PLoS ONE, 2014, Vol.9(1)
Maize grain yield varies highly with water availability as well as with fertilization and relevant agricultural management practices. With a 311-A optimized saturation design, field experiments were conducted between 2006 and 2009 to examine the yield response of spring maize (Zhengdan 958, Zea mays L) to irrigation ( I ), nitrogen fertilization (total nitrogen, urea-46% nitrogen,) and phosphorus fertilization (P 2 O 5 , calcium superphosphate-13% P 2 O 5 ) in a semi-arid area environment of Northeast China. According to our estimated yield function, the results showed that N is the dominant factor in determining maize grain yield followed by I , while P plays a relatively minor role. The strength of interaction effects among I , N and P on maize grain yield follows the sequence N + I 〉 P + I 〉 N + P . Individually, the interaction effects of N + I and N + P on maize grain yield are positive, whereas that of P + I is negative. To achieve maximum grain yield (10506.0 kg·ha −1 ) for spring maize in the study area, the optimum application rates of I , N and P are 930.4 m 3 ·ha −1 , 304.9 kg·ha −1 and 133.2 kg·ha −1 respectively that leads to a possible economic profit ( EP ) of 10548.4 CNY·ha −1 (CNY, Chinese Yuan). Alternately, to obtain the best EP (10827.3 CNY·ha −1 ), the optimum application rates of I , N and P are 682.4 m 3 ·ha −1 , 241.0 kg·ha −1 and 111.7 kg·ha −1 respectively that produces a potential grain yield of 10289.5 kg·ha −1 .
Research Article ; Agriculture ; Biology