Soil Health Research Articles

Cover crop residue decomposition triggered soil oxygen depletion and promoted nitrous oxide emissions

Cover cropping is a promising strategy to improve soil health, but it may also trigger greenhouse gas emissions, especially nitrous oxide (N2O). Beyond nitrogen (N) availability, cover crop residue decomposition may accelerate heterotrophic respiration to limit soil O2 availability, hence promote N2O emissions from denitrification under sub-optimal water-filled pore space (WFPS) conditions that are typically not conducive to large N2O production. We conducted a 21-day incubation experiment to examine the effects of contrasting cover crop residue (grass vs legume) decomposition on soil O2 and biogeochemical changes to influence N2O and CO2 emissions from 15N labeled fertilized soils under 50% and 80% WFPS levels. Irrespective of cover crop type, mixing cover crop residue with N fertilizer resulted in high cumulative N2O emissions under both WFPS conditions. In the absence of cover crop residues, the N fertilizer effect of N2O was only realized under 80% WFPS, whereas it was comparable to the control under 50% WFPS. The N2O peaks under 50% WFPS coincided with soil O2 depletion and concomitant high CO2 emissions when cover crop residues were mixed with N fertilizer. While N fertilizer largely contributed to the total N2O emissions from the cover crop treatments, soil organic matter and/or cover crop residue derived N2O had a greater contribution under 50% than 80% WFPS. Our results underscore the importance of N2O emissions from cover crop-based fertilized systems under relatively lower WFPS via a mechanism of respiration-induced anoxia and highlight potential risks of underestimating N2O emissions under sole reliance on WFPS.

Non-targeted impact of cyantraniliprole residues on soil quality, mechanism of residue degradation, and isolation of potential bacteria for its bioremediation.

Cyantraniliprole (CY), an anthranilic diamide insecticide widely used in grape farming for controlling various sucking pests, poses ecological concerns, particularly when applied as soil drenching due to the formation of more toxic and persistent metabolites. This study established the dissipation and degradation mechanisms of CY in grape rhizosphere soil using high-resolution Orbitrap-LC/MS analysis. The persistence of CY residues beyond 60days was observed, with dissipation following biphasic first + first-order kinetics and a half-life of 15 to 21days. The degradation mechanism of CY in the soil was elucidated, with identified metabolites such as IN-J9Z38, IN-JCZ38, IN-N7B69, and IN-QKV54. Notably, CY was found to predominantly convert to the highly persistent metabolite IN-J9Z38, raising environmental concerns. The impact of CY residues on soil enzyme activity was investigated, revealing a negative effect on dehydrogenase, alkaline phosphatase, and acid phosphatase activity, indicating significant implications for phosphorous mineralization and soil health. Furthermore, bacterial isolates were obtained from CY-enriched soil, with five isolates (CY3, CY4, CY9, CY11, and CY20) demonstrating substantial degradation potential, ranging from 66 to 92% of CY residues. These results indicate that the identified bacteria hold potential for commercial use in addressing pesticide residue contamination in soil through bioremediation techniques.

Studies on Benefits of Organic Food Products in Human Life during Covid-19

Organic food products have gained considerable attention in recent years due to their perceived health and environmental benefits. This comprehensive review examines the scientific evidence surrounding the advantages of consuming organic foods compared to conventionally produced counterparts. Firstly, organic farming practices emphasize the use of natural fertilizers and biological pest control methods, avoiding synthetic pesticides and genetically modified organisms (GMOs). Numerous studies have demonstrated that organic produce tends to have lower pesticide residues, reducing the potential health risks associated with pesticide exposure. Moreover, organic farming promotes soil health and biodiversity by minimizing the use of synthetic chemicals and fostering sustainable agricultural practices. Healthy soils are essential for nutrient-rich crops and contribute to long-term environmental sustainability. Additionally, organic agriculture typically utilizes crop rotation and intercropping techniques, which enhance soil fertility and resilience. Furthermore, organic livestock production adheres to stringent animal welfare standards, including access to outdoor grazing and the prohibition of routine antibiotic use and growth hormones. As a result, organic meat, dairy, and poultry products often contain higher levels of beneficial nutrients such as omega-3 fatty acids and antioxidants. In terms of nutritional quality, several meta-analyses have suggested that organic fruits and vegetables may have slightly higher levels of certain vitamins, minerals, and antioxidants compared to conventionally grown counterparts. While the differences may be modest, the cumulative effects of consuming organic foods over time could contribute to improved overall health outcomes. Beyond individual health benefits, supporting organic agriculture also has positive implications for environmental conservation and sustainable food systems. By minimizing chemical inputs and promoting biodiversity, organic farming helps mitigate soil erosion, water pollution, and greenhouse gas emissions associated with conventional agriculture.

Irrigation intelligence-enabling a cloud-based Internet of Things approach for enhanced water management in agriculture.

Advanced sensor technology, especially those that incorporate artificial intelligence (AI), has been recognized as increasingly important in various contemporary applications, including navigation, automation, water under imaging, environmental monitoring, and robotics. Data-driven decision-making and higher efficiency have enabled more excellent infrastructure thanks to integrating AI with sensors. The agricultural sector is one such area that has seen significant promise from this technology using the Internet of Things (IoT) capabilities. This paper describes an intelligent system for monitoring and analyzing agricultural environmental conditions, including weather, soil, and crop health, that uses internet-connected sensors and equipment. This work makes two significant contributions. It first makes it possible to use sensors linked to the IoT to accurately monitor the environment remotely. Gathering and analyzing data over time may give us valuable insights into daily fluctuations and long-term patterns. The second benefit of AI integration is the remote control; it provides for essential activities like irrigation, pest management, and disease detection. The technology can optimize water usage by tracking plant development and health and adjusting watering schedules accordingly. Intelligent Control Systems (Matlab/Simulink Ver. 2022b) use a hybrid controller that combines fuzzy logic with standard PID control to get high-efficiency performance from water pumps. In addition to monitoring crops, smart cameras allow farmers to make real-time adjustments based on soil moisture and plant needs. Potentially revolutionizing contemporary agriculture, this revolutionary approach might boost production, sustainability, and efficiency.

Agricultural Practices and Climate Resilience: Case Study in Vietnam

Purpose: To aim of the study was to analyze agricultural practices and climate resilience: case study in Vietnam.
 Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries.
 Findings: In Vietnam, agricultural practices significantly enhance climate resilience amidst growing climate variability. Diversified cropping systems and climate-smart techniques like conservation agriculture and agroforestry help mitigate climate-related risks by spreading vulnerabilities and improving soil health and water retention. Promoting resilient crop varieties and livestock breeds further reduces susceptibility to pests, diseases, and extreme weather events. Integrating these strategies into agricultural policies is vital for ensuring food security and sustainability in Vietnam's changing climate.
 Unique Contribution to Theory, Practice and Policy: Social-Ecological Systems Theory (SES), Adaptive Capacity Theory & Political Ecology Theory may be used to anchor future studies on agricultural practices and climate resilience: case study in Vietnam. Encourage diversification of crops and livestock to increase resilience to climate variability. Promote mixed cropping, agroforestry, and integrated livestock-crop systems, which enhance biodiversity, soil fertility, and pest resilience. Develop and implement policies that support climate-resilient agriculture.

Impact of participatory guarantee systems on sustainability outcomes: the case of vegetable farming in Vietnam

ABSTRACT Sustainable food systems require mechanisms that assure consumers about the sustainability of agricultural production. Building on the existing literature on the impact of sustainability standards, this study is the first to assess the effectiveness of participatory guarantee systems (PGS) for the certification of organic produce. The study uses representative farm-level data on local vegetable value chains in northern Vietnam and uses a broad set of sustainability outcomes as well as counterfactual analysis, including systematic robustness checks. The results show that PGS significantly improves farm profitability (+117%), agroecology performance (+40%), and gives farmers more choice of sales channels (+23%). However, PGS had no significant effect on returns to labour and reduced the average crop yield. Capacity development on nursery practices, transplanting of healthy seedlings rather than direct seeding, reduced tillage, and collective crop planning and management are some of the innovations that can counter adverse effects on crop yields, increase soil health as well as improve returns to labour, and thus attract more youth to farming. Overall, the study shows that organic PGS can make vegetable production more economically viable and more agroecologically sustainable.

SOIL HEALTH ANALYSIS AND CLASSIFICATION OF MICRONUTRIENTS FOR CROP SUGGESTION USING MACHINE LEARNING

An essential component of agriculture is soil. Many types of soil exists. Different parameters can be observed in each type of soil, and various crops can be grown on different types of soils. To understand which crops develop in certain types of soil, they need to be informed on the characteristics and features of various soil types. The capability to identify the inputs needed for productive and cost-effective farming was provided by soil analysis. A proper soil test will ensure that the proper amount of fertilizers are utilized, providing the crop to meet its needs while also profiting from the nutrients already available in the soil. The phrase "soil health" refers to the biological, chemical, and physical elements of the soil that are significant for plant nutrients. Soil analysis is a collection of different chemical processes that determines the amounts of available plant nutrients in the soil. The most important factors for producing a healthy crop are micronutrient analysis. The classification of soil's micronutrients is the primary objective of this analysis. In this case, machine learning methods may be helpful. It has made significant progress in recent years. Hence in this analysis, soil health analysis and classification of Micronutrients for crop suggestion using Machine Learning is presented. The coloured images of the soil samples are obtained and processed using a number of algorithms and filters. Color, texture, and other features can be extracted using these developed algorithms. Logistic Regression algorithm is used to classify micronutrients.

Effect of multiwall carbon nanotubes and surfactants characteristics on immobilization of heavy metals in contaminated soils

Soil is a vital resource to humans and soil health is a concern of modern societies. One of the problems is the existence of heavy metals (HMs) pollution, which can affect food, water sources and biodiversity. This experimental work studies the effect of multiwall carbon nanotubes (MWCNTs) and surfactants characteristics on HMs immobilization in a contaminated soil. The testing program comprises the characterization of the MWCNTs and surfactants, followed by two distinct adsorption tests: suspension tests designed to supply preliminary information regarding the adsorption capacity of soil particles towards the different HMs, and percolation tests to evaluate the HMs immobilization in conditions mimicking a real in-situ scenario. The different HMs exhibit different affinities order to the soil studied: Pb > Cu > Ni > Zn. Results indicated that the inherent soil particles can immobilize significant quantities of HMs (especially Pb and Cu) due to their fine size and the existence of a substantial amount of organic matter content in the soil matrix. Molecular weight and charge density of the surfactant are characteristics with an impact on the MWCNTs dispersion and also on the adsorption capacity of the different HMs, namely in the case of Ni2+ and even in the case of Zn2+ possessing lower electronegativity and higher mobility. The findings of the study allow concluding that MWCNTs possess the potential to reduce the mobility of heavy metals in soil, even when employed at very low concentration (0.01% w/w), which is an important feature considering their cost.

Application of Artificial Intelligence and Sensor Fusion for Soil Organic Matter Prediction.

Soil organic matter (SOM) is one of the best indicators to assess soil health and understand soil productivity and fertility. Therefore, measuring SOM content is a fundamental practice in soil science and agricultural research. The traditional approach (oven-dry) of measuring SOM is a costly, arduous, and time-consuming process. However, the integration of cutting-edge technology can significantly aid in the prediction of SOM, presenting a promising alternative to traditional methods. In this study, we tested the hypothesis that an accurate estimate of SOM might be obtained by combining the ground-based sensor-captured soil parameters and soil analysis data along with drone images of the farm. The data are gathered using three different methods: ground-based sensors detect soil parameters such as temperature, pH, humidity, nitrogen, phosphorous, and potassium of the soil; aerial photos taken by UAVs display the vegetative index (NDVI); and the Haney test of soil analysis reports measured in a lab from collected samples. Our datasets combined the soil parameters collected using ground-based sensors, soil analysis reports, and NDVI content of farms to perform the data analysis to predict SOM using different machine learning algorithms. We incorporated regression and ANOVA for analyzing the dataset and explored seven different machine learning algorithms, such as linear regression, Ridge regression, Lasso regression, random forest regression, Elastic Net regression, support vector machine, and Stochastic Gradient Descent regression to predict the soil organic matter content using other parameters as predictors.

Effect of Biodegradable Nonwoven Mulches from Natural and Renewable Sources on Lettuce Cultivation.

Numerous research showed that mulching with conventional agro foils elevates soil temperature and promotes plant growth, but negatively influences soil health and brings environmental concerns. Most of the published research on nonwoven mulches for plant cultivation includes nonwoven fabrics produced by extrusion processes providing nonwoven fabric structures similar to films. A limited number of studies investigate the impact of nonwoven mulches produced by a mechanical process on the cards and bonded by needling on plant cultivation. For this study, nonwoven mulches of mass per unit area of 400 g m-2 made from jute, hemp, viscose (CV), and polylactide (PLA) fibers were produced on the card bonded by needle punching. The field experiment was conducted two consecutive years in a row, in spring 2022 and 2023, by planting lettuce seedlings. The nonwoven mulches maintain lower temperatures and higher soil moisture levels compared to agro foil and the control field. The fibrous structure and their water absorption properties allow natural ventilation, regulating temperatures and retaining moisture of soil, consequently improving soil quality, lettuce yield, and quality. The fiber type from which the mulches were produced, influenced soil temperature and humidity, soil quality, and lettuce cultivation. The nonwoven mulches were successful in weed control concerning the weediness of the control field. Based on the obtained results, the newly produced mulches are likely to yield better results when used for the cultivation of vegetables with longer growing periods. Newly produced biodegradable nonwoven mulches could be an eco-friendly alternative to traditional agro foil, minimizing environmental harm during decomposition. The obtained results suggest that the newly produced mulches would be even more suitable for growing vegetables with longer growing seasons.

Biomass Source of Biochar and Genetic Background of Tomato Influence Plant Growth and Development and Fruit Quality

Maintaining healthy soils and restoring marginal lands are necessary to ensure efficient food production and food security. Biochar, a porous carbon-rich material generated from the pyrolysis of organic feedstock, is receiving attention as a soil amendment that can potentially restore soil health and enhance crop yields. However, the physical and chemical properties of biochar are influenced by pyrolysis parameters and organic feedstock sources. These determine its interaction with the soil, influencing its impact on soil health and plant productivity. While most studies report the evaluation of one biochar and a single plant cultivar, the role of genetic background in responding to biochar as a soil amendment remains unexplored. The impact of six biochars on agronomic performance and fruit quality of three tomato (Solanum lycopersicum) cultivars was evaluated to test the hypotheses that (1) biochars derived from different feedstock sources would produce unique phenotypes in a single cultivar of tomato, and (2) single feedstock-derived biochar would produce different phenotypes in each of the three tomato cultivars. The data supported both hypotheses. This study demonstrated that plant genetic background and biomass source are important variables that must be considered for using biochar as a soil amendment.

Sustainable Agriculture Practices: Utilizing Composted Sludge Fertilizer for Improved Crop Yield and Soil Health

It is desirable to recycle sewage sludge as fertilizer for agricultural fields. The application of sludge to agricultural soils is a measure that replaces chemical fertilizers and plays an important role in improving soil’s physicochemical and biological properties. However, there are concerns that the pollutants in sewage sludge will cause negative impacts on soil health. To closely monitor the soil–sludge interactions, a field study was conducted over a 20-year period in the North China Plain. In this study, the long-term effects of sewage sludge on the soil properties and soil microbial diversity were investigated. We examined the effects of various fertilization methods (control, chemical fertilizer, uncomposted sludge fertilizer, composted sludge fertilizer) on wheat production and several soil health indicators, such as the soil’s enzymatic activities, microbial biomass, microbial diversity, and crop yield. This long-term experiment supports that the composted sludge fertilizer increased crop production by 124.2% compared to the control treatment. The soil’s biological quality (e.g., the concentration of soil microbial biomass carbon) was also improved under the composted sludge fertilizer treatment. The concentrations of soil microbial biomass carbon under the uncomposted sludge fertilizer and composted sludge fertilizer treatments were 560.07 mg/kg and 551.07 mg/kg, respectively. The effect of the composted sludge fertilizer was greater than that of the uncomposted sludge fertilizer. The content of heavy metals did not exceed the national standard. The highest soil health index was 0.79 with the composted sludge fertilizer. Therefore, these results suggest that the application of composted sludge fertilizer has the potential to enhance long-term soil health and promote sustainable agricultural practices.

Integrated parasite management (IPM) and the pasture ecosystem: Optimizing outcomes for cattle, insect biodiversity, and soil health

Concerns over the negative environmental impacts of livestock parasiticide treatments and the widespread development of resistance has precipitated a move towards integrated parasite management (IPM). However, within the pasture ecosystem management strategies are likely to impact multiple processes in complex ways. This study investigates the impacts of IPM strategies on pest flies, gastrointestinal nematode (GIN) parasites, beneficial dung insects, and soil health. Twenty-nine grazing dairy farms participated in the study, representing different chemical and nonchemical parasite management and grazing strategies (continuous, rotational, or management intensive rotational (MIG)). Cattle managed using rotational grazing and MIG had significantly lower FEC than continuously grazed cattle. Farms using chemical parasiticides had significantly fewer pest flies, however farms releasing parasitoid wasps as biological control also had reduced abundances. Dung inhabiting beetle abundance was significantly correlated with reduced pest flies and GIN. Beneficial insects were negatively impacted on farms that used parasiticides. Continuously grazed pastures had higher beneficial insect abundances only on farms that did not use chemical parasiticides. Pastures managed under MIG had lower soil bulk density and higher active carbon compared to continuous grazing. There were positive associations between soil health and tunneling dung insects (Onthophagus spp. dung beetles). Finding optimal strategies will be context dependent, however the results of this study indicate that grazing strategies can control gastrointestinal parasites and improve soil health outcomes, natural enemies such as parasitoid wasps and dung inhabiting beetles can suppress pest fly populations, and the impacts of chemical control strategies may be mitigated through thoughtful implementation.

Assessment of Reclaimed Mined Area of Sahastradhara, Dehradun by Soil and Vegetation Analysis

This study investigates the impact of forest area mining on reclaimed limestone mined areas in Sahastradhara, Uttarakhand, India. Initiated in 1989-90, eco-restoration efforts aimed at rehabilitating the mined areas resulted in restoration ages of 25, 24, and 23 years across different sites. The study comprehensively examined vegetation and soil physicochemical properties at various depths, revealing the dominance of species like Murrayakoenigii, Acacia catechu, Vitex negundo, Eupatorium adenophorum, Grevillea robusta, and Lantana camara. Soil analyses unveiled variations in moisture content, bulk density, and coarse fragment percentage across the sites, a rise in organic carbon, phosphorous, and nitrogen levels, showcasing soil improvement post-restoration. Correlation analyses unveiled interrelationships between soil properties, emphasizing the importance of organic matter in influencing soil acidity. Vegetation analyses at different sites revealed evolving plant communities, with prominent species contributing to the ecological richness. The Importance Value Index (IVI) and Shannon Weiner Index (H') provided insights into species dominance and biodiversity. The results showed that the soil pH was slightly basic, and the available phosphorus and nitrogen levels were within the optimal range for plant growth. However, the bulk density and electrical conductivity values were higher than the recommended range. This study contributes valuable insights into the intricate interplay between mining activities, vegetation dynamics, and soil health, guiding future ecological restoration endeavors in similar contexts. The study concluded that the eco-restoration work carried out in the area has been successful in restoring the vegetation, but further assessment is required to ensure the long-term success of the restoration efforts.

The Role of Organic Farming in Sustainable Agriculture

Organic farming, as a sustainable alternative to conventional high-input practices reliant on synthetic fertilizers, fungicides, and pesticides, prioritizes the vitality of soil as a living ecosystem. Embracing practices such as crop rotation, animal manures, crop residues, green manures, and biological pest and disease control, organic agriculture aims to uphold soil health and productivity. By meeting present food demands in an environmentally conscientious manner, organic farming also safeguards the needs of future generations, thereby preserving and nurturing our ecosystem. Modern agriculture has detrimentally impacted the environment, leading to issues such as decreased soil fertility, elevated water hardness, insect resistance development, reduced genetic diversity in plants, heightened levels of toxic residues in the food chain and animal feed, contributing to health problems and environmental degradation. In contrast, organic farming nurtures plants with essential macronutrients and micronutrients while simultaneously enhancing soil physical, chemical, and biological characteristics. Guided by the ethos of sustainability, organic farming prioritizes mitigating health risks linked to synthetic inputs and cultivating a healthier ecosystem. The minimal environmental footprint of organic farming positions it as a practical solution for tackling urgent concerns like soil degradation, water pollution, and global ecological well-being. Essentially, organic farming stands out as a beacon of sustainable agriculture, paving the way to reconcile food production with environmental conservation. Moreover, organic farming's low environmental impact presents an opportunity to rehabilitate and enhance degraded agricultural lands.

Comparative Analysis of Vitamin, Mineral Content, and Antioxidant Capacity in Cereals and Legumes and Influence of Thermal Process.

Cereals, as the world's most consumed food, face challenges related to nutrient quality due to climate change and increased production impacting soil health. In this study, we investigated the vitamin and mineral content, polyphenols, and antioxidant activity in cereals from Western Romania, analyzing whole and hulled wheat, rye, oat, and soybeans before and after heat treatment. Samples from 2022 crops were processed into dough and subjected to 220 °C for 30 min. The results reveal that, despite efforts to optimize nutrient content, cereals, particularly after heat processing, exhibited lower vitamin and mineral levels than the recommended daily intake. The decrease in polyphenols and antioxidant capacity was notable, with rye flour experiencing the largest decline (15%). Mineral analysis showed copper levels in decorticated wheat decreased by 82.5%, while iron in rye decreased by 5.63%. Soy flour consistently displayed the highest calcium, magnesium, and potassium levels, whereas oat flour had the highest zinc and copper levels before and after heat processing. The study highlights the concerningly low vitamins and minerals contents in cereals, as well as in the final products reaching consumers in the Western part of Romania, and contributes to the assessment of measures that are meant to improve the contents of these minerals.

Intercomparison of Same-Day Remote Sensing Data for Measuring Winter Cover Crop Biophysical Traits.

Winter cover crops are planted during the fall to reduce nitrogen losses and soil erosion and improve soil health. Accurate estimations of winter cover crop performance and biophysical traits including biomass and fractional vegetative groundcover support accurate assessment of environmental benefits. We examined the comparability of measurements between ground-based and spaceborne sensors as well as between processing levels (e.g., surface vs. top-of-atmosphere reflectance) in estimating cover crop biophysical traits. This research examined the relationships between SPOT 5, Landsat 7, and WorldView-2 same-day paired satellite imagery and handheld multispectral proximal sensors on two days during the 2012-2013 winter cover crop season. We compared two processing levels from three satellites with spatially aggregated proximal data for red and green spectral bands as well as the normalized difference vegetation index (NDVI). We then compared NDVI estimated fractional green cover to in-situ photographs, and we derived cover crop biomass estimates from NDVI using existing calibration equations. We used slope and intercept contrasts to test whether estimates of biomass and fractional green cover differed statistically between sensors and processing levels. Compared to top-of-atmosphere imagery, surface reflectance imagery were more closely correlated with proximal sensors, with intercepts closer to zero, regression slopes nearer to the 1:1 line, and less variance between measured values. Additionally, surface reflectance NDVI derived from satellites showed strong agreement with passive handheld multispectral proximal sensor-sensor estimated fractional green cover and biomass (adj. R2 = 0.96 and 0.95; RMSE = 4.76% and 259 kg ha-1, respectively). Although active handheld multispectral proximal sensor-sensor derived fractional green cover and biomass estimates showed high accuracies (R2 = 0.96 and 0.96, respectively), they also demonstrated large intercept offsets (-25.5 and 4.51, respectively). Our results suggest that many passive multispectral remote sensing platforms may be used interchangeably to assess cover crop biophysical traits whereas SPOT 5 required an adjustment in NDVI intercept. Active sensors may require separate calibrations or intercept correction prior to combination with passive sensor data. Although surface reflectance products were highly correlated with proximal sensors, the standardized cloud mask failed to completely capture cloud shadows in Landsat 7, which dampened the signal of NIR and red bands in shadowed pixels.

Pedotransfer Functions for Field Capacity, Permanent Wilting Point, and Available Water Capacity Based on Random Forest Models for Routine Soil Health Analysis

ABSTRACT Available water capacity (AWC), field capacity (θFC), and permanent wilting point (θPWP) are regarded as key physical soil health indicators that directly capture the soil’s capacity to store plant available water but are expensive components of a comprehensive soil health analysis. To reduce costs, pedotransfer functions for θFC, θPWP, and AWC were developed from a dataset of 7,232 soil samples with texture, soil organic matter (SOM), permanganate-oxidizable carbon, soil respiration, AWC, θFC, θPWP, wet aggregate stability, and extractable potassium, magnesium, iron, and manganese. Three functions were developed for each property: a full random forest (RF) model containing all variables, a reduced RF model and a multiple linear regression model containing texture and SOM. Pedotransfer functions were validated with an independent dataset that contained 1,406 samples. The full RF models for θFC, θPWP, and AWC reduced the root mean square error (RMSE) by 16.3, 13.3, and 12.8%, compared to multiple linear regression models, respectively. Furthermore, the full RF models for θFC, θPWP, and AWC reduced RMSE by 11.6, 6.7, and 12.8%, compared to the reduced RF model, respectively. Permanganate-oxidizable carbon, wet aggregate stability, and extractable magnesium, potassium, and iron were useful novel predictor variables for improving prediction of θFC and AWC. AWC was sensitive in 20/57 long-term experiments, and full RF models were able to replicate 5/20 of those significant results. New RF pedotransfer functions for θFC, θPWP, and AWC can enhance prediction compared to traditional modeling techniques, fits into existing interpretative frameworks, and improves cost-effectiveness of comprehensive assessments of soil health.

Long-Term Cropping Management Practices Affect the Biochemical Properties of an Alabama Ultisol

Interest in improving the long-term sustainability of agricultural production systems has focused on identifying management practices that promote soil health. No tillage, cover cropping, and amending soils with broiler (Gallus gallus domesticus L.) litter are commonly adopted conservation practices that have been shown to improve soil fertility and crop yield. However, the overall influence of these conservation practices on soil health in the southeastern US are not well understood. Thus, a study was conducted to evaluate the influence of tillage, broiler litter (BL) applications, and cropping systems on soil biochemical properties. Soils were collected from field research plots under long-term management (>than 25 years of tillage, 15 years of broiler litter application, and 15 years of cropping system). Soil microbial biomass, C, N, and P, amidohydrolases, and dissolved organic matter (DOM) were evaluated as indicators of soil health. Adopting tillage and BL into the agricultural management system modified the biochemical parameters of the soils evaluated. Most of these modifications occurred in the 0–5 cm depth. Higher microbial biomass carbon (MBC; 85%) and nitrogen (MBN; 10%) and enzyme activities of asparaginase (65%) and glutaminase (70%) were observed in the 0–5 cm depth under no tillage (NT) compared to conventional tillage (CT), indicating greater biological activities were established in these soil ecosystems. Broiler litter applications increased microbial biomass N and activities of asparaginase and glutaminase in both soil depths. In addition, microbial biomass phosphorus (MBP) was increased following BL application in the 0–5 cm depth. The results suggest that long-term management of NT and BL additions can improve the health of eroded southeastern US soils by altering the soil biochemical parameters.

Role of Hazelnut Husk Compost and Phosphate Solubilizing Bacteria in Improving Productivity and Quality Parameters of Wheat (Triticum aestivum L.) and Their Effects on Some Soil Biological Properties

ABSTRACT Implementing compost can assist in improving soil structure and enable nutrient mobilization to plants that initiate an appropriate soil balance. In a greenhouse experiment, the influence of hazelnut husk compost (HHC), both in single and in combination with the phosphate solubilizing bacteria (PSB) on the wheat yield, yield parameters, and soil biological properties were investigated. A significant increase in yield and its quality parameters was recorded when the soil was treated with different doses of compost and bacteria. It was observed copious improvements in the soil biological properties with these applications. The microbial biomass carbon and total organic carbon ratios (Cmic:Corg) ranged from 1.51 to 2.09, were also remarkable in the organic amended soils. However, in all the treatments, the co-inoculation of bacteria with compost enhanced all the parameters significantly more than their individual applications. The highest yield increase over control (22.12%) was recorded from the integrated application of organic source and bio-fertilizer. This reflects a synergistic relationship between the compost and bacteria that eventually enhanced wheat production. It is therefore concluded that using HHC and PSB in soil can unfold promising possibilities for better soil health, which in the long run can contribute to sustainable food production.