Advisor: Guldekar, Dr. V. D.Authors: GOPNARAYAN, POOJA PRABHAKAR.2022-03-232022-03-232022-10-28Citation: GOPNARAYAN, POOJA PRABHAKAR. (2021). Nitrogen dynamics under long term Sorghum-Wheat cropping sequence in vertisols. Department of Soil Science and Agricultural Chemistry, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. M. Sc. 2021. Print. xii, 76p. (unpublished).https://krishikosh.egranth.ac.in/handle/1/5810183747Description: The research work was carried out during rabi season of 2020-2021 at National Highway Block, Central Research Station, Department of Soil Science and Agricultural Chemistry, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra. The experiment was laid out in Randomized Block Design (RBD) with twelve treatments and four replications. The variety adopted was AKW-4627 (Wheat).Abstract: The present investigation entitled “Nitrogen dynamics under long term sorghum-wheat cropping sequence in vertisols” was undertaken during 2020-21 (i. e. 33rd cycle) on existing AICRP Long Term Fertilizer Experiment initiated during 1988 (Kharif). The twelve treatments replicated four times in a randomized block design comprising various nutrient management practices. The soil of the experimental site was Vertisols, particularly montmorillonitic type, Hyperthermic family Typic Haplusterts. The soil was slightly alkaline reaction, medium in organic carbon, low in available nitrogen, low in available phosphorous and high in available potassium. The result revealed that, there was significant increase in soil organic carbon, total N and available N, available P, available K to the extent of per cent, 41.10%, 38.20%, 61.41%, 62.53% and 27.23% respectively as compared to initial soil status. The status of various N fractions of surface as well as subsurface soil was improved with the application of RDF in combination with FYM. The N fractions evaluated and showed an appreciable buildup under 100% NPK + FYM @ 5 t ha-1 followed by 75% NPK + 25% N through FYM in all depths. In surface soil, the magnitude of relative abundance of N fractions in soil followed the order of mineral-N > NO3-N > NH4-N which contributed to the extent of 7.77% > 6.68% > 6.40% of total N, respectively. Similar trend was also observed in subsurface soil. The grain and straw yield of wheat was correlated significantly with different fractions of N. The application of 100% NPK + FYM @ 5 t ha-1 recorded highest yield of wheat. Sulphur and zinc both the application significantly enhanced the yield of wheat. The NPK uptake generally followed the similar trend as that of yield of wheat. The results indicate that application of RDF along with FYM increased the availability of nutrients in soil. Hence, it can be concluded that for sorghum-wheat sequence integrated use of RDF along with FYM is essential to obtain maximum productivity on sustainable basis particularly for maintaining soil fertility.EnglishThesis