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Subject: Soil Science ×

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    ThesisItemOpen Access
    Spatial variability and mapping of soil health indicators using GIS techniques
    (SKUAST Kashmir, 2016) Ramzan, Shazia; Wani, Mushtaq A
    Information on the spatial variability and distribution of soil health indicators is critical to adopt site-specific management practices as well as for identification of the hot-spot areas of pollution for understanding ecosystem processes and designing sustainable soil-crop and environmental management decisions. Geostatistical methods have been widely used to determine the spatial correlation and the range of spatial dependence at different sampling scales. Soil samples were collected from Research farm of SKUAST-K Shalimar using Geographical Positioning System (GPS) under different landuse systems specified at a fixed distance of 50 × 50 m2 grid from 0-15 cm depth. The undisturbed orchards were sampled at two depths. Soil samples were analysed for physical (particle size distribution, bulk density, particle density, total porosity, soil resistance, water holding capacity, aggregate size distribution/mean weight diameter of aggregates and saturated hydraulic conductivity), chemical (soil reaction, electrical conductivity, organic carbon, available nitrogen, phosphorus, potassium, sulphur, calcium, magnesium, micronutrients and toxic elements) and biological properties (total viable microorganisms bacteria, fungi, actinomycetes, azotobacter, rhizobium and phosphorus solubilizing bacteria). The kriging was used to determine the values for the non-sampled locations. The physical characteristics confirmed the clay loam texture under all landuses. The results of the present study showed that soil resistance, pH, exchangeable potassium, sulphur, copper and total viable actinomycetes had significant differences across landuses, while rest of parameters showed non-significant difference among landuses. A depthwise distribution of soil properties showed a decrease in content of all chemical and biological properties except soil pH, EC, calcium, magnesium, lead and actinomycetes. Among physical properties soil porosity, water holding capacity, mean weight diameter and saturated hydraulic conductivity decreased down the depth while as bulk density, particle density and soil resistance increased down the depth. This study also evaluated the key soil health indicators and soil health index (SHI) of the research farm. Of the 41 soil quality parameters considered for study, organic carbon, potassium, sulphur, copper, CEC, bulk density, hydraulic conductivity (Ks), MWD and aggregates in the range of 0.2-0.5mm, 0.5-2mm and 5-8mm played a major role in influencing the soil health and were designated as the key indicators of ‘soil health’ for this system. The SHI obtained by the integration of key indicators was 0.96 and rated as good as per the index given by Chun-Juan et al. (2013). Results of descriptive statistics showed log normal distribution for water holding capacity, saturated hydraulic conductivity, potassium and copper. The coefficient of variation values (CV) indicates high variability for saturated hydraulic conductivity, soil resistance, aggregate size distribution and EC; all the micronutrients and calcium and magnesium among macronutrients; organic carbon, actinomycetes and azotobacter among biological properties. The experimental semivariogram of clay, bulk density, porosity, mean weight diameter, electrical conductivity, cation exchange capacity, nitrogen, lead, and total viable rhizobium were fitted to Gaussian model. Exponential model was found to be the best fit for experimental semivariogram of sand, silt, soil resistance, pH, phosphorus, potassium, sulphur, magnesium, copper, manganese, cadmium, organic carbon, total viable bacteria, fungi, actinomycetes and PSB. Spherical model was fitted to particle density, water holding capacity, saturated hydraulic conductivity, calcium, zinc, nickel and azotobacter. Stable semivariogram was best suited for only iron. Experimental semivariogram results indicated a strong spatial dependence for sand, clay, pH, zinc, copper, organic carbon and fungi; moderate for bulk density, mean weight diameter, saturated hydraulic conductivity, soil resistance, soil organic matter, phosphorus, potassium, sulphur, iron, manganese, lead and actinomycetes; weak for rest of parameters. Using such analyses, it is possible to plan appropriate soil management practices, including fertilization for agricultural production and environmental protection. Only two management zones for zinc and sulphur were identified in the research field of SKUAST-K.
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    ThesisItemOpen Access
    Rationalization of Nutrient Management Using Site Specific Nutrient Management Approach and Zinc Bio-fortification in Scented Rice (Cv. Pusa Sugandh-3)
    (SKUAST Kashmir, 2015) Lone, Aabid Hussain; Najar, G R
    Large field to field variability restricts efficient fertilizer management whenbroad based blanket recommendations are used in rice. Hence, the nutrient management for rice requires an approach that enables adjustments in N, P, and K applications to accommodate the site- specific needs of the crop for supplemental nutrients. This study was conducted to develop the field specific fertilizer recommendations for P and K by adopting the nutrient balance with full maintenance approach and to establish and evaluate the threshold leaf colour value to guide in-season need based fertilizer N top dressing in Pusa Sugandh-3. For determining P and K fertilizer requirements, the relationship between grain yield and nutrient accumulation in above ground dry matter (Reciprocal Internal Efficiency) was estimated. RIEP and RIEK respectively came out to be 2.85 kg P and 15.60 kg K per tonne of grain yield. The contribution of P and K from various sources viz. irrigation water, crop residue and organic manure was quantified by the product of their respective amounts on per hectare basis and their average nutrient status. KW, KCR and KOM were equal to 36.75, 9.54 and 41.1 kg K ha-1 and PCR and POM were equal to1.9 and 9 kg P ha-1 respectively. K leaching loss in absence of lysimeter was determined through K budgeting in soil and it came out to be 7.31 kg K ha-1. These values can be used in computer-based decision tools to predict field specific P and K requirements without doing a soil test. To determine threshold leaf colour value; growth parameters, yield parameters, N uptake and various indices of nitrogen use efficiency (NUE) were measured in both years. Almost all the measured parameters in LCC 4 @ 20 kg N ha-1 were significantly higher than remaining LCC and fixed time N management treatments as well as control. Following the principle that threshold value is the one which simultaneously optimizes grain yield and NUE, LCC 4 @ 20 kg N ha-1 was adjudged as the threshold value for real time nitrogen management in Pusa Sugandh-3. In addition to rationalize the nutrient management, another objective of this study was to investigate the effect of method and timing of fertilizer application on zinc biofortification. Grain zinc concentrations were greatly increased by zinc fertilization. Foliar application at milking stage was more effective than soil application while as foliar application at panicle initiation stage didn’t cause any significant increase in grain zinc levels. Highest grain zinc concentrations were obtained when soil application and foliar application at milking stage was combined. Zinc concentration in unhusked grain, brown rice and white rice were closely associated indicating a possible penetration of zinc from the husk into the inner layers of rice endosperm. A significant drop in zinc concentration in nitrogen omission plot suggests that N and Zn interact synergistically with each other inside plant system. Besides increasing grain zinc concentration, zinc bio-availability was also significantly increased by decreasing phytic acid (a classical anti-nutrient present in rice grain) concentration through both soil as well as foliar application at milking stage. However the combination of these two methods was most effective in increasing zinc bio-availability.
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    ThesisItemOpen Access
    Establishment and Application of DRIS norms for Apple (cv. Red Delicious) in District Kulgam
    (SKUAST Kashmir, 2016) Ganie, Mumtaz Ahmad; Malik, M A
    The present-day nutritionally important problem in cultivation of apple is uptake of calcium and deficiency of boron. Boron deficiency in apple is diagnosed by soil and or plant analysis. However, for boron soil analysis is very important as the range between its deficiency and toxicity is pretty narrow hence may prove toxic to plants after its application slightly over the optimum level. All the above mentioned problems highlights two issues; one the requirement for a careful assessment of the status of available boron in soils for judicious use of boron fertilizers and two area wise standardization of calcium and boron requirement for apple. Hence the main motive of the research problem was to work out the best extractant for soil boron analysis and address the requirement of calcium and boron supply through diagnosis and recommendation integrated system (DRIS). For fulfilling these objectives soil sampling was carried out in thirty orchards belonging to three physiographic zones in district Kulgam viz., High, mid and low altitude zones. The apple orchard soils from district Kulgam were moderately acidic in high altitude areas to neutral in low altitude areas. Organic carbon content was high in all the three zones and increased with the increase in altitude. The available nitrogen, potassium, zinc, copper, iron, manganese and boron increased with increase in altitude while as reverse trend was observed in case of phosphorus and magnesium, however, calcium and sulphur did not exhibit any relationship with altitude. Foliar nutrients followed the similar trend with altitude except calcium. Besides nutrient indexing four extractants widely used to determine plant-available boron from either acidic or alkaline soils were tested for boron extraction in apple orchard soils of district Kulgam. The hot-water-soluble boron (HWSB) extraction procedure was used as a benchmark to see any relative variation in available boron in comparison with alternate extractants like calcium chloride-mannitol (CaCl2-mannitol), Ammonium acetate and diethylene-triaminepentaacetic acid-sorbitol (DTPA-sorbtol). The greatest mean boron concentration (3.25 mg kg-1) was obtained by ammonium acetate followed by hot water extraction (2.29 mg kg-1), whereas the lowest was obtained by CaCl2-mannitol (0.71 mg kg-1). Although there was significant correlation obtained for available B among all the extractants tested, the strongest correlation (r = 0.975** at P < 0.01) was observed between HWSB and DTPA-sorbitol and hence may substitute the hot water extraction method for plant-available B. Besides soil, leaf samples (5 from each orchard) from 162 low yielding (< 100qha-1) and 138 high yielding (≥ 100qha-1) orchards were collected and investigated for nutritional status for development of DRIS norms. Meanwhile a field experiment was conducted in the farmer’s orchard at village Odura in district Kulgam to study the response of apple to different levels of foliar application of calcium and boron. The experiment was laid out in randomized block design with four levels of calcium-chloride spray (C0-0 mg kg-1, C1-1000 mg kg-1, C2-2000 mg kg-1 and C3-3000 mg kg-1) and four levels of boronspray (source boric acid) (B0-0 mg kg-1, B1-500 mg kg-1, B2-1000 mg kg-1 and B3-1500 mg kg-1). Three sprays each of calcium chloride and boron were given and the experiment was replicated thrice. First spray of boron was given at bud burst stage, followed by second spray at pink bud stage and finally third spray was given at beginning of flowering. However, first spray of calcium chloride was given 21 days after fruit set, followed by second spray after 21 days of first spray and finally third spray was given 21 days after second spray of calcium chloride. All apple trees were given uniform recommended dose of nitrogen, phosphorus and potassium of 1500g, 750g and 1500g urea, diammonium phosphate and potash tree-1, respectively along with farm yard manure of 25 kg tree-1. Leaf samples were collected treatment wise and analyzed for all the essential nutrients. Then the DRIS norms previously developed were used to work out the order of nutrient requirement and nutrient imbalance index (NII) as per the method of Beaufils (1973), Jones (1981) and Elwali and Gascho (1984). The treatment combination of C2B1 recorded maximum yield and minimum NII as per all the applied methods, hence the best combination for Kulgam district. Moreover the regression models of NII calculated by the above methods and yield depicted Beaufils (1973) method as the efficient one among the three.
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    ThesisItemOpen Access
    Nutrient Status of Grape Orchards of District Ganderbal
    (SKUAST Kashmir, 2016) Bhat, Zahoor Ahmad; Akhter, Farida
    The fertility status of the soil is of prime importance for the optimum land use to increase crop production. Since fertility status of main grape producing area of Jammu and Kashmir has not been documented so far, therefore a systematic investigation was carried out to study the nutrient status of grape orchard soils of district Ganderbal. Fifteen orchards with uniform age and vigour were selected and surveyed (simple random survey) for the purpose of collection of soil, petiole and fruit samples. The soil samples were collected from three depths viz; 0-30 cm, 30-60 cm and 60-90 cm. The samples were processed and analysed for different parameters. The soils belonged to three textural classes viz; silt loam, loam and clay loam. Soil pH at 95% confidence interval (C.I) varied from 6.73 to 6.93 and 6.92 to 7.05 with mean values of 6.83 and 6.99 in surface (0-30 cm) and sub-surface (30-90 cm) soils, respectively. The electrical conductivity (EC) of soils was normal showing a variation of 0.11 to 0.14 and 0.13-0.14 dS m-1, in surface and sub-surface soils, respectively at 95% C.I. In surface soils organic carbon and calcium carbonate content (CaCO3) ranged (at 95% C.I) from 1.30 to 1.54 and 0.15 to 0.20, with mean values of 1.42 and 0.17 per cent, respectively, whereas, in sub-surface soils they varied from 0.70 to 0.81 and 0.18 to 0.22 with mean values of 0.75 and 0.20 per cent, respectively. Average cation exchange capacity (CEC) of surface and sub-soils was 15.24 and 16.09 Cmol (P+) kg-1, respectively. Available nitrogen content of surface and sub-surface soils varied (at 95% C.I) from 152.3 to 169.7 and 76.0 to 88.5 ppm with mean values of 161.0 and 82.2 ppm, respectively and the soils were medium in available nitrogen. At 95% C.I available phosphorus content of soils showed variation from 11.3 to 12.2 with a mean value of 11.7 ppm in surface soils and 8.6 to 9.2 ppm with mean value of 8.9 ppm and most of soils were medium in available phosphorus. All the soils under investigation were high in available potassium, calcium and magnesium and these nutrients showed average values of 133.1, 1854.3, 282.2 ppm and 112.5, 1872.1 and 254.3 ppm in surface and sub-soils, respectively. Surface and sub-soil available sulphur content varied (at 95% C.I) from 10.2 to 10.7 and 9.3 to 9.9 ppm, respectively, with majority of soils medium in available sulphur content. The majority of soils were high in available iron, manganese and zinc and medium in available copper, boron and molybdenum content with available iron, manganese, zinc, copper, boron and molybdenum content ranging (at 95% C.I) from 32.16 to 35.51, 33.55 to 36.74, 1.28 to 1.36, 1.58 to 1.66, 0.55 to 0.62 and 0.19 to 0.26 ppm, and 30.67 to 33.48, 32.15 to 34.69, 1.15 to 1.24, 1.36 to 1.42, 0.45 to 0.50 and 0.12 to 0.15 ppm, respectively in surface and sub-soils. The average petiole nitrogen, phosphorus, potassium, calcium, magnesium and sulphur content values were 1.79, 0.18, 1.64, 1.17, 0.24 and 0.16 per cent, respectively and petiole iron, manganese, zinc, copper, boron and molybdenum showed average values of 135.53, 38.30, 33.34, 12.06, 24.51 and 0.37 ppm, respectively. The quality parameters such as total soluble salts, total sugars, acidity and anthocyanin content of grape berries showed mean values of 22.59, 14.27, 0.39 and 0.03 per cent, respectively. The yield of grape orchards at 95% C.I showed a variation from 1.80 to 1.84 t ha-1 with an average value of 1.82 t ha-1. The petiole nitrogen, phosphorus, sulphur, manganese and boron content of vineyards exhibited significant and positive correlation with available nitrogen, phosphorus, sulphur, manganese and boron content in surface soils. Available nitrogen, phosphorus and manganese, and petiole nitrogen, phosphorus, sulphur, manganese and boron contents showed significant and positive correlation with grape yield, thus yield of grape orchards is directly dependent upon the available nutrient status and nutrient concentration in the petioles of vineyards. The present investigation though first of its kind is expected to be quit useful for horticulturists for formulation of further research and development programmes for increasing grape production and improving berry quality.
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    ThesisItemOpen Access
    Response of Strawberry ( Fragaria ananassa Duch.) to the Application of Microbial Inoculants
    (SKUAST Kashmir, 2008) Zahoor Ahmad; Zargar, M Y
    The present investigation “Response of Strawberry (Fragaria ananassa Duch) to the application of microbial inoculants” was carried out at the experimental field of SKUAST-K, Shalimar, during the years 2005-2006 and 2006-2007. Free living aerobic N2 fixing microorganisms (Azotobactersp. and Azospirillum sp.), phosphorus solubilizing microorganisms (Bacillus sp.and Pseudomonas sp.), vesicular arbuscular mycorrhizae ( Glomus sp.and Sclerocystis sp.) and plant growth promoting rhizobacteria (Azotobacter sp. and Pseudomonas sp.) were isolated from the rhizosphere of strawberry and screened on the basis of various morpho-biochemical tests. The strains that exhibited maximum nitrogen fixing, phosphorus solubilizing and plant growth promoting activity were used in an experiment laid out in completely randomised design (factorial) with 45 treatment combinations and 5 replications. Treatment T42 (150 kg N ha-1 +100 kg P ha-1 + Azotobacter Sp.) recorded significantly higher plant height (36.80cm), number of leaves plant -1 (36.50), plant spread (32.85 cm2 ), leaf area index (100.17), plant fresh weight (81.14 g), plant dry weight (31.27 g), root fresh weight (29.06 g), root dry weight (12.59 g), fruit weight (16.65 g), nitrogen uptake (0.62 g), available nitrogen (171.09 kg ha-1), available copper(0.85ppm) and organic carbon(1.05%). Treatment T45 (150 kg N ha-1 + 100 kg P ha-1 +Glomus mossae) registered significantly higher number of fruits plant-1 (17.50), TSS (9.81%), fruit acidity (0.88%), phosphorus uptake (0.19 g), zinc uptake(11.88 ppm), copper uptake(5.06 ppm), manganese uptake(17.64 ppm), iron uptake (75.27 ppm) and VAM spore population (8.96 spores g-1 soil). Higher potassium uptake (0.73 g), available potassium (224.15 kg ha-1), available zinc (0.74 ppm), available manganese (50.40ppm) and available iron (45.02 ppm) were recorded from the pots receiving treatment T44 (150 kg N ha-1 + 100 kg P ha-1 + Pseudomonas sp.). However, available phosphorus content (15.01 kg ha-1) was significantly influenced by the treatment T43 (150 kg ha-1+ 100 kg p ha-1 + Bacillus Sp.) Treatment T40 (150 kg N ha-1 + 100 kg P ha-1 + No inoculant) reported significantly higher fungal population (66.9 × 103 g-1 soil). Treatment T33 (150 kg N ha-1 + 0 kg P ha-1 + Bacillus sp.) significantly decreased pH (6.64) and electrical conductivity (0.69 dSm-1). Higher population of bacteria (98.7 x 106 g-1soil) and PSB (19.94 x 106 g-1 soil) were recorded in treatments T28 (75 kg N ha-1+ 100 kg P ha-1 + Bacillus sp.) and T29 (75 kg N ha-1 + 100 kg P ha-1 + Pseudomonas sp.) respectively. Thus the present study indicates that the application of different types of microorganisms along with 150 kg N ha-1 and 100 kg P ha-1 has improved the plant growth, yield and fruit chemical characteristics besides, nutrient uptake, soil characteristics and soil microbial population. Thus there is a scope for further increase in the yield of strawberry by trying higher levels of nitrogenous and phosphatic fertilizers in integration with different microbial inoculants.
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    ThesisItemOpen Access
    Studies on pedogenesis and nutrient indexing of apple (Red Delicious) growing soils of Kashmir
    (SKUAST Kashmir, 2002) Najar, Gh.Rasool; Nirmal Singh
    Horticulture is an important fruit industry of the state economy contributing Rupees 500 crores towards the state exchequer through the production of 7,51,310 metric tonnes of apple fruit per year. The production of quality apple 10.5 tonnes ha-1 (GOI, 1998-99) though higher in the country is far below than 40.7 tonnes ha-1 of U.S.A. (Nagi et al.,1998). The various essentials like soil, site characteristics, pedogenesis and nutrition needed for high yields of quality apple have not been given due attention. Not only the inadequate and imbalanced fertilizer application effects the yield and quality of fruit even the balanced fertilizer application is likely to prove ineffective, if the knowledge of soil characteristics is not given due cognizance. The pedogenesis on the other hand provides information pertinent to the soil – site suitability for cultivation of fruit crops and also helps in transfer of agro technology. Since the information with regard to pedogenesis and nutrient indexing of apple (Red Delicious) growing soils of Kashmir are quite meager, therefore, the investigation entitled, “Studies on pedogenesis and nutrient indexing of apple (Red Delicious) growing soils of Kashmir” was undertaken with the following objectives: 1. To study the pedogenesis of apple growing soils and to classify them as per soil taxonomy. 2. To investigate the nutrient status of apple orchard soils and the leaf nutrient contents. 3. To study the mineralogical built up of apple soils. 4. To find out the relationship between soil characteristics leaf nutrient content and fruit yield. Twelve soil profiles exposed from three physiographic zones viz; high altitude, karewa and valley basin were studied for their morphological, physico-chemical and mineralogical characteristics. Based on soil taxonomy the soils were classified into Argiudolls, Hapludolls, Udorthents, Hapludalfs and Eutrochrepts. X-ray diffraction of the clays showed illite as pre dominant clay mineral followed by chlorite, kaolinite, smectite and mixed layer minerals. Besides soil, leaf and fruit samples from 36 orchards from these zones were collected and investigated for nutritional status, for findings the relationship between soil and leaf nutrient contents and soil and leaf nutrient content with yield. The apple orchard soils were slightly acidic to slightly alkaline in reaction with normal electrical conductivity. The pH and electrical conductivity varies significantly in these zones with their lower values in high altitude soils. The calcium carbonate content varied from 0.10 to 10.5 per cent and varied significantly in these zones with higher value in karewa soils. The organic carbon was medium to high and varied significantly in these zones with higher content in high altitude soils. The cation exchange capacity ranged from 11.40 to 25.40 [C mol (P+) kg-1] with exchangeable calcium as dominant cation followed by magnesium and potassium. The cation exchange capacity exhibited a significant variation with altitude. The available nitrogen, phosphorus and potassium ranged from 30.10 to 162.8, 8.0 to 27.5 and 93.0 to 280.8 ppm, respectively and varied significantly with altitude. The contents of available calcium, magnesium and sulphur varied from 1760.0 to 3680.0, 72.0 to 1088.0 and 7.60 to 12.10 ppm, respectively. The contents of these nutrients (Ca, Mg) varied significantly in these soils. The DTPA extractable zinc, copper, manganese and iron ranged from 0.16 to 0.95, 0.70 to 3.70, 7.0 to 82.0 and 11.0 to 92.0 ppm, respectively in these soils. These soils in general were medium to high in available micronutrients. The available boron and molybdenum ranged from 0.50 to 2.66 and 0.15 to 2.27 ppm, respectively in these soils. The content of boron showed significant differences in these soils. pH showed negatively significant correlation with nitrogen, phosphorus, zinc and manganese and positively significant correlation with calcium and magnesium, whereas organic carbon exhibited positively significant correlation with nitrogen, zinc, manganese, iron and boron. A negatively significant correlation was found between calcium carbonate and available phosphorus and copper, whereas calcium and magnesium showed significantly positive relationship with cation exchange capacity. The leaf nutrient contents viz; nitrogen, phosphorus, calcium, copper, iron and Boron showed significant differences in these zones. The leaf nutrients showed positively significant correlation with surface and subsurface soils in respect of nitrogen, sulphur and iron and with subsurface soils in respect of phosphorus, potassium, zinc, copper, manganese, iron, Boron and molybdenum did not show significant differences in these zones. A significantly positive correlation existed between yield and leaf and soil nutrient contents in respect of nitrogen, phosphorus, calcium and nitrogen, zinc, iron and boron respectively.
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    ThesisItemOpen Access
    Dynamics of Potassium Release in Some Soils of Kashmir
    (SKUAST Kashmir, 2005) Wani, Mushtaq Ahmad; Mir, S U
    Surface samples representing ten soils from three altitudes were collected and subjected to different studies, viz. physico-chemical characteristics, different forms of potassium, clay mineralogy, Q/I relationships of potassium and kinetic studies of potassium release. The forms of potassium were in dynamic equilibrium and in the order of total-K > lattice-K > mineral-K > fixed-K > NEK > Available-K > exchangeable-K > water soluble-K. The dominance clay minerals was in the order of illite > mixed layer > hydroxy interlayered vermiculite > kaolinite > chlorite > smectite > others (quartz & feldspars). Significant correlation coefficients of some clay minerals with K forms in soil indicated their dependence on these minerals. Similarly the relationship among different minerals in clay fraction indicated some chemical alteration in minerals. Activity ratios at equilibrium (ARe K) values were higher in low altitude soils (2.7x10-3) as compared to mid altitude soils (1.3x10-3) and high altitude soils [1.1x10-3 (ML-1)0.5]. PBCK showed wide variation. Ca2+ saturated soils and their separates were equilibrated with oxalic acid and H+-resin from 0.25 to 200 hours for NEK release. Much higher amount of K released to H+-resin than oxalic acid. NEK release was faster initially and then it was gradual with increasing time. On an average NEK release was maximum in clay fractions, followed by whole soil. Sand fractions released higher quantities of K than silt, using oxalic acid whereas in H+-resin, silt and fine sand released almost equal quantities of K and sand released lower amount of K. The kinetics of K release were evaluated using first order, zero order, Elovich, power function and parabolic diffusion equations. K release from non-exchangeable pool to oxalic acid and H+-resin in all soils confirmed well to Elovich equation, followed by parabolic diffusion equation, as evidenced by higher values of R2 and lowest values of SE. Parabolic diffusion equation was best fit in coarser fractions, whereas Elovich equation described the data better for finer fractions. With H+-resin, Elovich equation described the data of NEK release in majority of soils and separates, followed by parabolic diffusion equation. The rate coefficients were highest in clay and lowest in coarse sand using H+-resin, whereas using oxalic acid, lowest values of ‘b’ were in silt fraction and highest in clay fraction. Potassium releasing power of various soils was assessed by successively growing mustard, maize and oat. The decline in available-K was 14.78, 40.57 and 60.69% after the harvest of mustard, maize and end of experiment, respectively. Significant correlation of NEK released to crops with K released to H+-resin was observed. Better correlation coefficients between total K uptake and NEK released to H+-resin signified that NEK in soils can be used to predict and ascertain the long term K supplying power of soils. Key words: Clay mineralogy, Kashmir soils, kinetics, K release, Q/I parameters.
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    ThesisItemOpen Access
    Investigation on Phosphorus Fractions and its use efficiency in Rice (Oryza sativa L.) under Integrated Phosphorus Management System
    (SKUAST Kashmir, 2012) Saima Khursheed; Najar, G.R.
    A field experiment was conducted at Faculty of Agriculture, Wadura during the two consecutive kharif seasons of 2008-09 and 2009-10 for “Investigation on phosphorus fractions and its use efficiency in rice (Oryza sativa L.) under integrated phosphorus management system”. The experiment was laid out with 18 treatment combinations viz. three levels of inorganic phosphatic fertilizer (0, 30 and 60 kg P2O5 ha-1), three levels of organic manures (control, FYM @ 15 t ha-1 and PM @ 5 t ha-1) and two levels of biofertilizers (uninoculation and inoculation with PSB) in randomized complete block design with three replications. The results revealed that grain and straw yield of rice increased significantly with increase in recommended dose of phosphatic fertilizer. Application of PM @ 5 t ha-1 showed significantly superior results over other organic treatments. Inoculation with PSB showed significantly superior results over no inoculation. Yield attributing characters viz. number of effective tillers, number of spikelets, panicle length and 1000-grain weight showed significant increase with increasing levels of phosphatic fertilizer. The plant analysis showed significant increase in nutrient content (N, P, K and Zn) in grain and straw with application of recommended inorganic phosphatic fertilizer. Among organics, PM @ 5 t ha-1 showed superior results over FYM @ 15 t ha-1. Inoculation with PSB also showed significantly superior results for nutrient content (N, P, K and Zn) over control. Application of recommended inorganic phosphatic fertilizer significantly increased the soil P-fractions (Fe-P, Al-P, Ca-P and total P), available N, P, K and Zn content at harvest. Application of FYM @ 15 t ha-1 and PM @ 5 t ha-1 significantly increased various P-fractions (Fe-P, Al-P, Ca-P and total P) and also available N, P, K and Zn in soil at harvest over control. Inoculation with PSB showed significant increase in available N, P, K and Zn and P-fractions (Fe-P, Al-P, Ca-P and total P) over control. Organic manures enhanced the physico-chemical properties of the soil such as pH, EC, OC and CEC. Among organics PM @ 5 t ha-1 was found superior over FYM @ 15 t ha-1. Inoculation with PSB significantly improved soil physico-chemical properties over no inoculation.
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    ThesisItemOpen Access
    Studies on relationship between fruit yield and quality with soil and leaf nutrient content in apple orchards of Zangier block of district Baramulla Kashmir
    (SKUAST Kashmir, 2005) Farida Akhtar; Mir, S U
    Soil samples from twenty orchards of Zangier block were collected from various depths and analysed for various physico-chemical properties and nutrient status. Leaf and fruit samples were also collected from the same orchards and analysed for nutrient content, fruit mineral composition, quality parameters and yield. The soils were medium to fine textured having slightly acidic to slightly alkaline pH, normal EC, CEC, CaCO3 and high OC. The soils were medium to high in available N&K respectively, high in available P, Ca and Mg. All available nutrients showed significant differences in these orchards. The pH exhibited significant and negative correlation with N & P in surface and sub-surface soils and significant and positive correlation with Ca in surface soils. OC exhibited significant and positive correlation with available N in surface and sub-surface soils and with available P in surface soils only. Clay showed significant and positive correlation with K only. The N, P and Mg contents of the leaves were found to be sufficient where as 30 and 70 percent orchards were low in K and Ca, respectively. Leaf N & P showed significant and positive correlation with soil N and P in surface and sub-surface soils. K, Ca & Mg did not show any relationship with the available nutrients. Soil nitrogen exhibited negative and significant correlation with leaf K and Ca. The physical qualities of fruit viz. length, diameter, size volume, firmness, specific gravity and colour intensity showed significant differences in these orchards. Fruit yield ranged from 9.45 to 10.23 tonnes ha-1 with the mean value of 9.82 tonnes ha-1. The chemical qualities of fruit like TSS, total sugars, percent acidity and anthocyanin showed significant variations. The contents of fruit N,P,K,Ca and Mg ranged from 0.33 to 0.46, 0.073 to 0.122, 0.87 to 1.07, 0.24 to 0.38, 0.029 to 0.035 percent, respectively. A positive and significant correlation was shown by leaf N with fruit length, diameter, size, weight and volume respectively and significant negative relationship with specific gravity and firmness. Leaf K and Ca revealed significant and positive correlation with fruit firmness, TSS and total sugars. Available-K also showed significant positive correlation with total sugars. Leaf N exhibited significant and negative correlation with TSS and total sugars. Leaf K and Ca exhibited significant and negative correlation with fruit acidity and significant and positive correlation was observed between leaf N and percent acidity. Significant and positive correlation existed between yield and soil N and Ca and leaf N and P. Anthocyanin exhibited a positive relationship with leaf K and Ca and a negative relationship with leaf nitrogen. From the foregoing summarized results of investigation it is concluded that soil analysis of all the orchards revealed that by and large all the orchards were adequately supplied with N, P, K, Ca and Mg. The leaf analysis indicated that N, P & Mg contents were optimum while as, 30 and 70 percent samples were low in K and Ca respectively. The present investigation though first of its kind is expected to be useful for horticulturists for formulation of further research and development programmes. Maintaining leaf N, P, K, Ca and Mg percent in dry weight basis in leaf can yield quality fruit. Leaf N content should be maintained between 1.96 to 2.1 percent on dry weight basis for production of quality fruit.