K.P. SinghShanker Kumar Singh2024-08-102024-08-102001https://krishikosh.egranth.ac.in/handle/1/5810213106It is well established that a positive inter-relationship exist between fertilizer consumption and food grain production. But, sustaining soil fertility demands a more rational and balanced use of plant nutrients. The continuous use of chemical fertilizers and manures bring about change in the primary nutrient status of soils and their physico-chemical properties. Long term monitoring of soil fertility has shown a gradual decline with emergence of micronutrient deficiencies with unfavorable soil physical and biological environments. Manures and fertilizers along with intensive cropping are expected to effect the equilibria involving micronutrients also in soil-plant system. The information available on this aspect is scanty. With the above background, it was considered pertinent to study the status of micronutrients and different forms of Zn in soil as affected by continuous cropping and fertilizers use in Long Term Fert. Expt. in acid upland soil of Ranchi. It was observed that organic manuring and liming along with recommended levels of NPK fertilizers improved the physical condition of the soil. Soil samples from each plot were collected after harvest of wheat (95-96) and soybean (96-97) and analyzed for different soil properties and forms of Zn in soil. Grain and straw samples of wheat and soybean crops were analyzed for uptake of plant nutrients. There was little variation in mechanical composition (sand, silt and clay, due to continuous cropping & fertilization. The application of inorganic fertilizers decreased the soil pH which increased considerably by application of lime. Concentration o)NPK increased with increasing dose of inorganic fertilizers in both soil and plants. An increase on available micronutrient cation concentrations in soil and plants was observed with application of FYM + NPK. Availability of micronutrient cations in soil increased with increase in soil acidity. D.T.P.A. extractable micronutrients in soils decreased with lime application. Application of NPK + FYM maintained higher available micronutrient contents in soil as compared to N, NP, NPK, NPK + lime applied plots. All the forms of Zn in soil were found higher in NPK + FYM plot as compared to those in N, NP, NPK and NPK + lime plots. Different forms of Zn decline with application of NPK + lime. Among the soil zinc forms, water soluble and exchangeable forms showed their lower levels as compared to other forms. Total uptake of N, P, K, Fe, Mn, Zn and Cu by wheat + soybean was found to be highest in 100 per cent NPK + FYM treatment. In N and NP plots, plant nutrient uptake values were significantly low. Correlation studies revealed significant relationship among different forms of zinc in soil. Different fractions of Zn positively and significantly correlated with organic carbon and clay contents of soils. Results clearly point out the effect of balanced use of plant nutrients on soil fertility and crop yields. Monitoring of different chemical forms of Zn also suggests the need of integrated and balanced use of plant nutrientsEnglishThesis