Influence of Nitrogen Management Regimes on Milling Recovery and Grain Quality of Aromatic Rice in Different Rice Production Systems

To examine the effect of nitrogen (N) management regimes on rice quality in different rice production systems, a field experiment was conducted in 2017 and 2018. The experimental treatments comprised of two production systems (transplanted rice: TPR and dry direct-seeded rice: DDSR) and six N management treatments (0, 50, 100, and 150 kg N ha(-1) as basal, and 100 and 150 kg N ha(-1) in three splits which were regarded as N-1, N-2, N-3, N-4, N-5, and N-6, respectively). The results revealed that the rice quality attributes, i.e., broken rice recovery, abortive kernel, bursting, and curling were increased by 8%, 14%, 8%, and 14%, respectively, under DDSR than TPR. In the case of N management, split application of N reduced the chalky kernel (44%), abortive kernel (23%), opaque kernel (31%), bursting (24%), and curling (31%), while kernel protein contents, water absorption ratio, cooked grain length, and elongation ratio were increased by 41%, 88%, 25%, and 26%, respectively, as compared to the basal application of N. In short, DDSR cultivation reduced the appearance and cooking quality traits but white head rice recovery and nutritional quality were comparable to TPR. However, N application in splits either in DDSR or in TPR potentially improved the grain quality of rice compared with the basal application.