Soil Nutrient Status Research Articles

Assessment of nutrient status, macro faunal diversity and microbial isolates in date palm plantation in Damaturu Yobe State, Nigeria

This research assessed nutrient status, macro-faunal diversity and microbial isolates in the soil of date palm plantation in Mai Sandari Damaturu, Yobe State. Parameters evaluated include; data on nutrient status of soils, assemblage and diversity of soil macro invertebrates and assemblage of microbial isolates based on growth performances of the date palm. The plantation was divided according to growth variabilities. Eighteen (18) auger points were taken, six (6) in each performance site based on the corresponding variability as observed. Soil samples were collected within same points for physicochemical analysis, microbial isolates and for soil macro-invertebrates ‘identification and enumeration. One-way Analysis of Variance (ANOVA) was used to compare results of nutrient status of soils and to test for significant differences in nutrient concentration of the soils samples, mean separation was done using Least Significant Difference (LSD). Soil macro-invertebrate assemblage was analyzed for diversity indices of species using relevant formulae. Nutrient agar medium at 105 dilutions inoculated in a petri-dishes and incubated at 30±10°C for 2-5 days for bacteria colonies, while for fungi and actinomycetes, sabaurond dextrose agar was used at 25°C for 5-7 days and afterward microorganisms per colony forming units (Cfu) were counted. Analysis of variance for the soil parameters tested at p≤ 0.05 level of significance showed no significant differences in all the parameters of soil physical properties based on growth performance sites. However, organic carbon, organic matter and TN vary significantly after the post-hoc tests across growth performance sites in chemical properties (p ≤ 0.05). Results showed a total of 2646 macro fauna scattered within the study area. Eleven (11) families of macro fauna were also identified in the study. Results from the study area showed that the area is highly rich in microorganisms. A total of 5096 colonies were scattered within 10 families in the study area. The finding of this study revealed that there was no significant difference among the physical properties across the study site leading to the conclusion that soil physical properties may not have been responsible for the observed differences in the growth of the Date Palm Plantation. A different pattern was however observed in the values of the chemical properties of the plantation where significant differences exist in organic carbon, organic matter and total nitrogen across these sites. Based on the findings of the study it is recommended that all application of agrochemicals except fertilizers in the plantation should be suspended until evidence of their efficiency on the palm trees is shown.

Growth, yield, andrographolide content and total antioxidant activity of Kalmegh [Andrographis paniculata (Burm. f.) Wall. ex Nees] under variable nitrogen rates and organic manures application in Indo-Gangetic plains of India

Kalmegh is an important medicinal crop because of the most important biologically active phyto-chemical called andrographolide. Production of higher herbage yields with appropriate quality in terms of andrographolide is largely dependent upon efficient nutrient management. This study aimed to assess the effect of organic manures application and variable nitrogen rates on growth, yield, andrographolide content and total antioxidant activity of Kalmegh. The experiment was laid out in split plot design with three levels of organic manures [M1- Control, M2- vermicompost @ 5 t ha−1 and M3- poultry manure @ 5 t ha−1] and four fertility levels [F1- 0: 50: 50, F2- 50: 50: 50, F3- 75 (37.5 + 37.5): 50: 50 and F4- 75: 50: 50 kg ha−1 N, P2O5 and K2O, respectively] replicated thrice. The highest dry herbage yields and andrographolide content of kalmegh were recorded with vermicompost @ 5 t ha−1 + 75 (37.5 + 37.5): 50: 50 N, P2O5 and K2O kg ha−1 followed by poultry manure @ 5 t ha−1 + 75 (37.5 + 37.5): 50: 50 N, P2O5 and K2O kg ha−1 during both the years while, lower yields due to control. Dry herbage and andrographolide yield were found to be highest in M2×F3 compared with M1×F1. Our study concluded that the application of vermicompost @ 5 t ha−1 along with 75 kg ha−1 N in two splits and 50 kg ha−1of each P2O5 and K2O resulted higher yield and andrographolide content which, would provide better soil nutrient status in sustainable manner without affecting ecological balances.

The Influence of Integrated Nutrient Management on Major Nutrient Status and Physico-chemical Properties of Soil in Quinoa (Chenopodium quinoa Willd.)

The Influence of Integrated Nutrient Management on Major Nutrient Status and Physico-chemical Properties of Soil in Quinoa (Chenopodium quinoa Willd.)

Farm dairy effluent application

Dairy intensification produces a large amount of farm dairy effluents (FDE). The final disposal of FDE is generally to the soil as fertilizer. While this use of FDE as fertilizer has numerous benefits, such as reducing the application of synthetic fertilizers or improving soil quality, there are concerns about the environmental and health risks associated with microbial pathogens from animal waste, the spread of antibiotic resistance genes, nutrient losses and greenhouse gases (GHG) emissions. Furthermore, how this agricultural practice impacts the composition and functionality of soil microbial communities has not yet been elucidated. This thesis aimed to evaluate the impact of FDE applications on soil GHG emissions, the composition, activity and diversity of its microbial community, and health risks. The FDE were collected raw and from a two-stage stabilization lagoon. The N application rate normalized to 200 kg N ha−1 was divided into four seasonal applications compared to urea fertilization or a no-aggregate control. Soil samples were taken after each application for microbial and physicochemical characterization and GHG fluxes were measured up to twenty days after each application. The pasture was harvested according to typical grazing management. Repeated application of both types of FDE increased the soil nutrient status and enhanced microbial activity. Higher fescue pasture production and macronutrient content with FDE than the control positioned FDE application to soil as an alternative disposal. However, N2O emissions increased after applying both FDE’s, most notably with raw FDE. Soil microbial community composition was not significantly influenced by FDE applications, but functional diversity shifted with raw FDE. Lagoon storage effectively reduced organic C and total N along with pathogenic indicator bacteria and changed the bacterial community composition except in winter. Beta-lactam resistance genes were detected in both FDEs, but not in the soil after repeated applications.

Effect of biochar amendment on bacterial community and their role in nutrient acquisition in spinach (Spinacia oleracea L.) grown under elevated CO2

Global climate change is anticipated to shift the soil bacterial community structure and plant nutrient utilization. The use of biochar amendment can positively influence soil bacterial community structure, soil properties, and nutrient use efficiency of crops. However, little is known about the underlying mechanism and response of bacterial community structure to biochar amendment, and its role in nutrient enhancement in soil and plants under elevated CO2. Herein, the effect of biochar amendment (0, 0.5, 1.5%) on soil bacterial community structure, spinach growth, physiology, and soil and plant nutrient status were investigated under two CO2 concentrations (400 and 600 μmol mol−1). Findings showed that biochar application 1.5% (B.2.E) significantly increased the abundance of the bacterial community responsible for growth and nutrient uptake i.e. Firmicutes (42.25%) Bacteroidetes (10.46%), and Gemmatimonadetes (125.75%) as compared to respective control (CK.E) but interestingly abundance of proteobacteria decreased (9.18%) under elevated CO2. Furthermore, the soil available N, P, and K showed a significant increase in higher biochar-amended treatments under elevated CO2. Spinach plants exhibited a notable enhancement in growth and photosynthetic pigments when exposed to elevated CO2 levels and biochar, as compared to ambient CO2 conditions. However, there was variability observed in the leaf gas exchange attributes. Elevated CO2 reduced spinach roots and leaves nutrient concentration. In contrast, the biochar amendment (B2.E) enhanced root and shoot Zinc (494.99%–155.33%), magnesium (261.15%–183.37%), manganese (80.04%–152.86%), potassium (576.24%–355.17%), calcium (261.88%–165.65%), copper (325.42%–282.53%) and iron (717.63%–177.90%) concentration by influencing plant physiology and bacterial community. These findings provide insights into the interaction between plant and bacterial community under future agroecosystems in response to the addition of biochar contributing to a deeper understanding of ecological dynamics.

The influence of shade tree species and coffee varieties on selected soil physicochemical properties in coffee-based farming system of southwestern Ethiopia

Different shade tree species are used in various coffee production systems across the world. Outside the benefits of biodiversity protection, temperature protection, and carbon sequestration shade trees can influence soil nutrient states through litter inputs and nitrogen fixation. However, little information is available in coffee plantations whether shade tree species and type of coffee variety planted under shade tree have an influence on soil physical properties and nutrient status in coffee-based farming systems of southwestern Ethiopia. Hence, the study was carried out to investigate the effect of shade tree species and coffee varieties in coffee plantation on the physicochemical properties of the soil. The study was conducted in Chora Botor district (Chalalaki coffee plantation), located in Jimma Zone, Oromia regional states of Ethiopia. The study was superimposed on coffee farm that has been established using four released coffee varieties (7440,744, F59 and 75227) under three recommended coffee shade trees (Albizia gummifera, Millettia feruginea and Acacia abyssinica). Soil physical properties and nutrient status were investigated in response to shade tree species, coffee varieties and their combination. The results indicated that the physical and chemical properties of the soil vary across the shade trees and coffee variety grown. The effect of shade tree species on soil depends on the type of coffee varieties grown under the shade tree species, Albizia gummifera and Acacia abyssinica trees enhanced more soil nutrient content and water-holding capacity of the soil than Millttia ferrugnia. Total nitrogen, organic matter, available phosphorous, exchangeable potassium, Cations Exchange Capacity, and bulk density were higher underneath Albizia gummifera than other coffee shade tree species. On the other hand, moisture content, available P, exchangeable K and CEC were higher beneath Acacia abyssinica than other coffee shade tree species. Soil pH was negatively correlated with Millettia ferruginia. Use of Acacia abysinica and Albizia gummifera shade tree species with compatible coffee varieties could be a viable option to augment soil fertility management practices in the coffee production systems of the southwest Ethiopia.

Characteristics of inter-root soil bacterial community structure and diversity of different sand-fixing shrubs at the southeastern edge of the Mu Us Desert, China

PurposeThis study aimed to investigate the effects of different shrub plants on the structure and diversity of inter-root soil bacterial communities, in order to provide scientific support for ecological restoration and revegetation of the Mu Us Desert.MethodsThree major shrub plants (Artemisia ordosica, Salix psammophila, Caragana microphylla) in the Mu Us Desert were selected for this study. Using high-throughput sequencing technology, the bacterial community structure and diversity in the inter-root soils of these plants were analysed in depth, and combined with the determination of soil physicochemical and microbiological properties, the response characteristics of the bacterial diversity in the inter-root soils of the different plants were assessed comprehensively.ResultsIt was found that although the soil pH did not show significant differences among different plant growths, the SOC, TN and TP contents were higher in Salix psammophila sample plot and Artemisia ordosica sample plot, which indicated that the plant growths had a positive effect on the soil nutrient contents. Through Venn diagram analysis, it was observed that the number of OTUs of bacteria in the soils of different shrubland sites varied, and all of them were higher than those in the soils of the sample sites where no plants grew, which indicated that plants had an effect on soil bacterial diversity. The bacterial Chao1 index were higher in the Artemisia ordosica sample plot sample site, suggesting that the growth of Artemisia ordosica contributes to the enhancement of soil bacterial richness. Soil bacterial communities showed compositional differences among different sample plots, especially the higher relative abundance of Betaproteobacteria in the Artemisia ordosica sample plot sample plot, which may be related to the increase of soil organic matter content.ConclusionThe results of the study revealed that specific plants, such as Artemisia ordosica, can significantly improve the soil nutrient status of windy sandy soils, increase soil organic matter and nitrogen content, and thus enhance the diversity and abundance of soil microorganisms. The bacterial community structure in the inter-root soils of different plants differed significantly, with changes in the relative abundance of the dominant phyla, such as Alphaproteobacteria, Betaproteobacteria and Actinobacteria, reflecting the differences in soil nutrient status. These findings emphasise the important role of plants on soil chemical properties and microbial community structure, providing an important basis for soil management and ecological restoration.

Prairie soil improves wheat establishment and accelerates the developmental transition to flowering compared to agricultural soils.

Less than 1% of native prairie lands remain in the United States. Located in eastern Washington, the rare habitat called Palouse prairie was largely converted to wheat monocropping. With this conversion came numerous physical, chemical, and biological changes to the soil that may ultimately contribute to reduced wheat yields. Here, we explored how wheat (Tritcum aestivum L.) seedling establishment, plant size, and heading, signifying the developmental transition to flowering, were affected by being planted in prairie soil versus agricultural soils. We then sought to understand whether the observed effects were the result of changes to the soil microbiota due to agricultural intensification. We found that prairie soil enhanced both the probability of wheat seedling survival and heading compared to agricultural soil; however, wheat growth was largely unaffected by soil source. We did not detect effects on wheat developmental transitions or phenotype when inoculated with prairie microbes compared with agricultural microbes, but we did observe general antagonistic effects of microbes on plant size, regardless of soil source. This work indicates that agricultural intensification has affected soils in a way that changes early seedling establishment and the timing of heading for wheat, but these effects may not be caused by microbes, and instead may be caused by soil nutrient conditions.

Effects of organic amendments on crop production and soil fauna community in contrasting Zambian soils

AbstractThe use of organic materials has been widely promoted to improve soil health. Surface‐active soil macrofauna serves as a key biological indicator of soil health as it supports agricultural productivity. However, the effects of organic amendments on soil fauna and their relationships with crop production are still unknown in C‐limited soil conditions. A field experiment was conducted under different fertilizer management in two soils with contrasting C content (14.2/5.1 g C kg−1 at the Lusaka/Kabwe site) in Zambia. Our results show a contrast in soil fauna abundance in two soils. During the experimental period, we collected a total of 926 individual soil fauna in all plots at the Lusaka site, while only 145 individual soil fauna were collected at the Kabwe site. Soil fauna was predominantly composed of Araneae, Coleoptera, Dermaptera, Diplopoda, and Orthoptera. Organic amendments significantly increased soil fauna abundance only at the Lusaka site, and the abundance of Coleoptera and Diplopoda was highly related to the crop yield. At the Kabwe site, the effect of organic amendment on soil fauna abundance was minimal, although significantly higher crop yields were observed in soils with organic amendment. These contrasting results may be due to soil nutrient and water status between different sites. Our findings suggest that site‐specific strategies are required to protect and enhance soil fauna communities in C‐depleted soils.

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 < 0.01) and P (r = 0.776, p < 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.

Plant traits mediate foliar uptake of deposited nitrogen by mature woody plants.

Increased atmospheric nitrogen (N) deposition significantly disturbs ecosystem N cycle. Although foliar interception and uptake of N deposition can provide an important alternative N supply to forest ecosystems, the mechanisms regulating foliar N uptake from wet deposition are not fully understood. Here, we selected 19 woody species with a wide range of plant traits from different functional groups and conducted a 15N isotope labelling experiment through brushing 15NH4 + and 15NO3 - solution on canopy leaves. Our findings demonstrate that leaves can directly absorb N from wet deposition within a few hours. The average leaf 15N recoveries were 10% and 28% under 15NH4 + and 15NO3 - treatments across species, respectively, while twig N recoveries were only 1%-7% of leaf N recoveries. Differences in foliar N uptake efficiency among species were closely associated with leaf traits but were little influenced by meteorological conditions or soil nutrient status. Specifically, plants with higher leaf N concentration, larger specific leaf area and lower wax concentration exhibited higher leaf N recovery. Our results indicated that tree canopies could directly absorb N from atmospheric deposition. We highlight the critical role of leaf traits in determining canopy foliar N uptake, which may consequently influence plant competition under elevated N deposition.

Effect of Integrated Nitrogen Management on Productivity and Available Nutrient Status in Soil after Harvest of Dwarf Ricebean (Vigna Umbellata) under Rainfed Condition

Effect of Integrated Nitrogen Management on Productivity and Available Nutrient Status in Soil after Harvest of Dwarf Ricebean (Vigna Umbellata) under Rainfed Condition

Effect of organic and conventional cultivation practices on soil nutrient status in selected crops of Northern Telangana zone

Effect of organic and conventional cultivation practices on soil nutrient status in selected crops of Northern Telangana zone

Nutrient dynamics study and yield optimization for soybean through integrated nutrient and weed management

Soybean production faces many constraints with several factors, such as biotic and abiotic factors, and the crop management practices where inadequate nutrient management leads to a decline in production potential of the crop. Among the biotic factors, exploitation of resources by weeds not only causes a decline in production but also decreases the crop quality. Managing the weeds during the critical period of crop weed competition plays outstanding role in maximizing soybean production. In order to study the influence of integrated nutrient and weed management on nutrient dynamics and yield optimization of soybean an experiment was conducted in Split Plot Design with three nutrient management treatments in main plot {100% recommended dose of fertilizer (RDF), 75% RDF + 25% N through farmyard manure (FYM) + Phosphate solubilizing bacteria (PSB) and 50% RDF + Rhizobium + PSB} and five weed management treatments in the sub-plot (Hand weeding at 15, 30 and 45 DAS, Mechanical weeding at 20 and 40 DAS, Pendimethalin @ 1 kg a.i. ha−1 PE fb Hand weeding at 30 DAS, Propaquizafop @ 0.075 kg a.i. ha−1 PoE fb Hand weeding at 45 DAS, and Weedy check as control). The results indicated that application of 75% RDF + 25% N through FYM + PSB recorded the highest seed yield, nutrient content in seed and uptake of N, P, K, and S in the seed and stover, microbial population, and soil nutrient status. Highest partial factor productivity was recorded under 50% RDF + Rhizobium + PSB. Under weed management, hand weeding recorded the highest growth, yield attributes and nutrient content, but was found to be at par with Pendimethalin @ 1 kg a.i. ha−1 PE fb Hand weeding at 30 DAS and Propaquizafop @ 0.075 kg a.i. ha−1 PoE fb Hand weeding at 45 DAS. Application of 75% RDF + 25% N through FYM + PSB and pendimethalin @ 1 kg a.i. ha−1 fb hand weeding at 30 DAS proves to be an effective strategy for soybean cultivation. The experiment was conducted at the experimental farm of School of Agricultural Sciences, Nagaland University, Medziphema, India.

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.

Mapping Soil-crop Nutrient Dynamics in Continuous Cotton Cultivation Areas of Sangareddy District, Telangana

A soil-crop nutrient survey was conducted in Sangareddy district, Telangana during Rabi, 2023 to study the fertility status of cotton growing soils at 0-15 cm and 15-30 cm depth. Georeferenced soil and leaf samples were collected from 112 sites covering 23 mandals during flowering stage. Soil physical and physico-chemical properties and cotton leaf nutrient content were analysed. In the study area, bulk density, sand, silt and clay content ranged from 1.36-1.66 Mg m-3, 41.84-78.02 %, 6.74-29.60 % and 10.76-42.76 %, respectively. The soils were strongly acidic to slightly alkaline in reaction (4.25-7.98; 4.44-7.97), non-saline (0.026-0.254 dS m-1; 0.020-0.241 dS m-1) and low to high in organic carbon (2.03 to 11.52 g kg-1; 1.13 to 8.24 g kg-1) at 0-15 cm and 15-30 cm depths, respectively. Soil Nutrient Status: Available nitrogen, phosphorus, potassium and exchangeable magnesium contents ranged from 101 to 448 kg ha-1, 7 to 41 kg ha-1, and 154 to 763 kg ha-1 at 0-15 cm depth, respectively while 91 to 319 kg ha-1, 4 to 39 kg ha-1, and 142 to 730 kg ha-1 at 15-30 cm depth, respectively. Crop Nutrient Status: Total nitrogen, phosphorus, potassium and magnesium contents in the collected cotton leaves ranged from 0.53 to 3.64 %, 0.12 to 0.68 %, 0.80 to 1.84 % and 0.27 to 0.92 %, respectively. Soil Fertility Mapping: Soil fertility maps were prepared considering the low/deficient, medium and high/sufficient range of soil macronutrients (N, P, K and Mg) at the depth of 0-15 cm under QGIS 3.36.1. Soil fertility maps showed that soils of the study area were mostly low in available nitrogen, medium in available phosphorus, high in available potassium and sufficient in exchangeable magnesium. Regular soil testing is crucial to monitor the variations in nutrient levels and formulation of appropriate management strategies to address it.

Soil Fertility Mapping using Geo-spatial Technique for Khapradih Farm, DKS College of Agriculture and Research Station, Bhatapara, Chhattisgarh, India

The present study aimed to assess various chemical properties and available macro and micronutrients in the soil. Collection of 101 geo-referenced soil surface samples at 100-meter intervals of the Khapradih Farm of DKS College of Agriculture & Research Station, district Balodabazar-Bhatapara of Chhattisgarh state and examined in the laboratory for pH, electrical conductivity (EC), organic carbon (OC), and available macro-nutrients (N, P, K, S) and micro- nutrients (Fe, Mn, Cu, Zn, B). The results showed that the soil was generally neutral in pH, with a range of 5.7 to 7.6. The electrical conductivity indicated non-saline, varying from 0.11 to 0.26 dSm-1. Available nutrients were categorized as low, medium, or high based on nutrient index values. The study revealed that the soil in the area had low levels of available N and S, medium levels of available P and K, and high levels of available Fe, Mn, and Cu. Zn was found to be in the medium category, while B was low. Significant correlations were observed between various physico-chemical properties and available macro and micro nutrients. Using ArcGIS 10.4.1, thematic maps were created, representing the spatial distribution of soil properties and nutrient status. Based on these findings, fertilizer recommendations were developed for major crops grown in the area, resulting in enhanced crop productivity. The study concludes that GPS and GIS-based tools are valuable for soil fertility mapping, monitoring, and site-specific nutrient management, leading to sustainable and optimal crop yields.

Effect of Zinc and Silica Solubilizing Microbial Consortia on Soil and Plant Nutrient Status in Paddy

Effect of zinc and silica solubilizing bacteria and their consortia on paddy was studied under pot culture conditions at Agricultural Research Station, Janagamaheswarapuram, Andhra Pradesh, India. Thirteen treatments were assessed for availability of nutrients viz., Nitrogen, Phosphorus, Potassium, Zinc and Silica in soil and concentration of Nitrogen, Phosphorus and Potassium in plant at 45, 90 and 120 days after sowing (DAS). Significantly highest nitrogen (189.3, 249.4 and 239.7 kg ha-1), available phosphorus (34.6, 61.8 and 38.5 kg ha-1), potassium (214.2, 347.9 and 232.1 kg ha-1), zinc (0.78, 0.99 and 0.86 ppm) and silica (60.1, 90.8 and 78.4 ppm) were recorded in T13 (RDF + ZnKJJ-4 & ZnPGG-1 + SiKPP-1 & SiPYY-3) at 45, 90 and 120DAS. In plant, nitrogen (0.79, 0.99 and 0.89 %), phosphorus (0.37, 0.58 and 0.49 %) and potassium (1.78, 2.18 and 1.89 %) were significantly highest in T13. There was increase in available nutrient content upto 90 DAS which then decreased at 120DAS. It is inferred that consortia of two zinc solubilizing and two silica solubilizing microorganisms (T13) is useful for increased availability of Nitrogen, Phosphorus, Potassium, Zinc and Silica in soil and increased uptake of NPK by rice plant.

Effect of Biological Products on Yield, Production Economics and Soil Nutrient Status of Transplanted kharif Rice (Oryza sativa L.) in Gangetic Alluvial Soil of West Bengal, India

Field experiment was conducted during kharif season of 2017 and 2018 at Instructional Farm under Bidhan Chandra Krishi Viswavidyalaya, West Bengal in sandy loam soil to study the growth and yield of transplanted kharif rice variety Satabdi (cv. IET 4786) as influenced by biological products. The experiment was laid down in randomized complete block design (RCBD) with seven treatment combinations replicated thrice. Results revealed that RDF + soil applied Bolt GR @ 10 kg/ha produced higher growth attributes and yield of tested rice cultivar. The same treatment registered significantly higher total N and K uptake in tested cultivar; while the highest P uptake was recorded with RDF + Seed treatment with JumpStart2.0 @ 0.83 ml/kg seed. The treatment RDF + soil applied Azospirillum @ 2 kg/ha brought about significant positive changes of available N content in post-harvest soil over control situation (only RDF). However, significantly higher available P content was estimated in plots with RDF + soil applied PSB @ 2 kg/ha. Application of bio-products failed to exert any significant influence on residual soil K. The crop receiving RDF + soil applied Bolt GR @ 10 kg/ha gave highest gross return, net return and B:C ratio. Hence, application of RDF (60-30-30 kg N, P2O5 and K2O/ha) along with Bolt GR @ 10 kg/ha or Azospirillum @ 2 kg/ha may be recommended to achieve higher grain yield of tested cultivar Satabdi (cv. IET 4786).

Effects of Stand Density on Tree Growth, Diversity of Understory Vegetation, and Soil Properties in a Pinus koraiensis Plantation

The regulation of stand density has been studied in specific aspects of plantations with different age categories. A clearer understanding is still required of the extent to which stand density impacts multiple plantation attributes such as tree growth, understory vegetation diversity, and soil properties in Korean pine (Pinus koraeinsis Sieb. et Zucc) plantations. This study utilized a 43-year-old middle-aged Korean pine plantation in Qingping Forest Farm in northeast China to answer the research question posed. Three stand density levels, low stand density (LSD, 716 trees/ha), medium stand density (MSD, 850 trees/ha), and high stand density (HSD, 916 trees/ha) were studied for their effects on plantation attributes enumerated above. The results revealed a significant (p < 0.05) effect of stand density on mean stand volume (m3). Medium stand density had the highest mean stand volume of 26.16 (±0.27) m3 while the lowest stand volume was recorded for the low stand density at 14.90 (±1.72) m3. Also, significant differences in total nitrogen, total potassium, available nitrogen, available potassium, and percentage soil moisture content were observed among stand density levels. Additionally, stand density was found to have significant effects on species richness, Shannon–Wiener, and Simpson’s diversity indexes for the shrub and herb layers of the plantation. This study shows that a medium stand density is the most optimal for promoting tree growth and understory biodiversity, as well as enhancing the status of certain soil nutrients. Thus, medium density achieves a balance between growth, nutrient availability, and biodiversity in middle-aged Korean pine plantations after a short period of thinning. These findings provide valuable knowledge for forest management, emphasizing the significance of continuous, long-term, and site-specific research.