Effects of irrigation and nitrogen management on hybrid maize seed production in north-west China

Scientific irrigation and nitrogen management is important for agricultural production in arid areas. To quantify the effect of water and nitrogen management on yield components, biomass partitioning and harvest index (HI) of maize for seed production with plastic film-mulching, field experiments including different irrigation and N treatments were conducted in arid north-west China in 2013 and 2014. The results indicated that kernel number per plant (KN) was significantly affected by irrigation and N treatments. However, 100-kernel weight was relatively stable. Reducing irrigation quantity significantly increased stem partitioning index (PI<inf>stem</inf>) and leaf partitioning index (PI<inf>leaf</inf>), and decreased ear partitioning index (PI<inf>ear</inf>) at harvest, but lowering N rate (from 500 to 100 kg N·hm^-²) did not significantly reduce PI<inf>stem</inf>, PI<inf>leaf</inf>, and PI<inf>ear</inf> at harvest. HI was significantly reduced by reducing irrigation quantity, but not by reducing N rate. Linear relationships were found between KN, PI<inf>stem</inf>, PI<inf>leaf</inf>, PI<inf>ear</inf> at harvest and HI and evapotranspiration (ET)