Soil Nutrient Status Research Articles

High Ammonium Addition Changes the Diversity and Structure of Bacterial Communities in Temperate Wetland Soils of Northeastern China.

The soil microbiome is an important component of wetland ecosystems and plays a pivotal role in nutrient cycling and climate regulation. Nitrogen (N) addition influences the soil's microbial diversity, composition, and function by affecting the soil's nutrient status. The change in soil bacterial diversity and composition in temperate wetland ecosystems in response to high ammonium nitrogen additions remains unclear. In this study, we used high-throughput sequencing technology to study the changes of soil bacterial diversity and community structure with increasing ammonium concentrations [CK (control, 0 kg ha-1 a-1), LN (low nitrogen addition, 40 kg ha-1 a-1), and HN (high nitrogen addition, 80 kg ha-1 a-1)] at a field experimental site in the Sanjiang Plain wetland, China. Our results showed that except for soil organic carbon (SOC), other soil physicochemical parameters, i.e., soil moisture content (SMC), dissolved organic nitrogen (DON), total nitrogen (TN), pH, ammonium nitrogen (NH4+), and dissolved organic carbon (DOC), changed significantly among three ammonium nitrogen addition concentrations (p < 0.05). Compared to CK, LN did not change soil bacterial α-diversity (p > 0.05), and HN only decreased the Shannon (p < 0.05) and did not change the Chao (p > 0.05) indices of soil bacterial community. Ammonium nitrogen addition did not significantly affect the soil's bacterial community structure based on non-metric multidimensional scaling (NMDS) and PERMANOVA (ADONIS) analyses. Acidobacteriota (24.96-31.11%), Proteobacteria (16.82-26.78%), Chloroflexi (10.34-18.09%), Verrucomicrobiota (5.23-11.56%), and Actinobacteriota (5.63-8.75%) were the most abundant bacterial phyla in the soils. Nitrogen addition changed the complexity and stability of the bacterial network. SMC, NO3-, and pH were the main drivers of the bacterial community structure. These findings indicate that enhanced atmospheric nitrogen addition may have an impact on bacterial communities in soil, and this study will allow us to better understand the response of the soil microbiome in wetland ecosystems in the framework of increasing nitrogen deposition.

Long-term effect of manuring-fertilization on nutrients availability and yield under rice (Oryza sativa)-lentil (Lens culinaris) system

Soil health degradation is a major threat in agricultural sustainability specially under rainfed agriculture. The purpose of this study was to assess the impact of long-term fertilization and manuring on soil organic carbon, nutrient status, uptake and yield trends under a rainfed rice (Oryza sativa L.)-lentil (Lens culinaris L.) cropping system situated at Agriculture Research Farm of Banaras Hindu University, Varanasi, Uttar Pradesh. Soil samples were collected in 2019 and 2021 after harvesting of rainy (kharif) season rice from 34 years old long-term experiment with rice-lentil cropping system of dry sub-humid region of India and analysed for various pools of SOC, nutrients availability, uptake and yield attributes. Results showed that 50% NPK+FYM treatment significantly influenced soil organic carbon pools and improved macronutrients (Nitrogen, Phosphorus, Potassium), microbial biomass carbon and dehydrogenase activity in soil as compared to the control. In addition, the integrated application of farmyard manure and inorganic fertilizers significantly enhanced the nutrient uptake, productivity of rice and lentil, and maintained the nutrient balance in the soil. Therefore, the balanced use of inorganic fertilizer along with organic manure may be recommended for maintaining soil health and crop productivity under subtropical India.

Determination of optimal soil pH and nutrient concentrations for cultivated rooibos tea using the boundary line approach

Optimal soil pH and nutrient conditions for rooibos cultivation in South Africa have not yet been established as limited field research has been conducted. Soil chemical (0–300 mm) and yield data were collected from 120 commercial rooibos plantations in the main (170 km wide) production region in the Western and Northern Cape Provinces. The optimum and 90%-yield sufficiency soil ranges were determined using the boundary line approach and quadratic regression. The optimum (sufficiency range) soil chemical properties were a pH (KCl) of 4.5 (4.2–4.7), electrical conductivity of 0.23 mS m−1 (0.16–0.30 mS m−1) and acid saturation of 27.5% (17.1–37.8%). The optimum (sufficiency range) soil available macro- and micronutrients (in mg kg−1) were: 16.9 (7.4–26.4) for P, 20.8 (11.5–30.0) for K, 140.3 (95.9–184.7) for Ca, 50.0 (32.3–63.7) for Mg, 8.3 (4.9–11.7) for S, 34.6 (17.2–52.1) for Fe, 5.5 (2.2–8.8) for Mn, 0.30 (0.16–0.45) for Zn, 0.11 (0.07–0.15) for Cu and 0.11 (0.06–0.16) for B. The resultant optimal values for soil pH and available P, K and Mg corresponded with previous published reports on cultivated fynbos species, while published values were not available for the other parameters. The findings of this study are important for sustainable soil fertility management in commercial rooibos tea production in South Africa.

Different Farming Systems Concerning Soil Health and Yield of Arecanut and Black Pepper

We conducted two year (2020 and 2021) field experiment in the farmer’s field at Hanagal, Sirsi, Karnataka to study the impacts of different farming practices (Recommended package of practice; (RPP), Organic farming, Natural farming and Chemical farming) on rhizosphere microflora, soil nutrient status and yield of arecanut and black pepper. The results revealed that, soil pH and electrical conductivity did not vary significantly due to different farming systems. Whereas, the significantly (p&lt;0.05) highest soil organic carbon content was in organic farming (0.74%) which was on par with natural farming (0.66%) and least in chemical farming (0.71%). The highest available nitrogen (258.31 kg ha-1), phosphorus (39.06 kg ha-1) and potassium (205.47 kg ha-1) were in RPP. Whereas the highest secondary nutrients and micronutrients content were in organic and natural faming. The lowest of all these nutrients were recorded in chemical farming at the harvest stage of arecanut. Soil microflora, dehydrogenase and phosphatase activity in the arecanut and black pepper rhizosphere were significantly (p&lt;0.05) highest in natural farming and lowest in chemical farming. Concerning yield, the significantly highest arecanut (Chali yield 29.35 q.ha-1) and black pepper (dry yield 12.07 q. ha-1) yield was in RPP and maximum net return also observed in RPP (Rs. 10, 62, 500 ha-1).

Biochar amendment reassembles microbial community in a long-term phosphorus fertilization paddy soil.

This study investigates the effect of biochar amendment on microbial community structure and soil nutrient status in paddy soil that has been fertilized for an extended period of time, shedding light on sustainable agricultural practices. A 90-day incubation period revealed that biochar amendment, as opposed to long-term fertilization, significantly influenced the physicochemical properties and microbial composition of the soil. The microcosm experiment conducted using six treatments analyzed soil samples from a long-term rice ecosystem. We employed microbial biomarkers (phospholipid fatty acids, PLFAs; isoprenoid and branched glycerol dialkyl glycerol tetraethers, iGDGTs and brGDGTs; DNA) to assess microbial biomass and community structure. Biochar addition led to a decrease in PLFA biomass (15-32%) and archaeal iGDGT abundance (14-43%), while enhancing bacterial brGDGT abundance by 15-77%. Intact biochar increased archaeal and bacterial diversity, though fungal diversity remained unchanged. However, acid-washed biochar did not result in a uniform microbial diversity response. The abundance of various microbial taxa was changed by biochar amendment, including Crenarchaeota, Proteobacteria, Nitrospira, Basidiomycota, Halobacterota, Chloroflexi, Planctomycetota, and Ascomycota. Soil NH4+-N was found as the primary environmental factor impacting the composition of archaea, bacteria, and fungus in this study. These findings imply that the addition of biochar has a quick influence on the structure and activity of microbial communities, with fungi possibly having a critical role in acid paddy soil. This study contributes valuable knowledge for developing sustainable agricultural practices that promote healthy soil ecosystems. KEY POINTS: • Biochar type and phosphorus fertilization demonstrated an interactive effect on the diversity of archaea, but no such effect was observed for bacteria and fungi. • Soil fungi contribute to approximately 20% of the total phospholipid fatty acid (PLFA) content. • Biochar, especially acid-washed rice straw biochar, increases glucose metabolism in bacteria and archaea and decreases saprophytic fungi.

Responses of soil nematode abundance and food web to cover crops in a kiwifruit orchard.

Soil biodiversity plays an important role in both agricultural productivity and ecosystem functions. Cover crop species influence the primary productivity of the ecosystem and basal resources. However, it remains poorly understood how different cover crop treatments influence the community of soil nematodes in an orchard ecosystem. In this study, field experiments were conducted to investigate the effects of cover crop treatments with different species numbers, i.e., no cover crop (CK), two cover crop species (C2), four cover crop species (C4), and eight cover crop species (C8), on weed biomass, together with composition, abundance, and metabolic footprint of soil nematode community in a kiwifruit orchard. As compared to the CK group, the groups of cover crop treatments had lower weed biomass, which decreased with the increase of the cover crop diversity. Moreover, for the abundance of total nematodes, fungivores exhibited higher levels in C4 and C8 treatments than that in CK, bacterivores had a higher abundance in C4 treatment, and plant parasites had a higher abundance in C2 and C8 treatments. Cover crop treatments also changed the structure of nematode community and enhanced the nematode interactions and complexity of nematode community network. In addition, C4 increased the Wasilewska index but decreased the plant-parasite index. The metabolic footprints of fungivores were higher in cover crop treatments compared with CK, and C4 and C8 also increased the functional metabolic footprint of nematode. Soil nematode faunal analysis based on nematode metabolic footprints showed that C8 improved the soil nutrient status and food wed stability. Mantel test and redundancy analysis showed that soil microbial biomass nitrogen and carbon, organic carbon, nitrate nitrogen, moisture content, pH, and cover crop biomass were the main factors that affect soil nematode community. In conclusion, cover crop treatments with four or eight plant species displayed a positive role in weed control, improvement of soil health, and promotion of energy flow in the soil food web through the increase in the metabolic footprints of nematodes in kiwifruit orchard.

The Status and Stock of Soil Nutrients under Different Land Ownership Management of Rice Fields in Kuranji District Padang West Sumatra

This study aims to determine the status and stock of soil nutrients in three types of land ownership management. This research was conducted on smallholder farmers (SF), tenant farmers (TF), and owner farmers (OF) in Kuranji District, Padang, West Sumatra, and at the Soil Laboratory of the Faculty of Agriculture, Andalas University from March to September 2022. The range of nutrient status in the three types of land ownership is 0.06-0.35% C-organic and 0.06-0.13% N. The concentration ranges of Ca, Mg, K, Na, P, and Si, respectively, were 0.52-0.79; 0.58-1.34; 0.07-0.12; 0.03-0.09 cmol.kg-1and 2.52-12.7; 31.73- 49.33 ppm. The results showed that each management type’s status of organic carbon in soil was deficient. This result was presumably due to miss management of straws. The highest concentrations of Ca, Mg, K, and Na were found in smallholder farmers’ fields (SF), while the lowest concentrations were found in tenant farmers’ fields (TF). The stock of soil nutrients shows a similar trend to the nutrient status of the soil. The dose of fertilizer by SF and TF was 129.5 kg/ha N; 37.5 kg/ha P2O5; 37.7 kg/ha K2O, while OF is 176 kg/ha N, 65 kg/ha P2O5, 45 kg/ha K2O. The soil nutrient status among the farmer groups is not significantly related to the amount of fertilizer application. It is recommended to give a dose of fertilizer following the recommendations that have been set and balanced with the proper management of remaining straw after harvest for sustainable soil fertility and agriculture production.

Experimental Evaluation of Irrigation Methods on Soil Nutrient Status and Nutrient Uptake of Summer Groundnut

Aims: To study the nutrient uptake and status of available nutrients in soil after harvest of groundnut as affected by different irrigation levels and methods at Northern Transitional Zone of Karnataka.&#x0D; Study Design: The experiment was laid out in randomized block design with different irrigation levels and methods replicated thrice.&#x0D; Place and Duration of Study: AICRP on Groundnut, Main Agricultural Research Station, University of Agricultural Sciences, Dharwad during summer 2021.&#x0D; Methodology: We took 11 treatments involving different level and methods of irrigation using eight micro-sprinkler treatments, one drip fertigation treatment and two flood irrigation treatments. After harvesting soil nutrient status and nutrient uptake from the soil were analyzed.&#x0D; Results: Significantly higher total nitrogen, phosphorus and potassium uptake were recorded with drip irrigation applied at 0.6 ET0 at Seedling, 1.0 ET0 at Flowering, 1.25 ET0 at Pegging, 0.8 ET0 at Pod formation stages along with fertigation of N and P [3 splits at NF on 3rd, 4th and 5th week] and CaNO3 and S nutrients [3 splits at PGF on 7th, 8th and 9th week] (164.0, 27.6 and 129.3 kg ha-1, respectively) and was 40.0, 55.43 and 25.91 per cent higher compared to control (Flood FAO). Same treatment enhanced the soil chemical properties like pH, EC and organic carbon by 1.04, 16.12 and 7.40 per cent compared to control.&#x0D; Conclusion: Drip irrigation and fertigation enhanced nutrient uptake of groundnut and available soil nutrient status and also improved soil chemical properties as compared to control (Flood irrigation). So, this method can be proved beneficial in reducing the nutrient requirement of the crop under cultivation in the Northern Transitional Zone of Karnataka.

Effects of Different Green Manure Crops on Soil Water, Nitrogen, and Yield: Preliminary Results in an Apple Orchard on the Loess Plateau, China

Green manure crops intercropping is an effective agricultural practice to alleviate water and nutrient deficit by improving soil properties in the Loess Plateau of China. However, green manure crops intercropping could cause water and nutrient competition, but the effects of different green manure crops intercropping on soil water and nutrient status are rarely evaluated. Thus, we conducted a field experiment to investigate the responses of soil moisture, nitrogen, and yield to green manure crops intercropping. Three intercropping patterns, apple–ryegrass (AR), apple–spring rape (AS), and apple–alfalfa (AA), were set up with a blank control (CK), which employed clean tillage in the inter-row and row. All treatments had no significant difference on evapotranspiration. At maturity, AR, AS, and AA treatments reduced soil organic matter content by 4.2%, 6.5%, and 18.8%, and total nitrogen content by 0.01%, 1.3%, and 20.3%, relative to CK, respectively. The water competition degree in AR, AS, and AA were 38.4%, 48.8%, and 64.6%, respectively. Ryegrass, spring rape, and alfalfa’s nitrogen use efficiency were 19.71%, 29.24%, and 39.42%, respectively. AR and AS treatments increased the apple yield by 11.7% and 5.7%, and water-use efficiency (WUE) by 14.4% and 7.5%, relative to CK, respectively. AA treatment reduced the apple yield by 6.9% and WUE by 6.8%, relative to CK. All treatments had no significant difference on apple quality. Therefore, in normal water years, we suggest adapting the ryegrass–apple tree intercropping pattern for apple production on the Plateau Loess, China.

Organic amendments modulate the crop yield and rhizospheric bacterial community diversity: a 3-year field study with Cajanus cajan.

Excessive use of chemicals to enhance soil nutrient status and crop yield has resulted in a decline in soil health. Organic farming promotes organic amendments, which help to balance the ecosystem. Understanding the dynamic patterns of belowground microbial populations is essential for developing sustainable agricultural systems. Therefore, the study was designed to evaluate the effect of different agri-practices on rhizospheric bacterial diversity and crop yield in an Indian agricultural system. A 3-year field experiment was set up in a randomized block design using Cajanus cajan as a model crop, comparing conventional farming with organic practice (with animal manure and bio-compost as amendments). Plant and rhizospheric soil samples were collected at the harvest stage for assessing various growth attributes, and for characterizing rhizospheric bacterial diversity. Enhanced crop productivity was seen in conventional farming, with a 2.2-fold increase in grain yield over control. However, over the 3years, an overall positive impact was observed in the bio-compost-based organic amendment, in terms of bacterial abundance, over other treatments. At the harvest stage of the third cropping season, the bacterial diversity in the organic treatments showed little similarity to the initial bacterial community composition of the amendment applied, indicating stabilization along the growth cycles. The study emphasizes the significance of the choice of the amendment for ushering in agricultural sustainability.

Comparative verification of Mehlich 3 soil analysis methods in Northern Mozambique using microwave plasma–atomic emission spectrometry

ABSTRACT Regular testing of nutrients in soil samples is important for understanding soil fertility. This study investigated a combination of the Mehlich 3 extraction method and Microwave Plasma-Atomic Emission Spectrometry (MP – AES) for testing the nutrient status in soil to establish a labor-saving and cost-effective analytical method in Northern Mozambique. Available P, exchangeable cations, and micronutrients in the Mehlich 3 extract were measured using conventional methods and compared with those quantified using MP – AES to determine its accuracy. Linear regression analysis implied a high correlation between the Available P extracted via Mehlich 3 and quantified using MP – AES and that extracted via Mehlich 3, Bray 1, Olsen, and Mehlich 1 and quantified using UV – Vis. Moreover, a high determination coefficient (R2 = 0.920) was observed between Mehlich 3 quantified using MP – AES and that quantified using UV – Vis spectroscopy with a low root mean square error (RMSE = 9.245), MP – AES may have accuracy comparable to conventional methods. Linear regression of the exchangeable cations extracted using the Mehlich 3 method and quantified using MP – AES and those extracted using the 1 M NH4OAc method and quantified using ICP – AES revealed that the coefficients of determination of Ca, Mg, and K were 0.952, 0.878, and 0.826, respectively. The coefficient of determination for Na was small at 0.101. For the micronutrients, Mehlich 3 extraction with MP – AES quantification method showed a correlation with the conventional DTPA method; specifically, a strong correlation was observed for Cu and Zn. Although the correlation for Fe and Mn was also high, it was less accurate than that for the other elements. The method used in this study is considered effective for estimating field variability. To convert to conventional methods, variation in available elemental content between sites with different local soil properties should be considered.

Nutrient Status of Acid Sulphate Soils of Upper Kuttanad of Kerala, India

Nutrient Status of Acid Sulphate Soils of Upper Kuttanad of Kerala, India

Impact of patch age and size on forest soil characteristics in European agricultural landscapes

Many landscapes worldwide are characterized by the presence of a mosaic of forest patches with contrasting age and size embedded in a matrix of agricultural land. However, our understanding of the effects of these key forest patch features on the soil nutrient status (in terms of nitrogen, carbon, and phosphorus) and soil pH is still limited due to a lack of large-scale data. To address this research gap, we analyzed 830 soil samples from nearly 200 forest patches varying in age (recent versus ancient forests) and size (small versus larger patches) along a 2500-km latitudinal gradient across Europe. We also considered environmental covariates at multiple scales to increase the generality of our research, including variation in macroclimate, nitrogen deposition rates, forest cover in a buffer zone, basal area and soil type. Multiple linear mixed-effects models were performed to test the combined effects of patch features and environmental covariates on soil nutrients and pH. Recent patches had higher total soil phosphorus concentrations and stocks in the mineral soil layer, along with a lower nitrogen to phosphorus ratio within that layer. Small patches generally had a higher mineral soil pH. Mineral soil nitrogen stocks were lower in forest patches with older age and larger size, as a result of a significant interactive effect. Additionally, environmental covariates had significant effects on soil nutrients, including carbon, nitrogen, phosphorus, and their stoichiometry, depending on the specific covariates. In some cases, the effect of patch age on mineral soil phosphorus stocks was greater than that of environmental covariates. Our findings underpin the important roles of forest patch age and size for the forest soil nutrient status. Long-term studies assessing edge effects and soil development in post-agricultural forests are needed, especially in a context of changing land use and climate.

Assessment of Soil Fertility Status in Paroo and Saraiyan Blocks of Muzaffarpur District of Bihar Using GPS and GIS

The experiment was conducted during 2019‒21 at Paroo and Saraiya blocks of Muzaffarpur district of Bihar, India to identify the nutrients status for crop management. Soil fertility inventory research was carried out in these two identified blocks (Paroo and Saraiyan) for generation of thematic soil fertility map. For nutrient assessment altogether 40 (forty) geo-referenced composite soil samples were collected from the various locations of the studied area using a hand-held GARMIN GPS device. The processed soil samples were used for analysis of various soil fertility parameters by using prescribed standard methods. Soil nutrient status and fertility maps were created by using ArcGIS 10.4.1 software employing Inverse Distance Weighted (IDW) interpolation techniques. The results clearly indicated that the soils pH was alkaline in nature ranges from 7.4‒9.5. The mean value of Soil organic matter (0.55%) and potassium (150 to 250 kg ha-1) was found to be low to medium whereas, available nitrogen (119.9 to 319.1 kg ha-1) found 90% deficient, however, phosphorus (4.34 to 18.4 kg ha-1), and sulphur were recorded low in the blocks. However, most of the sample of micronutrients like copper (0.23 to 1.07 mg kg-1) and Iron (1.64 to 13.2 ppm) showed above critical limits while manganese, zinc deficiency were occurred in wide area. The intensive cropping system and imbalanced use of chemical fertilizer is degrading the soil quality in study area.

Tillage system and cover crop effects on organic carbon and available nutrient contents in light chestnut soil

Optimal use of management systems including tillage and cover crops are recommended to improve available nutrient contents in soils and sustain agricultural production. The effects on organic carbon and available nutrient contents of three tillage methods (conventional tillage, minimum tillage and no-tillage) and different cover crops such as flaxseed oil, buckwheat, soybean, pea, corn, sorghum, spring oilseed rape and sugar beet were evaluated in a short-term experiment on a light chestnut soil in Kazakhstan. Organic carbon and available nutrient contents were measured in the autumn of 2021. The field measurements included the yield of cover crops and input of organic matter into soils with root and other residues of cover crops. In the laboratory, total organic carbon, labile organic carbon, easily hydrolyzable nitrogen (NH4-N), NO3-N, available P and exchangeable K were measured. The results showed that one season of cover crop growth was not enough to find detectable changes in soil organic matter and available nutrient status in light chestnut soils. On the other hand, even in a short-term field experiment period of 3 months, the most labile organic carbon in soil organic carbon was obtained in conventional tillage. Overall, the results show that at least in the short term and under lower drip irrigation rate in summer for the study area, reduced tillage methods (no-tillage and minimum tillage) is suitable in the study area for soybean, corn and sugar beet production after intensive tillage in the previous year.

Stronger negative priming effect and lower basal respiration rates in nutrient-poor as compared to nutrient-rich forestry-drained peatland.

Land-use changes, e.g., forestry drainage, modify the characteristics of peatland soil and affect the peatland carbon (C) balance. Peat soil nutrient status, related mainly to the original peatland type, also has an impact on the C balance after drainage, as observed earlier at the ecosystem scale for two forestry-drained sites in Southern Finland. Here the aim was to compare the soil CO2 fluxes from the two sites, nutrient-poor and nutirent-rich forestry-drained peatlands, and study the effect of plant photosynthates on the decomposition of peat C. Therefore, the respiration rates and priming effect (PE) of peat soils with variable nutrient status were examined in the laboratory. Half of the samples were labelled with 13 C-glucose to study the effect of fresh C addition on the soil decomposition. The 13 CO2 -samples were analysed with isotope ratio mass spectrometry. A two-pool mixing model was applied to separate the soil- and sugar-derived respirations and to determine the PE. The nutrient-rich peat soil respired generally more than the nutrient-poor peat. A negative PE was observed in both peat soils, suggesting that the addition of fresh C did not increase the soil decomposition, but on the contrary decreased it. The negative PE was significantly more pronounced in nutrient-poor peat soil than in the nutrient-rich peat treatments, suggesting that the higher nutrient availability suppresses the negative PE. These results imply that microbes prefer utilizing fresh C instead of old C in the short term and that the peat decomposition is suppressed in the presence of fresh C inputs from vegetation at forestry-drained peatlands. These effects are even stronger in peat soils with less nutrients available. Ecosystem scale and soil process models could be improved with the help of these results.

Effect of Spacing and Nutrition on Soil Nutrient Status and Uptake of Broccoli (Brassica oleracea var. italica)

A field study was conducted to investigate the influence of spacing and nutrition on soil nutrient status and Uptake of Broccoli and the investigation was titled "Effect of spacing and nutrition on soil nutrient status and uptake of Broccoli." The experiment consists of 3 limits of spacing i.e., S1 (45x30 cm), S2 (45x45 cm), S3 (60x45 cm) and 3 limits of nutrient i.e., N1 (100 percent recommended dose of nutrients), N2 (75 percent recommended dose of nutrients), N3 (125 percent recommended dose of nutrients). It was designed in FRCBD includes nine treatment combinations with three replications. The analysed experimental data showed that the available nutrient in the soil and nutrient uptake by the plant after harvesting of Broccoli. Increasing the spacing and nutrient levels enhances the soil N, P and K availability and absorbed by the broccoli after harvesting. The maximum availability of N (296.57kg ha-1), P (116.54kg ha-1) and K (72.85kg ha-1) in the soil was found in the S3. The higher availability of N (275.20kg ha-1), P (104.88kg ha-1) and K (71.37kg ha-1) in the soil was shown in the fertilizer limit N3. The higher N (160.16kg ha-1), P (127.13kg ha-1) and K uptake (65.83kg ha-1) by the Broccoli was reported in the wider level of spacing S3. The maximum N (158.09kg ha-1), P (127.94kg ha-1) and K uptake (65.84kg ha-1) by Broccoli was observed in the nutrient level of N3.

GIS Based Spatial Prediction of Major Nutrient Status of Soils at Farm Scale for Site Specific Crop Management

ABSTRACT In the current research, Global Positioning System (GPS) based 121 surface soil samples were collected and analyzed in the laboratory for different soil fertility parameters. The results showed that the bulk density (BD) of soils of 1.39 Mg m−3, dark gray and grayish brown, sandy clay loam, neutral to slightly alkaline soil reaction (pH), safe in electrical conductivity (EC), low to medium in organic carbon (OC) and non-calcareous in nature. The nitrogen (N), phosphorus (P), potassium (K) and sulfur (S) were analyzed as low, medium, high and low with NI of 1.26, 2.19, 2.69 and 1.31, respectively. In the Farm, field (F) wise, OC, N, P, K and S content in soil varied from 4.89 (F20) to 7.33 g kg−1(F15), 196.71 (F20) to 264.25 kg ha−1 (F15), 4.10 (F19) to 27.04 kg ha−1 (F16), 292.72 (F2) to 674.80 kg ha−1 (F13) and 3.99 (F18) to 13.75 mg kg−1 (F13), respectively. Post hoc results also revealed that fields and land use types were significantly different. Ordinary Kriging in Geo-statistical tools revealed that the exponential model was best fitted for, N, P, K, OC, √CaCO3 and √K, which exhibited moderate spatial dependence (>25 but < 75%), whereas Gaussian model was used for BD, pH and CaCO3. Correlation ranges(m) for P was 717.57 m and exhibited strong spatial dependency (<25%). The J-Bessel model was used for EC and√EC. The spherical model was used for S which showed 57.95% spatial dependence. The spatial maps could be used as a basis for precision farming.

Mineral nutrition of rice and post-harvest soils influenced by self-made organic composts

Using self-made organic composts i.e., rice hull compost (RHC), rice straw compost (RSC), sawdust compost (SDC), and Vermicompost (V) an experiment was conducted to evaluate their responses on mineral nutrition of rice and post-harvest soils under field condition. The total nitrogen contents among the treatments ranged from 9.6 - 21.4, phosphorus: 1.1 – 4.42, potassium: 3.86 - 7.27, sulfur: 11.9 – 19.7, calcium: 3.30 – 11.87 and magnesium: 2.76 – 5.54 g kg-1 at the maturity stage of rice plants which were found to be positively influenced by the applied organic composts. The nutrient status of the post-harvest soils was also influenced by the applied organic composts. The maximum amount of 78.29 mg kg-1 available N was recorded in the T3 treatment, where available nitrogen content increased by 85.65% as compared to the control plot. There were significant (p ≤ 0.05) increases in other nutrient contents with the increased doses of the composts under rice production. Bangladesh J. Sci. Ind. Res. 58(2), 99-106, 2023

Evaluating Soil Fertility and Plant Nutrient Status of Lemon (Citrus Limon L.) Orchards in the North-Eastern Region of Bangladesh

Soil (0 to 15 cm and 15 to 30 cm depth), leaf and fruit samples were collected from seventeen orchards of lemon (Citrus limon L.) from different locations of Habiganj district to evaluate the physicochemical properties, nutrient status of soil, and nutrient concentrations in lemon leaves and fruits. The soil was found to vary pH from extreme to medium acidic (3.9 to 6.0), organic matter content 0.63 to 1.71% at 0 to 15 cm and 0.16 to 1.42% at 15 to 30 cm depth. Electrical Conductivity was found non-saline in nature which was 37.9 to 100.1 μS/cm at 0 to 15 cm and 25.1 to 69.0 μS/cm at 15 to 30 cm depth. The dominant soil textural class was sandy clay loam. The total N, P, K and S in soils were found 0.038 to 0.085%, 0.024 to 0.071%, 0.022 to 0.144%, and 0.040 to 0.294% at 0 to 15 cm depth, respectively and 0.012 to 0.076%, 0.024 to 0.056%, 0.012 to 0.139%, and 0.016 to 0.333% at 15 to 30 cm depth, respectively. Available N was found 20.37 to 67.90 mg/kg at 0 to 15 cm and 20.37 to 74.69 mg/kg at 15 to 30 cm depth. Major soil samples were found low in available phosphorous, 0.35 to 66.95 mg/kg at 0 to 15 cm and 0.83 to 29.19 mg/kg at 15 to 30 cm depth. Available sulphur was also found low in concentration, 4.62 to 68.48 mg/kg at 0 to 15 cm and 2.10 to 15.54 mg/kg at 15 to 30 cm depth. The exchangeable K+, Ca2+ and Mg2+ in soils at 0 to 15 cm depth were found 0.040 to 0.221 meq/100g, 0.002 to 0.046 meq/100g and 0.017 to 0.042 meq/100g, respectively and at 15 to 30 cm depth these were found from 0.025 to 0.097 meq/100g, 0.003 to 0.054 meq/100g, and 0.016 to 0.050 meq/100g, respectively. The concentrations of total N, P, K and S in leaf were 1.198 to 2.659%, 0.500 to 0.778%, 0.112 to 0.246% and 0.010 to 0.133%, respectively. The concentrations of total N, P, K and S in fruit were 0.760 to 1.549%, 0.250 to 0.611%, 0.107 to 0.190% and 0.005 to 0.031%, respectively. The present findings illustrated the low to medium soil fertility status under the lemon plantation in the north-eastern region of Bangladesh and growers could be recommended to plant lemons after applying soil amendments to improve the physico-chemical properties of soils in the north-eastern region of Bangladesh. J. Biodivers. Conserv. Bioresour. Manag. 2023, 9(1): 69-78