Effect of INM in aromatic rice (Oryza sativa) under SRI and its residual effect on wheat (Triticum aestivum)

Abstract

The field experiment was conducted at the Agricultural Research Farm, Banaras Hindu University, Varanasi, India during two consecutive rainy (kharij) and winter (rabi) seasons of 2015-16 and 2016-17 in split plot design to study the effect of integrated nitrogen management (INM) [100% recommended dose of nitrogen (RDN: 120 kg N/ha), 75% RDN + 25% N through Azolla microphylla, 75% RDN + 25% RDN through NADEP compost, 75% RDN + 25% RDN through sewage sludge and 75% RDN + 25% RDN through vermicompost] in aromatic rice (Oryza sativa L.) varieties (HUR-4-3, HUR-105, NDR-6093 and Rajendra Kasturi) under system of rice intensification and its residual effect on productivity of succeeding wheat (Triticum aestivum L.). The results of the study revealed that the variety HUR-4-3 and the INM with 75% RDN + 25% N through Azolla microphylla were found superior in terms of enhanced growth, yield attributes, yield, nutrient uptake, milling quality and length-breadth ratio (L/B) before cooking as compared to rest of the varieties and integrated nitrogen management, respectively. It was found that soil microbial population get improved when 75% RDN was coupled with 25% N through Azolla microphylla. Further, higher gross income, net return and output-input ratio were attributed to the variety Rajendra Kasturi (177.47x103 130.35x!03 ?/ha and 3.79, respectively) and the application of 75% RDN + 25% N through Azolla microphylla (162.21 x 103 117.14x 103 ?/ha and 3.6, respectively). Moreover, varieties did not show marked effect on yield of the succeeding wheat while significant yield enhancement was evident as a result of nitrogen management in preceding rice with 75% RDN + 25% N through Azolla microphylla.