水肥条件对小麦、玉米N、P、K吸收的影响

水、N是影响作物N、P、K吸收的重要因素。通过对 6个水分等级和 5个N肥等级相互搭配的研究结果表明 ,高水、高N处理不利于小麦N吸收 ,而玉米是耐肥作物 ,相同灌水条件下 ,玉米的吸N量随施N量的增加而增加。在低灌水条件下 (W 0、W 1处理 ) ,玉米子粒吸N量很低 ,变幅为 0～17.3kg/hm2,并且不受施N量的影响 ;而小麦子粒吸N量仍达 36.6～154.2kg/hm2。小麦与玉米吸P量的变化趋势与吸N量的变化趋势非常接近。但是 ,作物的吸K量随灌水量增加有明显增加的趋势 ,在玉米上表现尤其明显 ,并且作物的吸K量主要存在于茎秆中 ,因此 ,在当地推广和宣传秸秆还田很有必要

N,P,K uptake by winter wheat and maize as influence by different combinations of irrigation water and nitrogen fertilizer

Irrigation water and nitrogen fertilizer are key factors governing N, P, K uptake by crops. By studying on different combinations of irrigation water and nitrogen fertilizer which consist of six levels of irrigation water and five levels of N fertilizer, the experiment showed that treatments with high levels of irrigation water and high levels of nitrogen fertilizer were unfavorable for N uptake by winter wheat, while maize was fertilizer tolerable crop and the amount of N uptake by maize increased with nitrogen fertilizer when irrigation water remained constant. When irrigation water was in low level (such as: level of W0 or W1), the amount of N uptake by maize grain was very low which ranged from 0 to 17.3kg/hm² and was independent of applied nitrogen fertilizer, while the amount of N uptake by wheat grain reached as high as 36 6 to 154.2kg/hm². The curve of P uptake by both winter wheat and maize was similar to that of N uptake. However, the amount of K uptake by both of them increased with irrigation water, especially for maize. Moreover, most of absorbed K disturbed in the straw. Therefore, it is very important for us to publicize returning straw back to the farm field after harvest.