Soil Fertility Research Articles

Mesoplastic and Microplastic Pollution in the Soil of Small-Scale Agricultural Areas in Iligan, Mindanao, Philippines

ABSTRACT The Philippines is primarily an agricultural country in which most Filipinos depend on the health of the soil for livelihood. Plastic pollution adversely affects agriculture by degrading soil quality, fertility, and crop growth. However, the prevalence of plastic particles such as mesoplastics (>5 mm to 25 mm) and microplastics (<5 mm) in agricultural soils in the Philippines remains poorly understood. This study investigated the prevalence of mesoplastics and microplastics in agricultural soils in Iligan City, Philippines. We collected soil samples from the six sampling stations in high-elevation and low-elevation sites. Mesoplastics and microplastics were examined through manual sorting, categorized based on color, shape, and size, and identified using Fourier-transform infrared spectroscopy (FTIR). Mesoplastics were found to be more prevalent, averaging 2.22 items/kg compared to microplastics 0.83 items/kg. Mesoplastics were mainly white-colored (42%), mostly fragmented (55%), 5–10 mm in size (55%), and were predominantly polypropylene (85%). Microplastics were mainly transparent (40%), composed of fragments and film shapes(46%), and 3–4 mm (93%) in size. Polyethylene was the abundant microplastic polymer type (47%). It was observed that the low-elevation sites had a higher abundance of plastic particles, stressing the need to address local factors in tackling plastic pollution.

Soil Fertility Dynamics and Identify the Most Limiting Nutrients Affecting Walnut Productivity in Nepal

This study aimed to assess the soil nutrient status in walnut orchards of different ages in Jajarkot district, Nepal, to understand soil fertility dynamics and identify the most limiting nutrients affecting walnut productivity. The research employed a randomized complete block design (RCBD) with three treatments representing different age groups of walnut orchards (1-5 years, 6-10 years, and 11-15 years), each replicated seven times across various municipalities. The study was conducted in Jajarkot district, Karnali Province, Nepal, encompassing municipalities including Nalgad, Junichadey, and Barekot, from March to April 2023. Soil samples were collected from multiple depths (1, 2, and 3 feet) in each orchard and analyzed for pH, soil organic matter (SOM), total nitrogen, available phosphorus, and available potassium. Data analysis included descriptive statistics, one-way analysis of variance (ANOVA), and correlation analyses to explore relationships between soil parameters and orchard age. The study showed that significant variations were observed among different age groups of walnut orchards for soil pH, SOM, nitrogen, phosphorus, and potassium levels. Soil pH decreased with orchard age, while SOM, nitrogen, and phosphorus tended to increase with orchard age. Phosphorus was identified as the most limiting nutrient across all sampled soils, followed by nitrogen and potassium. Moreover, strong correlations were found between orchard age and soil N (r = 0.894, p &lt; 0.01) and P (r = 0.776, p &lt; 0.01), underscoring age-dependent nutrient dynamics. The study highlights the critical role of orchard age in shaping soil nutrient dynamics in walnut orchards. Older orchards exhibited higher levels of SOM, nitrogen, and phosphorus, indicating the accumulation of organic matter and nutrients over time. Phosphorus emerged as the primary limiting nutrient, essential for root growth, flowering, and fruiting in walnut trees. These findings underscore the importance of targeted fertilization strategies to optimize soil fertility and sustain long-term walnut productivity in the region.

The Contribution of Conservation Agriculture on Environmental Protection in Rwanda

Purpose: The study aimed to assess the contribution of Conservation agriculture on Environmental protection in Rwanda: case of Kayonza District. Materials and Methods: The study reviewed different studies related to Conservation agriculture and Environmental protection and used qualitative and quantitative approaches. The Data were collected using a questionnaire and face-to-face interview on Sample composed by 404 Respondents from Kayonza district. The data collected and analyzed by using Distributive statistics. Findings: The study indicated that CA techniques are contributing in environmental protection and there is a relationship between adopting Conservation Agriculture (CA) techniques and environmental protection. The decrease in organic matter content and high soil erosion are affecting soil fertility and health and one of the main causes of global warming is also intensive chemical fertilization of agricultural crops. In contrast, CA techniques combine minimum soil disturbance, mulching, water holding capacity, reduce soil compaction, reduce soil erosion and improve soil fertility and application of organic fertilizers and re use of crop residues, Study have shown that farmers who adopt CA experience the improvement and there improve. The study underscores the importance of adopting CA techniques to reduce the cost and protect environment. Implications to Theory, Practice and Policy: By adopting CA practices, farmers can contribute to the protection of natural resources, conservation of biodiversity, and mitigation of climate change while maintaining agricultural productivity by promoting sustainable land management practices that conserve soil, water, and biodiversity, mitigate climate change impacts, and reduce environmental degradation associated with conventional agricultural practices. But not all small holder farmers involved in implementing all CA techniques due to different factors, NGOs and Government can collaborate to develop subsidies, grants, and funding programs specifically aimed to promote conservation agriculture. By adopting CA techniques, agriculture in the next decade will have to sustainably produce more food from less land through more efficient use of natural resources and with minimal impact on the environment in order to meet growing population demands.

The Content of Soil Glomalin Concerning Selected Indicators of Soil Fertility

The glomalin content is generally considered an indicator of the soil organic matter (SOM) quality. The content of easily extractable glomalin (EEG) and the total glomalin (TG) content was investigated across 71 different sites in the Czech Republic with arable soil and crop production (12 chernozems, 30 luvisols, 17 cambisols, and 12 fluvisols). The majority of the crops in the crop rotation were cereals (45.5%—mainly winter wheat, winter barley, and spring barley). The proportion of winter canola within the crop rotation was 15.9%. The contribution of other crops was substantially smaller (alfalfa, clover, potatoes, beet, silage maize, grain maize). The representation of crops in the crop rotation is standard for conventional farming in the Czech Republic. Based on the results of long-term field monitoring at 71 sites in different soil–climate conditions, we can state the following. The TG content was significantly correlated with the soil organic matter carbon content (CSOM), as well as another important indicator of SOM quality (humic and fulvic acid carbon content ratio—CHA/CFA). A significant and positive correlation was also determined for the TG and clay content (size &lt; 0.002 mm), as well as particles smaller than 0.01 mm. The easily extractable glomalin content (EEG) did not differ based on the reference soil group (RSG). On the other hand, the total glomalin content (TG) was significantly higher in the chernozem RSG in comparison with other RSGs (luvisols, cambisols, fluvisols). There was no relationship between the pHCaCl2 and glomalin (EEG; TG). The same can be said about the relationship between glomalin (EEG; TG) and the bulk density and porosity. No link was established between the glomalin content (EEG; TG) and phosphorus plant-available content. There was no relationship between the amount of applied organic matter (carbon inputs) and the soil glomalin content (EEG; TG). This relationship was not influenced by the type of applied organic fertilizer. No significant relationship was found for either straw, manure, or compost. The data on the glomalin content are significantly influenced by the site (soil type and soil texture).

Soil Legacies of Tree Species Composition in Mature Forest Affect Tree Seedlings’ Performance

AbstractTrees affect the biotic and abiotic properties of the soil in which they grow. Tree species-specific effects can persist for a long time, even after the trees have been removed. We investigated to what extent such soil legacies of different tree species may impact tree seedlings in their emergence and growth. We performed a plant–soil feedback experiment, using soil that was conditioned in plots that vary in tree species composition in Białowieża Forest, Poland. Soil was taken from plots varying in proportion of birch, hornbeam, pine, and oak. In each soil, seeds of the same four target species were sown in pots. Seedling emergence and growth were monitored for one growing season. To further explore biotic implications of soil legacies, ectomycorrhizal root tip colonization of oak, a keystone forest species, was determined. We found no effect of soil legacies of tree species on the emergence measures. We, however, found a clear negative effect of pine legacies on the total biomass of all four seedling species. In addition, we found relationships between the presence of pine and soil fertility and between soil fertility and root tip colonization. Root tip colonization was positively correlated with the biomass of oak seedlings. We conclude that tree species can leave legacies that persist after that species has been removed. These legacies influence the growth of the next generation of trees likely via abiotic and biotic pathways. Thus, the choice of species in today’s forest may also matter for the structure and composition of future forests.

Assessing horticulture-based land management impacts on carbon dynamics and soil quality

The present study was carried during 2020 and 2021 at School of Agricultural Sciences and Rural Development (Nagaland University), Medziphema, Nagaland to study the effects of different horticulture-based land use systems on carbon stock, soil fertility and soil biological health in acidic hill soils of Nagaland. Average values of bulk density of the soils were 1.20 and 1.21 g/cm3 in surface and sub-surface soils, respectively irrespective of type of orchards. The maximum and minimum carbon stock was recorded in pineapple [Ananas comosus (L.) Merr.] (46.77 and 43.38 mg/ha) and citrus (Citrus spp.) (33.07 and 32.42 mg/ha) orchard soils. Soil microbial biomass carbon in pineapple (270.13 and 244.23 µg/g) and citrus orchard soils (165.64 and 152.49 µg/g) was recorded in surface and sub-surface layers, respectively. Banana (Musa spp.) orchard soils had greater values of dehydrogenase activity (15.26 and 9.83 µg TPF/g/h). Soils of banana orchard also recorded highest acid phosphatase activity (176.0 and 165.5 µg PNP/g/h), which was at par with mango (Mangifera indica L.) orchard soils (175 and 166 µg PNP/g/h). Minimum acid phosphatase activity (162.0 and 150.0 µg PNP/g/h) was recorded in citrus orchard soils. Maximum earthworm population density was recorded in banana orchard (12–20 number/m2) and minimum (4–12 number/m2) in citrus orchards.

Optimizing Nutrient Management for Pearl Millet: Insights from a Long-term Field Experiment

The study investigates the impact of integrated nutrient management strategies on the yield and nutrient uptake of pearl millet (Pennisetum glaucum), a vital crop in arid and semi-arid regions. Pearl millet is a significant source of dietary energy and essential nutrients for rural populations in India. However, its productivity remains low compared to other millet-producing countries. This research aims to enhance pearl millet yield through a combination of organic manures, biofertilizers, and chemical fertilizers, addressing the need for sustainable agricultural practices. The experiment was conducted at the Research Farm of Rajmata Vijayaraje Scindia Krishi Vishwavidyalaya during the kharif seasons of 2022 and 2023. Twelve treatment combinations were tested, including 100% NPK along with farmyard manure (FYM) and seed treatments with biofertilizers. Results indicated that the treatment combining 100% NPK with FYM at 10 t/ha/year and biofertilizers significantly improved biological yield, nutrient uptake, and soil organic carbon content. Specifically, the highest biological yield recorded was 8026 kg/ha, with notable increases in total nitrogen, phosphorus, and potassium uptake. This study underscores the importance of integrated nutrient management in enhancing pearl millet productivity while maintaining soil health. By adopting these practices, farmers can improve crop yields and contribute to food security in regions reliant on pearl millet. The findings provide a framework for future research and practical applications in sustainable agriculture, emphasizing the need for balanced nutrient supply systems to optimize crop performance and soil fertility.

Assessment of zinc sources and levels for urea coating to achieve higher productivity and soil fertility in spring maize (Zea mays)

An experiment was conducted during 2021 and 2022 at the research farm of ICAR-Indian Institute of Maize Research, Ludhiana, Punjab to study the efficacy of zinc oxide and zinc sulphate for urea coating to achieve higher productivity in maize (Zea mays L.). Experiment was laid out in a randomized block design (RBD) comprised of 11 treatments, viz. no Zn; 0.05% of Zn through ZnO; 0.12% of Zn through ZnO; 0.24% of Zn through ZnO; 0.47% of Zn through ZnO; 0.95% of Zn through ZnO; 0.26% of Zn through ZnSO4; 0.52% of Zn through ZnSO4; 1.03% of Zn through ZnSO4; 2.07% of Zn through ZnSO4; and 4.15% of Zn through ZnSO4, replicated thrice. Results indicated that grains/cob and cob weight/plant recorded higher with 1.03%, 2.07% and 4.15% of Zn through ZnSO4 compared to no Zn. Zn at 2.07% (5.68 and 6.36) and 4.15% (5.71 and 6.37) through ZnSO4 recorded higher grain yield followed by 0.95% of Zn (5.50 and 6.23) through ZnO and 1.03% (5.42 and 6.25) of Zn through ZnSO4 in 2021 and 2022. A higher Zn content in grain was registered with 4.15% (27.70 and 27.87 mg/kg) and 2.07% (26.33 and 27.67 mg/kg) of Zn through ZnSO4. Overall, Zn at 2.07% through ZnSO4 was found suitable for urea coating to enhance productivity, soil enzymatic activities and residual soil fertility in spring maize.

Influence of Soil on Crop Performance and Ecosystem Services: A Review

Globally, the soil has a direct or indirect role in effective and sustainable agricultural production. This is due to the soil's multiple benefits to the creation of food, whether it comes from crops or animals. The pH, organic matter content, and nutritional balance of soils all affect how well they perform as vital life supports and nourishment sources. In addition to supporting a variety of living things and aiding in water regulation, these substrates are essential for sequestering carbon, particularly in light of climate change. But because of climate and human influences, soils are under danger, necessitating proactive resource management techniques. Combating degradation of the soil, which is impacted by things like unsustainable agriculture, deforestation, and inadequate irrigation, is essential to stopping desertification. Sustainable practices like nutrient management and integrated soil fertility management, proper tillage operation, etc. aim to increase crop productivity and improve soil fertility. Management techniques and environmental modifications have the potential to boost sustainability and enhance ecosystem service and help create agroecosystems that are robust to stress, resource efficiency, and climate change.

Phosphorus fertilization enhanced overwintering, root system and forage yield of late-seeded alfalfa in sodic soils

Sowing date and soil fertility are very important factors in the overwintering and production performance of alfalfa (Medicago sativa L.), yet there’s a knowledge gap in knowledge on how late-seeded alfalfa responds to phosphorus (P) fertilization. A field study was conducted in Inner Mongolia from 2020 to 2022 using a split-plot design. The main plots consisted of five sowing dates (31 July, 8, 16, and 24 August, and 1 September), while the subplots involved five P application rates (0, 40, 70, 100, and 130 kg P2O5 ha−1). Throughout the growing seasons, the overwintering rate, root traits, forage yield, and yield components were measured. The results revealed a consistent decrease in overwintering ability and productivity with the delayed sowing. This reduction in overwintering rate was mainly due to diminished root traits, while the decrease in forage yield was largely associated with a reduction in plants per square meter. However, P fertilizer application to late-seeded alfalfa demonstrated potential in enhancing the diameter of both the crown and taproot, thus strengthening the root system and improving the overwintering rate, the rate of increase ranges from 11.6 to 49%. This adjustment could also improve the shoots per square meter and mass per shoot, increasing by 9.4–31.3% and 15.0–27.1% respectively in 2 years, which can offset the decline in forage yield caused by late sowing and might even increase the forage yield. Regression and path analysis indicated that alfalfa forage yield is primarily affected by mass per shoot rather than shoots per square meter. This study recommended that the sowing of alfalfa in similar regions of Inner Mongolia should not be later than mid-August. Moreover, applying P fertilizer (P2O5) at 70.6–85.9 kg ha−1 can enhance the forage yield and persistence of late-seeded alfalfa. Therefore, appropriate late sowing combined with the application of P fertilizer can be used as an efficient cultivation strategy for alfalfa cultivation after a short-season crop harvest in arid and cold regions.

Soil properties, tomato (Solanum lycopersicum) yield and monetary returns under different nutrient management practices

The experiment was conducted during 2019 and 2020 at research farm of Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu to study the effect of different manures proportion along with reduced fertilizers rate application on performance of tomato (Solanum lycopersicum L.) yield, produce quality and soil fertility indicators. Experiment was laid out in randomized block design (RBD) comprised of 6 treatments, viz. T1, 100% organic; T2, 75% organic + 3% Panchagavya spray + azophos @3 kg; T3, 100% inorganic recommended dose of fertilizer (RDF) alone; T4, State recommendation; T5, 50% organic + 50% inorganic; and T6, 75% organic + 25% inorganic. The results of two years mean showed that the soil quality indicators like SOC (8.12 g/kg), mineral N (266 kg/ha), available P (22.1 kg/ha), exchangeable K (482 kg/ha), microbial biomass carbon (256 mg/kg), dehydrogenase (35.8 μg TPF/g/ day), alkaline phosphatase (475 μg PNP/g/soil/h), bacteria (38.4 CFU × 106/g soil), fungi (15.0 CFU × 103/g soil) and actinobacteria population (10.3 CFU × 105/g soil) were better under 75% organic + 25% organic. Tomato yield was at par with 100% organic. On the basis of the above results, the tomato yield can be enhanced by about 99% and 150% in terms of production and monetary efficiency by the adoption of integrated nutrition management (INM) of organic (75%) and inorganic fertilizers (25%). Thus, the results suggest that the 75% organic + 25% inorganic could be adopted to get maximum benefits in terms of yield, fruit quality, soil fertility and fertilizer savings.

Fertility and ecotoxicological condition of light gray forest soils of the Ivanovo region

The results oflong-term monitoring of light gray forest soil for agricultural purposesin theIvanovo region are presented, which was carried outto establish the level of fertility according to the mainagrochemical indicators, the content of mobile forms of trace elementsand sulfur, the ecotoxicological state according to the content ofgross and mobile forms of heavy metals, arsenic, caesium-137 andstrontium-90.The average values of the indicators, their levels ofchange and trends in changes in the metabolic and hydrolyticacidity of the soil, availability of organic matter, mobile formsof nitrogen, phosphorus, potassium, exchangeable calcium, magnesium and other bases,mobile forms of boron, copper, zinc, molybdenum, cobalt, manganese andsulfur have been established.According to the content of traceelements in the soil, the needs for the use ofmicronutrients are determined.Changes, concentrations and trends in the mobileforms of cadmium, lead, copper, zinc, nickel, chromium, mercury andarsenic in the soil have been determined.The study establishedbackground values, changes and trends in the specific activities ofcaesium-137 and strontium-90, the density of their contamination of thesoil of the site and the power of the exposuredose of gamma radiation.According to thePearson–Spearman correlation coefficients,the peculiarities of the influence of the content of organicmatter, the level of acidity and the capacity of cationexchange on the content of mobile forms of trace elements,sulfur, gross and mobile forms of metals and radionuclides wereestablished.

Crop geometry and nutrient (N-P-K-S) management for kharif onion bulb (Allium cepa) crop

The experiment was conducted during rainy (kharif) seasons of 2020 and 2021 at College of Agriculture (Agriculture University, Jodhpur, Rajasthan), Sumerpur, Pali, Rajasthan to find out the optimal quantity of N-P-K-S nutrients and appropriate crop geometry to maximize the productivity and bulb quality of onion (Allium cepa L.). The experiment was conducted in split-plot design (SPD) by means of 3 levels of N-P-K-S nutrients in main plots and 5 crop geometries under sub-plot, replicated thrice. Widest crop geometry (15 cm × 15 cm) with highest level of nutrients (140 N-80 P-80 K-40 S) resulted in highest tallness of plant (97.8 cm), maximum leaves (19/plant), root length (9.9 cm), number of roots/plant (139.8), average bulb weight (133.9 g) and harvest index (51.2). Saleable bulbs (43.6 t/ ha), total income (6753.8 USD), net income (5462.6 USD) and Benefit: cost (B:C) ratio (4.23) was the highest in 10 cm × 10 cm geometry with highest level of N-P-K-S nutrients. Maximum biological production (125.8 t/ha), bulb production (61.8 t/ha) was observed at closest geometry (7.5 cm × 7.5 cm) with highest level of N-P-K-S nutrients. It was confirmed by experimentation, that the onion seedling should be transplanted at 10 cm × 10 cm geometry with 140 N-80 P-80 K-40 S kg/ha nutrients in medium fertile sandy loam soil in arid agro-climatic condition for maximum saleable good quality onion bulbs production.

Значение бактериальных удобрений в формировании урожая зерновых бобовых культур

Abstract. One of the directions of modern agricultural production is the biologization of agriculture, which provides for a wider use of biological preparations and bacterial fertilizers. The use of bacterial fertilizers restores the fertility of the soil, contributes to increasing the yield and quality of agricultural products. The purpose of the study is to establish the effectiveness of the use of bacterial fertilizers in the cultivation of grain legumes. Methods. The research was carried out for three years, observations and records were carried out according to the generally accepted methodology of field experience. Results. The effectiveness of the application of top dressing with bacterial fertilizers “Azotovit” and “Fosfatovit” in the cultivation of grain legumes (soybeans, lentils) on light gray forest soils has been established. The use of “Fosfatovit” accelerated the ripening of soybeans for 4 days, lentils for 5 days, “Azotovit” influenced the formation of vegetative mass, increasing the number of leaves and the weight of the plant. An increase in the microbiological activity of the soil was noted when applying top dressing with bacterial fertilizers, the maximum value was obtained in variants with joint top dressing with “Azotovit” and “Fosfatovit”, in the experiment with soy, it averaged 72.1 %, in the experiment with lentils 81.5 %. The maximum increase in soybean yield was provided by fertilizing with “Fosfatovit” for an average of 3.97 t/ha over three years. Fertilizing with “Azotovit” and “Fosfatovit” had the greatest effect on lentils, in this variant the yield increased by 0.59 t/ha, or 32.4 % compared to the control. Top dressing with bacterial fertilizers contributed to an increase in crude protein and crude fat in soy and lentil grains. The scientific novelty of the research is to establish the effectiveness of the application of top dressing with bacterial fertilizers in the cultivation of soybeans and lentils in the conditions of the Chuvash Republic.

N Fertilizer in Combination with Straw Improves Soil Physicochemical Properties and Crop Productivity in Sub-Humid, Drought-Prone Areas

Straw returning may be an efficient strategy to maintain agricultural sustainability. However, which straw returning strategy can effectively improve soil properties and crop yield remain unclear. A five-year (2011–2016) field experiment in sub-humid, drought-prone areas of northwestern China with uneven rainfall distribution and irrigation was conducted to evaluate the effects of nitrogen fertilizer without straw mulching (CK), with regular straw mulching (LSM), and with ammoniated straw plowing (ALSP) on soil water, soil aggregates, soil organic carbon (SOC), total nitrogen (TN), and water use efficiency (WUE) in an annual winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) rotation system. The results demonstrate that ALSP had a greater soil water content than CK in the 0–60 cm soil layer. ALSP also had substantially more soil water than LSM in the 0–100 cm layer during the wet year (2011–2012) and two dry years (2014–2015 and 2015–2016). In the normal years (2012–2013 and 2013–2014), the soil water content in ALSP was significantly lower than in LSM in the 0–20 cm soil layer. ALSP was better able to alleviate soil drought in dry years and excessive humidity in wet years. Compared to CK, SOC in the 0–20 cm soil layer in 2016 increased by 8.3% in LSM and 11.7% in ALSP, and TN in the upper soil increased by 6.6% in LSM and 10.1% in ALSP. The equivalent wheat yield and WUE increased in ALSP by 15.6% and 17.5%, respectively, relative to CK, and by 6.79% and 5.97%, respectively, relative to LSM. Thus, we concluded that plowing ammoniated straw with N fertilization is a promising strategy for improving soil fertility and crop productivity in winter wheat–summer maize rotation systems in the sub-humid, drought-prone areas of northwestern China.

Variables related to soil fertility in successional agroforestry systems: Serras do Sudeste, RS, Brazil

Variables related to soil fertility in successional agroforestry systems: Serras do Sudeste, RS, Brazil

Effect of Low Molecular Weight Organic Acids and Liming on Phosphorus Adsorption in Acidic Tea Soils in the Black Sea Region, Türkiye

ABSTRACT Agricultural productivity is significantly hindered by the limited availability of phosphorus in acidic soils due to the presence of aluminum and iron phosphates. Soil liming is commonly employed to enhance soil fertility. However, modifying the pH might also impact the interactions involving existing soil organic matter, leading to changes in the effective concentrations of competing low-molecular-weight acids (LMWOACs) participating in phosphorus adsorption. This study explored the impacts of citric, oxalic, and malic acids in acidic soils from tea cultivation regions within the Eastern Black Sea. These soils had undergone various levels of liming and were incubated for 15 months to assess their effects on phosphorus (P) adsorption in 7 acidic soils. The experimental sorption data were utilized to calculate the soil Langmuir and Freundlich adsorption parameters. In addition, the influences of organic acids and liming levels on the Freundlich and Langmuir model parameters were subjected to ANOVA analysis. The findings indicated that citric acid demonstrated the highest efficiency in diminishing phosphorus adsorption among the tested organic acids, followed by oxalic and malic acids. Three carboxyl groups (−COOH) in citric acid facilitated the formation of more complexes with adsorbed phosphorus on the soil surface. Furthermore, the 100% LR ratio of liming notably decreased phosphorus adsorption, especially in the lower end of the isotherms. Therefore, it can be concluded that the combination of LMWOACs and liming treatments could be used to overcome P deficiency in acid soils with very high P sorption ability.

Repercussions of Prolonged Pesticide Use on Natural Soil Microbiome Dynamics Using Metagenomics Approach.

The residual pesticides in soil can affect the natural microbiome composition and genetic profile that drive nutrient cycling and soil fertility. In the present study, metagenomic approach was leveraged to determine modulations in nutrient cycling and microbial composition along with connected nexus of pesticide, antibiotic, and heavy metal resistance in selected crop and fallow soils having history of consistent pesticide applications. GC-MS analysis estimated residuals of chlorpyrifos, hexachlorbenzene, and dieldrin showing persistent nature of pesticides that pose selective pressure for microbial adaptation. Taxonomic profiling showed increased abundance of pesticide degrading Streptomyces, Xanthomonas, Cupriavidus, and Pseudomonas across the selected soils. Genes encoding for pesticide degrading cytochrome p450, organophosphorus hydrolase, aldehyde dehydrogenase, and oxidase were predominant and positively correlated with Bacillus, Sphingobium, and Burkholderia. Nitrogen-fixing genes (nifH, narB, and nir) were relatively less abundant in crop soils, correlating to the decrease in nitrogen-fixing bacteria (Anabaena, Pantoea, and Azotobacter). Microbial enzymes involved in carbon (pfkA, gap, pgi, and tpiA) and phosphorus cycle (gmbh and phnJ) were significantly higher in crop soils indicating extensive utilization of pesticide residuals as a nutrient source by the indigenous soil microbiota. Additionally, presence of antibiotic and heavy metal resistance genes suggested potential cross-resistance under pressure from pesticide residues. The results implied selective increase in pesticide degrading microbes with decrease in beneficial bacteria that resulted in reduced soil health and fertility. The assessment of agricultural soil microbial profile will provide a framework to develop sustainable agriculture practices to conserve soil health and fertility.

Effect of Different Approaches of Nutrient Application on Soil Quality Index Under Maize-Wheat Cropping System in Mollisol Region of Uttarakhand

ABSTRACT A field experiment was conducted at GBPUA&T, Pantnagar, to study the effect of different approaches of nutrient application on soil fertility and soil quality under maize-wheat cropping system. Nine treatment combinations were compared namely, Recommended Doses of Fertilizers (RDF), Soil Test Crop Response (STCR), and various combinations of organic and inorganic fertilizers. This paper aims to develop Soil Quality Index (SQI) based on Minimum Data Set (MDS) using Principal Component Analysis (PCA). Different indicators were employed to formulate the SQI, derived from surface soil layer measurements (0–15 cm). Each MDS indicator was then converted into a dimensionless score using linear scoring function and then integrated into SQI. Results showed that the key soil quality indicators identified as MDS using PCA under maize-wheat cropping system were Water Holding Capacity, organic carbon, available N and dehydrogenase activity. These soil quality indicators were found to be best for monitoring soil health status. After rabi wheat 2019–2020, SQI varied from 1.22 to 2.21 across the treatments whereas, after rabi wheat 2020–2021, SQI varied from 1.13 to 2.23 across the treatments. Among different approaches of nutrient application, STCR-based use of fertilizers along with FYM (T4) helped in maintaining better soil physical, chemical and biological properties and ultimately sustaining soil quality, which was followed by the treatment receiving 75% STCR dose of N (inorganic mode) + full P and K (T5). Integration of organics with inorganic fertilizers maintained soil quality, environmental health and reduced greater dependency on chemical fertilizers.

NZVI@BC as a Soil Amendment and Its Effects on Potted Rice Growth and Soil Properties

This study investigated the effects of nano zero-valent iron-modified biochar (nZVI@BC) as a soil amendment on potted rice growth, soil properties, and heavy metal dynamics. Seven treatments with varying amounts of soil conditioner, biochar, and nZVI@BC were applied to potted rice. Results showed that nZVI@BC application significantly improved rice agronomic traits, with the 15 g·kg−1 treatment increasing the panicle formation rate by 15% and 100-grain weight by 8% compared to the control. Soil fertility was enhanced, with available phosphorus increasing from 137 to 281 mg·kg−1 in the most effective treatment. Heavy metal analysis revealed that nZVI@BC application did not increase soil heavy metal content, with Cd levels remaining below 0.3 mg·kg−1 across treatments. Notably, the 10 g·kg−1 nZVI@BC treatment showed potential for slight Cd immobilization, reducing its concentration from 0.32 to 0.26 mg·kg−1. Microbial community analysis showed that nZVI@BC altered soil microbial diversity and composition, with the 10 g·kg−1 treatment resulting in the highest fungal diversity (Chao1 index: 294.219). The relative abundance of the beneficial fungal class Agaricomycetes increased from 40% to 55% with optimal nZVI@BC application. These findings suggest that nZVI@BC has potential as an effective soil amendment for improving rice cultivation while maintaining soil health, microbial diversity, and potentially mitigating heavy metal contamination.