Soil Fertility Research Articles

Potential Impacts of Green Manure Incorporation on Soil Fertility Enhancement and Rice Yield

Potential Impacts of Green Manure Incorporation on Soil Fertility Enhancement and Rice Yield

Vitamin A Metabolism and Resistance of Hepatic Metastases to Immunotherapy.

The liver is an immune tolerant organ, allowing for organ transplantation with less immune suppression compared to other organs. It also provides fertile soil for tumor metastases, which tend to be more resistant to checkpoint blockade immunotherapy than metastases in other organs. This resistance may result from the sum of incremental evolutionary adaptions in various cell types to prevent overaction to antigens absorbed from the gut into the portal circulation or it might involve a central mechanism. Here we propose that metabolism of vitamin A, which is highly concentrated in the liver, is a root source of tolerance and resistance of hepatic metastases to checkpoint blockade. Suppression of retinoic acid synthesis from vitamin A with disulfiram may mitigate tolerance and produce enhanced immunotherapy treatment results for patients with liver metastases.

The ‘fertilizer island effect’ cannot eliminate competition between leguminous shrubs and symbiotic herbs in desert ecosystems

The ‘fertilizer island effect’ — a phenomenon engendered by shrubs — promotes the growth of symbiotic herbs and the stabilization of community structures in scrublands. Specifically, leguminous shrubs contribute significantly to the nitrogen input in desert ecosystems. However, the impact of these inputs on the nutrient balance in symbiotic herbs has seldom been explored. To enhance our understanding of the nutrient balance between nitrogen-fixing legume shrubs and symbiotic non-legume herbaceous plants in desert ecosystems, we focused on a typical legume shrub (Eremosparton songoricum) that grows in the Gurbantunggut Desert of northern China. Subsequently, we examined the biomass, ecological stoichiometry, and rhizosphere soil properties of two plant species (annual plant: Ceratocarpus arenarius; and ephemeral plant: Centaurea pulchella) growing across four horizontal distance ranges from E. songoricum. The results indicated that the closer a herbaceous plant was to the leguminous shrubs, the lower was its biomass and nutrient content. In contrast, herbaceous plants growing further away from the shrubs exhibited better growth conditions. The total biomass of Cer. arenarius and Cen. pulchella was greatest at a distance of D4 (90–100 cm), being 3.07, 2.15, and 1.23 times higher for Cer. arenarius and 2.05, 1.18, and 1.26 times higher for Cen. pulchella compared to distances of D1 (0–10 cm), D2 (30–40 cm), and D3 (60–70 cm), respectively. Meanwhile, the physicochemical properties of the rhizosphere root varied inversely with distance, with nutrient levels decreasing horizontally from D1 to D4 and vertically from 0–5 cm > 5–10 cm > 10–20 cm, showcasing a distinct ‘fertilizer island effect’. As the distance increased, the above-ground and below-ground parts of the symbiotic non-leguminous plants started to rely on different types of soil nutrients from different depths to maximize nutrient acquisition. According to the structural equation model, although soil fertility was higher closer to the central leguminous plants, the biomass of nearby herbaceous plants was lower. In summary, in desert ecosystems, the competitive dynamics exerted by leguminous shrubs significantly overshadowed the nutrient provisioning role of the ‘fertilizer island effect’. Furthermore, the utilization of nutrients by symbiotic non-leguminous plants did not exhibit species-specific patterns, and the dominant shrub continued to play a pivotal role. The evidence from this study promotes a deeper understanding of species coexistence mechanisms and ecological stability in desert environments.

Characteristics of organic amendments induce diverse microbial metabolisms for exogenous C turnover in Mollisols

The response of microbial community to organic amendments is closely related to the amendment-derived carbon (C) turnover, which in turn influences the enhancement of soil organic C, including the quantity and quality. The objective of this study was to quantify the decomposition and retention of exogenous C derived from amendments, and to identify the microbial regulatory mechanisms of exogenous C turnover in response to the characteristics of organic amendments. The 13C-labelled glucose, straw and biochar, characterizing organic amendments with high, medium and low labilities, respectively, were used to conduct a 90-day incubation experiment, in conjunction with stable isotope probing technology and amino sugar molecular biomarkers. It was found that the cumulative mineralization of amendment-derived C increased with increasing the corresponding lability of organic amendment, and the decompositions of the added glucose, straw and biochar, expressed as a percentage of the initially added C, were 53.6 %, 37.0 %, and 0.6 %, respectively. Among all treatments, the addition of straw significantly enhanced the total dissolved organic C (DOC) concentration and its ratio to total organic C by increasing the input of exogenous DOC and reducing the decomposition of native soil DOC. The exogenous C use efficiency by microorganisms was significantly enhanced with decreasing the amendment lability, and showed a positive correlation with the total amendment-derived C. However, the microbial growth efficiency was the highest when straw was added, and was closely related to the concentration of amendment-derived DOC. Different functional groups of soil microbes exhibited distinct capacities to metabolize various organic amendments. Generally, the incorporation of amendment-derived C into microbial biomass was significantly affected by fungi and gram-positive (G+) bacteria, while the relative contributions of microbial communities incorporating amendment-derived C into necromass were decreased in the order of gram-negative (G−) bacteria > fungi > actinomycetes > G+ bacteria. From the perspective of microbial metabolism, the larger incorporations of exogenous C into microbial biomass and necromass were observed in the soil with mediumly labile amendment, which contributed to enhance the quantity and quality of organic C in soil. These results would be informative to optimize the organic amendment strategy for integrated soil fertility management.

Carbon Sequestration and Soil Fertility Management in Sandy and Clayey Soils Revealed by Over Four Decades of Long‐Term Field Experiments in Thailand

Carbon Sequestration and Soil Fertility Management in Sandy and Clayey Soils Revealed by Over Four Decades of Long‐Term Field Experiments in Thailand

Design Development and Performance Evaluation of Solar Operated Pigeon Pea (Cajanus cajan L. Millsp.) Pruner

Pigeon pea (Cajanus cajan L. Millsp.) is a vital grain legume known for its contribution to food security and soil fertility. However, pruning, which enhances plant architecture and yield, remains a significant challenge in its cultivation, especially in large-scale operations. Manual pruning is labor-intensive, time-consuming, and costly, which has led to the need for mechanized alternatives, a solar-operated pruner was developed at IGKV, Raipur, to reduce labour, time, and costs. This study focuses on the design, development, and performance evaluation of a solar-operated pruner tailored specifically for pigeon pea. The pruner integrates key components such as a cutting blade, DC motor, solar panel, battery, and charge controller. A 12 V DC motor, generating 10.53 N of force and operating at 8500 RPM, ensures efficient pruning. The motor is powered by a 7.2 Ah battery, which can be charged in 4 hours using an AC adaptor or 8 hours via a 10 W solar panel. The battery allows for 4-6 hours of continuous operation. The pruner's lightweight PVC frame makes it portable and user-friendly, while the protective blade guard ensures operator safety. Performance evaluation of the pruner indicated a field efficiency of 81% and pruning efficiency of 76%. The actual field capacity was measured at 0.097 ha/h, with a walking speed of 1.2 km/h. Losses due to half-cut stems were calculated at 9.04%. The pruner demonstrated its ability to reduce labor costs, improve pruning efficiency, and promote sustainable agriculture through its solar-powered operation. This study highlights the economic and environmental benefits of adopting solar-operated pruners for pigeon pea cultivation.

Soil fertility status under mixed pastures in irrigated Tsitsikamma dairy farms: case studies

Animal manures are increasingly receiving renewed interest as an alternative to synthetic fertilizers. While they may improve ecosystem functions, there is limited information on short-term effects of organic amendments on soil reaction and nutrient dynamics in irrigated mixed dairy pastures, especially in the context of the Tsitsikamma region, South Africa. This study examined the soil fertility status of minimum tilled 6-year-old pasture-mixed dairy farms (F1, F2, F3, F4 and F5) in the Upper (UT) and Lower (LT) Tsitsikamma regions treated with different rates of NPK (nitrogen, phosphorus, potassium) fertilizer alone or in combination with poultry manure (PM) and/or dairy effluent (DE). Soil samples were collected at 0–15, 15–30, 30–45 and 45–60 cm depth intervals and analysed for soil pH, P, K, Ca and Mg. Results of this study revealed variable trends on soil pH and nutrient changes between farms, suggesting an influence of some inherent soil properties in addition to the 6-year applied management practices. When averaged over sampled farms, surface placement of soil amendments and limited soil disturbance resulted in surface stratification of soil pH, P, K, Ca and Mg. On the other hand, integration of organic and inorganic fertilizers induced significant changes in nutrient contents and stocks to a depth of 60 cm, especially in the LT region. A combination of NPK fertilizer, PM and/or DE applied in pasture mixtures generally showed potential to improve soil fertility in both regions. As such, adoption of this combination by farmers could cut down reliance on expensive synthetic fertilizers and costs of dairy production. However, studies are still necessary in this region to validate the observed results.

Evaluation of Faba Bean (Vicia faba L.) Varieties for Yield and Chocolate Spot (Botrytis fabae) Disease in Western Tigray, Ethiopia

Faba bean (Vicia faba L.) has an important pulse crop in Ethiopian. It is consumed in various forms and contributes to soil fertility improvement. However, its production and productivity are challenged by biotic and abiotic constraints. Chocolate spot is known as Botrytis fabae, is a significant biotic constraint that negatively impacts faba bean crops in highland areas of western Tigray. The aim of the study mentioned was to assess faba bean varieties for their grain yield and resistance to chocolate spot disease under field conditions. Field experiment was conducted at Welkayt and Tsegedie district during 2017 cropping season using five released faba bean varieties and one local check. Treatments were evaluated with RCBD and replicated three times. There was significant difference (p<0.01) among tested faba bean varieties and lactation, while, interaction effect of varieties and lactation were non-significant variation (p<0.05). In the analysis conducted on grain yield from different varieties, it was observed that the variety Hachalu achieved the highest grain yield at 632kg/ha, followed closely by Tumsa with a yield of 611.8kg/ha. While, minimum yield was obtained from variety Obse (384.3kg/ha) at Welkayt. Similarly, in Tsegedie maximum yield was calculated from variety Tumsa (339.8kg/ha) and Hachalu (334.4kg/ha), respectively. Minimum yield was obtained from variety Obse (238.8kg/ha). There was significant variation among faba bean varieties in terms of PSI at a significance level of P<0.05, while disease incidence did not show significant differences among the varieties tested. Lowest mean disease severity was recorded from varieties Hachalu (15%) followed by Tumsa (17.7%). However, Highest mean value was recorded from Obse variety (30.02%) at Welkayt. Similarly, in Tsegedie lowest disease severity was recorded from varieties Hachalu (28.7%) and Tumsa (28.8%). Highest mean value recorded from varieties Obse (susceptible) (50.13). There was positively and significant correlation among yield and Agronomic traits. However, there was negatively significant yield with PSI at both locations. Varieties with low disease severity are useful in breeding program aimed at developing with higher resistance of chocolate spot disease.

Mapping, Distribution, Function, and High-Throughput Methodological Strategies for Soil Microbial Communities in the Agroecosystem in the Last Decades

The intricate interplay between SMCs and agroecosystems has garnered substantial attention in recent decades due to its profound implications for agricultural productivity, ecosystem sustainability, and environmental health. Understanding the distribution of SMCs is complemented by investigations into their functional roles within agroecosystems. Soil microbes play pivotal roles in nutrient cycling, organic matter decomposition, disease suppression, and plant‒microbe interactions, profoundly influencing soil fertility, crop productivity, and ecosystem resilience. Elucidating the functional diversity and metabolic potential of SMCs is crucial for designing sustainable agricultural practices that harness the beneficial functions of soil microbes while minimizing detrimental impacts on ecosystem services. Various molecular techniques, such as next-generation sequencing and high-throughput sequencing, have facilitated the elucidation of microbial community structures and dynamics at different spatial scales. These efforts have revealed the influence of factors such as soil type, land management practices, climate, and land use change on microbial community composition and diversity. Advances in high-throughput methodological strategies have revolutionized our ability to characterize SMCs comprehensively and efficiently. These include amplicon sequencing, metagenomics, metatranscriptomics, and metaproteomics, which provide insights into microbial taxonomic composition, functional potential, gene expression, and protein profiles. The integration of multiomics approaches allows for a more holistic understanding of the complex interactions within SMCs and their responses to environmental perturbations. In conclusion, this review highlights the significant progress made in mapping, understanding the distribution, elucidating the functions, and employing high-throughput methodological strategies to study SMCs in agroecosystems.

Optimizing an Ultisol of marginal land for soybean cultivation through inorganic fertilizer substitution with Tithonia compost and biochar ameliorant

Soybean has a strategic role as a food commodity in Jambi, Indonesia, but until now, it has still not been self-sufficient. There is still an opportunity to increase soybean productivity in Jambi by 35-49.6% by optimizing the use of marginal, dominated by Ultisol, which has low inherent soil fertility. One of the efforts that can be made to improve soil fertility for cultivating soybean plants in Jambi is to utilize compost and biochar as soil ameliorants to substitute for inorganic fertilizer. This study aimed to assess the effect of compost and biochar ameliorant as substitutes for inorganic fertilizer on the growth and yield of soybean plants grown on an Ultisol of Jambi. The experiment was arranged in a simple randomized block design with the combination of the percentage of inorganic fertilizer with compost and biochar ameliorant (100+0, 75+25, 50+50, 25+75, and 0+100) as the treatment factors. The observed variables were plant height, number of branches, plant nitrogen content, rate of symbiotically fixed nitrogen, weight of 100 seeds, and yield. The results showed that providing compost and biochar ameliorants can replace the role of inorganic fertilizer, and providing 100% compost and biochar ameliorant and a combination of 25% inorganic fertilizer and 75% compost biochar ameliorant can provide the highest growth and yield in soybean plants planted in Ultisol dry land.

Distribution of soil fertility indices in aggregate size fractions under different land-use types for coarse-textured soils of the derived savannah

The research investigated the distribution of soil fertility indices among aggregate-size fractions across three land-use types (forested, cultivated, and fallow lands) for loamy sand at Ede-Oballa, a derived savannah in southeastern Nigeria. Surface soil samples from these land-use types were air-dried and separated into <0.25 mm, 0.25-0.5 mm, 0.5-1.0 mm, 1.0-2.0 mm, 2.0-4.0 mm, and 4.0-8.0 mm aggregates before analyses. There were significant interaction effects of land-use type and aggregate-size fraction on the distribution of soil particle sizes (sand, silt, and clay) and contents of total nitrogen, available phosphorus, exchangeable bases (Mg2+ and Na+), and exchangeable acidity as well as apparent cation exchange capacity (CEC). Land-use type affected soil pH, K+, Ca+, and percent base saturation but not soil organic carbon (SOC), which was rather unevenly distributed among the aggregate-size fractions. The distribution of most fertility indices, those defining CEC, and SOC content favoured >2.0 mm (large), 0.25-0.5 mm and <0.25 mm (micro-) aggregates, respectively, under cultivated land. However, soil total nitrogen and exchangeable acidity contents were best improved in the largest (4.0-8.0 mm) aggregates under forested and fallow lands, respectively. The study highlights the potential of land-use types generally and arable-crop cultivation specifically to engender aggregates of different sizes with specific roles in improving soil quality and fertility.

Assessment of the capability of Landsat-8 satellite imagery for predicting soil organic carbon distribution

Soil organic carbon (SOC) is an important component of soil and plays a crucial role in addressing climate change. As a key component of soil organic matter, SOC directly impacts soil fertility, water retention, nutrient cycling, and overall soil health. The determination of SOC concentrations in soil often relies on costly physical sampling and chemical analysis. The aim of this research was to build a predictive model of SOC using satellite imagery of Landsat 8 OLI/TIRS over an agricultural area (Oued El Alleug) in the north of Algeria. The statistical correlations between the spectral bands (B2 and B6) and chemically measured SOC concentrations showed that it is possible to predict spatially the SOC concentrations. The results also showed that the topographic variables are not determinant in the spatial prediction of SOC concentrations. The predicted model showed an acceptable performance with a coefficient of determination (R2) = 0.7 and a root mean square error (RMSE) = 7.08 g/kg during the validation phase. The results of this study are important, as they will facilitate decision-making in soil conservation practices and enhance land management, especially in areas facing increasing agricultural and environmental pressures.

Sustaining Soil Health in High Tunnels: A Paradigm Shift toward Soil-centered Management

This review was conducted to synthesize current knowledge, learn producer and Extension specialist perspectives, and identify gaps in understanding of the role of soil health in sustaining production in high tunnel (HT) systems. This synthesis includes findings from scholarly resources related to soil health in HTs, including research and Extension-based literature, perspectives from experienced HT producers and technical assistance providers, and the direct observations of a broad network of university research and Extension personnel working with HTs. Findings are intended to identify knowledge gaps and additional research and Extension resource needs of greatest priority to the HT producer community and technical assistance providers that support them at the time of publication. A review of 68 research articles and 58 Extension resources was conducted. Focus group interviews were conducted with small groups of experienced HT farmers in four regions of the eastern half of the United States, with in-depth farm case studies conducted in individual farmers in three of these regions. Growers across regions identified soil fertility management, soilborne diseases, soil compaction, and lack of consistency of soil analyses specific to HTs as the greatest soil-related challenges to HT production. Research and resources for technical assistance providers on mitigation strategies to remediate yield-limiting HT soil conditions, such as excessive soil salinity and high pathogen populations, were also lacking. As such, process-based research on techniques such as leaching, soil steaming, solarization, and anaerobic soil disinfestation in tunnels that consider short- and long-term costs, benefits, and effects on soil and plant productivity should be prioritized in the future when considering the impact of HT production on soil health. Interviews also indicated a need for networking opportunities for technical assistance providers across agencies (e.g., Natural Resources Conservation Service, Extension, nongovernmental organizations). Despite a high and increasing rate of adoption, there is currently a lack of information about maintaining HT systems. Given that HTs play a critical and growing economic role for specialty crop growers throughout the eastern United States, comprehensive intervention across the research–Extension spectrum to sustain productivity in HT systems is recommended.

Short-term continuous cropping leads to a decline in rhizosphere soil fertility by modulating the perilla root exudates

Short-term continuous cropping leads to a decline in rhizosphere soil fertility by modulating the perilla root exudates

The Main Soil Constraint Factors and Its Improvement Methods Based on Sustainable Development of Agricultural Economy in Tobacco Planting Area in Chenzhou City, Hunan Province of China

Farmland soil is the basis for agricultural production and a fundamental resource. It is beneficial to the sustainable development of agricultural economy to adopt different conservation measures for different soil types which exist various obstacles. In order to provide scientific guidance for accurate soil improvement for the fields under tobacco-rice rotation in Chenzhou City, Hunan Province of China, soil obstacle combination types were analyzed by sampling and determined based on the data of pH, organic matter (OM), available nitrogen (AN), phosphorous (AP) and potassium (AK) in the plough horizons (0–20 cm) of 1008 typical fields, and according soil obstacle combination types, different measures were adopted to improve the soil fertility and tobacco yield and quality. The results showed that based on the five soil quality indices, 61.31%–81.85% of the fields were in the high levels, 26.79%–33.83% of the fields were in the suitable levels, while only 9.66% on average the fields were in the low levels. In total 89 soil obstacle combination types were found in the fields, among which, 22 types (75.3%) with the field numbers were more than 1% of the total fields. The main ones were the types of Reducing pH, OM and NPK (17.76%), followed by the types of Reducing pH, OM and NP (8.43%), Reducing OM and NPK (5.26%), reducing pH, OM and PK (4.66%), and reducing pH, OM and N (4.07%). In conclusion, the comprehensive countermeasures (organic fertilizer and straw mulching) should be considered and taken for the accurate improvement of soil quality according to the actual situation in soil obstacle combinations, and reducing pH, OM and NPK should be considered first for most fields under tobacco-rice rotation.

Influence of indole acetic acid and trehalose, with and without zinc oxide nanoparticles coated urea on tomato growth in nitrogen deficient soils

Nitrogen deficiency in low organic matter soils significantly reduces crop yield and plant health. The effects of foliar applications of indole acetic acid (IAA), trehalose (TA), and nanoparticles-coated urea (NPCU) on the growth and physiological attributes of tomatoes in nitrogen-deficient soil are not well documented in the literature. This study aims to explore the influence of IAA, TA, and NPCU on tomato plants in nitrogen-deficient soil. Treatments included control, 2mM IAA, 0.1% TA, and 2mM IAA + 0.1% TA, applied with and without NPCU. Results showed that 2mM IAA + 0.1% TA with NPCU significantly improved shoot length (~ 30%), root length (~ 63%), plant fresh (~ 48%) and dry weight (~ 48%), number of leaves (~ 38%), and leaf area (~ 58%) compared to control (NPCU only). Additionally, significant improvements in chlorophyll content, total protein, and total soluble sugar, along with a decrease in antioxidant activity (POD, SOD, CAT, and APX), validated the effectiveness of 2mM IAA + 0.1% TA with NPCU. The combined application of 2mM IAA + 0.1% TA with NPCU can be recommended as an effective strategy to enhance tomato growth and yield in nitrogen-deficient soils. This approach can be integrated into current agricultural practices to improve crop resilience and productivity, especially in regions with poor soil fertility. To confirm the efficacy of 2mM IAA + 0.1% TA with NPCU in various crops and climatic conditions, additional field studies are required.

Effect of biochar on soil chemical properties of tidal wetland in Jambi, Indonesia, and growth and yield of various rice varieties

The study aimed to determine the effect of biochar on the growth and yield of several rice varieties in a tidal wetland agroecosystem. This research used a split-plot design with the main plot was biochar application, consisting of three levels (no biochar, rice husk biochar, and coconut shell biochar), and the subplot was rice variety consisting of ten varieties (Inpara, Inpari 30, Kuning, Karya Rendah, Bujang Pelawah, Pandan Wangi, Bujang Berinai, Kwatek Tinggi, Candu, and Serai). Plant parameters observed were plant height, number of tillers, productive tillers, panicle length, number of grains per panicle, number of empty grains per panicle, milled rice weight, and weight of 1,000 grains. Results of this study showed that the application of biochar improved soil fertility by increasing organic carbon, available phosphorus and potassium, cation exchange capacity, and reducing the soluble iron in the soil. However, the application of biochar did not significantly affect the height of rice plants. The application of coconut shell biochar yielded the best results in increasing the number of productive tillers, the number of grains per panicle, grain dry weight, and reducing the number of empty grains per panicle.

Impact of Weather Parameters on the Population Fluctuation of Major Sucking Pest in Summer Mung Bean [Vigna radiata (L.) Wilczek

Background: Mungbean may be grown in an extensive range of agro climatic zones in India and across the world. It is a crucial component of our diet. Because of its capacity to fix nitrogen, it also plays a vital role in managing soil fertility. Mung beans are one of the most significant crops for farmers as a cash crop. In order to implement control measures effectively and on schedule, it is crucial to monitor the population dynamics of major sucking pests, such as aphids, jassids and whiteflies in relation of weather parameters. Methods: PDM-139 (Samrat) variety seeds were manually planted 5-7cm deep in the ground. Weekly observations were made from 10 randomly chosen plants Split cage methods were used to record the observations of jassids and whiteflies and aphids from the top and bottom surfaces of the first three trifoliate plants were tallied. Averages population were computed. Result: The incidence of pest population start on the 14-15th standard meteorological weeks which attain their peak population in 19th SMW. The insect-pest population was established positive correlation with the max and min temperature whereas population was negatively correlated with R.H. and Rainfall.

Impact of Integrated Soil Fertility Management Practices on the Welfare of Smallholder Farmers in Ethiopia

Impact of Integrated Soil Fertility Management Practices on the Welfare of Smallholder Farmers in Ethiopia

Effect of bio-organics and seed priming on crop productivity, post-harvest soil fertility profile, biological counts and economics of pearl millet under rain-fed condition of Rajasthan

Effect of bio-organics and seed priming on crop productivity, post-harvest soil fertility profile, biological counts and economics of pearl millet under rain-fed condition of Rajasthan