Search

• 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]

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]

Optimizing the recommendation for the management of Liming Requirement (LR) is essential for cost reduction and increased yield of mango. Therefore, the objective of this study was to delimit management zones for the limestone recommendation in areas of irrigated mango in the Brazilian semi-arid region using precision agriculture techniques. The experiment was carried out in three commercial mango orchards located in the region of the São Francisco River Valley, Brazil. Soil samples were collected in the 0.0-0.2 m and 0.2-0.4 m layers following regular grids where the number of samples varied from 50 to 56. Soil analyses were performed. The kriging and inverse distance weighting methods were used to interpolate the maps. The LR map was created from the potential cation exchange capacity (T) and base saturation (BS) maps. It was verified that the Mandacaru area obtained 63.42% of the field requiring liming, being subdivided into four management zones. The Sempre Verde area obtained 1.20% of the area requiring liming and the Barreiro de Santa Fé area showed no need for the LR map. The use of precision farming techniques to delineate management zones was adequate to separate the areas into smaller and more homogeneous zones, for a more precise recommendation of liming. [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]

Precision agriculture (PA) provides techniques that favour the localized application of inputs allowing their rational use. This makes the PA a potential indicator of reduced operational costs, input volume, and environmental impacts. The objective of this study was to evaluate and compare the environmental effects of three different sampling methods used in PA for the lime application. The first sampling method evaluated was the grid sampling (GS). It was performed at a density of one sample per hectare in a 100×100 m georeferenced grid. The second method was the directed sampling, that was performed after defining the management zones by soil apparent electrical conductivity (ECa) using a soil electrical conductivity sensor. The lest sampling method was the Altitude-based management zone (AMZ) sampling that was developed based on altitude maps of the field. These sampling methods were tested in three different areas in the south of Brazil. This study evaluated the spatial variability of the lime volume in the soil and compared quantitatively and spatially the recommended application volumes achieved by each sampling method. Results highlighted that the sensor-directed soil sampling method was the alternative that would generate the lowest environmental impact. [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]

• 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]

Upon insertion of biomass into a boiler, the material is incinerated, generating heat for the system. The combustion of biomass in the boiler produces ash, which is comprised of inorganic and mineral components that possess the potential for usage as a soil amendment. This study aimed to evaluate the efficacy of utilizing bottom ash from a Eucalyptus wood panels company, either partially or wholly replacing liming, for Eucalyptus planting. Chemical, physical and morphological characterizations of the ash and chemical characterization of the soil were carried out. An experiment was set up for the development of clonal Eucalyptus (3 ×2 m spacing), using different concentrations of ash and/or lime in the soil. The chemical characterization of ash was considered safe for use in agriculture, according to current legislation in Brazil (Normative Instruction SDA, n° 27). The diameter above ground and height of the seedlings were evaluated during twelve months in the field. In all treatments, elements such as copper and zinc presented concentrations within the limit parameters for soil, set by the government agency, CETESB. The findings indicate the feasibility of partially or fully replacing liming with ash, thereby promoting a more sustainable integration of circular economy into forest-based industries' energy generation processes. • The above ground height and diameter of eucalyptus were not harmed by ash addition. • Heavy metal content in ash conformed to soil amendment safety standards. • Soil chemical constituents were within the limits set by Brazilian regulations. • Bottom ash supplied Ca and Mg, thus working as a liming substitute. [ABSTRACT FROM AUTHOR]

The rate and method of lime application modify soil chemical attributes, but the re-acidification process after liming remains poorly understood in the long-term. This study aimed to assess the long-term effect of surface and incorporated liming on shifting soil use from native grassland of South Brazilian Campos to no-tillage system (NTS) for grain production in a highly acidic sandy-loam Ultisol. In 1994, an experiment in a randomized block with split plot design and four replications was installed in Southern Brazil. The main plot consisted of lime application method (surface or incorporation by soil tillage), while the subplots were lime rates (0.0, 2.0, 8.5 and 17.0 Mg ha −1 ), corresponding, approximately, to 0, 1/8, 1/2, and 1 fold the recommended dose to rise soil pH to 6.0 in the 0–20 cm soil layer. The 2 Mg ha ‒1 treatment had reapplication every two years until soil accumulated 8 Mg ha ‒1 of lime. In October 2006 and 2012 (i.e., 12 and 18 years after lime application), soil samples were collected at every centimeter from 1 to 10 cm depth, every 2.5 cm from 10 to 25 cm, every 5 cm from 25 to 50 cm and 50 to 60 cm. The chemical attributes related to soil acidity were evaluated. Even after 18 years of lime application, the re-acidification process recovered only 50% of the exchangeable Al and 30% of the potential acidity compared to native soil. Lime incorporation before NTS adoption proved to be more rapid and efficient to mitigate soil acidity than surface liming, and it is suitable for correction of deep-layered soil acidity in the soil profile. Surface lime application induced a lower alkalinization front in the soil profile, and even after 18 years there was no neutralization of total exchangeable Al in the 10–20 cm layer. [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]

Abstract: Soil acidity and low natural fertility are the main problems for grain production in Brazilian ‘cerrado’. Although lime has been the most applied source for soil correction, silicate may be an alternative material due to its lower solubility and Si supply, which is beneficial to several crops. This work aimed to evaluate the efficiency of superficial liming and calcium/magnesium silicate application on soil chemical attributes, plant nutrition, yield components and final yield of a soybean/white oat/maize/bean rotation under no-tillage system in a dry-winter region. The experiment was conducted under no tillage system in a deep acid clayey Rhodic Hapludox, Botucatu-SP, Brazil. The design was the completely randomized block with sixteen replications. Treatments consisted of two sources for soil acidity correction (dolomitic lime: ECC=90%, CaO=36% and MgO=12%; calcium/magnesium silicate: ECC=80%, CaO=34%, MgO=10% and SiO2 =22%) applied in October 2006 to raise base saturation up to 70% and a control, with no soil correction. Soybean and white oat were sown in 2006/2007 as the main crop and off-season, respectively. Maize and bean were cropped in the next year (2007/2008). Products from silicate dissociation reach deeper soil layers after 18months from the application, compared to liming. Additionally, silicate is more efficient than lime to increasing phosphorus availability and reducing toxic aluminum. Such benefits in soil chemical attributes were only evidenced during bean cropping, when grain yield was higher after silicate application comparatively to liming. Both correction sources were improved mineral nutrition of all the other crops, mainly Ca and Mg levels and agronomical characteristics, reflecting in higher yield. [Copyright &y& Elsevier]

Liming increases soil negative charges and thus affects the chemical equilibrium of cations between the solid phase and the soil solution with consequences for the mobility of cations. The effects of lime and potassium chloride (KCl) addition on the vertical movement of potassium (K), calcium (Ca), and magnesium (Mg) were investigated in two Brazilian soils. The experiment was carried out in leaching columns. Treatments included a combination of rates of KCl (0, 50, 100, and 200 mg kg−1 K) and acidity levels (without and with liming). Seven water percolations (400 mL per column) were performed at weekly intervals, totaling an equivalent to 357 mm of rain. Raising the soil pH decreased the leaching of K, in both soils, up to 50% because of the increase of its electrostatic adsorption on created negative charges. Addition of KCl increased the percolation of K, Ca, and Mg proportionally to the rate applied, and it was more efficient than calcium carbonate to percolate Ca in both soils. Liming must be taken into consideration when K leaching or plant needs of K are estimated in predominantly variable-charge soils. [ABSTRACT FROM AUTHOR]

Abstract: The stabilisation of soil organic matter (SOM) is the result of the simultaneous action of three mechanisms: chemical stabilisation, biochemical stabilisation and physical protection. The objectives of this study were (i) to evaluate carbon-protection mechanisms in different SOM pools in soil aggregates and (ii) to identify the association of Ca2+ with total organic carbon (TOC) under the influence of surface liming in a medium-textured Oxisol in a long-term experiment under no-till system (NTS) in southern Brazil (25° 10′ S, 50° 05′ W). The treatments consisted of application of zero or 6tons ha−1 of dolomitic lime on the soil surface in 1993 and a reapplication of zero or 3tons ha−1 of dolomitic lime in 2000 to plots with or without previous lime application. Soil samples collected at depths of 0–2.5, 2.5–5, 5–10 and 10–20cm were separated into seven aggregate classes. In each of these classes, TOC, particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) were analysed. The 8–19mm sized aggregates from the 0–2.5cm layer were assessed by energy-dispersive X-ray spectroscopy (EDS) for the elemental analysis of carbon (C) and calcium (Ca). The liming caused an accumulation of TOC in the aggregates, mainly at a depth of 0–2.5cm. The aggregates from soils treated with lime had a higher mean weight diameter (MWD) that resulted in the accumulation of TOC, especially in the 8–19mm aggregate class, that was linear and closely related with C input (R2 =0.99). The proportion of large aggregates in the treatments with lime was closely correlated with the TOC content of the whole sample. The largest dose of lime (9tons ha−1) resulted in higher TOC, POC and MAOC values, mainly in the 8–19mm aggregate class. The elemental analyses for C and Ca revealed similar spectra between them for the surface-liming treatments in the clay fraction found in the centres of the 8–19mm aggregates. The surface application of lime to NT fields provided greater stability and protection of the intra-aggregate C, presumably due to Ca2+ acting as a cationic bridge between OC and the kaolinite in the clay fraction. [Copyright &y& Elsevier]

The castor bean is an oilseed crop of outstanding importance in Brazil and worldwide. Besides the wide application in chemical industry, is important due to its tolerance to drought, making it a viable crop for the semi-arid region of Brazil, where there are few agricultural alternatives. However, this culture is not unique to semi-arid region and is also planted with excellent results in various regions of the country. The study aimed to evaluate the effects of liming and potassium fertilization on the crop of castor bean. The experiment was conducted in a greenhouse in a randomized complete block randomized in a factorial 3 x 2, where the first factor consisted of potassium (0, 30 and 60 kg ha-1) and in the presence or absence lime to raise the base saturation to 60%. It was found that liming in combination with an intermediate dose of K2O (30 kg ha-1) elevates the production of dry mass of the area, however not change the concentration nutrients in the castor bean. [ABSTRACT FROM AUTHOR]

Citrus cultures have a fundamental importance to the Brazilian economy; certain aspects such as plant nutrition, yield, and fruit quality are vital for the citrus industry sustainability. The present study evaluated the nutritional status of manganese in adult Pear orange trees using different lime rates topically applied to the soil. The direct evaluation of lime rates effects on leaf manganese (Mn) levels revealed a decrease of the nutrient correlated to its increased, as well as passage of time between application and measurement. Foliar sampling 30 months after surface lime application evidenced a high correlation of foliar manganese levels with soil base saturation of 10-20 cm. Leaf manganese levels which showed a great probability of high productivity were between 33 and 70 mg kg-1. [ABSTRACT FROM AUTHOR]

Abstract: Crop residues that are left on the soil surface to serve as mulch can diminish the soybean response to surface application of lime under no-till management by ameliorating soil chemical and physical attributes and the plant nutrition. A field experiment was performed in the period from 2000 through 2003 in Parana State, Brazil, on a clayey-sandy Rhodic Hapludox. Soil chemical attributes and soybean [Glycine max (L.) Merrill] nutrition, grain yield, and quality were evaluated after surface application of lime and covering with crop residues of black oat (Avena strigosa Schreb) and corn (Zea mays L.) under a no-till system. Dolomitic lime was surface applied at the rates of 0, 2.5, 5.0, and 7.5 t ha-1 on the main plots, and three treatments with vegetable covering were applied on the subplots: (i) without covering, (ii) with covering of corn straw, and (iii) with covering of corn straw and black oat residue (oat-corn-oat). After 30 months, surface-applied lime increased soil pH and the exchangeable calcium (Ca2+) and magnesium (Mg2+) levels down to a 10-cm depth, independent of the vegetable covering treatments. The black oat and corn residues on the soil surface increased the soil exchangeable K+ level at the 5- to 10-cm depth. Liming increased leaf potassium (K) content and phosphorus (P) content in the soybean grain and reduced leaf zinc (Zn) content and manganese (Mn) content in the soybean leaf and grain. There was no effect of liming on soybean grain, oil, or protein yields, independent of the vegetable residues kept on the soil surface. The treatment with black oat covering and corn straw increased leaf N content, P content in the leaf and grain, and the contents of K, Mg, copper (Cu), and Zn in the soybean grain. It also increased soybean grain and protein yields. The corn straw left at the surface after harvesting was very important to the performance of the no-till soybean. [ABSTRACT FROM AUTHOR]

To restore a degraded pasture of Brachiaria decumbens, located in São Carlos — SP, southeastern Brazil, under altitude tropical climate, an experiment was carried out to study the effects of limestone, buried or not buried in the soil, and fertilizer use on mineral content and forage yield, after 3 years of treatment. Limestone and phosphorus were applied once, one month before starting. NK were applied after each cutting, for fertilized plots, four to five times a year. Experimental design was a random block (100 m2), with 6 replications and 4 treatments. Each block received 4 t/ha of limestone, except the control. Forage samples were collected 14 cm above soil surface. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine the mineral contents. Dry matter yield was affected positively with liming when compared with the limestone control, but the effect of limestone use was more pronounced with the concomitant use of NK fertilizer. The contents of Ca, Cs, Fe, La, Mg, Rb, Sc, Sm and Th in forage were negatively affected with the NK use, perhaps due to a dilution effect, while a reverse were observed for K, Cl, perhaps due to input of KCl, besides Br, Mn and Se. It seems that limestone is not a key input to restore degraded tropical pastureland, grown on acid soils, when nitrogen is lacking. INAA allowed the monitoring of some not routine elements that may be under observation to avoid potential plant nutritional disorders in production systems with high limestone and fertilizer use. [ABSTRACT FROM AUTHOR]

The degradation of chlorsulfuron was studied in laboratory experiments in three oxisols from south and south-east Brazil. Three soil profiles were sampled by horizon, and classified according to USDA soil taxonomy and the Brazilian system. Degradation assays were made to evaluate the influence of temperature, humidity and liming on chlorsulfuron decomposition. Further experiments were set up to study enhanced biodegradation. Abiotic degradation was also studied in sterile soils, to evaluate, by comparison with non-sterile soils, the role of microorganisms in degradation. The degradation always followed first-order kinetics and was generally faster in samples from A than B horizons. An increase in temperature (from 25 to40°C) increased chlorsulfuron degradation. Further, an increase in moisture content increased chlorsulfuron degradation in samples from the A horizons of all soils, whereas for two out of three soils, degradation in samples from the B horizon was greater at lower water content. The biotic contribution to degradation was significant only for the soil with higher fertility. Soil liming significantly increased chlorsulfuron half-life in all samples. Significant enhancement of degradation (decrease in half-life on reapplication) was observed only in soil from A horizons, where a higher microbial activity was likely. [ABSTRACT FROM AUTHOR]

Naturally dense soils have been commonly managed for coffee plantations in Vertentes Fields physiographic zone of Minas Gerais state, Brazil. Such dense soils in association with the irregular rainfall in recent years have increased risks for crop productivity. Therefore, management practices aiming at improving subsoil root exploration have been recommended for enhancing absorption of water and nutrient uptake, thus mitigating the edaphic drought process and ensuring the development, productivity, and longevity of the coffee crop. A field experiment was carried out in an area of dense Inceptisols through the planting of the coffee crop to investigate the effect of deep furrowing with additional liming on soil quality indexes and as a function of normalized pore distribution by volume [S*(h)]. The experimental design was in randomized blocks with 5 treatments: 40 (conventional soil preparation with furrows at 0.40 m of depth); 60 (soil preparation with furrow to 0.60 m of depth with conventional (60S) and complementary liming application (60C)); 80 (soil preparation with furrow to 0.80 m of depth with conventional (80S) and complementary liming application (80C)). These treatments were compared to an area under native Cerrado vegetation. Undisturbed soil samples were collected at different depths in each treatment. On these samples, water content was measured at different matrix potentials, and physical quality indicators along with the S*(h) were calculated. The results indicated that soil management practices, compared to the native condition, promoted a better distribution of water and air (P AWC , RFC, P MAC and S index) as well S*(h) up to 0.40 m. Below this depth, none of the management practices were able to promote significant improvements (p < 0.05) of these variables in relation to the soil native condition. The 80C treatment had the best air and water availability, with increased of pore size class having functions of drainage and aeration. Moreover, this treatment stood out in comparison to the conventional management (40) for all measured variables, maintaining the adequate conditions of the native area in depth. For the managed areas, the depth of 0.60 m gave the best improved growth and vegetative vigor of the coffee plants. Unlabelled Image • Soil management increases aeration and water availability in dense and shallow Inceptisols. • Optimum limits for physical quality indicators should be proposed considering soil classes. • Deep furrow in shallow and dense soils can mitigate the effects of water deficit for coffee trees. • Physical quality indicators correlate with Normalized Difference Vegetation Index and plant height of coffee trees. [ABSTRACT FROM AUTHOR]