Suman, S.N.Minz, Suman2020-12-042020-12-042020M/SS/336/2018-19https://krishikosh.egranth.ac.in/handle/1/5810156273Field experiment” was evaluated after seven years to study the “Long-term effect of soil test crop response based fertilizer recommendation on soil N-fractions under rice-wheat cropping system” during Kharif season in 2019-20. Experimental design of the present investigation was RBD which comprising with the 9 treatments viz. T1 - Control, T2 - Farmers Practice (97:57:33 N: P2O5: K2O kg ha-1), T3 – RDF (120:60:40 N: P2O5: K2O kg ha-1) , T4 -Y1 without IPNS (desired targeted yield with 3.5 t/ha), T5 –Y2 without IPNS (desired targeted yield with 4.0 t/ha), T6 –Y3 without IPNS (desired targeted yield with 4.5 t/ha), T7 - Y1 with IPNS (desired targeted yield with 3.5 t/ha) , T8 - Y2 with IPNS (desired targeted yield with 4.0 t/ha) , T9 - Y3 with IPNS (desired targeted yield with 4.5 t/ha) and 3 replications. The purpose of the whole investigation was to study the effect of long-term STCR technology on yield attributing characters, yield and uptake of N, P and K by the rice crop, soil nitrogen fractions, biological and chemical parameters of post-harvest soil under “rice-wheat cropping system in calcareous soil of Pusa”. Among all the treatments, maximum improvement in yield and yield attributing characters of rice crop was recorded in treatment T9 - Y3 with IPNS (desired targeted yield with 4.5 t/ha). It was observed that maximum value of biological and chemical parameters of post harvest soil recorded in treatment T9 - Y3 with IPNS (desired 10 targeted yield with 4.5 t/ha) over the control where no inorganic or organic sources were applied. Post-harvest surface soil samples (0-15 cm) were analyzed for soil nitrogen fractions, biological and chemical properties after the harvest of 7th rice crop under “rice-wheat cropping system” in calcareous soil. Integration of fertilizers along with compost (5 t ha-1) had found to be effective and resulted to give a significant improvement in soil nitrogen fractions. The higher value of soil inorganic nitrogen fraction (NO3--N+ NH4+-N) was obtained in T9 - Y3 with IPNS (98.9 mg kg-1) and the lower value was obtained in T1 - control plot (68.4 mg kg-1). Among organic fraction of nitrogen in soil, total hydrolysable nitrogen varied significantly from 228.60 mg kg-1 in control plot to 305.50 mg kg-1 in T9 - Y3 with IPNS, non-hydrolysable nitrogen varied significantly from 106.30 mg kg-1 in control plot to 125.80 mg kg-1 in T9 - Y3 with IPNS. The higher value of total soil nitrogen was obtained in T9 - Y3 with IPNS (530.2 mg kg-1) and lower value was obtained in T1 – Control plot (403.30 mg kg-1). Significantly Positive correlation was obtained among the various nitrogen fractions and between available nitrogen, organic carbon and with plant parameters which indicated that different fractions of soil nitrogen were present in the dynamic equanimity within the soil and improves the nutrient availability and nutrient uptake by the rice crop. Contribution on the percentage basis of different nitrogen fraction viz. NO3--N, Ex. NH4+-N, non- hydrolysable nitrogen and total hydrolysable nitrogen were 6%, 12%, 25% and 57% respectively and among total hydrolysable nitrogen hexose amine-N, hydrolysable NH4+-N, amino acid-N and hydrolysable unidentified-N were 8%, 26%, 31% and 35% respectively. The significant positive change was observed for nitrogen under T9 - Y3 with IPNS, T8- Y2 with IPNS and T3- RDF than the initial value of soil nitrogen. Soil Test Crop Response based fertilizer application along with the integration of Plant Nutrient System, T9 - Y3 with IPNS was found to be effective to achieve desired targeted yield by the rice crop and also in improvement of different organic and inorganic soil nitrogen fractions.EnglishThesis