不同水分条件下化肥对玉米产量的贡献

以16年长期定位试验为平台,研究了8种施肥制度与4种降雨年景条件下肥料的增产、稳产性能及其对产量的贡献。结果表明:施肥与水分条件对玉米产量均有显著影响,平水年份玉米产量最高,肥料增产效果也达到最佳,其次为丰水年,旱、涝年份最低;N、P和K配施玉米产量最高,无N肥处理作物产量偏低,但在旱、涝条件下P、K肥有利于提高玉米的抗逆性;对玉米产量贡献NPK,单施K肥其在平、丰水年对产量贡献率为负值,说明这一地区K尚未成为玉米生产中的限制因子,其只有与N肥配施才可发挥增产作用。综上,合理的养分配施可以提高肥料对玉米产量的贡献,促进肥料交互作用对产量的提升,同时,适宜的水分条件可使肥料增产作用更好发挥。

Contribution of fertilizers to maize yield under different precipitations

Based on a 16-year located experiment, this paper studied the yield-increasing effect, yield-stabilizing feature and contribution rate of fertilizers to maize yield under different fertilization and precipitation conditions. The results showed that fertilization and precipitation had obvious influences on crop output. In normal precipitation years the yields were the highest and the yield-increasing effect of chemical fertilizers was the best. In the higher precipitation years the yield was the highest under NPK treatment and was lower under non-nitrogen treatments, but P and K could increase the stress resistance of maize. The contribution rate of chemical fertilizers to maize yield was N>P>K and maize yield under K treatment was lower than CK treatment in normal or higher precipitation years. It suggests that K was not a limiting factor for crop yield and K could increase maize yield when applied with N. Proper nutrients and water supply would improve the contribution rate of fertilizers to maize yield and promote the interaction between fertilizers on yield-increasing effect.