Silty Clay Loam Research Articles

Effect of organic manure, Biofertilizer and foliar spray of Ascorbic acid on vegetative growth and fruit quality of Basheqi cv. of Olive (Olea europaea L.)

ABSTRACT: This experiment was conducted in a private olive orchard located in the village of Kasara, Dohuk governorate, Kurdistan region, Iraq, during growing season 2021-2022 on 14 years old olive trees cv. Basheqi (Olea europaea L) planted at 4x8m apart in (silty clay loam) soil, under drip irrigation system. Three levels of Organic manure (poultry manure) at (0, 4 and 8) kg/tree was added to the soil at the second week of December in 2021 season, three levels of Bio-fertilizers (Bio Health) at conc. (0, 10 and 15) g.l-1 and three concentrations (0, 300 & 600 mg.l-1 ) of foliar spray of ascorbic acid. Bio-fertilizers and ascorbic acid was carried out two times per season, First: Prior-Flowering, Second: After Setting in order to investigate there influence on growth and Fruit Quality of olive trees. A factorial experiment with three replications was carried out in a randomized complete block design (RCBD), using one tree for each experimental unit. Results indicated that soil application of organic manure (poultry manure) at 8 Kg/tree significantly increased all studied characters {average leaf area, chlorophyll content, Protein % in Leaves, Fruit Total Soluble Solids TSS %, Total Carbohydrates %, Anthocyanin Content, Ascorbic acid (Vit.C), Percentage of Oil}. Soil application of biofertilizer (bio health) at 15g.l-1 significantly increased all study characters except TSS. Foliar application of Ascorbic acid at 600 mg/l-1 significantly increased average leaf area, total chlorophyll content, Protein % in Leaves, Ascorbic acid, Percentage of Oil. In comparison to other interactions, the interaction of (8 kg O.M./tree, 15 g.l-1 bio fertilizer, and 600 mg.l-1 ascorbic acid) appeared to be more efficient in enhancing all characteristics studied in this experiment.

Assessment of the Performance Efficiency of Eight-Purpose Compound Equipment in One

A field experiment was conducted to assess the performance of a locally developed and assembled eight-purpose compound equipment and determine its effect on some physical soil properties in a silty clay loam soil in one of the fields of the College of Agricultural Engineering Sciences / University of Baghdad / Jadriyah for the growing season 2022-2023. The experiment used two tractors, the (MF-650) MASSEY FERGUSON and the (MF-5640) MASSEY FERGUSON. The study included two factors: the first factor had three seed rates (3, 4, and 5 kg/donum), and the second factor had three tillage depths (15, 20, and 25 cm). Some performance indicators of the machinery unit were studied, including pulling force, fuel consumption, slippage percentage, and bulk density of the soil. The experiment was conducted using a randomized complete block design (RCBD) with split-plot arrangement and three replications. Seed rates allocated to the main plot, while the tillage depth treatments allocated to the sub-plot. The least significant difference (LSD) at a significance level of 0.05 was used to compare the means of the variables. The results showed significant differences in the performance indicators of the machinery unit due to the tillage depth and seed rate. The depth of 15 cm showed the lowest pulling force, which was 5 kilo Newtons, the lowest slippage percentage of 4.26%, and the lowest fuel consumption of 42.58 L ha-1. The results also confirmed the absence of significant differences in the performance indicators of the machinery unit due to the seed rate and the absence of significant differences in the performance indicators due to the interaction between tillage depth and seed rate.

Reduction of nitrous oxide emission by using stearic acid combined zinc coated urea in silty clay and sandy loam soils under bare and planted conditions

Overuse of chemical fertilizers in agroecosystems leads to the increased economic burden, low crop production in terms of input and environmental pollution. Due to its improved nutrient management and degrading properties, synthetic slow release fertilizers have become a significant advancement in the fertilizer sector. In this study we evaluated the effect of slow release urea on nitrous oxide (N2O) emission, crop growth and crop nutrient contents. Measurements were carried out in two different texture soils (sandy loam and silty clay) under two different conditions (bare soil and planted). The N2O emission was measured for 15 days from bare soils and 48 days from planted soil. Plant fresh weight, dry weight, chlorophyll contents, N and Zn were measured in the end of the experiment. The results showed that N2O emission was reduced 33–39 % from coated urea as compared to conventional urea in bare soil. In planted soil, the coated urea reduced the N2O emission 29–33 %. The deep placement of urea in silty clay soil reduced the N2O emission up to 22.8 % as compared to surface placement. Plant fresh matter, dry matter, N and Zn contents were significantly (p ≤ 0.05) higher with coated urea as compared to conventional urea. It is concluded that the coating of urea with hydrophobic materials like stearic acid, along with Zn sources i.e. Zn fortified nano-bentonite or the ZnO nanoparticles (NPs) presents opportunities to overcome the environmental pollution and increasing the crop production and quality.

Soil carbon mineralization, enzyme activities, and crop residue decomposition under varying soil moisture regimes

AbstractIn the Lower Mississippi River Basin, farmlands are flooded in late fall and winter by impeding drainage to provide a habitat for migratory birds stopover. A laboratory incubation study was conducted to study the influence of temporary wetting of these soils on carbon (C) and nitrogen (N) mineralization from residue decomposition. Surface soils (0–15 cm) were collected from fields with clay and silty clay loam soils. Both soils were incubated with five crop residues—corn (Zea mays), soybean (Glycine max), cotton (Gossypium hirsutum), sorghum (Sorghum bicolor), and sweet potato (Ipomea batatus)—at 50% and 100% water holding capacity (WHC). Soil carbon dioxide (CO2) efflux was measured during 74 days of incubation. Soil moisture had the largest effect on soil CO2 efflux and most of the enzyme activities followed by residue and soil type. Cumulative soil CO2 efflux was reduced by 46% at 100% WHC compared to 50% WHC. Clay soil had higher cumulative CO2 efflux, aryl sulfatase, aryl phosphatase, and β‐N‐acetyl glucose aminidase activities than silty clay loam soil. Residue type had the largest effect on post‐incubation soil inorganic‐N, remaining biomass, and residue C and residue N. Sweet potato residue had the lowest remaining biomass, significantly lower than cotton, corn, and sorghum, but statistically similar to soybean. After incubation, residue N concentration had a positive association with cumulative CO2 efflux and a negative association with remaining residue biomass percentage. Winter flooding might limit the loss of soil C as CO2 depending on the crops grown and soil type.

Efficacy of Herbicide Mixtures for Transplanted Aman Rice in Silty Clay Loam Soil of Bangladesh

Weed management plays an important role in obtaining target yield. A field experiment was carried out at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, from July to December 2019 to get the most effective weed control strategy for transplanted Aman rice. The soil of the study field was silty clay loam in nature. The study consisted of two factors i.e., variety (4: Chinigura, BR11(Mukta), BRRI dhan56, and BRRI hybrid dhan6) and herbicide (4) viz., Bispyribac-sodium WP @ 150 g ha-1, Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1, Pretilachlor 6% + pyrazosulfuron 0.15% WP @ 9.88 kg ha-1, and weedy check as a control. The experiment was laid out in a split-plot design with three replications. Thirteen weed species were found in the experimental plots, mostly broadleaf and sedge. Monochoria vaginalis was the most dominant weed species. The study noticed that the application of mixed herbicides offered better weed control over single herbicide application. Application of Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1 significantly reduced weed density and biomass and was the best way of controlling complex weed flora. The study marked out BR11 (Mukta) as the most potential aman rice variety to produce the highest yields at applying Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1. This treatment gave the highest gross return (Tk. 1,46,010), net return (Tk. 88,699), and benefit-cost ratio (2.55). Therefore, the study suggests the application of mixed herbicides and BR11 (Mukta) to get the optimum yield of transplanted Aman rice and maximum economic benefit.
 Bangladesh Agron. J. 2023, 26(1): 56-74

An improved method for extraction of soil fungal mycelium

Fungal mycelium is a major component of the soil microbiome. The soil hyphosphere represents a complex and dynamic niche for specific microorganisms, where multitrophic interactions occur, affecting ecosystem processes. However, extracting fungal mycelium from the soil to enable its taxonomical, chemical, and structural characterisation is challenging in the absence of a fast, efficient, and low-cost procedure. In this study, an old method (Bingle and Paul 1985), based on successive soil wet filtrations and density gradient centrifugation, was improved and tested in three different soil types (silty clay, silty clay loam, and loamy sand). The improved method reduced the number of filtrations by about five times and the centrifugation time from 40 min to 1 min. It avoided using any chemical substance which may impair further chemical analyses or DNA isolation and amplification. The method efficiency was about 50 % in the clay and 23 % in the sandy soils. However, a pre-step consisting of removing the fine-root fragments and other debris under the stereomicroscope may increase the method efficiency to more than 65 %, independent of the soil type.•A simple, efficient, and low-cost method suitable for extracting soil mycelium from a large number of samples.•The protocol includes successive soil wet filtrations and sucrose gradient centrifugation.•The method efficiency increases if the fine-root fragments and other debris are previously removed from the soil.

Soil health, microbial communities, and annual ryegrass yield under contrasting management practices

AbstractBiological indicators are often used to evaluate the effect of management practices on soil health. However, determining which indicators can detect changes in soil health after implementation of conservation practices and how these indicators relate to plant growth in grass seed production systems remains unclear. The goal of this study was to explore the relationships between management practice history, soil health metrics, plant growth, and soil microbial communities in annual ryegrass grown under greenhouse conditions. Soils were collected from 12 annual ryegrass [Lolium multiflorum (L.) Husnot] fields managed under conventional (till/bale) or conservation (no‐till/full straw) management practices, with three silt loams and three silty clay loams collected for each practice. Annual ryegrass was grown for 5 months on each of the 12 soils in a greenhouse. Soils with a history of conservation management improved the majority of the carbon cycling‐related metrics for the silt loam soils. Management practices had no effect on seed yield, however, conservation management significantly improved aboveground biomass in silty clay loam soils. Contrasting management practices resulted in distinct microbial communities, making them sensitive indicators of changes in soil conditions. Soil health and plant metrics were positively associated with the microbial communities in soils under conservation management. Total C and organic matter were positively correlated to plant parameters in silt loams, while few indicators were correlated to plant metrics in silty clay loams. These results highlight the complex interplay between microbial communities, soil health, and plant growth and the importance of considering inherent soil properties like texture.

Evaluating soil water movement and soil water content uniformity under sprinkler irrigation with different soil texture and irrigation uniformity using numerical simulation

Water movement and its distribution uniformity in the soil are essential for the design of sprinkler irrigation systems. They are both crucial factors influencing nutrient migration and the productivity of crops. In this study, a new numerical simulation method was proposed to investigate the soil water movement in sprinkler irrigation under nonuniform infiltration boundary conditions using COMSOL software. Besides, two soil tank experiments were conducted to test the reliability of the simulation model. Finally, the model was applied to evaluate the effects of sprinkler irrigation uniformity, soil texture, and initial soil water content on soil wetting patterns and soil water content uniformity. The results showed that the COMSOL-2D predictions of the vertical wetting fronts were in good agreement with the experimental data. The soil texture and initial soil water content influenced the soil wetting pattern and the risks of surface runoff and deep percolation in sprinkler irrigation systems. When the water application rate was 11.35 mm h−1 with an irrigation duration of 10 h, it was easy to cause surface runoff in silty clay loam while deep percolation in loamy sand. Additionally, when the initial soil water content is high, it should be better to avoid irrigation or cut down the irrigation duration to prevent percolation. The water within the soil was more uniformly distributed than that applied through a sprinkler irrigation system. The uniformity coefficient of soil water content distribution (CUs) increased from 87.75 % to 95.56 %, as the uniformity coefficient of sprinkler irrigation (CU) increased from 40.74 % to 82.41 %. Although a higher initial soil water content brought a higher soil CUs value, it also led to a higher risk of percolation. The experimental and simulation results indicated that the COMSOL-2D model could be used to accurately simulate soil water movement in sprinkler irrigation and determine the suitable operation mode of low-pressure sprinklers.

Effect of Adding Levels of Palm Fronds Compost and Mineral Fertilizer on Fertile Soil Characteristics, Quality, and Productivity of Maize Yield (Zea Mays L.)

An experiment was carried out in one of the fields of the Soil Research Department - Agricultural Research Department/Ministry of Agriculture in the Abu Ghraib district at latitude 33° 17" 31 N and longitude 44° 03" 56 E and 35 m above sea level. This field study was conducted in the autumn season 2021-2022 for the cultivation of yellow maize ( Maha cultivar) in sedimentary soil with silty clay loam texture, with a Split Plot Design. The treatments were distributed using the RCBD for three replicates with two factors. The first factor represents the main plots that include the addition of mineral fertilizer 120, 80, and 320 kg.ha-1 for each of (N, P, and K), respectively, at three levels (0, 50, and 100%) of the fertilizer recommendation. On the other hand, the second factor was a subplot of organic fertilizer (palm frond compost) at three levels (0, 5, and 10) μg.ha-1 . Soil samples were taken to estimate the availability of nitrogen, phosphorous, and potassium, where the total yield and percentage of protein for yellow maize were estimated. The results showed that adding organic fertilizers (palm fronds) with the levels of mineral fertilizers increased the availability of nutrients and the yield of maize. Accordingly, the treatment O2M2 achieved the highest values of nutrient availability, quantity, and quality of yield, reaching (59.167, 33.407, and 257.967) mg.kg-1 soil and (10,096) μg.ha-1 and (9.435%) for each of nitrogen, phosphorous, potassium, yield, and protein percentage, respectively. Moreover, there were no significant differences between the treatments of O1M2 and O2M1 in the amount of yield and the percentage of protein, which gave the values of 8.403 and 8.134 μg.ha-1, respectively, and the protein percentage of 8.630 and 8.915% respectively. It can be concluded that organic fertilizers can be added to compensate for mineral fertilizers, reduce environmental pollution, and reduce the economic cost and soil preservation because organic fertilizers are considered safe and environmentally friendly. Keywords: yellow maize, mineral fertilizer, palm fronds compost.

Long-Term Effect of Prescription-Based Fertilization on Culturable Soil Microorganisms and Carbon Dynamics in Northwest Himalayas

ABSTRACT The different approaches of fertilizer application can play an important role in altering soil biological properties, organic carbon retention, and its dynamics. The mechanisms implicit in the long-term accumulation and protection of soil organic carbon and improvement in soil biological environment, however, have not been well documented for maize crop cultivated in acid soils of the Northwest Himalayas. Based on a 13-year experiment, the effects of prescription-based fertilization on soil culturable microorganisms and soil carbon dynamics were investigated under a continuous maize cropping at Palampur, India. The experiment was initiated during 2007 in randomized block design (RBD) with 8 treatments which were replicated three times. The soil of the experimental site was acidic, having silty clay loam texture and classified taxonomically as “Typic Hapludalf.” The surface soil samples from 0.15 m depth were drawn after the harvest of maize crop in 2019 for estimation of culturable soil microorganisms and carbon dynamics. Based on soil-test crop response approach, the application of 110 kg ha−1 nitrogen and 82 kg ha−1 phosphorus with 5 Mg ha−1 farmyard manure (FYM) for attaining the target yield of 4.0 Mg ha−1 of maize recorded significantly highest population of soil bacteria (40.7 × 105 CFU g−1 soil), fungi (57.0 × 105 CFU g−1 soil), actinomycetes (38.2 × 105 CFU g−1 soil), microbial biomass carbon (147.2 µg g−1), dehydrogenase enzyme activity (4.3 µg TPF g−1 hr−1), different fraction of organic carbon, i.e. very labile (4.6 g kg−1), labile (2.60 g kg−1), less labile (2.70 g kg−1), non-labile (2.94 g kg−1), soil organic carbon (8.9 g kg−1), total soil organic carbon (11.8 g kg−1), total carbon stock (16.1 t ha−1), carbon sequestration (3.24 t ha−1) and carbon sequestration rate (1.24t ha−1year−1) when compared with control plot. Based on the data associated with microbial soil environment and carbon dynamics, it was inferred that application of prescription-based fertilizers along with farmyard manure for a longer period not only improved population of soil culturable microorganisms but also enhanced soil carbon sequestration and minimized carbon di-oxide (CO2) emission to atmosphere.

Soil macroporosity modulates the extent of negative microbial associations during organic substance decomposition

Microbial species interactions are expected to influence the community-level properties, such as the production of extracellular enzymes and the degradation of organic substances. This work examined how microbial diversity, composition and the overall sign of microbial associations were altered with soil texture and structure following the amendment of organic substances. Two sets of microcosms (1:100 and 1:1) of a 4 × 3 factorial design were constructed, with four artificial textural classes (a sandy loam, two loams, and a (silty) clay loam) and three organics (TSB, tryptic soy broth; CA, a mixture of cellulose and humic/fulvic acids; BS, barley straw). As the ‘microbial inoculant’, an agricultural soil was added to the 1:100 and 1:1 microcosms at 1% and 50%, respectively. A few of microbial taxa were specifically enriched after soil addition of TSB, CA, or BS, but distributions across textural classes were inconsistent between microcosms or between organic amendments. Regardless, top abundant bacterial and fungal OTUs were overall negatively associated, suggesting that microbial competition for the shared resource dominated the decomposition of both simple and complex organics. Microbial associations were also modified by soil pore size distribution (PSD), being fewer negative (or more positive) in soils of greater macroporosity than in soils of lower macroporosity. The PSD-based differences in microbial associations were coordinated with PSD-based differences in the activities of exoglucanase and β-glucosidase in TSB-amended soils or soil respiration characteristics in CA-amended soils. Our results provide new insight into how soil structure regulates microbial interactions and, accordingly, the degradation of organic matter.

An economic appraisal of the effect of tire inflation pressure for alternative tillage systems on a silty clay loam soil

AbstractCompacting soil has an adverse effect on soil properties, decreases crop productivity, and subsequently reduces farm income. Low tire inflation pressure (LTP) help in managing soil compaction and protecting the soil environment; however, there is scant economic data available on LTP in US Midwest farming systems. Hence, a 3‐year study investigated the effects of LTP, compared to tires inflated to the standard tire inflation pressure systems, on crop yield and farm economy for a typical maize/soybean rotation. The effect of the two tire inflation pressure systems was factorialized with three tillage systems: deep tillage (DT, 450 mm), shallow tillage (ST, 100 mm), and no‐till systems. The results showed that LTP systems increased maize (Zea mays) yield by 4.51% (2017) and 2.70% (2018) and soybean (Glycine max) by 3.70% in 2018. Annual earnings for both 200‐ and 800‐ha farms increased for all tillage systems with LTP tires based on a partial budget analysis. The payback periods for LTP tires were very short, ranging from 0.32 years for DT on an 800‐ha farm to 1.18 years for ST on a 200‐ha farm. The net present value of the higher returns with LTP tires was substantial, especially for the DT system. This study shows a strong economic benefit from investments in LTP tires on silty clay loam soils in the US Midwest.

Enhancing Density Prediction of Agricultural Land Soil through Void Area Curve Analysis

Thresholding is a digital image analysis method used to distinguish objects from the background in images and it is mainly used for void and density analysis in soil. It is important to select an appropriate thresholding method because the accuracy of void analysis can vary significantly depending on the threshold value; however, there is currently no standard for soil density analysis. Therefore, this study proposes an image analysis method for soil density prediction. The experimental process involved collecting soil samples from agricultural lands, encompassing various soil textures including sandy loam, loam, silt loam, and silty clay loam. These samples were then meticulously prepared under controlled conditions, ensuring a comprehensive range of dry densities and water content levels. Digital images of the soil samples were acquired using a Canon EOS100d camera, employing a high-resolution setup that provided precise imaging capabilities. The porosity of the soil image is calculated by various thresholding methods. Based on the analysis results, we propose a void area curve, a new approach that can be applied to the soil density prediction. The void area curve is the relationship curve between the threshold value and porosity of the soil image. The standard deviation of the void area curve showed a high correlation with the dry density of the soil. The standard deviation of the void area curve was used to predict the dry density under various soil texture and water content conditions, and the RMSE was 0.037 t/m3. The method of estimating soil density with the standard deviation of the void area curve can be used more generally than the existing analysis method because there is no need to select a specific threshold value.

The short-term response of soil microbial communities to digestate application depends on the characteristics of the digestate and soil type

Anaerobic digestion of organic waste is a key process to produce renewable energy and meet the growing demand for sustainable energy. The residues of anaerobic digestion – called digestates – can be used as soil amendments to improve crop yields. However, the effect of digestates on the soil biota, especially on microorganisms, needs to be better documented before a large scale use of digestates in agriculture. In addition, how the quality and composition of the digestate may affect soil microbial communities has not been properly addressed yet. We designed a microcosm experiment under controlled experimental conditions to compare effects (42 days) of four digestates produced from varying intakes (cattle manure and/or energy crop and/or food residues and/or slurry) on soil microbial communities; a control microcosm made of undigested cattle manure was also used. Each digestate was applied on three contrasting soils representing contrasted pedo-climatic conditions (especially soil type and climate). These three soils presented different prokaryotic and fungal communities structures. The effect of digestate inputs on the soil microbial biomass and diversity was assessed using molecular DNA-based tools (quantification of extracted soil DNA and high-throughput sequencing, respectively) in comparison to the untreated cattle manure control condition. Our results show that 42 days after digestate application, significant differences of soil microbial communities were observed according to the digestate characteristics; these differences were soil-dependent. Thus, in the silty clay loam soil, no effect of digestates was observed on soil microbial biomass or diversity (P > 0.05), as compared to the undigested cattle manure. In the two other soil types (loam and sandy loam), soil microbial biomass decreased (around −40 %, P < 0.001) when digestates having a low total organic carbon content (from 0.61 to 3.3 g.100 g−1) were applied. None of the digestates affected the soil prokaryotic diversity whatever the soil type (P > 0.05). Digestate application resulted in higher fungal diversity (around +35 %; P < 0.001) in soils with low C/N ratio (9.14 in average). The microbial community structure of coarse-textured soil appeared more impacted by organic inputs than fine-textured soils. To conclude, our results show that different soil types, harboring distinct microbial community structures, responded differently to different digestates application. This response was also digestate-dependent.

Limited effectiveness of selected bioeffectors combined with recycling phosphorus fertilizers for maize cultivation under Swiss farming conditions.

The use of plant biostimulants, also known as bioeffectors (BEs), has attracted increasing attention as an environmentally friendly strategy for more sustainable crop production. BEs are substances or microorganisms that are applied to plants or the surrounding soil to stimulate natural processes to enhance nutrient uptake, stress tolerance, and plant growth. Here, we tested the effectiveness of five BEs to enhance maize growth and phosphorus (P) uptake from various recycled P fertilizers in a series of pot and field experiments. First, the impact of two bacterial BEs and one soil-specific plant-based BE on crop performance was assessed in a 4-week screening experiment conducted in two arable, P-deficient soils of differing soil pH (a silty clay loam of pH 7.1 and a silty loam of pH 7.8) amended with recycled P-fertilizers (rock phosphate, biogas digestate, green waste compost, composted dairy manure, and chicken manure pellets). Then, for each soil type, the plant growth-promoting effect of the most promising BE-fertilizer combinations was re-assessed in an 8-week experiment. In addition, over a period of up to 3 years, three field experiments were conducted with maize in which up to two bacterial BEs were used either alone or in combination with a plant-based BE. Our experiments show that while BEs in combination with specific P-fertilizers can promote maize growth within the first weeks of growth under controlled conditions, the observed effects vanished in the long term, both in pots and under field conditions. In a tracing experiment, in which we tested the persistence of one bacterial BE over a period of 5 weeks, we observed a drastic decrease in colony-forming units already 2 weeks after inoculation. As previously shown in other studies, our data indicate that the plant growth-promoting effects of BEs found under controlled conditions are not directly transferable to field conditions. It is suggested that the drastic decline in inoculated bacterial strains in the tracing experiment is the reason for the decline in plant growth effect.

A modified approach to model the hydrological effects of living moss and fallen leaves on carbonate-derived laterite in karst forests

Due to recent vegetation restoration projects in karst mountainous areas of China, the living moss and litter layer play important roles in controlling soil water dynamics in karst forests. However, the underlying mechanisms of the effects of moss and the litter layer on soil water dynamics are still controversial. To explore the underlying mechanisms, we employ the CoreKarHydro model, capturing soil water content dynamics driven by evapotranspiration and influenced by living moss and fallen leaves. This model integrates surface changes' impact on evapotranspiration, categorizing the domain into: no cover (S), moss (SM), pine needles (SP), and both (SMP). Model validation employs the MOCOM-UA method, using diverse metrics (RMSE, R2, ACC, ED, KGE and SA) against lysimeter data with 4 moss biomass levels and 3 pine needle biomass levels. The results indicated: 1) The CoreKarHydro model exhibited reliable performance in simulating the soil water content curves, with an RMSE ranging from 1.49% to 4.21% and an R2 value ranging from 0.60 to 0.77. 2) Among the factors that influenced evaporation processes, soil hydraulic properties emerged as the most sensitive parameters, whereas the properties of the moss and pine needles played a relatively lesser role. 3) The impact of moss cover on evaporation processes varied depending on the soil texture and the stage of evaporation. Moss cover reduced evaporation loss in 8 out of 12 soil textures (loamy sand, loam, silt, silt loam, sandy clay loam, silty clay loam, sandy clay, and silty clay). On the other hand, moss cover increased evaporation loss in 4 out of 12 soil textures (sand, sandy loam, clay loam, and clay). This study contributes to the understanding of the mechanisms of coupled soil-moss(litter)-hydrological processes in karst areas.

Agro-morphological Characterization for Evaluation of Potential Upland Red Rice Cultivars in Manipur, India

The present investigation was carried out during the two consecutive kharif seasons of 2020 and 2021 at Tamenglong district, Manipur. The aim of the research was to determine the high-yielding upland red rice cultivars in Manipur. The study materials consisted of twelve red rice cultivars that thrived in upland conditions, sourced from various districts in Manipur. The experiment was laid out in a randomised block design (RBD) with twelve cultivars and three replications. The soil of the experimental field was silty clay loam in nature, having an acidic reaction (pH 3.9), low in available nitrogen (237.96 kg/ha) and available phosphorus (14.8 kg/ha), medium in available potassium (263.66 kg/ha) and high in organic carbon (1.0%). The crop received a total rainfall of 2344.2 mm during the cropping season. The values of growth attributes such as plant height and LAI were found to be maximum in the cultivar Mariumiu kahengbo, and the number of tillers was found to be maximum in the cultivar Chatee. The number of effective tillers was found to be at its maximum in Chatee. The highest grain yield was recorded in the cultivar Chatee. The research findings recommend that farmers focus on cultivating the Chatee cultivar among the studied cultivars.

Heavy Metal Transport in Different Drip-Irrigated Soil Types with Potato Crop

Heavy metal (HM)-polluted soil is a serious concern, especially as brackish water is widely used for irrigation purposes in water-scarce countries. In this study, the HYDRUS-2D model was used to simulate HM (copper (Cu), lead (Pb), and zinc (Zn)) transport through agricultural land cultivated with potato crops under surface drip irrigation to explore the potential groundwater contamination risk. Three soil types, namely, silty clay loam, sandy loam, and sandy soil, and two irrigation schemes, irrigation every two days (scheme A) and irrigation every four days (scheme B), were considered during the simulations. Firstly, the ability of HYDRUS-2D to simulate water flow was validated using data obtained from a full growing season of the potato crop in a lysimeter irrigated by surface drip irrigation using El-Salam Canal water, Egypt (i.e., water contaminated by HMs). Secondly, the model was calibrated for solute transport parameters. After that, the investigated simulation scenarios were executed. The results showed that HYDRUS-2D effectively simulated water flow. Moreover, a good agreement between the simulations and experimental results of HM concentrations under the calibrated solute parameters was obtained with R2 values of 0.99, 0.91, and 0.71 for Cu, Pb, and Zn concentrations, respectively. HM distribution is considerably influenced by the HMs’ adsorption isotherm. The results of the investigated scenarios reveal that soil texture has a greater impact on HM concentrations in the simulation domain and on the contamination risk of the groundwater than the irrigation scheme. Under both irrigation schemes, lower HM concentrations were observed in sand, while higher values were observed in silty clay loam. Subsequently, the potential shallow groundwater contamination risk is greater when cultivating potatoes in sand, as higher HM concentrations were found in drainage water compared to the two other investigated soils, regardless of the irrigation scheme. The cumulative Cu, Pb, and Zn concentrations in drainage water corresponding to scheme A for silty clay loam and sandy loam were 1.65, 1.67, and 1.67 and 1.15, 1.14, and 1.15 times higher, respectively, than scheme B. To safeguard the sustainability of groundwater and agricultural lands irrigated with water contaminated by HMs, it is recommended to adopt an irrigation frequency of once every four days in soils with silty clay loam and sandy loam textures.

Changes in selected properties of Calcic Chernozem due to cultivation of Robinia pseudoacacia and Quercus robur

Abstract The results of a comprehensive study on the particle size distribution, soil organic matter (SOM) content, and plant-available water in Calcic Chernozem are presented, along with the impact of Robinia pseudoacacia L. and Quercus robur L. plantations on these indicators. The study revealed that Calcic Chernozem under steppe vegetation and Q. robur plantation exhibited a silty clay loam texture. However, under the influence of R. pseudoacacia plantation, the chernozem’s texture transformed into loam. The planting of R. pseudoacacia resulted in a noticeable decrease in SOM content, while the growth of Q. robur plantations led to an increase in SOM content. Furthermore, both R. pseudoacacia and Q. robur plantations contributed to an increased content of plant-available water in the 0–20 cm layer of chernozem. These findings highlight the more pronounced effect of R. pseudoacacia plantation on the particle size distribution, SOM content, and plant-available water in Calcic Chernozem compared to Q. robur plantation.

Tree age affects soil physico-chemical properties of mango orchard in Dong Thap province

The study was carried out to investigate the effect of tree age to soil physical and chemical characteristics of mango orchard. Effect of 4 different tree ages (&lt;10, 10 - 20, 21 – 30, and over 30 years) on soil physic-chemical properties of farmers’ Mango field in Dong Thap province. The research was handled from June to November 2021. Soil samples at two depths (0 - 20 and 20 - 50 cm) were collected from the tree basin and were subjected to laboratory analysis from November to December 2021. Data showed that soil properties varied across mango tree’ age and depths. Bulk density was higher in over 10-year-old tree and soil texture of silty clay-loam represented in the whole observed orchards. The results showed that the chemical properties of the soils were characterized by the low to rather low pH values (4.0 - 6.0) of the topsoil and tended to decrease gradually with depths and tree ages. Unimpacted EC (electrical conductivity) in mango orchards was recorded, while total N, P, K, soil organic carbon and CEC tended to decrease with tree age and depths. These values declined for 10 years old onwards for both depths of 0 - 20 and 20 - 50 cm.