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Relevance. The productivity and especially the quality of flax products largely depend on a set of technological techniques that take into account varietal characteristics, agrochemical properties of the soil and the fertilizers used. Identification of the reaction to the production process of a new high-yielding flax variety of Universal is an important element of agricultural technology.Methods. The sod-podzolic medium loamy soil is characterized by a slightly acidic reaction of the soil solution pHKCl-5.44, a very high content of phosphorus (298 mg/kg) and medium potassium (85 mg/kg), low humus — 2.05%, medium boron (0.33 mg/kg), low zinc (0.56 mg/kg). The HTC (hydrothermal coefficient) for May — August by year was — 1.56 optimal (2017), — 1.09 arid (2018), — 1.80 wet(2019).Results. Studies have shown that the Universal flax variety has a high responsiveness to the use of fertilizers. The yield increases were: for flax straw 24 to 43%, for flax seeds from 27 to 49%, depending on the form of fertilizer and the method of their application. The advantage of the complex organomineral OMU “Universal” and mineral nitrogen-phosphorus-potassium with boron containing trace elements over the azofoska in equalized doses of nitrogen is noted. The increase in the yield of the flax stock of these fertilizers with the row method of application was lower by 40 and 34% of their main application, but the profitability of this method increased from 46 to 234% and from 62 to 219%. The application of organic fertilizer Sivid — Bor for seed treatment and Sivid-Zinc for crop processing on the background of reducing the dose of azofoski from 1.5 to 1.0 c/ha allowed to raise close to making azofoski of 1.5 c/ha, but with a greater profitability of 115%.

Indiscriminate use of pesticides and growing awareness of environmental and health problems had led to monitoring their residues in soil and crops. Ethofumesate is one of the widely used herbicides for controlling weeds in sugar beet. Dissipation kinetics and terminal residues of ethofumesate were investigated in two diverse soils under subtropical field conditions. Ethofumesate dissipated slowly after application and follows biphasic first-order kinetics in soils. The average half-life for initial and later phases in sandy loam soil, respectively, was 14.54 and 20.42 and 51.83 and 65.21 days, while for silty clay loam, it was 10.09 and 13.00 and 71.42 and 73.10 days, respectively. Recoveries in soil, leaves, and beetroot ranged from 78.15 to 88.05, 77.01 to 88.58, and 76.25 to 84.50%, respectively. The quantitation limit for soil, roots, and leaves was 0.002 μg g−1. At harvest, no residues were detected in soils, leaves, and sugar beetroots. Residues were below the maximum residue limits in sugar beetroots and leaves as set by EU (0.2 ppm). Ethofumesate is safe from weed control and environmental aspects as it does not persist for a long duration in soils and does not appear to pose any adverse effect on human/animal health under subtropical field conditions.

Introduction. The article studies the strength of hardened ash-soil materials, with different ratios of pond ash, natural clay soil and lime in various proportions when adding a stabilizing additive “Sattelit”.Materials and methods. As part of the study, tests were carried out to determine the maximum density of dry soil and the optimal mixture of ash-soil materials (100% ash-and-slag mixture, 25% ash-and-slag and 75% loam and 50% ash-and-slag and 50% loam), and the subsequent determination of the ultimate strength for uniaxial compression at age seven, twenty-eight and ninety days. The samples were gaining strength in the normal hardening chamber. The samples are placed in a device for capillary water saturation of the samples.Results. As a result of the study, a regularity of the increase in the strength of the soil-ash mixtrues was revealed, depending on the amount of binder, the proportion of materials and the age of the mixture. It was also revealed that with an increase in the dosage of clay soil in the pond ash, the strength of the obtained soil-ash mixtrues sharply increases.Discussion and conclusion. The results of the studies carried out show the potential possibility of using zoological soil materials fortified with lime when installing an additional layer of the base of highways with capital or lightweight pavement on roads in the I-V road-climatic zone. However, additional research is required to determine the frost resistance and water resistance of zoological soil composites reinforced with lime.

Soil is an important source of human life and agricultural production. Studying on the pedon and its site characteristics pave the way for understanding the nature of soils and its utility. A study on pedological characterization of soils in Melur block, Madurai District (Tamil Nadu), was carried out during 2019-2020 using grid sampling with village map/cadastral maps. Soil mapping unit-based soil samples were collected in Chunampoor, Thuvarangulam, Poonjuthi and Veppapadupu and pedons were characterized as per the standard procedure. The results showed that soils were moderately deep to very deep in nature, ranging from 2.5 YR 3/6 to 10YR 4/6. The soil texture varied from sandy clay loam to sandy clay with weak to moderate sub-angular blocky structure. The consistency of soil varied from slightly hard to very hard when dry, very friable to firm when moist, slightly sticky to very sticky and slightly plastic to very plastic in wet condition. The crops viz., paddy, sugarcane, banana, groundnut and vegetables were very suitable for such type of soil of the Madurai district.

An experiment was executed at field condition to evaluate ecological impact of Bt cotton (Mech 162 + Bt) on soil microbes and Bt protein behavior in soil. Root exudates of Bt cotton plant containing Bt protein enter into soil which persisted in soil for atleast 235 days after sowing (DAS). During vegetative and flowering stage, Bt protein was not detectable in both qualitative and quantitative assay but, during onset of boll formation at 150 DAS, a level of 0.0013 μg/g of Cry 1Ac protein was quantified in rhizospheric soil which further increased exponentially up to 0.0033 μg/g at 195 DAS and then maintained at the same level till 235 DAS with Cry1Ac expression level of 0.0029 μg/g soil. Rhizospheric soil of Bt cotton had significantly higher (p

Spent drilling mud (DM), a co-product during horizontal directional drilling operations, needs proper disposal to comply with social and environmental sustainability awareness, with one option being its cost-effective reuse as a soil amendment. The possibility was investigated of DM applications to improve the physical quality of loamy sand soil. The soil was treated with increasing DM contents in a laboratory at volumetric DM-to-soil ratios of 0:100 (DM0, no DM), 25:75 (DM25), 50:50 (DM50), 75:25 (DM75), and 100:0 (DM100, no soil). The mixtures were analyzed for water retention, available water capacity, water storage capacity, S-index, soil aggregate stability (SAS), and chemical quality based on pH, effective electrical conductivity (ECe), sodium adsorption ratio (SAR), and exchangeable sodium percentage (ESP). The optimal ratio of DM and the control (DM0) in the batch experiment were selected for application to three species of forest plant seedlings in the field. The results showed that DM positively influenced soil physical qualities. The water retention increased (from 10 to 67%) with increasing DM, but the most suitable ratio was DM25, considering its water storage capacity deviated the least (1.4%) from the optimal value. DM25 also produced the highest S-index (0.081). The SAR data increased with the drilling mud application rate (1.1 to 10.9). However, the DM25 pH remained at 7.7, with an ECe of 2.5 dS m-1, a SAR of 7.0, and an ESP of 9.2, which were still favorable regarding soil structure, as indicated by no decrease in SAS with added drilling mud. In the field experiment, DM25 also decreased the water deficit of the three species of forest plant seedlings, suggesting a positive attribution to other relevant soil-plant systems. DM could be a feasible option to improve soil physical quality, but further long-term experiments are necessary before applying it as a soil amendment in real situations.Implications: With the demand in energy-driven economics, establishing national energy security nationwide in Thailand requires the installation capacity, transmission, and distribution pipelines. Horizontal directional drilling (HDD) operations are generally used to install underground pipelines, generating large amounts of drilling mud rich in sodium bentonite as a co-product. At present, drilling mud is becoming a more serious solid waste and has been raised in proper management. The best management practices are expected to reuse as a soil amendment, a cost-effective approach, for coarse-textured soils. Before any drilling mud application can be introduced to agriculture and the environment, we must clarify the optimal rate of drilling mud. This rate has to significantly improve soil physical quality associated with air-water capacity balance while minimizing the adverse effect of residual sodium to favor soil structure and sensitive plants.

In Tamil Nadu, one of the most important agro-climatic zone dictating the total rice production is by Cauvery Delta zone. In Cauvery Delta zone the area under rice cultivation has been reduced drastically and this situation forms the base for a paradigm shift from rice cultivation to alternate crops that requires less amount of irrigation water. Suitable alternate cropping pattern plays an important role in improving the purchasing power of farmer with the help of inclusion of commercial crops in rice based cropping system. Chilli is an important spice cum vegetable crop cultivated extensively in India. This project is indented to study the fertigation system in one of promising alternate crops in chillies in rice ecosystem. By keeping all these points in view, the present investigation was undertaken to study the response of chilli to drip irrigation on sandy clay loam soil under Madukkur soil series (Typic Ustropept) in cauvery new delta zone. Field experiment was conducted at Soil and Water Management Research Institute, Kattuthottam, Thanjavur financially supported by Department of Science and Technology under SERB programme with a budget outlay of Rs. 13.0 lakhs for three years during 2012-2015 in strip plot design with four replications. The results revealed that Sub surface drip fertigation at 10 cm depth recorded the maximum plant height, number of branches, number of flowers and number of fruits at B2 irrigation regime (IW/CPE = 0.75). Total green chillies yield was higher under sub surface drip fertigation @ 10 cm depth at IW/CPE=1 (15.59 t ha-1) followed by surface drip fertigation at IW/CPE = 0.75 (13.50 t ha-1) and sub surface drip fertigation @ 10 cm depth at IW/CPE = 0.75 (11.17 t ha-1).Thus, introduction of chillies as an alternate crop under sub surface drip fertigation @ 10 cm depth technology during January under Broad bed furrow method of cultivation paves the way for improving the social security to the rice farmers.

Purpose. To evaluate forecasting methods and processes of soil alkalinization with different granulometric structures, which have been irrigated by drip irrigation in southern Ukraine for 20 years. Methods. Analytical, field, and laboratory experiments, systems analysis, and methods of mathematical statistics. Results. The manuscript systematizes the results obtained during many years of personal observations on changes in the soil absorption complex (SAC) and alkalinization soil processes of southern chernozem, dark chestnut, sod, and meadow-chernozem soils with different soil structure under drip irrigation. The experiment was established in 2009 on perennial fruit crops. Fertilizers (organo-mineral (Rost-concentrate), mineral (N120P30-90K75-120), and organic (Gumoplant)) were applied with drip irrigation of different water quality, and soil field moisture capacity was in the range of 75-90%, depending on the soil structure. Predictive models of soil behavior according to the scenario have been developed when the drip irrigation regimes, soil fertilization systems, and irrigation water quality remain constant. Changes in the SAC of the soils are characterized, and prognostic models up to 8 years have been developed for them. On the example of southern heavy loam chernozem, which was irrigated of the partially suitable water for irrigation, the forecasting results as a holistic system depending on different scenarios of anthropogenic load – irrigation norms, fertilization systems is presented in more detail. Through spatial modeling, the distribution of alkalinization soils in time and space is constructed, which can be further used to create a conceptual model for determining the danger of these processes in the soilplant system. Findings. It was established that under the influence of different quality water and fertilizers in locally moist soils, alkalinizetion processes developed differentiated. In quantitative terms, soil capacity changed slowly during the forecast period, especially in heavy loam soils. Changes in sandy and medium loam soils were almost imperceptible.

A laboratory study for adsorption of potassium (K) determination was conducted on six soils located in Sharazur plain from the Kurdistan Region of Iraq in 2021 using the batch technique method. Potassium (K) adsorption isotherms were achieved by equilibrating 5.0 g of soil samples with eight grades of K (0 to 300 mg L-1) as KCl in 50 ml of 0.01M CaCl2 solution. To match the data of adsorption, Freundlich, Langmuir, and Temkin adsorption isotherms were used. The results show that the amount of adsorbed K ranged between (45.78 to 52.49) % added K. The Freundlich model fit the equilibrium K adsorption data better for the Serwan location of soil (silty loam), as demonstrated by a greater coefficient of determination (R2 =0.90). The value of heterogeneity factor 1/n for the Freundlich model ranged from (0.34 to 0.47) kg mg-1, which was less than one. The sorption processes for all of the studied soils were normal adsorption. The constant of the Langmuir isotherm (KL) aligned from (0.107 to o.425) L mg-1. Smaller KL values mean that more adsorbed K would be transformed to a non-exchangeable form, either through the creation of crystalline K or through ion occultation. The RL values indicate the type of isotherm, the values of RL> 1 that means the adsorption nature to be unfavorable. The Temkin equilibrium binding constant (AT) was high for all studied soils except the soils of Bestan Sur and Grdigo locations, the high value of AT indicates high binding energy. The Temkin constant (bT) ranged from (10.46 to 13.47) J mole-1 that was related to the nature of the adsorption energy, a positive value indicates that the adsorption process is exothermic.

An evaluation of a fulvic acid (FA) was made in a Loam soil, by selecting the best dose to achieve salt displacement under a drip emitter. In trial 1, PVC columns were filled with a loam soil and irrigated with a KCl solution of electrical conductivity (EC) of 12.5 dS m-1. Once the soil solution EC reached the value of the KCl solution, FA doses of 0, 2.1, 5.3 and 10.5 kg ha-1 were applied. The bulk electric conductivity and soil chemical properties were evaluated after 6 irrigation cycles. In trial 2, the same soil salinized with the KCl solution was placed in 0.8 m3 containers. Two irrigations treatments were performed: a control and the best FA dose from trial 1. The displacement of the salt bulb created from irrigation with a dropper in the soil profile was characterized. In trial 1, the dose of 5.3 kg ha-1 reached the lowest EC after the third irrigation. In trial 2, the selected dose reduced EC until 3.75 dS m-1 at 0.3 m depth at the third irrigation, saving 246 L of water compared to control. Additionally, the salinity bulbs were more horizontally extended in the FA treatment. Highlights: Application of FA (5.3 kg ha -1) reduced the water use by 50% compared to leaching carried out exclusively with water. The use of Fulvic acid showed to be an alternative to consider in the recovery of saline soils under drip irrigation when irrigation water is scarce. Little or not residual effect was found after the use of Fulvic acid.

The salinity of soil is a crucial challenge for growers irrigating in semi-arid zones. To accomplish salinity, growers require information about salt's basis and processes of the salt mobility through the root zone. Soil salinity can be managed by exceptional irrigating farming practices including irrigation scheduling to leach down salts through the root zone. This study aimed at examining the salts movement in saline soil in a semi-arid region in Sindh, Pakistan. This field experiment was conducted during the summer of 2017 on a salt-affected land by using three irrigation treatments of canal water including T1 (7 day irrigation interval), T2 (14 day irrigation interval) and T3 (21 days irrigation interval) under 10, 9 and 8 cm depths of irrigation water, respectively. The texture of soil was silty clay loam having an electrical conductivity (EC) ranging from 7.73 to 20.69 dS/m. However, the pH of the soil ranged from 7.89 to 8.04. The findings of a two-way analysis of variance were consistent with the statistical examination of EC and pH data day- wise (7, 14 and 21 days) and depths-wise (10, 9 and 8 cm). Average reductions in the EC and pH of the soil were observed at 7 days interval and 10cm depth at P

The straw generated from crops significantly affects the soil microbial community when returned to the soil. However, the effects of different application times of straw return treatment on the microbial community remain unknown. Soil samples were collected from different depths (0–30 cm) at different straw return times (every year return (E0y), every 2 years (E1y), and every 3 years (E2y) besides from unfertilized soil (CK) in Fuxin Mongol Autonomous County, Liaoning, China. Soil physicochemical properties analysis and high-throughput sequencing technique were performed to analyze the structure and composition of the soil microbial communities. In deep layer soil, straw return significantly increased the soil water content, field capacity, and porosity and decreased soil bulk density. However, an increase in the soil porosity was not evident when the straw return was applied for consecutive years. When the straw return was applied every 3 years, it significantly increased the alkali-hydrolyzed nitrogen, available phosphorus, and available potassium levels in the deep layer of the soil, but it decreased the soil organic matter levels. Bacterial and fungi community diversity varied between straw return treatments and soil depths. Variations in the relative abundance of some trace microbes (Nitrospirae, Parcubacteria, Acidobacteria, Cercozoa, Rozellomycota, Blastocladiomycota) in different layer soil confirmed the different effects of straw application time on microbial community structure. Straw return treatment applied every 2 or 3 years significantly improved soil structure, increased soil nutrient decomposition, and affected microbial community composition in brown loam soil.

Application of municipal solid waste compost (MSWC) to marginal soil enhances crop growth but could also serve as source of pollutants into agroecosystem. There is scanty report on bioavailability of potentially toxic element (PTE) and the health risk of consuming popcorn kernel harvested from field fertilized with MSWC. Field trial was carried out in 2017–2019 to evaluate bioavailability of PTEs in kernel of popcorn harvested from field fertilized with MSWC. The trial was conducted at the experimental field of North-West University, Mafikeng campus South Africa. The treatments comprised three rates of MSWC including 0 t/ha (unamended, control), 4 t/ha and 8 t/ha arranged in randomized complete block design and replicated four times. One seed of popcorn was sown at 20 × 70 cm spacing per hole of 3 cm depth in a 6 × 4.2 m plot size. Growth and yield data were collected at maturity. Ears were harvested at maturity and the kernels were dried to 12% moisture content. Air-dried kernels (50 g) samples were collected and analyzed for essential mineral nutrient and some heavy metal(loid)s using ICP-MS. Measured concentrations of these heavy metal(loid)s were then used to calculate the health risk for adults and children. The results showed that uptake concentration was in the order K+ > HPO42− > Mg+2 > Ca2+ > Fe2+ > Cr6+ > Zn2+ > Mn2+ > Cu2+(mg/kg). Uptake concentration of metalloids: Al and Pd was significantly higher in the unamended. Bioavailability of PTE was highest in unamended plots. The average daily intake of the PTEs was within the recommended permissible level. The risk index value for oral pathway was

To investigate the relationship among field capacity (FC) in–situ and laboratory determinations of soil moisture content under different applied pressures of different soil textural classes, one hundred and sixty-eight of surface samples were collected. The collected samples were classified to seven groups based on the USDA texture triangle. Simulated field determinations of in-situ FC were done and the obtained results revealed that the elapsed time to reach FC and the values of soil moisture tension are different according to soil textural class. Generally, increasing water-holding pores and/or fine capillary pores, both moisture tension at FC (hfc) and elapsed time to reach it after heavy irrigation (tfc) are increased. Sand and loamy sand soils, have the highest significant correlation coefficient between in- situ FC and soil water content balanced with 60 mbar of applied pressure. While sandy loam soil achieves the highest significant value of correlation coefficient, at 100 mbar of applied pressure. The significant correlation coefficients among FC - in situ - and soil moisture content balanced with 330 mbar of applied pressure of the other soil textural classes under study are found.

Soil water deficit is increasingly threatening the sustainable vegetation restoration and ecological construction on the Loess Plateau of China due to the climate warming and human activities. To determine the response thresholds of Amygdalus pedunculata (AP) and Salix psammophila (SP) to soil water availability under different textural soils, we measured the changes in net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), leaf water potential (ψw), water use efficiency (WUE) and daily transpiration rate (Td) of the two plant species during soil water content (SWC) decreased from 100% field capacity (FC) to 20% FC in the sandy and loamy soils on the Loess Plateau in the growing season from June to August in 2018. Results showed that Pn, Gs, WUE and Td of AP and SP remained relatively constant at the beginning of soil water deficit but decreased rapidly as plant available soil water content (PASWC) fell below the threshold values in both the sandy and loamy soils. The PASWC thresholds corresponding to Pn, Gs and Ci of AP in the loamy soil (0.61, 0.62 and 0.70, respectively) were lower than those in the sandy soil (0.70, 0.63 and 0.75, respectively), whereas the PASWC thresholds corresponding to Pn, Gs and Ci of SP in the loamy soil (0.63, 0.68 and 0.78, respectively) were higher than those in the sandy soil (0.58, 0.62 and 0.66, respectively). In addition, the PASWC thresholds in relation to Td and WUE of AP (0.60 and 0.58, respectively) and SP (0.62 and 0.60, respectively) in the loamy soil were higher than the corresponding PASWC thresholds of AP (0.58 and 0.52, respectively) and SP (0.55 and 0.56, respectively) in the sandy soil. Furthermore, the PASWC thresholds for the instantaneous gas exchange parameters (e.g., Pn and Gs) at the transient scale were higher than the thresholds for the parameters (e.g., Td) at the daily scale. Our study demonstrates that different plant species and/or different physiological parameters exhibit different thresholds of PASWC and that the thresholds are affected by soil texture. The result can provide guidance for the rational allocation and sustainable management of reforestation species under different soil conditions in the loess regions.

The radial migration of total petroleum hydrocarbons (TPH) in soil and their inflow into lysimetric leachates have been estimated to determine the permissible residual content of TPH (PRCTPH) in the main soil types of Sakhalin Island. The maximal concentrations of TPH, of their medium- and high-boiling fractions in particular, are allocated to peat and humus horizons, as well as to soil horizons of heavy loamy granulometric composition, which represent radial geochemical barriers for migrating pollutants. Benzene and its homologues are detected in filtrates from soil lysimeters after the percolation of water in the amount of three-quarters of the annual precipitation. After the filtration of the water amount equal to the annual precipitation, these compounds are not revealed. The toxicity of leachates has been assessed by bioassay, using ceriodaphnia and ciliates. The PRCTPH in soils with respect to the water migration index may be determined by the concentration of TPH and the content of monoaromatic compounds in leachates and their toxicity for hydrobionts in lysimetric experiments.

Synthetic nitrogen fertilizer use comes with unsustainable financial and environmental costs, making it not attractive to small-scale and organic farmers. Poultry manure (PM) when available is a primary fertilizer source for small-scale and organic farmers but there is still limited research on its effects of specific crops and soil fertility under specific practices. The study investigated PM effects on garden egg in three seasons in Ghana and PM effects soil fertility in sandy-loam soils of Arizona after three years under flood irrigation and no-till. The PM application improved garden egg growth (dry matter by 73%) and increased yield by 66% in slightly acidic sandy-loam tropical soils, which could be related to soil mineral improvement. In the semi-arid soil, three years PM application increased cation exchange capacity (41%), P (471%), K (18%), S (244%), Ca (45%), Mg (31%), Zn (5%) and Mn (19%) with reduction in nitrate (−26%), Fe (−38%) and Cu (−11%). The reduction in the nitrate and Fe in the semi-arid Arizona cropland could be associated to flood irrigation and high soil pH, respectively. To gain the full potential from PM applications, best management practice is recommended to reduce nitrate leaching.

This study quantified the relationships between soil, textural, and hydraulic properties at the field-scale for a conventional tilled Memphis silt loam that had undergone a 10-year corn and cotton rotation and described their spatial variability. Composite soil samples collected from the plow layer at 272 nodes on 15 x 15 m grids were analyzed for texture and bulk density. These values were used as pedotransfer functions to predict unsaturated (Ko) and saturated hydraulic (Ks) conductivities as well as the van Genuchten curve shape parameters α and n. Regression analyses quantified relationships between the measured and model predicted soil properties. While correlations between textural and model predicted soil properties including bulk density were significant (p

The structural response of small diameter (

This study aimed to characterize the effect of amending soils with biochars derived from soybean residues, sugarcane bagasse, and wood chips on the sorption-desorption of indaziflam and indaziflam-triazinediamine (FDAT), indaziflam-triazine-indanone (ITI), and indaziflam-carboxylic acid (ICA) metabolites applied to soils from three Midwestern U.S. states, a silt loam and a silty clay loam. Biochars produced from different feedstock were used as soil amendments and compared with raw feedstock. Sorption-desorption experiments of indaziflam and its three metabolites were performed using the batch equilibration method and analyzed for 14C activity by liquid scintillation counting (radiometric technique). In all soils, the use of organic amendments promoted greater sorption and less desorption of indaziflam and ITI. The addition of biochar to soils promoted greater sorption of the four tested chemical products compared with the corresponding raw materials. Among the biochars, grape wood chips showed greater potential in sorb indaziflam and ITI. In general, none of the biochars affected the sorption and desorption of FDAT and ICA. Characterization of biochar to be used as a soil amendment (immobilizer) is highly recommended prior to field addition to optimize the sorption process and to prevent increased soil and water contamination of indaziflam and its metabolites following biochar addition.

QUALIDADE FÍSICO-QUÍMICA DE FRUTOS DE MARACUJAZEIRO EM FUNÇÃO DAS FORMAS DE PROPAGAÇÃO E POTENCIAIS DE ÁGUA NO SOLO LÚCIO ADERITO DOS ANJOS VEIMROBER JÚNIOR1; ALISSON JADAVI PEREIRA DA SILVA2; HANS RAJ GHEYI1; MAIRTON GOMES DA SILVA1; FÁBIO TAYRONE OLIVEIRA DE FREITAS1 E MAURÍCIO ANTÔNIO COELHO FILHO3 1 Programa de Pós-Graduação em Engenharia Agrícola, Núcleo de Engenharia de Água e Solo, Universidade Federal do Recôncavo da Bahia, Rua Rui Barbosa, 710 - Campus Universitário, CEP: 44380-000, Cruz das Almas-BA, Brasil. E-mail: agrolucio10@gmail.com, mairtong@hotmail.com, hgheyi@gmail.com, oibaf.freitas@hotmail.com 2 Instituto Federal de Educação, Ciência e Tecnologia Baiano, Rua Waldemar Mascarenhas, s/n, CEP: 44350-000, Governador Mangabeira-BA, Brasil. E-mail: alissonagr@gmail.com 3 Embrapa Mandioca e Fruticultura, Rua Embrapa, s/n, CEP: 44380-000, Cruz das Almas-BA, Brasil. E-mail: mauricio-antonio.coelho@embrapa.br 1 RESUMO No presente estudo foram avaliadas a qualidade físico-química de frutos de maracujazeiro (Passiflora edulis Sims, ‘BRS Gigante Amarelo’) propagado a partir de sementes e estaquia sob diferentes potenciais de água no solo. O experimento foi realizado em casa de vegetação, entre os meses de novembro de 2019 e junho de 2020, na Universidade Federal do Recôncavo da Bahia, Cruz das Almas, BA. O maracujazeiro foi cultivado em lisímetros de drenagem, cada um com área superficial de 1,44 m² e altura de 0,6 m, preenchidos com solo de textura franco-arenosa. Adotou-se o delineamento experimental inteiramente casualizado em esquema fatorial 2 x 4: duas formas de propagação vegetativa (semente e estaquia) e quatro potenciais matriciais de água no solo (-6, -10, -20 e -33 kPa), com quatro repetições. Avaliaram-se as massas frescas do fruto e da polpa, diâmetro e comprimento do fruto, razão comprimento/diâmetro do fruto, rendimento da polpa do fruto, espessura da casca, sólidos solúveis totais, acidez total titulável, razão entre sólidos solúveis totais/acidez total titulável e pH da polpa. As formas de propagação afetaram as principais variáveis da qualidade física dos frutos do maracujazeiro. A qualidade química da polpa dos frutos do maracujazeiro não foi afetada pelos fatores em estudo. Palavras-chave: Passiflora edulis Sims, manejo da irrigação, reprodução vegetal. VEIMROBER JÚNIOR, L. A. A.; SILVA, A. J. P.; GHEYI, H. R.; SILVA, M. G.; FREITAS, F. T. O.; COELHO FILHO, M. A. PHYSICAL AND CHEMICAL QUALITY OF PASSION FRUIT UNDER PROPAGATION METHOD AND WATER POTENTIAL IN THE SOIL 2 ABSTRACT In this study, the physicochemical quality of passion fruit (Passiflora edulis Sims, ‘BRS Gigante Amarelo’) propagated from seeds or cuttings and subjected to different soil water potential was evaluated. The experiment was conducted in a greenhouse, between November 2019 and June 2020, at the Federal University of Recôncavo of Bahia, Cruz das Almas, BA. The passion fruit was grown in drainage lysimeters, each one with a surface area of 1.44 m² and 0.6 m high, and filled with sandy loamy soil. The experiment was performed in a completely randomized design in a 2 x 4 factorial scheme: two forms of vegetative propagation (seed or cuttings) and four soil water potential (-6, -10, -20, and -33 kPa), with four replicates. Fruit fresh weight, fresh weight of the fruit pulp, fruit diameter and length, fruit length/diameter ratio, fruit pulp yield, rind thickness, total soluble solids, total titratable acidity, total soluble solids/total titratable acidity ratio and pH of the pulp was evaluated. The forms of propagation affected the main physical quality variables of the fruits of passion fruit. The chemical quality of the passion fruit pulp was not affected by the factors under study. Keywords: Passiflora edulis Sims, irrigation management, vegetative propagation.

Field experiments were conducted to compare nano NPK fertilizers with ordinary mineral NPK fertilizers on maize (Zea mays L. Triple hybrid Giza 320) grown on a saline sodic sandy loam soil. Two experiments were conducted on 2018 and 2019 seasons at Romanh Village, North Sinai Egypt. The design was a randomized complete block, factorial (split plot). Factor1: Source (i.e. mineral ‘S1’ and nano ‘S2’). Factor2 Dose “rate” (i.e. kgha-1 NPK of 0/0/0, 120/180/60; 180/36/120 and 240/72/180 for D0, D1, D2 and D3 respectively. The fertilized treatments using the nano forms were much superior then those of the regular mineral ones. Superiority was up to the followings for each 8 and 12% for grain and straw yields respectively. For the other traits, superiorities for uptakes were up to 29% (straw N) 3% (grains N), 41% (straw P), 7 % (grain P), 27% (straw K) and 34% (grain K.). Fertilization enhanced plants to sustain salinity stress conditions. The mineral fertilization caused plants to accumulate more proline “g kg-1 fresh matter”: average of 44.3 for the mineral and 27.4 for the nano.

A pot experiment was conducted applying 8% olive pomace compost, 4% perlite and 0.12% hydrophilic polymers on loam and clay loam soils with three replications. Tomato (Lycopersicon lycopersicum L.) seedlings were transferred to each pot and plants were grown under controlled atmosphere conditions. Effects of different soil conditioners on plant water use efficiency and tomato plant growth was determined. As a result, olive pomace compost applications to loam soil saved irrigation water 45.12%, 42.99% and 38.88% compared to control, perlite and hydrophilic polymers treatments respectively. On the other hand, hydrophilic polymers treatments saved irrigation water 17.82%, 46.76% and 27.29% compared to control, perlite and olive pomace compost treatments respectively for clay loam soil. Soil pH decreased and electrical conductivity (EC) increased for both soils after the experiment. The highest soil EC value was dedected with the application of olive pomace compost. Perlite application increased plant fresh weight and length while olive pomace compost increased branch numbers of tomato for clay loam soil. Root length and surface areas were maximum under olive pomace compost applications for both soils.

The present field study was conducted on loamy sand soil at the Research Farm, Department of Soil Science, Punjab Agricultural University, Ludhiana, India under a rice–wheat cropping system to stud...

The field experiment on identifying differences in the effect of the herbicide and foliar feeding of plants with liquid nitrogen fertilizer (UAN-32) against the background of autumn tillage with a cultivator or plow on potato yield and phytopathologic characteristics of tubers during storage was carried out in 2019-2020 in the Nizhny Novgorod region. The experiment was laid on sod-podzolic sandy loamy soil in production conditions on two varieties of potato ‒ the super-early Сolomba variety and the medium-early Innovator variety grown for seeds. The variants under study were surface application of the soil herbicide Gezagard in a tank mixture with UAN-32 and foliar feeding of plants with UAN-32 (N42) during the growing season against the background of N42P42K169 (calcium chloride in autumn + ammonium nitrate phosphate in spring). The results indicate that the background fertilization provides the yield of Colombа variety potato of 20.7-29.0 t/ha, the Innovator variety – 17.4-23.1 t/ha. The use of the herbicide is more effective during autumn tillage with a cultivator, providing an increase in yield of 28-37 % on both potato varieties, feeding of plants with UAN-32 contributes to an increase in yield (8-10 %) only on the Сolomba variety. Plowing the soil for potatoes helps to avoid the pest damage of tubers and to reduce their susceptibility to rhizoctonia by 6-27 %, to wet rot ‒ up to 55 %. In general, it has been established that due to autumn plowing with fertilization at a dose of N42P42K169, it is possible to obtain an increase in potato yield exceeding the increase provided both by herbicides and the use of foliar feeding of potatoes.

Subsurface drip irrigation is the most efficient irrigation technology available to agricultural producers. The dimensions of wetted areas, affected by subsurface drip irrigation (SDI) system design and initial soil moisture conditions, were evaluated around emitters in three different indoor soil bins with a growing alfalfa (Medicago sativa L.) crop. To investigate the dynamics of soil moisture an emitter flow rate of 0.432 L hr−1 was implemented for 3, 4, 5, 6, 7 h of continuous irrigation application in all three bins. Moreover, a normal single pulse application (6 h) to three multi-pulse [three 2-h pulses separated by 4 h (3 × 2 h), a 2-h and 4-h pulse separated by 6 h (2 + 4 h), a 4-h and 2-h pulse separated by 6 h (4 + 2 h)] were compared. The results showed that at applications of five or more hours, single irrigation events in the Clay loam (CL) and Loamy sand (LS) bins could generate connected wetted areas around emitters along driplines with width (W) values larger than 60 cm. In the LS bin, without separation between dry and wet initial conditions, the increase of height (H) as a function of application duration was steeper than in the CL and C bins. Soil moisture differences between multi-pulse and single-pulse irrigation applications disappeared within 24 h after the start of the first irrigation event. Therefore, sub-daily multi- pulse irrigation is not relevant for crop water management.

Potassium (K) availability to plants varies with the adsorption characteristics of soil, to evaluate the adsorption capacity, five soil series of different characteristics were used. K adsorption isotherms were performed by equilibrating 2.5 g soil samples with 10 levels of K (30-300 mg kg-1) as KCl in 0.01 CaCl2 solutions and shaken for 24 h at 25oC. The amount of K adsorbed ranged from 33.2 to 94.9% of added K. Freundlich model explained K adsorption behavior better than the other two equations. Higher coefficient of regression values 0.99, 0.97 and 0.96 were recorded in Sultanpur (Silt loam), Naivela (Fine sandy loam) and Bhutesar (Clay loam), respectively. The highest 1/n value 1.54 kg mg-1 and kf value 31.47 mg kg-1 of Freundlich isotherm were observed in Sultanpur (silt loam) due to high pH, high OM and high clay contents, lowest values of constants were observed in Wajan (loamy sand) with 1/n value 0.44 kg mg-1 and kf value 0.28 mg kg-1 might be due to high EC, high CaCO3 and sand contents. The K adsorption of soil varied with physico – chemical characteristics of soil, especially clay content, alkaline pH and organic matter content.

Introduction The soils of the forest and agrarian experimental sites in the State Enterprise ‘Mariupol Forest Research Station’ have been influenced by the ameliorative system of rare protective forest stands, the history of which is more than 125 years. Therefore, it is urgent to study a current chemical composition of the soils. The aim of the research was to study and analyse chemical characteristics of the soils on the arable land and in the forest shelterbelts in the State Enterprise ‘Mariupol Forest Research Station’ as well as in the farm of the Donetsk Region. Materials and Methods The object of the research was medium-humus chernozems formed on heavy loamy soils under forb-fescue-feather grass vegetation on agricultural land and those under the shelterbelts in studied farms. To do the research, we used field, laboratory-analytical, and statistical methods. A chemical analysis was carried out on 33 soil samples. The forest stands were inspected with commonly accepted methods. The results were analysed by means of statistical methods. Results Inspected field shelterbelts are dominated by Quercus robur L. of 50–126 years old. Their area makes 0.7–3.8 ha; the relative density of stocking is 0.6–0.8. The arable land occupies from 9.8 to 34.0 ha. The forested index of the arable land in SE ‘Mariupol Forest Research Station’ is from 9.0 to 13.9 km·km-2, that of the farm land is 3.2 km·km-2. The highest humus content was found in the soils under field shelterbelts in the permanent forest and agrarian experimental site (8.44–17.36%). It was 5.08–6.96% on the arable land. The difference of average values is 6.06%. This value varies more in the stands than in the field. In the soil of the fields and stands of the farm, the content of humus is about 6.0%. The reduction of humus content in the soil in the fields for 60 years is 0.51–0.82%, in the field shelterbelts it is about 2%. At the studied sites, pH of the soil-water extract for the arable soil is 6.8–7.75 (actual soil acidity) and pH of the salt extract is 5.7–6.8 (exchangeable soil acidity). In the field shelterbelts the values were 6.2–7.75 and 5.25–7.0, respectively. The content of nitrogen and potassium is higher in the shelterbelt soil while that of phosphorus is higher in arable land. Conclusions The highest content of humus was found in the 0–10-cm layer of chernozems under the forest shelterbelts in the permanent forest and agrarian experimental site (from 8.44 to 17.36%); on arable land this value varies from 5.08 to 6.96%. The content of humus in the soils in 92–126-year-old forest shelterbelts (SE ‘Mariupol Forest Research Station’) exceeds the value on arable land by 6.06%. In the soils of the farm, the contents of humus in the field and in the stands do not differ significantly (about 6.0%). There has been a decrease in the content of humus in the soil of some fields of agricultural land (about 1.0%) and forest shelterbelts (about 2%) of the permanent forest and agrarian experimental site for the last 60 years. The soil pH in the sites is mostly neutral. The content of nitrogen and potassium is higher in soils in the shelterbelts, while that of is higher in arable land.

Relevance. The aim of the work was to study the influence of predecessors cultivated in three crop rotations with a short rotation on the weedness of fiber flax crops and the yield of flax products. The study was carried out in field experiments in 2016–2019, on medium and weakly acidic soddy-podzolic light and medium loamy soils of the Tver region with a high phosphorus content. Methods . As the precursors of fiber flax, vetch-oat mixture and white mustard were cultivated with post-cut cultivation of white mustard for green fertilization, and also repeated sowing of fiber flax was carried out in the same field for three years in a row after the predecessor of barley. Results . As a result of the studies, it was found that the greatest lowering the weediness of fiber flax crops and an increase in the yield of flax products was observed in the crop rotation with the cultivation of white mustard for green fertilization after the precursor of the vetch-oat mixture for green fodder and the introduction of the biofungicide Sternifag after the precursor of barley with the addition of 12 kg/ha of ammonium nitrate. There was a decrease in the number of stems of couch grass ( Agroperon repens ) by 2.8 times, a significant increase in the yield of fiber flax — by 5 dt/ha a compared with repeated cultivation of fiber flax in the same field and by 1.4 dt/ha compared with cultivation after barley without the use of biofungicide. At the same time, the yield of flax straw was 29.1 dt/ha, of flax stock 22.4 dt/ha, of flax fiber — 6 dt/ha. In the crop rotation with the sowing of fiber flax after barley in the same field for three years in a row, there was a decrease in the yield of flax fiber by 0.3 and 0.8 dt/ha, including fiber scutched flax — by 1.6 and 1.7 dt/ha in comparison with cultivation in crop rotations with post-harvest use of white mustard for green fertilization.

Biochars have potential to reduce soil acidity and Al3+ toxicity, and increase the availability of soil nutrients. This study aimed to compare the effectiveness of biochars and their raw feedstocks in amelioration of soil acidity. Ten ameliorants comprising of five biochars (pyrolyzed at 550°C) and their corresponding feedstocks (wheat chaff, canola stubble, vetch hay, lucerne pellets, and poultry litter) were added (1% of soil weight) to sandy Tenosol and loamy Chromosol with both having similar Al3+ concentrations but Chromosol having nine times greater pH buffer capacity. The soils with the ameliorants were incubated for 7 weeks (incubation phase), before being planted with an Al-sensitive wheat (ES8) for 18 days (plant phase). Biochars outperformed their feedstocks in increasing soil pH, leading to a significant reduction of Al3+ toxicity. Biochar additions increased shoot growth by 137‒341% for Tenosol and 10‒295% for Chromosol, whereas their feedstocks increased shoot growth by 25‒233% for Tenosol and -38‒136% for Chromosol. Poultry-litter biochar increased soil pH greater than the corresponding poultry-litter treatments by 1.59 units in the Tenosol and 0.79 units in the Chromosol at the end of the plant phase. In addition, all organic amendments (except wheat-chaff and its biochar) significantly increased shoot P concentrations with poultry-litter biochar achieving the highest Olsen P and shoot P concentrations in both soils. Evidently, high alkalinity and nutrient contents of poultry-litter biochar resulted in the greatest increases in soil pH and shoot biomass in both soils. Biochars were more effective at ameliorating soil acidity than their corresponding feedstocks primarily via increasing soil pH and supplying plant nutrients, depending on soil type. Poultry-litter biochar was the most effective on both soils.

The present work aims to determine the effect of land configurations and Pongamia pinnata mulch on soil moisture content and yield of yellow sorghum during kharif, 2018-19 on sandy clay loam soils of Hyderabad. The experiment was conducted at the College of Agriculture, Professor Jayashankar Telangana State Agricultural University, Rajendranagar, Hyderabad. The treatments included land configurations (Flatbed, Ridge and furrow, Broad bed and furrow, Flatbed + Mulch, Ridge and Furrow + Mulch, Broad bed and furrow + Mulch) and yellow sorghum genotypes (PYPS 101, PYPS 102, PYPS 103 and PYPS 104). Mulch used in this investigation was Pongamia leaf mulch applied @ 6 t ha-1 uniformly at 20 DAS. Soil moisture played a vital role in increasing crop yields in the rainfed regions of the semi-arid tropics. During most crop growth stages, the availability of soil water was increased by Broad bed and furrow + mulch, resulting in increased grain yield by 37 % (1701 kg ha-1) of yellow sorghum over flatbed. Ridge and furrow + mulch were found to be the next best treatment, with a grain yield of 1590 kg ha-1. Mulched treatments of flatbed, ridge and furrow and broad bed and furrow increased the grain yield by 20%, 28% and 37%, respectively, compared to flatbed without mulch. The present study will help in recognizing profitable moisture conservation practices and the role of Pongamia mulch in soil moisture conservation and yield maximization of yellow sorghum.

Carex is the most species-rich genus in the family of Cyperaceae. Carex with Phragmites australis or Bolboschoenus maritimus dominates in the building the plant cover of wet habitats. Value of mossy Carex as forage is too low, even in the hay [1]. Forage plants, as bottle sedge (Carex physodes, Carex subphysodes) growing on sand and sandy soil and Carex pachystylis growing on loamy grey soil, are distinguished by its high content in protein and being valuable forage plants [1].

For sustainable irrigated agriculture, scheduling irrigations based on accurate estimates of crop water requirements (ETc, crop evapotranspiration) are critical. ETc was estimated as a product of a reference crop evapotranspiration computed from weather data and a crop coefficient (Kc) in weather-based irrigation scheduling. In this investigation, an eddy covariance (EC) method was used for quantifying soybean (cv. Asgro 46X4) Kc in a farmer’s field under a humid climate. ETc quantified using the EC method was used for developing Kc for alfalfa (Kcr) and grass (Kco) reference crops computed from measured weather data. Experiments were conducted during three crop seasons (2017–2019) in a 500-ha furrow-irrigated soybean field—planted in silt loam soil in late April to early May and harvested in September. Harvested soybean yields were 4771, 5783, and 4909 kg ha−1, consuming 584, 640, and 593 mm ETc (average 605 mm), respectively, in 2017, 2018, and 2019. Monthly averaged daily ETc across the crop seasons varied between 2.1 mm in May 2019 to 6.2 mm in June 2018. Seasonally averaged daily ETc across the three crop seasons varied between 4.3 and 5.2 mm with an average of 4.8 mm. Across the crop seasons, ETc was 22% less and 2% greater than computed grass (ETo) and alfalfa (ETr) reference crop evapotranspiration. Monthly averaged daily Kco varied between 0.79 and 1.18, and Kcr ranged between 0.65 and 0.97. The Kc established can help develop soybean irrigation schedules, across climates and soils, based on ETo or ETr computed from real-time weather data.

A mesocosm experiment was conducted to assess the side effects of the fungicide QuadrisR on soil bacterial functioning. QuadrisR was applied to a loamy sand soil at increasing concentrations (0.0–35.0 mg kg−1 dry soil) calculated according to its active ingredient azoxystrobin (Az). Soil sampling was carried out from the 1st to the 120th day of soil incubation to determine the changes occurred in bacterial catabolism using the technique of community-level physiological profiling (CLPP) via Biolog EcoPlates™. It was found that the field recommended fungicide concentration (2.90 mg kg−1 dry soil) altered mostly the low-available Biolog carbon sources ( 1.00 OD) utilizable ones. Pearson correlation analysis revealed that the main environmental factors correlated with the utilization rates of Biolog carbon sources (CSs) were soil nutrients and pH. No linear relationships were found between Az soil residues and the use of CSs. We concluded that QuadrisR affects bacterial catabolic profiles in loamy sand soils through soil acidification and altering soil nutrient pool. The study also revealed that CLPP and EcoPlate™ are useful practical tools for testing the fungicide ecotoxicity.

The ploughing of soils in autumn drastically loosens the soil structure and, at the same time, reduces its stability against external stresses. A fragmentation of these artificially produced soil clods during wintertime is often observed in areas with air temperatures fluctuating around the freezing point. From the pore perspective, it is still unclear (i) under which conditions frost action has a measurable effect on soil structure, (ii) what the impact on soil hydraulic properties is, and (iii) how many freeze–thaw cycles (FTCs) are necessary to induce soil structure changes. The aim of this study was to analyse the cumulative effects of multiple FTC on soil structure and soil hydraulic properties for two different textures and two different initial structures. A silt clay with a substantial amount of swelling clay minerals and a silty loam with fewer swell/shrink dynamics were either kept intact in undisturbed soil cores taken from the topsoil from a grassland or repacked with soil clods taken from a ploughed field nearby. FTCs were simulated under controlled conditions and changes in pore structure ≥ 48 µm were regularly recorded using X-ray µCT. After 19 FTCs, the impact on hydraulic properties were measured, and the resolution of structural characteristics were enhanced towards narrow macropores with subsamples scanned at 10 µm. The impact of FTC on soil structure was dependent on the initial structure, soil texture, and the number of FTCs. Frost action induced a consolidation of repacked soil clods, resulting in a systematic reduction in pore sizes and macropore connectivity. In contrast, the macropore systems of the undisturbed soils were only slightly affected. Independent of the initial structure, a fragmentation of soil clods and macro-aggregates larger than 0.8 to 1.2 mm increased the connectivity of pores smaller than 0.5 to 0.8 mm. The fragmentation increased the unsaturated hydraulic conductivity of all treatments by a factor of 3 in by a factor of 3 in a matrix potential range of −100 to −350 hPa, while water retention was only slightly affected for the silt clay soil. Already 2 to 5 FTCs enforced a well-connected pore system of narrow macropores in all treatments, but it was steadily improved by further FTCs. The implications of fewer FTCs during milder winters caused by global warming are twofold. In ploughed soils, the beneficial seedbed consolidation will be less intense. In grassland soils, which have reached a soil structure in dynamic equilibrium that has experienced many FTCs in the making, there is still a beneficial increase in water supply through increasing unsaturated hydraulic conductivity by continued FTCs that might also be less efficient in the future.

The ability to use the protoporphyrinogen oxidase (PPO)-inhibiting herbicides fomesafen, flumioxazin, and sulfentrazone in potato is limited regionally or by soil texture, largely because of crop injury noted in research in the 1990s. With that in mind, we evaluated whether reducing the herbicide rates could maintain weed control while providing more consistent crop safety. Studies were conducted on a silt loam and a coarse-textured loamy sand soil. Soil texture played a greater than anticipated role in PPO-inhibitor herbicide injury risk as it relates to high-precipitation events. For example, in 2020 at the silt loam location, there were five precipitation events across the season that exceeded 2.5 cm, including one 6 d after treatment (DAT), and a seasonal total precipitation that was over 10 cm greater than the previous year. Despite excessive moisture and initial potato injury as high as 27% where flumioxazin was applied at the high rate with S-metolachlor, by 29 DAT injury was less than 10% in all treatments, and marketable tuber yield was similar among treatments. In contrast, in 2020 at the loamy sand location, there were four precipitation events across the season that exceeded 2.5 cm, and potato injury was as much as 60%. In 2020 the high amount of injury from flumioxazin was hypothesized to be caused by precipitation before herbicide application and not after, suggesting a need for more research in this area. This work documents the fine line between yield reduction presumably caused by reduced weed control and yield reduction assumed to be related to herbicide injury. This delineation between adequate weed control and consistent crop safety may differ by soil texture and environmental conditions, supporting the notion that custom-tailored weed management may become more necessary as high-precipitation events become more common in upper midwestern U.S. agricultural systems.

Salinity may increase metal mobilization with a potentially significant consequence for soil enzymatic activity and nutrient cycling. The goal of this study was to investigate changes in soil enzyme activity in response to salinization of a clay loam soil artificially polluted with cadmium (Cd) and lead (Pb) during a 120-day incubation experiment. Soil samples were polluted with Cd (10 mg Cd kg−1), Pb (150 mg Pb kg−1), and a combination of Cd and Pb, then preincubated for aging and eventually salinized with three levels of NaCl solution (control, low and high). NaCl salinity consistently increased the mobilization of Cd (12–22%) and Pb (5–16%) with greater increases at high (17–22% for Cd, 9–16% for Pb) than low (12% for Cd, 5–7% for Pb) salinity levels. While the increased Cd mobilization was greater in co-polluted (22%) than Cd-polluted (17%) soils, the increase of Pb mobilization was lower in co-polluted (9%) than Pb-polluted (16%) soils at high salinity level. The salinity-induced increases in metal mobilization significantly depressed soil microbial respiration (up to 43%), microbial biomass content (up to 63%), and enzymatic activities (up to 87%). The multivariate analysis further supported that the increased soil electrical conductivity, Cd mobilization, and pH after salinization were the most important factors governing microbial activity and biomass in metal-polluted soils. Results showed that changes in microbial biomass and mobile metal pool with increasing salinity had a major effect on enzyme activities, particularly under the combined metals. This study indicated that the secondary salinization of metal-polluted soils would impose an additional stress on enzymatic activities as biochemical indicators of soil quality, and therefore should be avoided for the maintenance of soil microbial and biochemical functions, especially in arid regions. In metal-polluted soils, the observed responses of extracellular and intracellular enzymes to salinity can be used to advance our knowledge of microbial processes when modeling the carbon and nutrient cycling.

Objectives: To assess the soil heterogenicity and mapping of spatial distribution of soil fertility indicators for efficient nutrient management in apple orchards using geostatistical tool. Methods: Soil samples were collected from 50 apple orchards in district Ziarat where 20 from Ziarat and 30 from Sanjavi tehsil. GPS locations were marked at each orchard. Four soil cores were dug below each of the 8 apple tree canopy and composited into one sample. The samples were air-dried, ground, sieved through 2 mm sieve and analyzed for soil texture, organic matter, pH, EC, macro (N, P and K) and micro (Cu, Fe, Mn and Zn) nutrients. Descriptive statistics was carried out using Microsoft Excel. Geostatistical analysis was conducted by ArcGIS 8.1. Findings: Texturally, soil of the apple orchards were grouped into silt loam, sandy loam and loam where silt loam was dominant class as 82% samples were silt loam. Soil was non-saline (0.42 dSm-1) and have pH in alkaline ranges (7.71-8.45) with average value of 7.93. Kjeldhal’s N, AB-DTPA extractable nutrients i.e. P, K, Cu, Fe, Mn, and Zn were in the range of 0.02-0.15%, 0.26-9.41, 21.0-203.60, 0.21-1.35, 0.25-6.29, 0.41-65.97 and 1.80-27.01 mgkg-1 respectively. Most of the orchards (54%) expressed soil organic matter in adequate range and 46% orchards\' soil showed medium level TN. Low level P, K and Fe was noted in 72, 50 and 74% orchards\' soil. The findings of geostatistical analysis showed that Soil pH, Cu and Mn had a weak spatial autocorrelation. While TN, and Zn had a medium whereas P, K and Fe had a higher spatial autocorrelation. Novelty: This research study provides procedural input for precise utilization of fertilizers as per soil properties of the area with minimum wastage and greater output. Keywords apple orchard, geostatistics, plant nutrients, soil properties, spatial variability

AimAgronomic biofortification of fruit with iodine (I) has become an innovative approach in contemporary agriculture. In this study, we evaluated the influence of soil- and foliar I applications on absorption of this nutrient by apple (Malus domesticaBorth.) trees, as well as on growth and yield responses of the plants.MethodsIn 2018–2019, ‘Red Jonaprince’ apple trees, grown on sandy loam soil, were treated with potassium iodide (KI) or K-iodate (KIO3) through soil application (at a rate of 4 kg, 8 kg or 12 kg I ha−1) or preharvest sprays (at a rate of 0.5 kg, 1 kg or 1.5 kg I ha−1).ResultsThe I sprays increased apple I contents to the targeted range of 50–100 µg 100 g−1fresh weight and even to the recommended daily intake of I for adults (the KI sprays at rates of 1 kg and 1.5 kg I ha−1). Although the I sprays caused leaf injuries, they did not affect tree growth and yield. However, the spray of KI and KIO3at the highest rate decreased the soluble solid concentration in fruit. For soil-supplied trees with I, an increase in apple I concentration was found only in the first year of the study.ConclusionsApple tree is a suitable target plant for agronomic I biofortification, and from the economic point of view, the spray of KI or KIO3at a rate of 0.5 kg I ha−1should be recommended in orchards.

Effective management of the issues related to increasing water scarcity in semi-arid regions needs special attention to minimize the negative influence of water stress conditions and prevent soil degradation to ensure global food security. The present study develops an eco-friendly, low-cost superabsorbent hydrogel composite (SHC) through recycling natural fibre using graft polymerization method. Effectiveness of the synthesized SHC for conservation of irrigation water was investigated by measuring its water absorbency in different salt, and pH solutions, reswelling capacity, and the soil–water retention curve (SWRC) of SHC amended soil. The synthesized SHC showed water absorbency of 342 g/g in distilled water, indicating its suitability for agricultural application. The SHC showed excellent re-swelling characteristics for more than eight alternate wetting–drying cycles. The sensitivity of SHC to different inorganic salt solutions was investigated, which showed its water absorbency higher than 90 g/g at the maximum salinity level permitted for plant growth. The addition of SHC in silt loam soil showed an increase in water availability of 56%, 81%, and 125%, with the SHC concentrations of 0.1%, 0.2%, and 0.4%, respectively. The addition of SHC had reduced the irrigation water requirement by 29% as compared to bare soil at an optimum application rate of 0.2%. The study promotes the use of synthesized SHC for the conservation of irrigation water, as well as soil ecosystem, with an additional advantage of contributing to the mass utilization of waste materials.

In this study, we investigate the effect of nitrogen fertilizer application rates with and without phosphorus-loaded biochar (BCP) on the productivity of tomato (Solanum lycopersicum cv GS) planted on a contaminated soil based on pot and incubation experiments. The release kinetic of toxic metals as affected by BCP was also investigated. BCP at rate of 2% (w/w) and nitrogen levels (250 and 500 mg N kg-1) were added to sandy loam soil polluted with Cd, Pb, Zn, and Cu. The experiment consisted of five treatments including: Control (C), nitrogen a rate of 250 (N250), or 500 mg kg (N500), BCP + N250, and BCP + N500. Maximum tomato growth was achieved in the soil that was treated with BCP + N500, followed by BCP + N250, while lowest one was observed in the control. Tomato yield as affected by the BCP and N-fertilization was in the descending order: BCP + N500 > BCP + N250 > N500 = N250 > C. The addition of N250, N500, BCP + N250, and BCP + N500 increased the fruit yield by 24, 31, 35, 58% in comparison with the control. Levels of Zn, Cu, and Pb in tomato fruit was in the descending order: N500> N250 > C > BCP + N500 > BCP + N250. The combined application of BCP and N-fertilization augmented the availability and uptake of essential nutrients and effectively reduced those of toxic ones. The addition of BCP + N250 decreased Zn, Cu, Cd, and Pb content in fruit of tomato by 16, 10, 54, 54, and 58%, respectively, compared to the control soil, while these decreases were 13, 16, 60, 60, and 72% in the case of BCP + N500. BCP succeeded significantly in reducing the release of toxic chemicals, which ultimately may restrict the transfer of toxic chemical to the food chain solution. Novelty statement Tomato grown on metal-contaminated soils contains high levels of toxic metals. Phosphorus-loaded biochar (BCP) reduced the negative effects of high inorganic-N rates by reducing the release of toxic metals to the soil solution. BCP enhanced the soil quality indicators and increased the soil microbe's activity.

Este informe presenta la reconstrucción histórica de aproximadamente los últimos 150 años de un núcleo sedimentario recolectado en julio 2016 en Cayos Perlas (Laguna de Perlas, Caribe Sur de Nicaragua) donde se estimaron las tasas de sedimentación y acumulación de sedimentos mediante la técnica nuclear de 210Pb. El núcleo sedimentario, Buttonwood NIC II, fue dominado por la fracción de limo y superó el 50% de las partículas, seguido de arcilla (19% - 27%) y arena (7% - 24%). De acuerdo a la granulometría y distribución del tamaño de grano el núcleo presentó la textura franco limosa. Los valores de susceptibilidad magnética registraron variaciones con respecto a la profundidad, observándose cinco diferentes cambios drásticos en la calidad de las partículas de sedimento depositadas en las profundidades de 5,5 cm, 11,0, cm, 17,5 cm, 18,5 cm y 28,5 cm. La edad de las diferentes secciones del perfil de sedimento se evaluó usando el método de flujo constante (CRS) y varió entre 2,14 años a 130,91 años, registrándose de esta manera la historia de los últimos 128 años. Los resultados en la tasa de sedimentación osciló entre 0,022 a 0,725 cm.año-1 entre 2014 - 1886; observándose cambios bruscos a partir de 1965. La tasa de acumulación de sedimentos varió entre 0,016 a 0,308 g.cm-2. año-1 entre 2014 - 1886 mostrando un incremento a partir de 1970, lo que sugiere que estos cambios están relacionados con diversos factores como incremento de la población e influencia de fenómenos naturales (huracanes y tormentas tropicales).

The current formula of critical hydraulic gradient is not adapted to solve critical hydraulic gradient of cohesive soil. Assume that the seepage failure mode of the cohesive soil foundation was cylindrical or inverted circular truncated cone, based on the calculation formula of the critical hydraulic gradient of Terzaghi, the analytical formula of the critical hydraulic gradient considering the influence of the shear strength of the soil was derived. Then, the seepage failure process of the clay layer was simulated numerically, and the effects of the clay layer thickness, failure radius, and shear strength indexes on the critical hydraulic slope were analyzed. The comparison results show that the numerical test results are in good agreement with the calculated results of the new formula. In addition, the critical hydraulic gradient of sandy loam and loess under different working conditions was studied severally by a self-made permeation failure instrument. The results show that the critical hydraulic gradient decreases with the increase of soil thickness and failure radius, and the maximum error between the test and the corresponding formula results is no more than 16%.