Advances in researches of yield and environmental effect of alternate furrow irrigation with separated water and N fertilizer supply on summer maize

Water shortage, lower fertilizer use efficiency, contaminant of ground and surface water have become serious issues in agricultural production and countryside ecosystem safety, needing to be worked out urgently in China now. Developing water saving and fertilization efficient techniques are attempted as effective solutions to these issues. In this paper, we introduced the origin, developing history of alternate furrow irrigation with separated water and N fertilizer (AFISWN), as well as the economic and environmental effects. AFISWN is one of water saving techniques, based on the deficit irrigation or part root drying irrigation. It effectively cuts down irrigating quota, increases water use efficiency and prevents nitrate deep leaching etc. It also mitigates the ammonia volatilization and N₂O emission, and enhances yields under optima water and N rate. However, the effects of AFISWN are closely related with the irrigating quota, N rate, plant density and environmental conditions, such as rainfall and frost etc. The technique parameters need to be modified in the practices for specific area. For this purpose, temporal and spatial distribution and transformation of water and nutrients in soil need to be investigated more carefully; the mechanism of water and nutrient uptake and regulating by plants also needs to be comprehensive studied.