry mass yield of young olive trees, especially in conditions of lower soil acidity, with increases of 92, 34 and 33 % respectively, compared to the soil without inoculation. Less acidic environments, more favorable for olive tree development, enhanced the positive effect of these microorganisms. The microorganisms also mitigated the effects in potentially more stressful conditions, as observed by the higher concentration of photosynthesizing pigments, the reduction in hydrogen peroxide content, and the reduction in antioxidant enzyme activities in leaves and roots, in soil pH below that recommended for olive cultivation. [ABSTRACT FROM AUTHOR]

Accurate predictions of the short-term reactivity of liming products are needed for situations where rapid soil pH adjustment is desired. Lime efficiency (LE) describes the capacity of a liming material to neutralize soil acidity in comparison with a finely ground CaCO3 standard (LE = 100%). Our objectives were to evaluate LE for calcitic liming materials varying in particle size at 1–12 months after soil incorporation using pH change (LEpH) and CO2 evolution (LECO2) as response indicators, and to evaluate a 15-min citric acid (CA) test as a predictor of LE. We evaluated LE for lime particle size separates from 10 to 200 USA mesh (< 2000 µm to 75 µm) and for three commercial liming products (65, 25 and 11 µm average particle size) in a sandy loam soil. In field microplots, it took 6 months to achieve LE of > 80% with lime particles of <60 mesh (< 250 µm). LEpH was linearly related to LECO2 at one month following lime incorporation into soil. Both LEpH and LECO2 increased as a function of CA test values, as described by logarithmic equations. Lime particle size, CO2 evolution, and CA test values were all useful indicators of short-term LE. [ABSTRACT FROM AUTHOR]

Soil acidification is a major and growing concern in many cropping regions globally. Whilst spatial variability in acidification is a common consideration in the management of soil health and fertility at sub-paddock scale, insufficient focus has been directed toward the identification of this variability. Suitability of portable visible near infrared reflectance (vis–NIR) spectroscopy was assessed in this study as a potential technique to achieve rapid, precise, inexpensive and spatially specific quantification of key soil parameters to inform lime requirements. Spectral fingerprints were taken using a 1 ha grid sampling approach, with four sampling protocols investigated as follows, scans: (i) directly on cleared soil surfaces; (ii) on 0–100 mm undisturbed cores; (iii) on dried 0–100 mm cores; and finally (iv) on dried, ground, sieved and mixed cores. Data was analysed using a partial least squares regression (PLSR) model to identify the strength of linear relationship between reference chemistry data and predictions derived from spectral readings. Lime requirement maps using vis–NIR predictions were then theoretically compared against traditional aggregated sampling patterns while considering the trade-offs between accuracy, economics and agronomy associated with the identification of spatial variability. The vis–NIR measurements demonstrated moderate predictive capabilities in field for determining pH (R2 = 0.3–0.5) and liming requirements (R2 = 0.5–0.6) rapidly at high spatial resolution. Vis–NIR in field mapping techniques, which enable the use of site specific management of soil resources, were found to positively redirect lime resources from alkaline areas toward acidic areas of the paddock, resulting in minimal difference to overall expenditure on lime purchase and potential for increased agronomic benefits over the long-term. Further spectral library development, calibration, and research on in-field sampling methods is recommended. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at Zonal Agricultural Research Station, Mandya to evaluate the effect of biochar, lime and fertilizer on soil acidity and microbiological properties in an acidic soil. The experiment was laid out in randomized complete block design with seven treatments and three replications. The results revealed that application of fertilizer based on the soil test value (STV) either in combination with biochar or lime influenced soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), dehydrogenase, urease and phosphatase activities significantly. Similarly, application of STV-based fertilizer along with biochar+FYM (Farm Yard Manure) + ZnSO4 significantly decreased exchangeable aluminum, exchangeable acidity and total acidity as compared with recommended dose of fertilizer (RDF) + FYM+ ZnSO4 treatment. The grain yield of rice was increased by 37.90% in STV + biochar + FYM + ZnSO4 and by 22.87% in STV + lime +FYM + ZnSO4 plots than RDF + FYM + ZnSO4 plot. Seed and haulm yield of cowpea increased by 33.57% and 18.53% in STV + biochar + FYM + ZnSO4 treatments as compared with RDF + FYM + ZnSO4 treatment. Exchangeable aluminum and exchangeable acidity were found to be negatively correlated with yield of rice (r = -0.179) and cowpea (r = -0.266). However, yield of rice and cowpea showed the significantly and positively correlated with microbiological properties. The exchangeable Al and exchangeable acidity were found to be negatively correlated with SMBC, SMBN, dehydrogenase activity, urease activity and phosphatase activity. [ABSTRACT FROM AUTHOR]

Soil acidification is a natural phenomenon that human activity can accelerate or manage. Acid soils limit plant growth by reducing nutrient availability and causing aluminum toxicity, significantly reducing crop production. Liming has proven efficient for increasing crop yield on acidic soils. Knowledge is required on the effect of liming on the soil pH dynamics to find the suitable material, application rate, timing, and method. The objective of this study was to develop a prediction model of soil pH temporal variations after lime application using data from the literature. A database was built from research results extracted from 16 scientific papers that provided data on soil acidity changes over time under different liming treatments. Machine learning (ML) was used to predict soil pH dynamics from eight predictive parameters: rate of application, time since application, neutralizing value (CCE), grind fineness (D50), pH measurement depth, soil acidity (pH prior to liming), the type of solution used for pH measurement (water or CaCl 2) and the soil:solution ratio used to measure pH. Since soil pH fluctuates with seasons, all pH values were expressed as difference between the actual pH value and that of an unlimed control (ΔpH). The Random Forest (RF) algorithm was tested to predict ΔpH over time. On testing, we obtained an R2 between measured and predicted ΔpH values of 0.881 and an RMSE of 0.230. These results are excellent, considering the heterogeneity in soils, liming materials, and pedoclimatic conditions found in the 16 papers. The primary factors influencing ΔpH, ranked by their impact are application rate, time elapsed post-application, and lime characteristics including its grind fineness and neutralizing value. • Random Forest robustly predicts soil pH change over time following lime application. • The predictors are: rate, neutralizing value, particle size, depth, and initial pH. • The model predicts that, on average, lime increases soil pH for 82 weeks. • Machine learning models are promising tools in managing liming practices. [ABSTRACT FROM AUTHOR]

Soil acidity is the most limiting factor for agricultural yield and sustainability in acid soils. Liming is the management practice recommended for reducing soil acidity and increasing the availability of macronutrients, but it can also lead to reduction in the availability of cationic micronutrients when applied at high rates. The aim of this study was to evaluate the effect of application of high rates of limestone, incorporated in the 0–0.40 m soil layer, on nutrient availability and their relation to cumulative grain yield in an annual crop production system. Three experiments were set up in 2017 with six liming rates (0, 3, 6, 9, 12, and 15 Mg ha−1), with incorporation in the 0–0.40 m layer. Soil and leaf samples were collected for determination of macro- and micronutrient concentration in the leaves. Regression and linear correlation analyses were used to evaluate the effect of the application rates on the availability of nutrients and on cumulative yield in soybean, maize, dry bean (common bean) wheat crops over three crop years. The micronutrient that showed the greatest reduction in level in the soil through liming was Fe, in contrast with Zn, which was not affected. The concentrations of micronutrients in soybean and common bean leaves were more sensitive to the effect of deep liming than the levels in the soil, and reductions were observed in the concentrations of B, Fe, Mn, and Zn; however, they remained at suitable levels according to regional standards. Thus, even with the reductions in the availability of the micronutrients brought about by incorporation of higher doses of limestone (≥ 9 Mg ha−1), the cumulative grain yields showed an increase in accordance with liming rates, with the optimal dosage from 8.77 to 12.6 Mg ha−1, depending on the site. The main factors that had positive correlation with yield were soil pH and the macronutrients concentration in the leaves, which generally increased along with the liming rates. • Micronutrients availability to plants reduces with increasing limestone doses incorporated at 0.40 m. • The concentrations of macronutrients in the leaves increased with increasing limestone rates incorporated at 0.40 m. • There is a positive correlation with grain yield and soil pH and macronutrient concentration in leaves. • Accumulated grain yield increases with increasing limestone rates incorporated at 0.40 m. [ABSTRACT FROM AUTHOR]

Two liming fertilizers for soil deacidifi cation in Polissya were investigated: dolomite and lime fl our, which were applied at the beginning of the 8-year crop rotation with medium fertilizer N112P82K105 between 2011 and 2019. The experiments were performed in a stationary fi eld trial by the Institute of Agriculture of Western Polissya of the National Academy of Agrarian Sciences of Ukraine on crop rotation of winter wheat, corn, barley and winter rape. The object of the research was Albic Retisol (Arenic, Aric) (WRB, 2014) in a stationary trial. Before starting the research, soil pHKCl was 4.3 and hydrolytic acidity (Hh) 2.80–2.97 cmol(+)·kg–1. Liming fertilizer doses were determined on the basis of soil hydrolitic acidity (Hh) for dolomite fl our: 0.5 Hh – Dd0.5 2.230 t∙ha–1; 1 Hh – Dd1.0 4,740 t∙ha–1; 1.5 Hh – Dd1,5 6,700 t∙ha–1 and lime fl our: 1 Hh – Dl1.0 4,940 t∙ha–1. Application of dolomite fl our at a dose of Dd1.5 6,700 t∙ha–1 proved to be the most effective. It neutralised the acidity of the soil to the highest level pHKCl (6.64) and maintained in this case pHKCl 6.04 until the end of the 8-year of crop rotation. 3D modeling showed that the effectiveness of soil deacidifi cation by dolomite fl our increases with moderate simultaneous climate warming and humidifi cation. Meanwhile, the simultaneous stronger increase of temperature and humidity weaken the neutralising effect of this liming fertilizer. The usage of dolomite and lime causes a gradual increase in Ca2+ soil content from 1.68 to 2.57 cmol(+)·kg–1 of soil similar to the dynamics of Mg2+ concentration (from 0.28 to 0.84 cmol(+)·kg–1 of soil). The usage of lime causes a maximum reduction content of soil Mg2+ (0.23 cmol(+)·kg–1 of soil) against the highest Ca2+ content. Doses of dolomite and lime had a signifi cant effect on the Al3+ soil content. The concentration of Al3+ was highest in non-limed and fertilized areas in the fi nal year of the crop rotation. The usage of dolomite rapidly reduced the content of exchangeable Al3+ from 2.48 and 2.67 cmol(+)·kg–1 of soil to 1.31 cmol(+)·kg–1 a 1.5 Hh dose. The average long-term crop-rotation productivity (in grain units) depended on the mineral fertilization and the type and doses of the liming fertilizers applied. Mineral fertilizers within the normal range N112Р82К105 without liming have contributed to the collection of 3.06 t∙ha–1 grain units. The maximum crop yield was set on the option of applying 1.5 Hh dose of dolomite fl our on the background of the average annual mineral fertilizer norms of N112P82K105 – 5.33 t∙ha–1 grain units. Lime fl our proved to be less effective as it reduced the Mg2+ soil content, which is an important element for plants, and with a smaller impact on crop yield. [ABSTRACT FROM AUTHOR]

All forms of potassium in the soil are in a dynamic equilibrium with K in the soil solution, which affects K availability to the plants and it is affected by the soil pH. The objective of this study was to evaluate the effect of the soil pH and K application on the distribution of soil K forms in five Brazilian soils. The experiment was conducted in laboratory, using five soils. Treatments consisted of a factorial combination including rates of limestone (0, 0.25, 0.5, 1.0 and 1.5 times the amount of lime indicated by the SMP method to raise soil pH to 6.0) and two rates of K (0 and 1000 mg kg-1). Addition of KCl, together with limestone, promoted lower values of soil pH relatively to limestone alone. Solution K was the most sensitive K form affected by liming rates, which decreased in all soils with increases on K rate, regardless of K addition. Exchangeable K also decreased in all soils with the increase on lime applied, except on the Argisol. The non-exchangeable K levels were the least affected by liming. Addition of lime affects the distribution of K among all K forms and this may affect the availability of K to the plants. [ABSTRACT FROM AUTHOR]

Globally, about 50% of all arable soils are classified as acidic. As crop and plant growth are significantly hampered under acidic soil conditions, many farmers, but increasingly as well forest managers, apply lime to raise the soil pH. Besides its direct effect on soil pH, liming also affects soil C and nutrient cycles and associated greenhouse gas (GHG) fluxes. In this meta‐analysis, we reviewed 1570 observations reported in 121 field‐based studies worldwide, to assess liming effects on soil GHG fluxes and plant productivity. We found that liming significantly increases crop yield by 36.3%. Also, soil organic C (SOC) stocks were found to increase by 4.51% annually, though soil respiration is stimulated too (7.57%). Moreover, liming was found to reduce soil N2O emission by 21.3%, yield‐scaled N2O emission by 21.5%, and CH4 emission and yield‐scaled CH4 emission from rice paddies by 19.0% and 12.4%, respectively. Assuming that all acid agricultural soils are limed periodically, liming results in a total GHG balance benefit of 633−749 Tg CO2‐eq year−1 due to reductions in soil N2O emissions (0.60−0.67 Tg N2O‐N year−1) and paddy soil CH4 emissions (1.75−2.21 Tg CH4 year−1) and increases in SOC stocks (65.7–110 Tg C year−1). However, this comes at the cost of an additional CO2 release (c. 624–656 Tg CO2 year−1) deriving from lime mining, transport and application, and lime dissolution, so that the overall GHG balance is likely neutral. Nevertheless, liming of acid agricultural soils will increase yields by at least 6.64 × 108 Mg year−1, covering the food supply of 876 million people. Overall, our study shows for the first time that a general strategy of liming of acid agricultural soils is likely to result in an increasing sustainability of global agricultural production, indicating the potential benefit of liming acid soils for climate change mitigation and food security. [ABSTRACT FROM AUTHOR]

Lime and gypsum application is one strategy for correcting soil acidity and improving soil fertility. However, soil compaction in no-till systems can influence these dynamics. This study aimed to assess the effect of lime and gypsum application under different soil compaction levels on soybean yield and soil chemical attributes. The application of lime and gypsum under artificial compaction levels and the movement of exchangeable calcium (Ca2+), magnesium (Mg2+), potassium (K+), and soil pH were monitored in the 0–0.05, 0.05–0.10, 0.10–0.20, and 0.20–0.40 m soil layer depths. Soybean grain yield was not influenced by the gypsum and lime applications and artificial compaction levels. In the 0.05–0.1, 0.1–0.2, and 0.2–0.4 m soil layers, the exclusive surface application of lime was effective in increasing the soil pH. Ca2+ and Mg2+ carbonates had low solubility and mobility in the soil; however, a rapid reaction to the surface over a relatively short period was observed. K+ concentration in the 0–0.05 m soil layer did not vary after the gypsum and lime applications. Therefore, the superficial application of lime is effective in acidity correction in no-till systems when the soil is not compacted. [ABSTRACT FROM AUTHOR]

Evaluating agricultural management practices, such as liming, is essential in regions with acidic soils to increase the yield of agricultural crops. The aim was to evaluate soil fertility, agronomic performance, and grain quality of cowpea cultivars under application of limestone doses. The experiment was carried out in Argissolo Vermelho Amarelo (Ultisol), with initial base saturation of 26%, during two agricultural years. A randomized block design was used, in split plots, with four replications. The plots were composed of five limestone doses (0, 1, 2, 3 and 4 times the recommended rate to reach 50% base saturation), and the subplots were formed by two cowpea cultivars (BR 17 Gurgueia and BRS Guariba). The applied doses of limestone, with relative total neutralizing power (RTNP) of 91%, were 0, 1.3, 2.6, 3.9 and 5.2 t ha-1. Liming increased soil fertility, increasing pH, calcium, magnesium, and base saturation, and decreasing soil acidity. Maximum grain yields were obtained with limestone doses between 3.1 and 3.2 t ha-1 for the cultivar BR 17 Gurgueia and between 3.3 and 3.4 t ha-1 for the cultivar BRS Guariba, reaching average base saturation values of approximately 48 and 55%, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • 5 RDs neutralise 500 up to 10 000 mmol H+/kg, variation in mineralogy and target pH. • Automatic titration (pH stat) estimates pH-dependent dissolution rates and slopes. • Novel soil-RD suspension estimates fast/slow pools of acid neutralising capacity. • Low and high doses (12 Mg/ha, 340 Mg/ha) for validation in 2 year soil-RD mesocosm. • Mechanistic model using pH stat and soil-RD suspension predicts mesocosm soil pH. The ongoing acidification of soil poses a significant threat to the proper functioning of various ecosystems worldwide. Silicate rock dusts (RD) are increasingly amended to acid soils to restore their pH, but the acid neutralising capacity (ANC) and dissolution rate of these products are highly variable and lack proper assessment protocols. It is expected that pH-dependent RD ANCs and dissolution rates dictate the pH increase in soils depending on the initial pH and pH buffer power of the soil. This study addressed these questions by comparing and validating three accelerated weathering tests for their capacity to predict the gradual liming effects in a two-year outdoor mesocosm. Five commercial RDs (two basalts, phonolite, foidite, and trachy-andesite) were tested in four acidified forest soils varying in initial pH, in texture and associated pH buffer power. First, RD dissolution was measured in aqueous batch renewal systems during one year at various starting pH (3.5, 4.5, and 5.5) and constant temperatures (20 °C, 37 °C, and 65 °C). These showed that the ANCs of RDs exhibit a fast fraction (half-life < 1 day) followed by a slower fraction. Second, titration tests of RDs at fixed solution pH, i.e., pH stat , performed between pH 3.5 and 4.5 revealed surface normalised dissolution rates that decreased factors 10–100 per unit pH increase, the slope depending on the RD's mineralogy. Indeed, the rate ranking of observed surface area normalised dissolution rates confirmed that of literature-based values, weighed by the XRD-derived mineralogical fractions. Third, lime-calibrated agitated soil-RD suspension tests were conducted for two months, illustrating the dependency of RD ANC on soil context, and yielding ANCs that were factor 2–5 times larger than in the batch renewal test because of pH buffering effects of soil particulates. Finally, an outdoor soil mesocosm on the four acid soils amended with RDs at 12 Mg/ha and 340 Mg/ha was established and soil pH was monitored for 2 years. The observed pH trends corresponded well for both the low dose (R2 a = 0.67) and the high dose (R2 a = 0.93) with model predictions made using the pH- and temperature-dependent RD dissolution rates (pH stat test) and the soil pH buffer power and RD slow ANC-fraction (soil-RD suspension test). This model predicts half-lives of RD dissolution ranging between <1 month to >100 years depending on the starting pH of the soil, its pH buffer power, the RD mineralogy (XRD based) and its specific surface area. This study shows that the dissolution and ANC of RD can be most pragmatically predicted with a series of lime-calibrated soil-RD suspension tests of maximally two months. [ABSTRACT FROM AUTHOR]

The solubility of cadmium (Cd) in soil and its transfer to plants are influenced by soil pH. While increasing soil pH reduces Cd solubility and accumulation in rice plants grown in acidic soils, its effect on Cd accumulation in vegetables remains inconclusive. Here, we investigated the impact of soil pH on Cd accumulation in dicotyledonous vegetables and elucidated the underlying molecular mechanisms. Soils collected from various locations were supplemented with varying quantities of lime to achieve soil pH values of around 5.0, 6.0, 7.0, and 8.0. Raising soil pH from around 5.0 to 8.0 markedly decreased extractable Cd. However, increasing soil pH tended to promote shoot Cd accumulation in dicotyledonous vegetable species including lettuce, pakchoi, and Chinese cabbage, and the model dicotyledonous plant Arabidopsis thaliana. Conversely, soil pH increase resulted in a monotonic decrease in rice Cd accumulation. In our hydroponic experiments, we discovered that iron (Fe) deficiency substantially increased Cd uptake and accumulation in dicotyledonous plants but not in rice. Increasing soil pH reduced soil Fe availability and induced the Fe transporter gene IRT1 expression in dicotyledonous vegetables roots, which led to an increase in IRT1-mediated Cd uptake and subsequently increased Cd accumulation as soil pH increases. A comprehensive model incorporating extractable Cd and root IRT1 expression better explained Cd accumulation in vegetable shoots. The application of 50 mg/kg of Fe fertilizer in neutral or alkaline soils resulted in a significant reduction in Cd accumulation by 34–58% in dicotyledonous vegetables. These findings reveal that increasing soil pH has two opposite effects, decreasing soil Cd availability while promoting Cd uptake through IRT1 upregulation, reconciling the inconsistency in its effect on Cd accumulation in dicotyledonous plants. Our findings provide important insights for understanding the factors affecting Cd uptake in plants and offer a practical solution to mitigate Cd contamination in vegetables. [Display omitted] • Elevating soil pH increases Cd accumulation in lettuce, pakchoi, and cabbage. • Fe-deficiency increases IRT1-mediated Cd uptake by dicotyledonous vegetables. • Fe-transporter gene IRT1 is responsible for Cd uptake in dicotyledonous vegetables. • Applying Fe fertilizer can decrease Cd accumulation in dicotyledonous vegetables. [ABSTRACT FROM AUTHOR]

There is a wide application of rhizobia inoculants to legume crops in Africa, irrespective of the soil acidity, though the latter limits the effectiveness of inoculants. Two trials were conducted in a controlled environment to determine suitable soil pH and impact of liming on soybean nodulation and nitrogen fixation to inform proper application of the rhizobia-inoculant technology on acid soils. In the first trial; soil, variety and inoculation had significant influence (p < 0.05) on weighed nodule effectiveness (WNE) and N fixation. Strongly acidic soils recorded low WNE and N fixation. In the second trial, WNE and N fixation significantly increased with co-application of lime and inoculation (p < 0.05). The results showed that soybean inoculation is effective in increasing nodulation and N fixation in moderate acidic soils, contrarily to strongly acidic soils. Interestingly, co-application of lime and inoculation has potential of increasing nodulation and N fixation in strongly acidic soils. The WNE is recommended as a robust formula to report nodule effectiveness, compared to the current percentage method. [ABSTRACT FROM AUTHOR]

Low phosphorus (P) constrains productivity of many of the permanent pastures of south-eastern Australia where wool and meat production are important. Whereas the need for fertilisation with P is indisputable for many soils, the benefits of liming to ameliorate soil acidification are not always clear in terms of forage production or quality. This experiment, by measuring botanical composition and groundcover over 10 years, aimed to address the issue of forage composition and groundcover. Merino wethers were continuously grazed on a permanent pasture under two stocking rates (low and high) following treatments with three rates of surface-applied lime and two rates of P. The lime rates were: nil, and sufficient to raise the pHCaCl2 of the 0–10 cm soil layer to 5.0 and to 5.5. Phosphorus was added as two rates of single superphosphate: 125 kg ha–1 every 2–3 years, and 250 kg ha–1 every year. Two hypotheses were proposed: (i) as lime application rate increased, it would lead to the pasture swards having a higher percentage of species favourable for grazing animal production, and a higher level of sward groundcover would be maintained; and (ii) legume presence would be favoured by a higher level of applied P over the long term. The Millennium Drought (1997–2008), which coincided with this experiment (1998–2008), tended to mask or reduce lime effects; nevertheless, the higher legume content in the sward, as well as the superior groundcover found in the high lime–high P treatments at various times throughout the experiment and at its completion compared with the nil-lime control, indicated positive forage effects of lime application. Moreover, by the termination of the experiment in 2008, groundcover generally tended to be lower under nil lime than in treatments that had received lime. The higher proportion of legume in the sward was closely linked to greater applied P, although this did not occur at the low stocking rate in the absence of lime. By contrast, similar high P–low stocking rate treatments but with applied lime had the highest clover contents. It is proposed that the poor persistence of the treatment without lime may be due to a combination of poor legume seedset, because of excessive competition from accompanying grasses, and aluminium toxicity adversely affecting legume growth. Soil acidity is a serious problem reducing the production of crops and grazing animals, and although lime can reduce acidity, it is expensive because high rates are required. This research follows the effect of lime on the pasture composition of desirable legumes and perennial grasses. The higher legume content in the sward found in high lime–high phosphorus treatments at times throughout the experiment and at its completion compared with the nil-lime control indicated the value of lime application. [ABSTRACT FROM AUTHOR]

Lime is a common amendment to overcome soil acidity in agricultural production systems. However, plant root effects on lime and soil carbon (C) dynamics in acidic soils under varied temperature remain largely unknown. We monitored root effects of soybean on the fate of lime applied to an acidic soil at 20 and 30°C in growth chambers. Soil respired CO2 was continuously trapped in columns without and with plants until the final stage of vegetative growth. Lime‐derived CO2 was separated from total respired CO2 based on δ13C measurements in CO2. Leaching was induced at early and late vegetative growth stages, and the leachates were analysed for dissolved organic (DOC) and inorganic C (DIC) concentrations. Soil respiration significantly increased with lime addition at both temperatures (p < 0.001). The presence of soybean doubled the recovery of lime‐derived CO2‐C at 20°C at the early growth stage; however, by the end of the experiment, the contribution of lime‐derived CO2‐C to soil respiration was negligible in all treatments, indicating that the contribution of lime to soil respiration was shortlived. In contrast, DIC and DOC concentrations in leachates remained elevated with liming and were greater in the presence of soybean. We observed no main temperature effects and no interactive effects of temperature and soybean presence on lime‐derived CO2‐C, DIC and DOC. These results highlight the role of plant‐modulated processes in CO2 release and C leaching from lime in acidic soils, whereas an increase in temperature may be less important. Temperature and plant roots alter the rate of key processes controlling C dynamics in a limed acidic soil. Lime‐derived CO2‐C, DIC and DOC increased more in the presence of plants than with increased temperature. Root effects are more important than temperature for inorganic and organic carbon dynamics in limed acidic soils. [ABSTRACT FROM AUTHOR]

Although cherry-tomato is becoming more popular in the last years, there are no specific recommendations for P and K fertilization or liming strategies for this specific variety. Our aim was to assess rates of P and K and liming strategies in order to improve the yield of cherry-tomato grown on an Oxisol with a limited P-availability. Two pot experiments were developed. In the first-one, a two-factor factorial design was developed with 4 P (first-factor) and 4 K rates (second-factor), being these rates the 0%, 50%, 100%, and 200% of the recommended fertilization for tomato in South-Brazil. In the second experiment, the soil pH (4.3) was adjusted to 5.5, 6.0, and 6.5 with limestone. Soil P-availability, plant growth, diameter, number of fruits and cherry tomato yields were increased with the P addition, while a non-significant effect was observed after adding K. The highest yield was produced with 50% of the suggested amount of P for tomato in comparison with the non-fertilized plants (yield increase of 674%), while higher P rates (100% and 200%) produced a lower yield increase. The significant effect of soil liming was observed on increase of the flower bunches number when the soil pH was amended to 6.5. Cherry-tomato requirements seem to be different from the recommended for other varieties. Our results indicate that higher yields were achieved with a lower amount of chemical inputs than the recommended for tomato in general, stressing the importance of P for tomato cherry production over the other factors assessed here. [ABSTRACT FROM AUTHOR]

There is currently no quick available method for assessing chemical reactivity of liming materials used to neutralize soil acidity. This study was conducted to assess the effectiveness of a method developed to determine the chemical reactivity of liming materials. The reactivity of five conventional liming materials, biochar, charcoal and wood ash was determined using the method. Liming materials were applied to surface samples of two Ultisols at rates intended to neutralize exchangeable acidity. Physico-chemical and mineralogical properties of liming materials and soils were determined. Soils treated with the liming materials were incubated for 12 weeks in plastic containers using a soil: water ratio of 1:1. The pH and exchangeable acidity of the samples were measured every fortnight. The reactivity of the conventional liming materials was found to be strongly and positively (r = 0.99) correlated with their calcite contents, and strongly and negatively (r = −0.98) correlated with their dolomite contents. Strong positive linear relationships (R2 ≥ 0.79, p <.05) were observed between the reactivity and mean pH of the two soils between the 2nd and the 12th week, while strong negative linear relationship (R2 ≥ 0.79, p <.05) was observed between the reactivity and mean exchangeable acidity of the soils. Conventional liming materials were better than biochar and charcoal in neutralizing acidity. The new method was effective in predicting the ability of liming materials to neutralize exchangeable acidity and to raise the pH of acid soils. It can be used by farmers and lime producers to assess the reactivity of liming materials. [ABSTRACT FROM AUTHOR]

The conversion of Pampa Biome soils into no-till system for grain production requires acidity correction, at least to fully neutralize exchangeable aluminum (Al). The aim of the study is to evaluate changes in solid phase acidity and Al speciation in soil solution that was conducted to prepare the soil for the implementation of a no-tillage system in a natural pasture area in Southern Brazil. We collected soil samples from the 0–5, 5–10, 10–15 and 15–20 cm layers in soils subjected, or not, to acidity correction to pH 6.0, as well as in soils with, and without, limestone incorporation through plowing and harrowing. Changes in the solid and solution phase attributes, such as soil acidity, were limited to 5 and 10 cm, respectively, 44 months after surface and incorporated liming. Regardless of liming addition to, or lack of thereof in the soil, Al found in the soil solution was mainly associated with organic carbon. This was the main way to decrease plant toxicity under these conditions, which can be supported by plant behavior, especially that of soybean. Liming induced the soil solution Al to exchange its ligand from organic carbon to hydroxyl. [ABSTRACT FROM AUTHOR]

Many agricultural soils are naturally acidic, and agricultural production can acidify soil through processes such as nitrogen (N) fixation by legumes and application of N fertiliser. This means that decisions about mitigation of soil acidity (e.g. through application of lime), crop rotation and N fertiliser application are interdependent. This paper presents a dynamic model to determine jointly the optimal lime application strategies and N application rates in a rainfed cropping system in Western Australia. The model accounts for two crop rotations (with and without a legume break crop), for the acid tolerance of different crop types, and for differences in the acidifying effect of different N fertilisers. Results show that liming is a profitable strategy to treat acidic soils in the study region, but that there are interactions between N and acidity management. Choice of fertiliser affects optimal lime rates substantially, with the use of a more acidifying ammonium-based fertiliser leading to higher lime rates. The optimal liming strategy is also sensitive to inclusion of a legume crop in the rotation, because its fixed N can be less acidifying than fertiliser, and it allows a reduction in fertiliser rates. Higher rainfall zones have greater N leaching, which contributes to a higher optimal rate of lime. We find that injection of lime into the subsoil increases profit. Optimal lime rates in the absence of subsoil incorporation are higher than usual current practice, although the economic gains from increasing rates are small. [ABSTRACT FROM AUTHOR]

Many soil improvement practices are directly related to the reduction of weed infestation in crops. Sustainable use of the acid moraine loam Bathygleyic Distric Glossic Retisol prevailing in Western Lithuania is associated with the appropriate intensity of liming and tillage. Research was carried out at the Vėžaičiai Branch of Lithuanian Research Centre for Agriculture and Forestry during the period 2015-2018 in two long-term field experiments: liming (established in 1949) and soil tillage methods (established in 2003). The aim of the study was to establish the trends in weed infestation variation in the crop rotation after a long-term application of agronomic practices of different intensity (soil tillage and liming). Treatments of the soil tillage were as follows: conventional ploughing, shallow ploughing and shallow ploughless tillage. Treatments of liming were as follows: unlimed (pHKCl 4.0-4.1) and limed (pHKCl 6.2-6.8). The following weed infestation indicators were investigated: weed number and mass, weed species number, weed seed bank in the soil depths of 0-10, 10-20 and 20-30 cm. Findings of the study suggest that the long-term liming had an impact on the disappearance of dominating acidophilic weeds from crop communities. In a limed soil (pH 6.4-6.8), the total number of weeds was 4.1 times lower compared to that in a naturally acid soil (pH 4.0-4.1). The contamination with weed seeds was 14.2 times greater in the naturally acid soil; however, irrespective of the soil acidity (pH), vertical seed distribution was determined to be similar in different depths of the soil. The long-term conventional ploughing reduced crop weediness in the soil of low acidity (5.1-5.3). The total weed number and mass were 1.6 and 1.4 times greater in the treatment of reduced tillage soil. The effect of long-term regular soil tillage tended to cause changes to the depth of soil loosening, affecting vertical weed seed distribution. Under reduced tillage conditions, the soil depth of 0-10 cm was the most contaminated with weed seeds. [ABSTRACT FROM AUTHOR]

• Surface liming reduced soil acidity down to −60 cm one year after its application. • Liming increased soybean grain yield by 9%, but it had no effect on cereal crops. • The lime reactivity had no effect on crop grain yield. • Gypsum did not increase crop grain yield in this moderate acidic Oxisol. • Combined application of gypsum and lime did not benefit crop yields. The low solubility of lime (CaCO 3) and the absence of soil disturbance in fields under no-tillage (NT) may diminish the effectiveness of surface liming to reduce exchangeable Al3+ (toxic to plants) and increase the base saturation in deep soil layers. However, the effects of subsurface soil acidity can be attenuated by applying agricultural gypsum (CaSO 4 ⋅2H 2 O), which is more soluble than lime, and thus, can leached bases (exchangeable Ca2+, Mg2+ and K+) and S-SO 4 2− to deeper soil layers as well as decrease Al3+ toxicity to plants. Therefore, gypsum can be applied individually or in combination with lime. Herein, we conducted a field experiment aiming to evaluate short- (1 year) and long-term (11 years) effects of surface liming and gypsum application on the chemical properties of the 0.00–0.10, 0.10–0.20, 0.20–0.40 and 0.40–0.60 m soil layers and also on crop yield of 22 crop seasons (i.e., 10 soybean, 3 maize, 4 white oat, 3 wheat and 2 barley crops). The study was performed in a clayey Typic Hapludox of moderate acidity managed under NT for more than 25 years in Guarapuava, Paraná State, southern Brazil. Three soil surface-applied lime strategies were tested in order to raise base saturation to 70%, namely: (a) 4.62 Mg ha–1 rate of lime of low effective calcium carbonate equivalent (ECCE = 75%); (b) 3.47 Mg ha–1 rate of lime with a high ECCE value (101%); and (c) the same rate of high-ECCE lime split in three applications (i.e., 1/3 at the start of experiment; 1/3 after 1 year and 1/3 after 2 years). A control treatment without liming was also conducted. The liming strategies were combined with four rates of agricultural gypsum (i.e., 0, 3, 6 and 9 Mg ha–1) applied at the start of the experiment. Our findings did not reveal synergistic effect of lime and gypsum on soil chemical properties nor on crop yield. Gypsum resulted in very slight gains in grain yield (4% on average) and limited to just 25% of cereal (corn and winter cereals) crop seasons. On the other hand, liming increased soybean yields by 14% in 40% of crop seasons. Gypsum was more efficient than lime in raising exchangeable Ca2+ levels up to −0.60 m in the short term; however, lime promoted greater reduction of soil acidity and had a more marked residual effect on exchangeable Ca2+ contents than gypsum. The liming strategies did no promote substantial differences in crop yield, but low-ECCE lime sustained better soil chemical condition to plant growth for a longer period. Surface liming efficiently reduced subsurface acidity in a moderately acidic Oxisol managed under NT even in the short-term, promoting increments on soybean crop yields. In this case, the application of gypsum rates did not bring additional benefits to soil or plant yield. [ABSTRACT FROM AUTHOR]

Acidification of soils is one of the most important soil degradation processes and this type of soils can be provisionally remediated towards increasing soil fertility by liming practices. However, Ca / Mg containing liming materials cannot be used in areas where perennial calcifuge plants are present. The aim of this study is to determine the ability of materials such as milled fine-grained forms of zeolite and feldspar with alkaline character to neutralize acid ions in soil environment. The ability to buffer H ions was determined by equilibrating HCl solution at varying concentrations with zeolite samples having a particle size of 1-0.5 mm, 0.5-0.25 mm and 0.1 mm and feldspar with a particle size <0.1 mm. The titration curves of the zeolite samples were found to vary significantly depending on the particle size and all zeolite sizes had better buffering ability than the feldspar. As a result, it has been concluded that zeolite and feldspar can be used as an alternative liming material for calcifuge plants both in remediating the acidity and in improving the chemical properties of soils. [ABSTRACT FROM AUTHOR]

Abstract An 18-year field experiment was conducted on a highly acidic soil in the mixed farming zone of south-eastern Australia. The experiment was a fully phased design with three major treatment contrasts: perennial systems versus annual systems; unlimed versus limed treatments; and permanent pasture versus pasture-crop rotations. The hypotheses tested in this study were that a) perennial systems would be less acidifying than annual systems, and b) surface liming would lead to amelioration of subsurface soil acidity over time. Results showed that there was no significant difference in soil pH in terms of acidification rate and amelioration rate between perennial and annual systems, thus we rejected the first hypothesis. However, both perennial and annual systems did acidify or re-acidify soil. The re-acidification rate was at least 0.09 pH units per year in the 0–0.10 m depth under the limed treatment. The acidification rate was 0.005 pH units per year in the 0.10–0.20 m depth under the unlimed treatment. The vigorous lime regime of maintaining pH ≥5.5 (measured in 0.01 M CaCl 2) in the 0–0.10 m depth increased soil pH in the 0.10–0.20 m depth at a rate of the 0.04 pH units per year, hence we accepted the second hypothesis. There was clear evidence of alkali movement vertically over time, but it was confined within the top 0.30 m depth over the 18-year period of experiment. It is recommended that soil should be limed regularly to maintain pH ≥5.5 to keep the system productive and sustainable. Highlights • Both perennial and annual systems acidify soil in depths at a similar rate. • Surface liming can alleviate subsurface (below 0.10 m) soil acidity. • Soil re-acidification rate is 0.09 pH units per year in the 0–0.10 m depth. • Soil acidity amelioration rate is 0.04 pH unit per year in the 0.10–0.20 m depth. • Soil should be limed regularly to maintain pH ≥5.5 to keep the system productive and sustainable. [ABSTRACT FROM AUTHOR]

Abstract Agricultural liming materials are broadly utilized in the world to ameliorate soil acidity. Crushed limestone (CaCO 3) and dolomite (MgCO 3 ·CaCO 3) are most common liming materials. The CO 2 emission coefficient was proposed as 0.12 Mg C per Mg for CaCO 3 by the Intergovernmental Panel on Climate Change (IPCC), which indicates that 100% of C in CaCO 3 is eventually released to the atmosphere in the form of CO 2. However, this assumption appears unlikely based on current knowledge of the very low solubility of CaCO 3 and carbonate transport through soil. To develop the direct CO 2 emission factor from the C-containing liming materials applied in moderately acidic soil, CaCO 3 was applied in a typical temperate upland soil at different levels (0–2 Mg ha−1 yr−1), and the CO 2 emission rates were determined using the closed chamber method for two years. The direct CO 2 emission factor from CaCO 3 was estimated using 13CO 2 fluxes from 13C-CaCO 3 applied soils. Approximately 0.026 Mg C per Mg of CaCO 3 was emitted as CO 2 from CaCO 3 in cropping lands. This value was much lower than the IPCC default value (0.12 Mg C per Mg of CaCO 3). The current CO 2 emission coefficient was comparable with the United States Environmental Protection Agency (EPA) emission factor (0.046 Mg C per Mg of CaCO 3) from the agricultural field. If the EPA emission factor from the ocean (0.013 Mg C per Mg of CaCO 3) is added to the currently developed CO 2 emission factor of the inner agricultural field, the total CO 2 emission factor from lime may be close to 0.039 Mg C per Mg of CaCO 3 in the selected upland soil. Therefore, we propose that the current IPCC guideline value of the CO 2 emission factor from lime should be revised as 0.039 Mg C per Mg of CaCO 3 for Korean upland soils. Highlights • IPCC proposed 0.12 Mg CO 2 -C per Mg CaCO 3 as the CO 2 emission factor from CaCO 3 in soil. • 0.026 Mg CO 2 -C per Mg CaCO 3 was emitted from CaCO 3 during maize cultivation. • EPA estimated 0.013 Mg CO 2 -C per Mg CaCO 3 of CO 2 emission factor released from agricultural field. • CO 2 emission factor of CaCO 3 should be revised with 0.039 Mg CO 2 -C per Mg CaCO 3 in Korean upland soil. [ABSTRACT FROM AUTHOR]

The effect of pre-sowing seed treatment with inoculant and its combination with a plant growth stimulant in terms of the optimization of the level of soil acidity on the formation of symbiotic plant productivity and the accumulation of biological nitrogen in the soil has been studied. On the basis of the results obtained it has been found that the use of pre-sowing treatment of alfalfa seeds with rhizobophyte in combination with Emistym S against the background of soil liming and the application of the full rate of lime subject to hydrolytic acidity provides the accumulation of the largest amount of biologically fixed nitrogen. This is on average over the years of research has run at 236.1 kg/ha. [ABSTRACT FROM AUTHOR]

[Display omitted] • No-liming decreased approximately 30% of P use efficiency in CT and NT systems. • The use of NT increased P use efficiency by about 10–12% compared to the CT system. • NT without lime resulted in the highest P legacy but was non-accessible due to high Al3+. • Soil P forms and P use efficiency in NT and occasional tillage systems were similar. • Liming with soil incorporation effects persists for four decades, enhancing P use by crops. Liming combined with no-tillage (NT) can increase the efficiency of P use by accumulating soil P in more available forms and improving root exploration due to the absence of toxic Al3+. This study aimed to evaluate the long-term effect of different combinations of soil tillage managements and liming in a subtropical Oxisol on the accumulation of P forms, legacy P index, and P use efficiency. A long-term experiment was used, established in 1987 testing (i) conventional tillage with lime (lime-CT) and control (control-CT), (ii) NT with lime (lime-NT) and control (control-NT), and (iii) occasional tillage with lime (lime-OT). The NPK fertilization was the same for all treatments. The accumulated grain yield and P use efficiency of 56 crops between 1987 and 2019 were evaluated. In 2019, soil samples were collected in the 0–5, 5–10, and 10–20 cm layers and submitted to a sequential chemical fractionation of P, P indexes, and soil acidity parameters. The results reveal that is necessary to correct acidity to increase crop yields and P use efficiency, regardless of the soil management used. This increase is enhanced when soil acidity correction by liming is combined with the use of conservation systems such as NT. Furthermore, after liming with incorporation, liming can be done on the soil surface, without the need to repeat the operation of lime incorporation, ensuring high efficiency of P use even after more than four decades. [ABSTRACT FROM AUTHOR]

The new EU regulations on maximum levels of cadmium (Cd) in cacao products sparked research on countermeasures to reduce Cd concentrations in cacao beans. This study was set up to test the effects of soil amendments in two established cacao orchards (soil pH 6.6 and 5.1) in Ecuador. Soil amendments included: 1) agricultural limestone at 2.0 and 4.0 Mg ha−1 y−1, 2) gypsum at 2.0 and 4.0 Mg ha−1 y−1 and 3) compost at 12.5 and 25 Mg ha−1 y−1, all amendments were applied at the surface during two subsequent years. Lime application increased the soil pH by one unit down to 20 cm depth. On the acid soil, leaf Cd concentrations decreased by lime application and the reduction factor gradually rose to 1.5 after 30 months. No effects of liming or gypsum on leaf Cd was found in the pH neutral soil. Compost application in the pH neutral soil reduced leaf Cd concentration with factor 1.2 at 22 months but that effect was absent at 30 months after application. Bean Cd concentrations were unaffected by any of the treatments at 22 months after application (acid soil) or 30 months (pH neutral soil) suggesting that any treatment effects on bean Cd might be even more delayed than in leaves. Soil columns experiments in the laboratory showed that mixing lime with compost largely enhanced the depth of lime penetration compared to lime only. Compost + lime reduced 10−3 M CaCl 2 extractable Cd in soil without lowering extractable Zn. Our results suggest that soil liming has the potential to lower Cd uptake in cacao in the long term in acid soils and that the compost + lime treatment should be tested at field scale to accelerate the effects of the mitigation. [Display omitted] • Soil amendments significantly reduced Cd in leaves but not cacao beans in long-term field experiments. • Surface lime application increased soil pH only at the first 15 cm soil layer. • The lowest leaf Cd concentrations occurred during the flowering/filling stage of cacao. • Compost and gypsum effects on elemental leaf composition were inconsistent over time. • Lime + compost applications are advocated for future research as compost increases lime penetration into the soil profile. [ABSTRACT FROM AUTHOR]

Perhaps the most outstanding features of the soil solution are its reaction i.e. whether it is acidic or alkaline or neutral. Acid soils are problematic soils because of the fact that soil acidity is a serious threat to profitable crop production and lime is essential for correlation of acidity as well as of toxic and infertile condition likely to be prevalent in the acid soils. A considerable amount of work is necessary to define the optimum pH range for the principle crops and rotation systems practiced in the state, to measure the yield responses to be expected for the more important soil types and to determine the longevity of the lime response. Adsorbed cations, Hydrogen (H+) and Aluminium (Al3+) are largely responsible for soil acidity. The present study was conducted in the Department of Chemistry, Techno India, Batanagar in the year 2015 to determine the Lime Requirement (LR) of acid soils collected from three soil series of Jamtara district of Jharkhand viz., Kunjabana (I), Bhandarbera and Kunjabana (II). In order to determine the LR, the soils were incubated with different doses of lime (Calcium Carbonate) and the result obtained was in the following order: Kunjabana I>Kunjabana II>Bhandarbera. The lime requirement showed significant correlation with pH (H2O) (r=-0.69), pH (KC1) (r=-0.59), clay content (r=-0.53), organic matter (r=0.65), the product of the increase in pH value due to liming and organic matter (r=0.71), CEC (r=0.63), log CEC (r=0.65), A1KC1 (r=0.71), FeNH4OAc (r=0.65), A1NH4OAC (r=0.59), total potential acidity (r=0.52) and lime potential (r=-0.84). [ABSTRACT FROM AUTHOR]

A significant area in Brazil is covered with degraded pasturelands, which could be more appropriately used under no-till system. These soils are highly acid and physically fragile, and then there is a need to identify a better liming strategy that will improve the establishment of no-till systems. We hypothesized that the surface application of lime would be more efficient to alleviate soil acidity on degraded pastureland soils. A 4-year field trial examined the effect of a lime application (4.8 Mg ha −1 ) that had either been incorporated (0–20 cm) or surface-applied to an acid sandy loam Oxisol, originally under degraded pasture in Southern Brazil. Control treatments (no-lime) were applied with and without soil disturbance. A black oat ( Avena strigosa Schreb) – soybean ( Glycine max L. Merrill) cropping sequence was used for 4 years after no-till establishment. Soil chemical attributes, plant nutrient uptake, black oat dry biomass production and soybean grain yield were assessed. Soil acidity amelioration was achieved either by incorporating the lime or applying it onto the soil surface. Lime incorporation resulted in a faster neutralization reaction, whereas surface-applied lime provided longer lasting soil profile benefits. At 0–5 cm layer, both tillage treatments, especially with lime application, provided lower soil organic carbon levels than no-till treatments, with or without lime application, until the second year. These differences in soil organic carbon levels were not observed at the end of evaluation, after 4 years, probably because the residual tillage effect disappeared. Over time, the soil organic carbon levels at 5–10 cm layer were slightly increased or maintained close to the initial level, regardless of treatment. Overall, the plants responded to lime application, with an increase by 35% on soybean yield, regardless of the application method. Surface liming provided better economic returns than incorporated liming. Lime incorporation is not recommended in degraded lands due to the risks of SOC losses with soil disturbance and rapid pH increase. Despite of high soil acidity before no-till cultivation, the surface application of lime was the best alternative for alleviating soil acidity when establishing a no-till system on degraded pastureland. [ABSTRACT FROM AUTHOR]

• Liming and labile C addition interacted to affect N 2 O emission. • Liming reduced N 2 O emission by 13–28% compared to unlimed soil following labile C addition. • Liming reduced the Q 10 of N 2 O following labile C addition. • Labile C addition facilitated denitrification. • N 2 O emission was positively related to (nirK + nirS)/(nosZI + nosZII) ratio and NO 3 − consumption. Lime has been widely applied for ameliorating soil acidification, potentially improving soil fertility and crop production. However, the long-term effects of liming and its interaction with carbon (C) availability on the emission and temperature sensitivity (Q 10) of greenhouse gas nitrous oxide (N 2 O) from acidic arable soil are not well understood. Here, the limed and unlimed acidic soils collected from a long-term field trial, amended with and without glucose as labile C, were incubated at 15℃ and 25℃ to investigate the responses of the emission and Q 10 of N 2 O and the underlying mechanisms. Results showed that liming had no effect on N 2 O emission without labile C addition. While after labile C addition, N 2 O emissions were 13–28% lower in the limed relative to unlimed soils, indicating that the mitigation effect of liming on N 2 O emission can mainly be seen when labile C (e.g., from rhizodeposition) is highly available in soils. High temperature did not affect N 2 O emissions from soil without labile C addition, but greatly increased N 2 O emissions after labile C addition with significantly lower Q 10 of N 2 O in the limed (1.23) relative to unlimed soils (1.48). These results suggested that liming could decrease the Q 10 of N 2 O emission in the presence of labile C. Elevated soil pH by liming caused increases in the abundances of N 2 O reductase genes (nosZI and nosZII) over nitrite reductase genes (nirK and nirS), thus significantly lowering (nirK + nirS)/(nosZI + nosZII) ratio compared to the unlimed soil, particularly after labile C addition. Soil N 2 O emissions were strongly positively related to the nirK abundance, (nirK + nirS)/(nosZI + nosZII) ratio, and NO 3 − consumption after labile C addition, indicating that denitrification was mostly responsible for N 2 O emission. Concluding, long-term liming could potentially reduce N 2 O emission and its Q 10 via decreased (nirK + nirS)/(nosZI + nosZII) ratio in acidic soils in the presence of labile C. [ABSTRACT FROM AUTHOR]

The paper describes the influence of long-term (more than 30 years) fertilizer and lime application on the soil acidity (pHCl) and identifies the influence of soil acidity on the productivity of crops. At the Research Institute of Agriculture of Latvian University of Agriculture in Skrīveri, a long-term subsurface drainage field experiment was established in 1981 under the guidance of professor J. Štikāns on the uncultivated gleyic sod-podzolic Hypostagnic Endogleyic Albeluvisol (Hypereutric, stw-ng-AB(he)) loam. Four (slate ash with 80% neutralizing value) lime rates 0 (L0), 2.58 (L1), 5.70 (L2) and 11.40 (L3) t ha-1 CaCO3 were used. Primary liming was done in 1981; the maintenance liming was performed in 1994 and in 2014. Four rates of mineral fertilizers: without fertilizers (F0), N45P30K45 (F1), N90P60K90 (F2) and N135P90K135 (F3) were applied annually. Since 1994, a seven-year crop rotation was created: (1) winter triticale → (2) potatoes → (3) spring wheat → (4) spring oilseed rape → (5) spring barley → (6) and (7) perennial grasses (red clover, timothy), 1st and 2nd year of use. At the beginning of the experiment, the soil in treatments F0 and F2 was very strongly acid (pHKCl 4.7) but in treatments F1 and F3 - moderately acid (pHKCl 5.6). In limed treatments the soil acidity decreased from pH 4.8 to pH 5.8-6.0. In the following years till 1994, the soil acidity in limed treatments gradually increased (for about 0.4-0.6 pH units). After the first maintenance liming, the soil acidity reached nearly the previous highest level. Within the next twenty years, in the treatments with highest liming rate (11.40 t ha-1 CaCO3) the soil acidity increased to pH 5.2. In treatments with low liming rate (2.58 t ha-1 CaCO3), the soil acidity increased to pH 4.6, which was even lower than at the beginning of the experiment (pH 4.8). Without maintenance liming, the soil acidity during 20 years increased by 0.7-0.8 pH units. In the unlimed treatments, the soil acidity gradually increased from pH 4.8 to 4.4. [ABSTRACT FROM AUTHOR]

Aims: We hypothesised that a) species with greater acid soil tolerance have an increased capacity to utilise incipient rainfall; and b) liming increases the productivity and the ability of pasture species to utilise available water resources in the profile of an acid soil. Methods: A field experiment was established on a moderately acidic yellow Kandosol and monitored over 5 years. Five perennial pasture species including lucerne ( Medicago sativa L.), phalaris ( Phalaris aquatica L.), chicory ( Cichorium intybus L.), tall fescue ( Festuca arundinacea Schreb.) and cocksfoot ( Dactylis glomerata L.), were sown in monocultures with and without 2.9 t/ha lime. Results: Both lucerne and phalaris were more persistent than chicory, tall fescue and cocksfoot under severe drought, despite both being considered sensitive to soil acidity. Surface liming increased the soil water deficit by up to 27 mm at 0.75-1.65 m under perennial pastures compared to unlimed treatments, despite lime having no physical presence at that depth. Lime increased lucerne, phalaris and cocksfoot cumulative herbage biomass by 150, 30 and 20 %, respectively, but had no significant effect on chicory or tall fescue biomass. Conclusions: The two most acid-sensitive species, lucerne and phalaris, were more resilient under drought despite the acidic nature of the soil. We contend that species sensitive to acidity can be a valuable addition to pastures on acid soils. Lime used in conjunction with deep-rooted perennial species is likely to maximise the ability of pastures to utilise scarce available soil water reserves. [ABSTRACT FROM AUTHOR]

The problems of soybean cultivation on tidal land are low in soil fertility, aluminum (Al) toxicity and poor availability of macro nutrients. Soil acidity and Al toxicity are often fixed by liming. The research aimed to determine the calculation method of lime requirement and its application method for soybean on tidal land. The research was conducted on tidal land in South Kalimantan, Indonesia. Treatment consisted of two factors and arranged in randomize complete block design, replicated three times. The first factor was the method of lime rate calculation: (1) no liming, (2) liming based on 10% of Al saturation, (3) liming based on 20% of Al saturation, (4) liming based on 30% of Al saturation, (5) liming based on 0.5× exchangeable Al, and (6) liming based on 1× exchangeable Al. The second factor was the method of application: (1) surface and (2) mixed within 20 cm soil depth. The results showed that liming by mixing dolomite with soil within 20 cm depth resulted in 8% higher plant height compared to that applied on the soil surface. The highest yield was obtained when liming at rate equivalent to 10% of Al saturation was mixed with soil within 20 cm depth. [ABSTRACT FROM AUTHOR]

The influence of sugar foam amendment on the moisture-retention properties of three profiles of an acidic vineyard soil in Retuerta del Bullaque (Ciudad Real, Spain) has been studied. The values obtained for the surface horizons of modified soils and the original soil (under natural vegetation) were compared, as were those for the surface and subsurface horizons of the liming profiles. The water-retention curves (drying curve) were determined in triplicate on the sieved soil with Richards plates and the field capacity (FC), permanent wilting point (PWP), and available water-retention capacity (AWRC) were calculated. In the original soil FC, PWP, and AWRC values were greater than the average values for the amended soils (36.5 percent, 15.1 percent, and 21.5 percent versus 23.5 percent, 10.35 percent, and 13.1 percent, respectively). Comparison of the surface horizons and the subsurface horizons of the three profiles showed that the values for the AWRC were greater in the former (13.1 percent, 12.5 percent, and 14 percent for P1, P2, and P3, respectively) than in the latter (11.9 percent, 9 percent, and 8.6 percent for P1, P2, and P3, respectively), although FC and PWP were lower in A horizons than in B horizons. [ABSTRACT FROM AUTHOR]