Mondal, Asim KumarKaur, Paramdeep2020-12-022020-12-022020-09-28J-17-M-516https://krishikosh.egranth.ac.in/handle/1/5810156124Considering biofertilizer use in basmati rice to manage nitrogenous fertilizers being increasing day by day, an investigation entitled “Effect of nitrogen fixing biofertilizer on its dynamics and its use efficiency in irrigated basmati” was conducted at the research farm of division of Soil Science and Agriculture Chemistry, Chatha SKUAST-Jammu. The objectives of this study were assessment of nitrogen dynamics with different biofertilizer for better nitrogen use efficiency in basmati-370, and to standardize the fertilization dose. The experiment was laid out in randomized complete block design (RCBD) with following treatments: T1: Control (unfertilized), T2: 100% recommended chemical nitrogenous fertilizers, T3: Blue green algae @ 5 kg ha-1, T4: Azospirillum (root dip method), T5: Azolla @ 10 q ha-1, T6: 75% RNF¥ plus BGA @ 5 kg ha-1, T7: 75% RNF¥ plus Azospirillum (root dip method), T8: 75% RNF¥ plus Azolla @ 10 q ha-1, T9: 50% RNF¥ plus BGA @ 5 kg ha-1, T10: 50% RNF¥ plus Azospirillum (root dip method) , T11: 50% RNF¥ plus Azolla @ 10 q ha-1. The soil of the experimental field was sandy clay loam in texture, slightly alkaline pH in reaction, low in available nitrogen and phosphorus and medium in potassium, organic carbon and electrical conductivity in the safer range. The application of integrated use of different biofertilizers along with inorganic nitrogen source significantly improved the growth parameters i.e., plant height, number of tillers, dry matter accumulation that led to the increase in yield attributes which resulted in increase in yield. Moreover, significant relation were found between various growth and yield parameters viz., plant height at 60 DAT and at harvest, dry matter accumulation at 60 DAT and at harvest, number of effective tillers, number of grains per panicle, 1000 grain weight, uptake of N, P K, yield of basmati in grain and straw. The pH and electrical conductivity ranges from 7.27 to 7.35 and 0.14 to 0.19 dSm-1 respectively. The organic carbon ranges from 3.65 to 3.85 g kg-1 and microbial biomass carbon ranges from 79.98 to 110.63 mg kg-1. The significantly highest value of available nitrogen, phosphorus and potassium was obtained in treatment 75% RNF¥ plus BGA @ 5 kg ha-1 (T6) with the value of 146.10, 12.30 and 134.63 kg ha-1 in soil at harvest. Uptake of N, P and K were 42.70, 7.30 and 3.52 kg ha-1 in grain, and 41.18, 7.56 and 20.17 kg ha-1 in straw, respectively. Significantly highest yield was recorded in treatment 75% recommended chemical nitrogenous fertilizers plus BGA @ 5 kg ha-1 which was at par with 75% RNF¥ plus Azospirillum (root dip method) T8. The highest return in terms of rupees and benefit cost ratio was obtained in treatment T6 (2.03). It was concluded that the application of different biofertilizer along with chemical fertilizers can be regarded as best management practice for better soil chemical and biological properties thus yield of basmati under irrigated condition. However, 75% recommended chemical nitrogenous fertilizers plus BGA was effective in terms of increase in grain yield up to 29 % and even shows improvement in yield attributes, nutrient uptake including growth parameters of basmati-370.English36564Thesis