Soil Chemical Properties Research Articles

Investigating the interaction Effect of Irrigation Water Quality and Type of Irrigation System on the Soil Physical and Chemical Properties under the Conditions of Using Treated Municipal Wastewater

Investigating the interaction Effect of Irrigation Water Quality and Type of Irrigation System on the Soil Physical and Chemical Properties under the Conditions of Using Treated Municipal Wastewater

Exploring Spatial Variability and Yield-Determining Factors in Cotton Production: A Multivariate Analysis

ABSTRACT The yield of cotton crops is severely affected by the soil’s chemical characteristics. This research probes the influence of soil properties on cotton yield, with a focus on assessing within-field spatial variability for advanced site-specific management in cotton production. Geostatistical analysis and semivariograms were conducted to examine the spatial variability of soil chemical properties. While multivariate analysis was employed to identify key yield-determining factors. Principal Component Analysis (PCA) was employed to explore leading soil indicators, as opposed to using a pre-defined set of indicators, and to analyze the spatial variability of soil properties. The soil characteristics encompassed saturation, soil pH, electrical conductivity (EC), organic matter (OM), phosphorous (P), potassium (K), calcium carbonate (CC), and micronutrients such as zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and boron (B). For this study, one thousand soil samples were meticulously collected from the Multan district, facilitated by Global Positioning System (GPS) devices. The PCA revealed that the first four PCs accounted for 57% of the total variation. The first PC, Cu, B, Mn, OM, and Fe emerged as the most influential variables, while the second PC exhibited a high correlation with CC, pH, and saturation. The third PC highlighted the dominant role of K and P in its construction, whereas the fourth PC was primarily shaped by Zn. The Principal Component Regression (PCR) analysis further revealed that EC, K, P, and Zn had positive impacts on cotton yield, while pH, Cu, Fe, Mn, and B had negative impacts.

Biochar and chicken manure improve soil chemical properties and nutritional status of rosewood seedlings grown in clay soil

Biochar and chicken manure improve soil chemical properties and nutritional status of rosewood seedlings grown in clay soil

PENGARUH REVEGETASI TERHADAP SIFAT-SIFAT TANAH PADA LAHAN BEKAS TAMBANG TEMBAGA DI NUSA TENGGARA BARAT

Copper mining activities mainly using open-pit techniques, lead to environmental issues such as overburden waste in waste dump areas that have potential to generate acid mine drainage (AMD), which can decrease soil pH and increase heavy metal toxicity. Reclamation efforts, including revegetation using pioneer plants and cover crops are necessary to restore degraded land in waste dump areas. The aim of this research is to analyze soil physical and chemical properties improvement after revegetation on copper post-mining land as an evaluation and to provide recommendations for future reclamation. The research was carried out by analyzing and interpreting laboratory data from soil observations in revegetation areas for the 2016, 2018, 2019 and 2020 planting years, as well as natural forests belonging to PT. Amman Mineral Nusa Tenggara. Revegetation of copper post-mining land does not show a significant improvement in soil physical properties because improving physical properties takes quite a long time, especially in post-mining areas with heavy structural damage. Soil chemical properties analysis shows that revegetation can increase base saturation (BS), cation exchange capacity (CEC), exch-Ca, exch-Mg, and reduce soil Al saturation. In contrast, soil pH, organic-C, total-N, and soil available-P in the revegetation area did not increase as the revegetation age increased. The effect of revegetation appears to be more significant at the age of 2 to 3 years. However, based on the Tukey test, the age of revegetation mostly does not have a significant effect on enhancing soil chemical properties.

Effect of blended NPS fertilizer and cattle manure on soil property and hot pepper productivity in Jabi Tehnan Ethiopia

Hot pepper is one of the most important spice vegetable crops in Ethiopia and is widely cultivated for dry pod production. However, its productivity is low in Ethiopia due to degraded soil fertility and an unbalanced nutrient supply in the soil. An experiment was conducted to evaluate the effect of NPS fertilizer and cattle manure (CM) on soil chemical properties and hot pepper dry pod yield under irrigation in Jabi Tehnan. This experiment was arranged in factorial combinations of four NPS fertilizer (0, 100, 200, and 300 kg ha−1) and four CM (0, 5, 10, and 15 t ha−1) levels in a randomized complete block design with three replicates. Soil chemical properties, hot pepper phenology, growth, yield, and yield-related traits were recorded and analyzed using SAS software version 9.4. The main and interaction effects of NPS and CM fertilizers had a significant effect on soil chemical properties, hot pepper phenology, growth, yield, and yield-related traits. The combination of NPS fertilizer and CM significantly increased soil chemical properties and hot pepper traits. However, soil chemical properties and hot pepper yield traits showed a somewhat decreasing trend as the combination levels of two fertilizers further increased. The highest marketable (2.90 t ha−1) and total dry pod yield (2.99 t ha−1) were produced at the combination of 200 kg NPS ha−1 and 15 t CM ha−1. However, the partial budget analysis showed that the combination of 200 kg NPS ha−1 and 10 t CM ha−1 had the highest net benefit with an acceptable MRR and can be recommended for profitable hot pepper dry pod production in the study area. However, the experiment was limited to a single location and variety; it should be repeated at multiple locations over the seasons to make a strong recommendation.

Physical and Chemical Properties of Soil of Different Villages of District Solan, Himachal Pradesh, India

The research was conducted to assess the physical and chemical properties of soils from twenty-one villages of Solan district, Himachal Pradesh within its geographical coordinates ranging from the latitude 30°44’53” to 31°22’01” N and longitude 76°36’10” to 77°15’14” E, during 2023-2024, India. The villages represent diverse landforms, including contour farming, plains, and slopes. Soil samples were collected from two depths, 0-15 and 15-30 cm, and analysed them using standard laboratory protocols. The predominant soil texture was sandy loam, bulk density ranges from 1.22 to 1.39 Mg m-3, particle density from 2.42 to 2.67 Mg m-3, and percent pore space varied between 40.50% and 46.68%, while the percent water holding capacity ranges from 37.65% to 45.53%. Soil pH ranged from 6.61 to 7.47. Electrical conductivity was measured between 0.18 and 0.34 dS m-1, indicating non-saline conditions. Organic carbon content was medium 0.30% to high 0.61%. The available nitrogen content ranged from 232.68 to 279.64 Kg ha-1, available phosphorus from 37.23 to 64.54 Kg ha-1, and available potassium from 262.14 to 365.34 Kg ha-1. These findings provide valuable insights into the soil health of the region, with implications for agricultural practices and land management.

The influence of soil types and agricultural management practices on soil chemical properties and microbial dynamics

Soil provides essential nutrients for plant growth, but excess salts hinder development, making crops more vulnerable under climate change conditions. Soil microorganisms play a significant role in nutrient cycling. However, limited information is available on microbial behavior/community changes, and functional diversity in different soil types (normal, sodic, and highly sodic) and cropping systems [rice-wheat (RW); rice-wheat-mungbean (RWMb); maize-wheat-mungbean (MWMb)] and management practices in the north-western Indo-Gangetic Plains of India. We investigated the influence of different soil types on physical and chemical properties at the surface level (0–15 cm) in relation to soil microbial population, activities, and functional diversity, focusing on community-level physiological profiling (CLPP) under different agriculture systems. Seven treatment combinations of soil types, cropping systems, and management practices were evaluated. Soil pHs were found to be lower in zero-till (ZT)-based sodic soil than in conventional-till (CT) sodic soil. Soil organic carbon (SOC) (0.91 and 0.90%) content and available N (154.46 and 132.74 kg ha−1) were higher with the ZT-based system under normal (N) soils (ZT-RWMb-N and ZT-MWMb-N) than in CT-based normal soil (0.67 and 121.04 kg ha−1). Similarly, higher SOC and N (0.85 and 76.11 kg ha−1) were found under ZT management in sodic soils (S) than under CT management (0.73% and 121.05 kg ha−1). Substrate utilization (amino acids, amines, carbohydrates, carboxylic acids, phenolic compounds, and polymers) increased with the incubation period. During 0–120 h of incubation, the highest utilization of amino acids, amines, carboxylic acids, phenolic compounds, and polymers was observed for ZT-MWMb-S soils, while the lowest was recorded for ZT-MWMb-N soils. Under high salt conditions, soil enzymatic activities (dehydrogenase, acid phosphatase, alkaline phosphatase, etc.) declined significantly compared to normal soils, affecting soil chemical and physical conditions. Microbial population and enzyme activities decreased with increasing salt stress across all cropping systems. These findings suggest that adopting efficient crop management practices can help mitigate the adverse effects of soil salinity on microbial diversity and soil health, thereby enhancing sustainable agricultural productivity in salt-affected regions.

Chemical and micronutrients assessment in Himalayan Foothill highway soil surface

This study examines the chemical properties and micronutrient concentrations of roadside soil in the ecologically sensitive Himalayan foothills of Uttarakhand, India. The primary objective is to assess soil contamination levels and their implications for urban ecosystem services. Soil samples from 13 locations were systematically collected, processed, and analyzed using atomic absorption spectrophotometry. Results indicated average concentrations of Zn, Cu, Fe, Mn, and Ni at 9.94, 3.28, 24.32, 17.35, and 0.28 mg/kg, respectively. Significant variations in soil chemical properties and micronutrient levels (p < 0.05) were observed across different sites, excluding phosphate levels. These findings underscore the critical need for targeted environmental management strategies to mitigate soil contamination and preserve vital ecosystem services in urbanized regions. The data provided can guide administrators in developing policies that promote sustainable development and environmental resilience.

Impacts of climate-smart soil and water conservation practices and slope gradient on selected soil chemical properties in Eastern Ethiopia: A case study of the Kulkullessa Sub-watershed, Goro Gutu District

The productivity and sustainability of agricultural systems are heavily influenced by soil fertility and physicochemical properties. This study investigated the effects of climate-smart soil and water conservation (SWC) practices and slope gradient on selected soil physicochemical properties and soil organic carbon stock (SOCS) in the Kulkullessa Sub-Watershed of Goro Gutu District, Eastern Ethiopia. The research focused on farmland conserved by stone bunds (SB), bench terraces (BT), and grass strips (GS) five years post-implementation, across two slope gradients (15-20% and 21-30%). Twenty-four composite soil samples were collected from a depth of 0-20 cm and analyzed at the Haramaya University soil laboratory. Results demonstrated that climate-smart SWC practices significantly improved soil physicochemical properties and SOCS in the study area. Slope gradients also induced considerable variations in these parameters. Conserved farmland and areas with lower slope gradients exhibited higher clay content and lower sand fractions. Bench terraces were associated with lower bulk density (BD) and significantly higher total porosity (p ≤ 0.05). Conserved farmlands showed higher electrical conductivity (EC) and lower pH values, both statistically significant (p ≤ 0.05). Stone bunds were most effective in increasing soil organic matter (SOM) content and total nitrogen (TN). Climate-smart SWC practices also enhanced exchangeable bases in the farmlands. Cation exchange capacity (CEC) was significantly improved (p ≤ 0.05) on farmland conserved by SB and BT. In conclusion, climate-smart SWC practices demonstrated substantial potential for improving agriculturally and environmentally relevant soil physicochemical properties and organic carbon stocks. These findings underscore the importance of such conservation measures in enhancing soil quality and promoting sustainable agriculture in the region.

TEKNOLOGI REKLAMASI LAHAN BEKAS TAMBANG TIMAH MELALUI PEMBERIAN BAHAN AMELIORAN DAN PEMILIHAN JENIS TANAMAN: STUDI KASUS KEPULAUAN BANGKA BELITUNG

Indonesia, besides being the country with the largest nickel reserves in the world, also holds the largest tin reserves globally in 2023. Meanwhile, in terms of production, Indonesia ranks second after China. Tin mining in Indonesia has led to serious environmental damage, illustrated by the numerous open pits and inadequately restored tin mining sites. The characteristics of soil in these post-mining lands generally include sandy texture, low pH, nutrient deficiencies, low organic carbon content, and low water holding capacity. This study aims to improve the soil chemical properties in post-mining lands by utilizing the KOMFABA technology, which consists of a mixture of compost and fly ash-bottom ash with appropriate dosages tailored to the type of crops to be planted, along with revegetation strategies involving suitable plant selections. The research methodology consists of field experiments to test the application of KOMFABA with various dosages and crop types, as well as a literature review to identify suitable revegetation strategies. The research result show that Indonesia holds tin reserves of 800,000 tons, making it the largest in the world, with a production of 74,000 tons, placing it second after China. Additionally, the results of KOMFABA testing demonstrate its effectiveness in improving soil chemical properties such as soil pH, organic carbon content, cation exchange capacity (CEC), nutrient content, and soil base saturation. The success of reclaiming post-mining lands also dependent on proper fertilization dosages and suitable plants selection.

Soil Fertility Level In The Aek Kundur River Area Regardless Of Factory Waste Disposal

Soil fertility is the ability of the soil to provide the nutrients needed by plants in adequate quantities and in a form that can be absorbed by plant roots. The aim of this research is to determine the level of soil fertility in the Aek Kundur river area regarding factory waste disposal in Lingga Tiga Village, District. West Bar. This research was carried out in June 2024 in Lingga Tiga Village, Bilah Hulu District, Labuhanbatu Regency with an altitude of 28 meters above sea level with coordinates N: 98022'44.34" E: 02032'34.23". Analysis of the physical and chemical properties of soil was carried out at the Laboratory of the Faculty of Agriculture, University of North Sumatra using an exploratory-descriptive survey method. Research results on the physical properties of the soil in Lingga Tiga Village have a clayey clay texture and in Liga Tiga Village have a clay texture. Furthermore, the chemical properties of the soil in Lingga Tiga Village have criteria, namely neutral pH, low organic C, moderate P2O5 and low soil fertility status in the Aek Kundur river area against factory waste disposal. For this reason, fertilization treatment is needed to improve soil fertility status.

Effect of Nitrogen on Microbial Communities of Purple Mudstone Weathering Products in Southwest China: A Column Experiment.

Nitrogen application significantly affects microorganisms in agricultural ecosystems. However, it is still unclear how nitrogen application affects soil chemical properties and microbial communities in purple mudstone weathering products. In this study, a field soil column experiment was conducted in a typical purple soil area with four nitrogen fertilizer application gradients of 0 [CK], 280 [N1], 560 [N2], and 840 [N3] N kg ha-1. Nitrogen addition decreased the bacterial chao1 value and increased the bacterial evenness index. For both α- and β-diversity, the effect of nitrogen addition on bacteria was much greater than that on fungi. Nitrogen addition significantly increased the relative abundance of Proteobacteria, Gemmatimonadetes, Bacteroidetes, and Ascomycota and decreased the relative abundance of Actinobacteria, Cyanobacteria, and Basidiomycota. Both pH and TC are the most important soil chemical properties influencing the bacterial and fungal communities. With the increases in the nitrogen application rate, the co-occurrence network complexity increased and then decreased. In summary, nitrogen fertilizer application could significantly change the soil chemical properties, microbial community diversity, composition, and co-occurrence network of purple mudstone weathering products. Among them, the N2 treatment (560 N kg∙ha-1) can more effectively stimulate the soil nutrients, enhance microbial network complexity, and promote further weathering of purple mudstone.

Changes in the taxonomic composition of soil bacterial communities under different inter-row tillage managements in a sloping vineyard of the Balaton Uplands (Hungary).

The common grape (Vitis vinifera L.) has been cultivated for thousands of years. Nowadays, it is cultivated using a variety of tillage practices that affect the structure of the soil microbial communities and thus the health of the vine. The aim of this study was to explore and compare the effects of tillage (shallow tillage with bare soil) and no-tillage (perennial grass cover) practices on soil physical and chemical properties and soil bacterial community diversities in a small catchment. Soil samples were taken in July and October 2020 at different slope positions of two vineyards exposed to erosion. The two sampling sites were separated by the agricultural inter-row management type: tilled and no-tilled slopes. The taxonomic diversity of bacterial communities was determined using 16S rRNA gene-based amplicon sequencing method on Illumina MiSeq platform. Based on the examined soil properties, the sampling areas were separated from each other according to the positions of the upper and lower slopes and the sampling times. Both the tilled and no-tilled soil samples were dominated by sequences assigned to phyla Pseudomonadota, Acidobacteriota, Bacteroidota, Verrucomicrobiota, Actinobacteriota, and Gemmatimonadota. The results showed that tillage had no significant effect compared to the no-tilled samples in the studied area. Water runoff and seasonally changed soil physical and chemical properties affected mainly the bacterial community structures.

Geochemistry and microbiology of boreal alluvial soil under salinisation

Soil salinisation in taiga landscapes is in most cases caused by anthropogenic activities. The study was carried out in Perm region (Russia) on the territory of the Verkhnekamskoe Potash Deposit. The inflow of sodium chloride drainage water into ground and surface waters during the production of potash fertilisers contributed to the technogenic salinisation of river valleys in the taiga zone. The purpose of the research was to investigate the microbial composition and chemical properties of alluvial soils in the area affected by NaCl waters in the Lyonva River valley. The chemical properties of soils were determined standard methods such as potentiometric method, titration, and spectrophotometry. The microbial community was determined by 16 s rRNA gene metagenomic analysis. The soil's mineralogical composition was determined using a binocular microscope and diffractometer for XRD. The morphology and microstructure of the samples has been studied using an analytical scanning electron microscope. In Solonchaks, an interdependence of salinity and bacterial species composition was discovered, along with the bacteria's geochemical processes. The topsoil contains a considerable amount of toxic salts, ranging from 5.9 to 17%. The ratio of exchangeable cations in the soil absorption complex changes when exchangeable calcium is replaced by sodium. Salinisation caused the neutralisation of acidic alluvial soils. Bacteria originating from marine and highly mineralised environments predominate in the soil. The soils are dominated by bacteria originating from marine and highly mineralised environments, such as Proteobacteria, Shewanella (75–79%), Thiomicrospira (26%), Desulfuromonas, Marinomonas and Idiomarina (9–10%), Alicyclobacillus (4%). The correlation revealed the connection of some taxa with ions of aqueous extract, as well as with exchangeable sodium, mobile iron and total sulphur. Some bacteria promote azonal geochemical processes within alluvial forest soil, such as the reduction of iron and manganese, the production of sulphides, and the oxidation of sulphur, hydrogen, and iron. Sulphide accumulation resulting in the formation of a hydrotroilite horizon (FeS × nH2O) and iron-bearing formations were found on the soil surface. Studying the properties and degree of soil disturbance makes it possible to identify the contribution of enterprises to environmental pollution, as well as to apply new methods for monitoring, purifying, and storing potassium waste.

Vermicompost Effects on Soil Chemistry and Biology: Correlations with Basil's (Ocimum basilicum L.) Total Phenolic Content and Phenological Traits

This study explores the effects of vermicompost on the chemical and biological properties of soils, their nutrient content, and the impact on the growth and phenolic content of basil (Ocimum basilicum L.). Using a controlled experimental setup, we tested five dosages of vermicompost (0%, 4%, 12%, 20%, and 24%) to evaluate their influence on soil biological activity by measuring basal respiration (CO2-C), microbial biomass C (MBC-C), and dehydrogenase enzyme activity (DHA) as well as on basil's growth parameters and total phenolic content (TPC). The results show that vermicompost addition to soil enhanced soil microbial activity in direct proportion to the dose of vermicompost. The application of lower dosages of vermicompost (4% and 12%) significantly enhanced both fresh and dry weights, suggesting an improvement in nutrient uptake and soil structure, which likely facilitated better root growth and nutrient absorption. However, higher dosages (20% and 24%) were associated with reduced growth metrics, likely due to nutrient overload or salt stress. Notably, the highest vermicompost concentration (24%) led to a substantial increase in total phenolic content (TPC) in basil leaves, correlating with decreased growth metrics. This response indicates the plant's defensive mechanism against oxidative stress caused by excess nutrients or salinity from the vermicompost. A multiple regression analysis following a correlation analysis also revealed an inversely proportional relationship between phosphorus content in the soil and total phenolic content in basil leaves. Our findings illustrate that while moderate vermicompost dosages optimize plant growth and health, higher concentrations can strategically enhance phenolic content due to nutrient overload or salt-induced stress. These results offer critical insights for tailoring organic amendment applications to balance plant growth and biochemical properties in agricultural practices.

The Impact of Agricultural Land Use on Some Chemical Properties of Desert Soils in the Holy Karbala Governorate

The Impact of Agricultural Land Use on Some Chemical Properties of Desert Soils in the Holy Karbala Governorate

Characterization and detailed mapping of C by spectral sensor for soils of the Western Plateau of São Paulo

Soil mineralogy and texture are directly related to soil carbon due to the physical properties of the clay surface. Traditional techniques for quantifying carbon in soil are time-consuming and expensive, making large-scale quantification for mapping unfeasible. The alternative is the use of soil sensors, such as diffuse reflectance spectroscopy (DRS), an economical, fast, and accurate technique for predicting carbon stocks. In this sense, this study aimed to (a) investigate the relationship of C with different soil mineralogical, chemical, and physical attributes for different geological and geomorphological compartments; (b) understand which spectral bands are most important for estimating C content; (c) estimate C content from diffuse reflectance spectroscopy using different mathematical techniques and indicate which one is the best for tropical soil conditions; and (d) map C contents in detail. The study area was the Western Plateau of São Paulo (WPSP), which covers approximately 13 million hectares (~ 48% of the State of São Paulo, Brazil). A total of 265 samples were collected in this area. The attributes clay, silt, sand, crystalline and non-crystalline iron, base saturation, soil density, total pore volume, total C, C stock, kaolinite/(kaolinite + gibbsite) and hematite/(hematite + goethite), hematite and goethite contents, and spectral curves were evaluated. The spectra were recorded at 0.5-nm intervals, with an integration time of 2.43 nm s−1 over the 350 to 2500-nm range (350–800 nm—visible—VIS and 801–2500 nm—near-infrared—NIR). The data were subjected to descriptive statistics, Spearman correlation, stepwise analysis, and cluster grouping for characterization purposes; partial least squares regression (PLSR) and random forest (RF) for estimation purposes; and geostatistics analysis for creation of spatial maps. Our results indicate that the highest C contents are associated with more clayey soils, oxidic mineralogy, higher total pore volume, and lower soil density in highly dissected basalt compartments. The random forest algorithm associated with the Vis–NIR spectral range is more efficient for estimating and mapping C contents. This suggests that integrating diffuse reflectance spectroscopy with machine learning techniques holds promise for shaping public policies related to land use, mitigating CO2 emissions, and facilitating the implementation of carbon credit policies in a rapid and economically efficient manner.

Enterobacter cloacae Rs-2 inoculum replaces fertiliser application by half in the field and modifies microbial community structure

Using microbial inoculant partial substitution synthetic fertilizer is a new type of environmentally friendly way to significantly improve the corps production and ecological environment. The effects of supplementing Enterobacter cloacae Rs-2 with synthetic fertilizer on the maize growth and soil microbial community diversity in field were investigated in this paper. The optimal fermentation conditions were determined as 5 g·L−1 industrial glucose, 30 g·L−1 industrial peptone, 1 g·L−1 MgSO4 and 0.5 g·L−1 KCl firstly. Field experiment showed that the fresh weight of shoots and roots was increased by 39.69% and 32.46% when half synthetic fertilizer was replaced by microbial inoculant. The soil physical and chemical properties were also greatly improved, especially the contents of available phosphorus, water-soluble calcium and alkali-hydrolyzed nitrogen were significantly increased in T4 (Rs-2 and half chemical fertilizer) and full chemical fertilizer treatment. This result was accompanied by increased the relative abundance of genes related to phospholipid metabolism, phosphotransferase system (PTS) and oxidative phosphorylation metabolism, indicating that Rs-2 may play an important role in the transformation and utilization of phosphorus in soil. The richness, dominance of Proteobacteria, Enterobacteriaceae in the microbial communities were further improved when the microbial inoculant applied. Function prediction PICRUSt analysis indicated that amines and amino acids were the most representative of the total carbon source utilization by the soil microbial communities. It was concluded that the application of 50% of the synthetic fertilizer supplemented with 30 mL microbial inoculant enhanced both the functional diversity of soil microbial communities and maize yield.

Effect of phosphorus and zinc application on zinc transformation and phyto-availability of zinc fraction in rice soil

Application of high dose of phosphorus (P) changes the soil chemical properties which may lead to redistribution of Zn fractions in soil. A field experiment was conducted to study the effect of added zinc (Zn) and P on Zn transformations in a New Alluvial soil (Aeric Haplaquept), together with dry matter yield and Zn uptake by rice plants. The treatments included four levels of P (0, 40, 60, and 80 kg ha−1) and three levels of Zn (0, 5, and 10 kg ha−1). Although P application increased the dry matter yield of rice, Zn concentration and uptake was decreased significantly at higher dose of P application. Application of P caused a decrease in all the fractions of soil Zn except amorphous and crystalline Fe-oxide bound zinc. The order of preponderance of different zinc fractions followed the order, water soluble plus exchangeable (WE-Zn) < carbonate bound (Car-Zn) < organically bound (Org-Zn) < manganese oxide (MnOx-Zn) < crystalline sesquioxide (CFeOx-Zn) < amorphous sesquioxide (AFeOx-Zn) < residual Zn (Res-Zn). Residual Zn was the most dominant form of Zn, contributing about 69.07% to total Zn. Correlation data indicated that those fractions are in a state of dynamic equilibrium among different fractions and governs the plant-available Zn in soil. Path coefficient analysis of different Zn-fractions with Zn-uptake in rice plant showed that among the all pools of Zn, Org-Zn fraction plays the most vital role in contributing to Zn uptake by plants.

Dairy effluent applications to a pasture enhance soil fertility and microbial activity without impacting soil bacterial and fungal community composition

Farm dairy effluents (FDE) from washing the milking parlor contain manure, urine, and chemicals and constitute a large amount of wastewater. Applying FDE as soil fertilizers to pastures can enhance forage yield and improve soil nutrient status. Since the dairy industry is increasingly attempting to maximize returns through better utilization of forage with lesser inputs, there is demand for a supply of FDE as fertilizers. Nevertheless, the impact of this practice on soil microbiota remains largely unexplored. It must be studied before large-scale soil disposal to avoid diminishing microbial diversity or enhancing pathogen abundance. This study evaluated the effects of applying lagoon-stored (Lagoon) and raw dairy effluents (Raw) at a rate of 50 kg N ha−1 in four equal doses, in comparison to urea fertilization, on soil fertility and the activity, abundance, and community structure of soil microbiota. Raw was obtained after solid separation, and Lagoon corresponds to the Raw stationed in a two-lagoon system. Microbial activity was assessed as basal respiration, potentially mineralizable N, potential nitrification activity, and enzymatic activities. The catabolic activity of the microbial community was evaluated using Biolog Ecoplates™. Bacterial and fungal community composition and diversity were analyzed through amplicon sequencing of 16S rRNA and ITS2. The application of FDE benefited soil fertility and microbial activity. Lagoon had the most potent effects on soil available P and extractable K+, Na+, Mg2+ and Ca2+. Soil treated with Raw displayed higher microbial activities, such as dehydrogenase, basal respiration, urease, and potentially mineralizable N, than the other treatments. FDE did not significantly alter the microbial composition, abundance, or functional diversity. In conclusion, in this short-term trial, despite changes in soil chemical properties and microbial activity, the composition and diversity of the bacterial and fungal communities remained unaffected by FDE irrigation.