A preliminary precision rice management system for increasing both grain yield and nitrogen use efficiency

How to ensure both food security and sustainable development is one of the largest challenges in the 21st century. Over 10% of the world's population is still chronically malnourished today. Our environment has been severely degraded by agricultural systems in many parts of the world. Precious agricultural resources are not efficiently utilized, but regrettably wasted in large quantities. Precision agriculture has the potential to improve crop yield, resource use efficiency and at the same time, protect the environment. However, current precision agricultural research has mainly focused on improving resource use efficiencies, without much impact on yield. Here we developed a preliminary integrated precision rice (Oryza sativa L.) management (PRM) system by combining site-specific nutrient management with alternate drying and wetting irrigation and optimized transplanting density, with the aim to increase both yield and nitrogen (N) use efficiency (NUE). It was compared with a high efficiency system optimizing nutrient and water management (HEM), a high yield system optimizing transplanting density and water management (HYM) and farmer's practice (FP) in an on-farm plot experiment conducted in 2010 and 2011 in Northeast China. It was further evaluated in three on-farm demonstration experiments conducted in 2010. Our results show that this PRM system increased grain yield by 10% and NUE by 51-97% over FP. The on-farm results show that it increased yield by 16% and N agronomic efficiency by 27%. The HEM system improved NUE by 46-63% over FP, without significantly affecting yield. The HYM system increased yield by 11% and NUE by 19-89% over FP. Compared with HEM system, the PRM system increased grain yield by 10% and NUE by 1-33%. Compared with HYM system, the PRM system achieved similar yield, but increased NUE by 5-27%. It is concluded that the preliminary integrated PRM system can optimize both grain yield and N use efficiency better than either the high efficiency or the high yield management system. This study demonstrates the potential of precision crop management to simultaneously contribute to food security and sustainable development.