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Open Access
Status of nitrogen mineralizing enzymes in Soils under different land use systems of district Kupwara
(SKUAST Kashmir, 2022) Tanveer Hussain Bhat; Hakeem, Shahid. A.
Land uses have significant impact on soil biological properties that incessantly intimates the soil quality change, assessed by soil microbial and biochemical indicators. Soil enzymes mediate key processes and functions of the soils such as organic matter decomposition and nutrient cycling in both natural and agricultural ecosystems thus can be used as potential indicators of nutrient cycling processes and fertility management. The present study entitled “Status of Nitrogen Mineralizing Enzymes in Soils under different land use systems of district Kupwara” was undertaken during year 2020-2021. Four different land use systems viz., forest, pasture, horticulture (apple) and agriculture (paddy) were selected and were analyzed for enzyme activity viz., urease, protease, amylase and amidase. Physico-chemical and biological properties were investigated during the investigation. The study revealed that the highest mean bulk density (1.32 Mgm-3) and highest mean particle density (2.52 Mgm-3) was recorded in agriculture (paddy) soils and lowest 1.14 Mgm-3 and 2.00 Mgm-3 was recorded in forest soils, respectively. Soil pH varied slightly acidic to slightly alkaline in reaction under different land uses with highest mean pH 7.37 recorded in paddy soils and lowest of 6.21 in forest soils. The electrical conductivity values were less than one dSm-1 indicating no salinity hazard. The highest mean value of soil organic carbon 2.05 gkg-1and available nitrogen 538 kgha-1 was recorded in forest soils and lowest mean value of organic carbon 0.31 gkg-1 and available nitrogen 267.21 kgha-1 was recorded in agricultural soils. The biological properties viz., microbiological biomass carbon, microbial biomass nitrogen, soil urease activity, soil protease activity, soil amylase activity and soil protease activity were recorded highest in forest soils and lowest in agriculture soils. The maximum mean microbial biomass carbon 255.63 μgg-¹soil and microbial biomass nitrogen 538 μgg-¹soil was found in forest soils and minimum mean value of microbial biomass carbon 78.40 μgg-¹soil and minimum mean microbial biomass nitrogen 267.21 μgg-¹soil was found in agriculture soils. The highest mean value of soil urease activity 32.82 μgNH4-Ng-¹soil 2h-¹, soil protease activity 1856.58 μg tyrosine g-¹2h-¹, soil amidase activity 149.87 μgNH4-Ng-¹soil h-¹ and soil amylase activity 1.44 mgg-¹soil 3h-¹ was recorded under forest soils and lowest mean value of soil urease activity 13.80 μg NH4-Ng-¹soil 2h-¹, soil protease activity 151.08 μg tyrosine g-¹2h-¹, soil amidase activity 78.44 μgNH4-Ng-¹soil h-¹ and soil amylase activity 1.07 mgg-¹soil 3h-¹ was recorded under agricultural soils. The soil nitrogen mineralizing enzymes viz., urease, protease, amylase and amidase shows highly significant positive correlation with organic carbon, available nitrogen and clay content, whereas highly non-significant negative correlation with pH, electrical conductivity and bulk density. The status of soil enzymes viz., urease, protease, amidase and amylase followed the sequence of forest > pasture > horticulture (apple) > agriculture (paddy) under different land uses. Based on soil organic carbon content, intensive cultivation practices adopted and biological properties, it is obvious that continuous disturbance has reduced soil enzyme activity in cultivated soils than uncultivated soils.
Open Access
Evaluation of Chemical Extractants for Available Phosphorus in Soils of Kashmir
(SKUAST Kashmir, 2022) Syed, Muzamil Mehraj; Bhat, Mohammad Auyoub
Phosphorus (P) is an essential component of life on earth and is a key factor in crop production. Different P extractants are being employed all over the globe with varying degree of favourable outcomes to determine the soil P status and its subsequent availability to the crop. The present study entitled ‘Evaluation of Chemical Extractants for Available Phosphorus in Soils of Kashmir’ was undertaken in the year 2021-2022. For this study three land uses viz. agriculture, horticulture and forest were selected. A total of forty five composite soil samples were collected in bulk from selected land uses (fifteen samples from each land use) prevalent in Baramulla, Bandipora, Kupwara, Budgam and Anantnag districts of Kashmir. Soil samples were taken at 0-25 cm depth and analysed for their physico-chemical properties. The maximum mean pH (7.30) was recorded in soils of agriculture (paddy) and minimum (6.16) in soils of forest land use system. Electrical conductivity across all the land uses was less than 1 dSm-1 indicating no salinity hazard. The highest soil organic carbon (2.02%) was recorded in forest and lowest (0.68%) in agriculture. Highest cation exchange capacity (21.51 cmolckg-1) was observed in forest soils and lowest (13.89 cmolckg-1) in agricultural soils. For estimation of available P, chemical extractants viz. Olsen, Bray no. 1, Bray no. 2, calcium chloride (CaCl2) and ammonium bicarbonate-diethylene triamine penta acetic acid (AB-DTPA) were used. Among five extractants used, Bray no. 2 extractable P was found to be the greatest (9.98 mg kg-1) while CaCl2 extractable P the lowest (2.65 mg kg-1) for the soils of agricultural land use. It was observed that Bray no. 2 extracted maximum (13.57 and 17.92 mg kg-1) and CaCl2 extracted minimum (3.93 and 4.32 mg kg-1) amount of P in horticultural and forest soils, respectively. A pot experiment on soils from the respective sampling sites was also conducted in this study to determine the plant uptake of phosphorus using oats (Avena sativa) as a test crop. With the P uptake of oat plants, Olsen-P followed by AB-DTPA-P showed the highest significant positive correlation in agricultural soils and Bray no. 1-P followed by Olsen-P in horticultural and forest soils. Hence, from the current study it is concluded that Olsen followed by AB-DTPA exhibited highest efficiency for the determination of available P in soils of agricultural land use system, while as Bray no. 1 followed by Olsen exhibited the highest efficiency for the determination of available P in soils of horticultural and forest land use systems.
Open Access
Evaluation of Different Extractants forEstimation of P, K, Ca, Mg & Micro-nutrient Cations in Soils ofKashmirValley
(SKUAST Kashmir, 2022) Syed, Andleeba Jan; Chesti, Majeed-ul-Hassan
The existing chemical methods for determination of available soil nutrients areeffective and accurate,however, they involve use of separate analytical methods, extractants and processing which makes them costly, laborious and time consuming. This emphasizes on need of an alternative multi-nutrient extractant solutions forsimultaneous determination for more than one nutrient. Therefore, present study was undertaken to compare the suitability of multi-nutrient extractants viz., ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)and acid ammonium acetate-ethylene diamine tetra acetic acid (AAAc-EDTA) with standard methods for determination of P, K, Ca, Mg& micronutrient cations. The soil samples were collected randomly from different parts of valley and categorized on the basis of pH into <6.50, 6.50-7.50, >7.50. In soils having pH < 6.50 Bray extracted more P than other extractants but all extractants were at par with each other. In case of soils with pH 6.50 -7.50 and >7.50, Olsen method extracted more P but it was also same as extracted by AAAc-EDTA. Among K extractants, NH4OAc extracted more K followed by AB-DTPA and AAAc-EDTA at all pH ranges. In case of Ca and Mg, AAAc-EDTA extracted maximum Ca & Mg followed by Versenate titration & AB-DTPA. For micronutrient cations, AB-DTPA extracted more as compared to CaCl2-DTPA and AAAc-EDTAfor extraction of Fe and Cu. In case of Zn,AB-DTPA extracted more Zn than other methods at pH<6.50 but at pH 6.50-7.50 and >7.50, CaCl2-DTPA extracted more Zn followed by AB-DTPA. Correlation studies revealed that a positive and highly significant correlation was observed between AB-DTPA and AAAc-EDTA with standard methods for P, K, Ca, Mg and micronutrient cations except for Zn which had significant correlation with AAAc-EDTA only. Hence at all pH ranges, there is a possibility of using AAAc-EDTA by replacing individual extractants for determination of more than one available nutrient in order to save time, money and energy.
Open Access
Spatial Variability of Physico-Chemical Properties of Vishav micro-watershed of Kashmir valley
(SKUAST Kashmir, 2022) Raieesa; Shaista Nazir
The characterization of the spatial variability of soil attributes is essential to achieve a better understanding of the complex relations between soil properties and to establish appropriate management practices for soil resources use. Spatial variability of soil physical and chemical properties within or among agricultural fields is inherent in nature due to geological and pedological soil forming factors, but part of the variability may be induced by tillage and other soil management practices. Geostatistical methods have been widely used to determine the spatial correlation and the range of spatial dependence at different sampling scales. The objective of this study was to investigate the spatial variability of soil physical and chemical properties and the preparation of thematic maps of the Vishav Microwatershed of Kashmir Valley. Soil samples were collected from 40 sites using Global Positioning System (GPS) under different land use systems. Soil samples were analysed for physical (particle size distribution, bulk density, particle density, total porosity, soil aggregate stability) and chemical properties (soil reaction, electrical conductivity, organic carbon, available nitrogen phosphorus, potassium, micronutrients). The bulk densities ranged from 0.93- 1.28 gcm-3 Sand, silt and clay content were in the range of 27.48 to 53.34 %, 30.53 to 40.90 % and 16.14 to 32.97 % respectively, the soils were broadly categorized as clay loam and sandy loam. The soils of Vishav micro-watershed were slightly acidic to slightly alkaline in reaction, devoid of salts, majority of samples were having EC ˂0.8 dsm-1. The soils were medium to high in organic carbon contents, medium in available Nitrogen and available phosphorus and high in available potassium. The coefficient of variation values (CV %) indicated low to medium variability across various soil properties of the watershed. Using such analyses, it is possible to plan appropriate soil management practices, including fertilization for agricultural production and environmental protection. It is recommended that inputs such as irrigation and fertilizer application must be varied based on varying soil conditions across the watershed.
Open Access
Relative Distribution of Boron Fractions in Cultivated Soils of Lolab Valley
(SKUAST Kashmir, 2022) Mehnaz Gull; Mir, Aamir Hassan
The knowledge of different fractions and availability of boron is essential while studying the response of crops to boron. Fractionation measures the bioavailability of boron and reveals its chemistry. The present study entitled “Relative Distribution of Boron fractions in Cultivated Soils of Lolab valley”. was conducted during the year 2020-2021. The different cultivated soils in the current study include maize, vegetable and paddy. The soil samples were collected from 30 different sites and land use cover at a depth of 0-25cm. A sum total of 90 composite soil samples were collected by random sampling method. The experimental findings revealed that soil texture ranged from clay loam to silty clay loam. The highest bulk density of 1.38 g cm-3 and particle density 2.56 g cm-3 were recorded in paddy soils and lowest bulk density (1.22 g cm-3) and particle density (2.43 gcm-3) in vegetable growing soils, respectively. Soil pH varied from slightly acidic to neutral in reaction under different cultivated soils with highest pH of 6.71 recorded in paddy soils followed by maize (6.50) and lowest pH of 6.25 observed under vegetable growing soils. The electrical conductivity value of all examined cultivated soils was less than 1 dSm-1 indicating no salinity hazard. The soil organic carbon of 1.69% was found highest under vegetable growing soils followed by maize (1.35%) and lowest in soils samples collected from paddy cultivation (1.19%). The cation exchange capacity was found highest under vegetable (17.40 cmol kg-1) followed by maize (17.03 cmol kg-1) and lowest (15.66 Cmol kg-1) under paddy soils. The maximum available boron of 0.55 mg kg-1 was found in soils under vegetable cultivation followed by maize (0.50 mg kg-1) and lowest of 0.46 mg kg-1was recorded in paddy growing soils. The mean value of Rs-B and Spa-B were observed in the range of 0.34, 0.35, 0.37 and 1.49, 1.38, 1.34 mg kg-1, under paddy, maize and vegetable soils, respectively, due to higher clay content. While as, oxide boron was found highest (7.37 mg kg-1) in soils under vegetables due to low soil pH followed by maize (6.58 mg kg-1) and lowest of 6.47 mg kg-1 under paddy soils. The organically bound boron (11.31 mg kg-1) was recorded maximum under vegetable soils due to higher organic matter content followed by 10.77 mg kg-1 under maize and minimum of 10.15 mg kg-1 under paddy soils .The residual boron (47.30 mg kg-1) was found highest in soils under paddy cultivation followed by (42.93 mg kg-1) maize and lowest of 42.15 mg kg-1 under vegetable growing soils. Among all fractions residual fraction of boron was found to be the most dominant pool of soil B and the relative contribution of other fractions was in the order, organically bound B > oxide bound B > specifically adsorbed B > readily soluble B. The correlation study revealed that the clay and organic carbon had greater impact on different fractions of boron as organic matter was main contributing factor affecting boron availability in soil. Soil pH and EC showed significant and positive correlation with available-B, Rs-B, Spa-B and Res-B and negative correlation with ox-B and org-B. Organic carbon showed positive correlation with all boron fractions except oxide boron. Clay and CEC showed positive correlation with all fractions except organically bound boron. Sand showed negative and significant correlation with all fractions except oxide boron. Higher CEC, clay and organic carbon content in fine textured soils favoured higher adsorption of boron.Therefore, The study may prove beneficial to farmers of the valley to manage boron nutrition in their cultivated soils.
Open Access
Influence of Intercropping on Soil Quality of Apple Orchards of District Baramulla
(SKUAST Kashmir, 2022) Teli, Manoj Kumar; Khan, Inayat M.
The intercropping system and management practices greatly impact the different soil properties and ultimately the degree of soil quality. The present study entitled ‘‘Influence of Intercropping on Soil Quality of Apple Orchards of District Baramulla’’ was conducted during the year 2021-2022. The aim of the study was to investigate the impact of intercropping system on soil physico-chemical properties and organic carbon fractions. The different intercropping system in the current study include apple + maize, apple + common bean, apple + french bean, apple + chilli, apple + knol khol, apple + tomato and sole apple. Six geo-referenced locations for each intercropping system were selected and the samples were taken from two depths 0-20 and 20-40 cm. The results revealed that the highest mean value of bulk density (1.37 Mg m-3) was recorded in sole apple and lowest (1.30 Mg m-3) in apple + french bean, highest mean value of particle density (2.62 Mg m-3) was observed in sole apple and lowest (2.46 Mg m-3) in apple + common bean intercropping system with increasing trend along the depth, respectively. Porosity was observed highest in apple + common bean with mean value (48.00%) and lowest (43.27%) in apple + knol khol soil with a decreasing trend along the depth. pH was recorded slightly acidic to slightly alkaline in investigated intercropping system with highest mean value (7.33) in apple + knol khol and lowest (6.26) in apple + common bean with increasing trend in all intercropping system with soil depth. No salinity hazard was observed as electrical conductivity values were found <1 dSm-1 among the studied intercropping system. The CEC was recorded highest (22.93 Cmolc kg-1) in apple + common bean and lowest (17.08 Cmolc kg-1) in sole apple with a decreasing trend in lower horizons. The maximum available NPK recorded in sole apple and lowest in apple + chilli intercropping system. Apple + common bean had the highest value of total viable bacterial count and dehydrogenase enzyme activity and lowest under sole apple with mean value 188.83×106 cfu g-1soil, 61.50 µg TPF g-1soil 24 h-1 and 130.83×106 cfu g-1 soil, 42.61 µg TPFg-1 soil 24 h-1, respectively. Particulate organic carbon (POC) was observed highest with mean value (1044.48 mg kg-1) in apple + maize and lowest (915.34 mg kg-1) in sole apple, while microbial biomass carbon highest (1227.50 mg kg-1) in apple + common bean and lowest (1034.40 mg kg-1) under sole apple with a decreasing trend along soil depth. Bulk density, particle density, EC and pH showed significantly negative correlation with all primary nutrients. Organic carbon fractions and CEC showed significantly positive correlation with all primary nutrients. The soil quality indices computed through principal component analysis for studied intercropping system revealed the following order of soil quality: apple + bean (1) > apple + french bean (0.96) > apple + chilli (0.89) > apple + tomato (0.89) > apple + knol khol (.88) > apple + maize (0.88) > sole apple (control) (.84). Overall, soil quality was observed better in case of legume as intercrops as compared to cereals and vegetables in apple orchard soils.
Open Access
Soil Carbon Pools and Stocks under Different Land uses in the Lesser Himalayan region of North Kashmir
(SKUAST Kashmir, 2022) Mattoo, Mahrukh Masrat; Mir, Aamir Hassan
The study was conducted to assess the impact of land use on different carbon pools and stocks in the study area during year 2019-20. Correlation studies between the physico-chemical properties and the carbon pools were worked out. Soil samples were collected from seven different locations at three depths; 0-15, 15-30 and 30-45 cm. At each location the samples were collected from 5 land-use systems viz., Agriculture, Horticulture, Forest, Pastures and Wastelands. The soil carbon pools that were quantified included: Soil organic carbon (SOC), Total organic carbon (TOC), Potassium permanganate oxidisable carbon (KOC), Microbial biomass carbon (MBC), Total inorganic carbon (TIC) and Water soluble organic carbon (WSOC). The results revealed that all carbon pools except TIC were highest in soils under forest followed by pastures, horticulture, agriculture and wastelands that decreased with the increase in depth. However TIC increased with increase in depth. The overall mean of the soil carbon stocks were highest in forest (31.64 Mg ha−1) followed by pastures (25.9 Mg ha−1), horticulture (27.05 Mg ha−1), agriculture (24.4 Mg ha−1) and wasteland (9.3 Mg ha−1). Soils were also evaluated for other important physico-chemical properties like pH, CEC, BD, and soil texture. It was found that soil bulk density was highest in wastelands followed by agriculture, horticulture, pastures and forest. Soil texture varied from silty clay loam to silty loam. The soils of the study area were moderately acidic to moderately alkaline. The cation exchange capacity was highest in pastures followed by horticulture, agriculture, forest and. The correlation studies revealed that all carbon pools were both significantly and non-significantly correlated with the soil physico-chemical properties. CEC sand and clay were positively correlated with all the carbon pools except TIC whereas pH, BD and silt s howed a negative correlation with all the carbon pools except TIC.
Open Access
Spatial Variability of Soil Properties and Erodibility Indices of Sankoo Watershed of Kargil, Ladakh
(SKUAST Kashmir, 2022) Liyaqat Ali; Mir, Aamir Hassan
The present study entitled “Spatial Variability of Soil Properties and Erodibility Indices of Sankoo Watershed of Kargil, Ladakh” was undertaken during the year 2020-2021.In total 100 soil samples were selected from sankoo watershed. The samples were taken from one depth (0-15cm). The highest bulk density 1.74 g cm-3 and lowest 1.23 g cm-3 was recorded with the mean value 1.47 g cm-3 and porosity of the collected soils ranged between 0.32 to 0.68 per cent. Soil pH is varied from neutral to alkaline, with highest pH recorded 9.14 and lowest was 7.04 in Sankoo watershed. The electrical conductivity values of all samples were less than 1 dSm-1. Soil organic carbon levels were highest 0.81 percent and lowest 0.31 percent. The CEC of soils ranged from 10.25 to 20.21 Cmolc kg-1 with a mean value of 14.89 cmolc kg-1, respectively. N, P, K showed a range of 206 to 520, 10.63 to 13.32, 100 to 458 kg ha-1 and Ca and Mg content recorded a range of 1.02 to 5.90, 0.11 to 1.13 cmolc kg-1. Soil micronutrients like Fe, Mn, Zn and Cu content ranged from 3.16 to 9.99, 1.09 to 2.96, 1.05 to 2.21, 0.82 to 2.82 mg kg-1 with a mean of 7.79, 2.06, 1.35 and 1.73 mg kg-1, respectively. Dispersion ratio (120.86), Clay moisture equivalent ratio (28.66), Clay ratio (5.86), Modified clay ratio (89.45), Erosion index (214.11), Percolation ratio (1.11), and Maximum water holding capacity were the soil erodibility indices recorded with the mean values of collected samples (32.19). According to evaluation made for erodibility indices; dispersion ratio, clay to moisture equivalent ratio and erodibility indices suggested that soils were susceptible to erosion. Erodibility indices generally indicated that barren land soils were the most sensitive to erosion followed by cultivated land use system: agriculture and horticulture.
Open Access
Sequential Extraction of Calcium and Boron in Apple Growing Soils of North Kashmir
(SKUAST Kashmir, 2022) Humyera Jan
Sequential extraction provides detailed information about origin, chemical forms, distribution, mobility and transformation of nutrients in the soil. The main focus of the present investigation was to apply sequential extraction procedure for speciation of calcium and boron in apple growing soils of North Kashmir. In this context, three apple growing districts namely Kupwara, Bandipora and Baramulla lying in North Kashmir were selected and 20 composite surface soil (0-30 cm) samples were collected from each district by random sampling technique. The soil samples were assessed for calcium and boron distribution in various chemical fractions and their relationship with physico-chemical properties. The findings confirmed that the texture of soils varied from clay loam to silty clay loam. The soils were slightly acidic to neutral in reaction having low values of electrical conductivity and calcium carbonate content in all the three districts. The organic carbon content was medium to high in all three districts recording highest value in district Baramulla (1.12%) followed by Kupwara (1.09%) and lowest in Bandipora (1.05%). The soils of Baramulla had highest cation exchange capacity followed by Bandipora and Kupwara with respective mean values of 19.52, 19.60 and 22.43 Cmolc kg-1. Among various fractions of calcium, water soluble calcium was observed to be the lowest and exchangeable calcium greatest in all the three districts and their relative contribution was found in the order: exchangeable calcium > carbonate bound calcium > oxide bound calcium > water soluble calcium. Among various boron fractions, readily soluble boron represented the smallest fraction and residual boron the most dominant fraction and were found in the order: residual boron > organically bound boron > oxide bound boron > specifically adsorbed boron > readily soluble boron. The correlation coefficients indicated that almost all soil properties influenced the distribution and availability of calcium and boron in soils. It was observed that pH, EC and clay showed a significant and negative correlation with water soluble calcium. Exchangeable calcium had a positive and significant correlation with clay, CEC, pH and EC. Organic carbon, pH, EC and CaCO3 were significantly and positively correlated with carbonate bound calcium. All the boron fractions showed significant and negative correlation with sand except oxide bound boron. Soil pH and EC showed significant and positive correlation with readily soluble, specifically adsorbed and residual boron and a negative correlation with oxide bound and organically bound boron. Organic carbon showed positive correlation with all boron fractions except oxide bound boron. Clay and CEC had positive correlation with all the boron fractions except organically bound boron. The stepwise regression analysis of the data revealed that cation exchange capacity, electrical conductivity and calcium carbonate are the main contributing factors that affects the distribution and bioavailability of calcium (water soluble, exchangeable calcium and carbonate bound calcium) and the cation exchange capacity and clay content were the prime factors that affects availability of boron (readily soluble boron and specifically adsorbed boron) in soils. The study may prove beneficial to local farming community in managing calcium and boron nutrition and thus, improving quality and production of apple.

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