Productivity and profitability of mechanized deep nitrogen fertilization in mechanical pot?seedling transplanting rice in South China

The deep nitrogen (N) fertilization coupled with mechanical pot-seedling transplanting rice (DNF-MPT) is an effective alternative to traditional transplanted (Oryza sativa L.) broadcasting fertilizer; however, little known about its effects on grain yield, nutrient accumulation, and economic profitability. In present study, a 2-yr field experiment was conducted in early seasons (Mar.–July) of 2019 2020. All seedlings were by DNF-MPT, whereas four treatments designed as mechanized placement all fertilizers basal fertilizer (MD); 70% 30% at panicle initiation (MDB); manual 40, 30, the transplanting, tillering, stages, respectively (MB); no (CK). results indicated that MD treatment substantially improved yield 33.48–36.35%, total N accumulation 26.38–44.15%, phosphorus (P) 28.72–30.23%, potassium (K) 25.61–37.33% compared MB. Deep treatments, is, MDB, remarkably promoted root morphological indexes including volume, length, superficial area. Furthermore, nitrate reductase, glutamine synthetase activities, chlorophyll content leaves also enhanced under fertilizer. Overall, had highest benefit/cost ratio due high gross returns low input costs. Therefore, could be better conventional production system more benefits.