Saini, S.P.Prabhjot Singh2021-01-122021-01-122020Prabhjot Singh (2020). Effect of long-term integrated nutrient management on the availability of micronutrients in soil under rice-wheat cropping system (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810159885The present research study was conducted to investigate the effect of long-term integrated nutrient management on the availability of micronutrients in soil under rice-wheat cropping system. The experiment was carried out in the ongoing long-term fertilizer experiment initiated during 1999 at research farm of Department of Soil Science, Punjab Agricultural University, Ludhiana. The experiment was conducted in randomized block design with nine treatments replicated three times for rice-wheat cropping system by growing PR 126 (rice) and Unnat PBW 550 (wheat) varieties during 2017-18. There were total of nine different treatments comprising control, 50% NPK+FYM, 50% NPK+GM, 100% NPK, 100% NPK (P wheat), 100% NPK+FYM, 100% NPK+GM, 100% NPK+SI and 150% NPK. The soil of the experimental area was loamy sand in texture, (Typic Ustrocherpt), low in soil organic C, available-N and K, medium in, P. Surface and sub-surface soil samples were collected after harvest of wheat crop and analyzed for different micronutrient cations (Zn, Fe, Mn and Cu) and various chemical properties of soil in 2018. Highest nutrient uptake, yield and yield contributing attributes in wheat and rice crop were recorded under treatments with conjunctive use of inorganic fertilizers and organic amendments. Micronutrients content and its uptake in both wheat and rice at different growth stages (max. tillering and anthesis) was increased with graded dose of fertilizers and highest content and uptake of micronutrients was recorded in 100% NPK+FYM treatment as compared to other treatments. Various soil properties such as SOC, available N, available P and available K improved with the continuous application of fertilizers and organic amendments. On the contrary, soil pH decreased with integrated nutrient management system. Use of organic amendments along with chemical fertilizers also led to Zn-fortification of grains in both wheat and rice crops. Availability of DTPA-extractable micronutrient cations also increased with long-term use of fertilizers and organic amendments. Periodic changes in micronutrients availability might be due to decrease in soil pH and increase in SOC over period of time.EnglishThesis