灌溉施肥深度对玉米同化物分配和水分利用效率的影响

EFFECT OF FERTIGATION DEPTH ON DRY MATTER PARTITION AND WATER USE EFFICIENCY OF CORN

以夏玉米 (ZeamaysL .) (陕单 9号 )为供试材料 ,采用置于遮雨棚下的模拟土柱的方法 ,进行了不同灌溉施肥深度对夏玉米生长发育、地上与地下部分同化物分配、产量及水分利用效率的影响的试验研究。灌溉施肥深度分 4个处理 :表面灌施 ;2 0cm深度灌水施肥 ;30cm深度灌水施肥和 40cm深度灌水施肥。后 3个处理为土表下灌施处理。 4个重复。试验结果表明 :土表下灌施抑制了玉米生育早期的地上部分生长 ,使根系向土壤中下层的分布加强 ,从而保证了作物中后期对水分养分的吸收利用 ,提高了水分利用效率。在本试验条件下 ,玉米生长的最佳灌施深度为 30cm。

Research has shown that plants are adversely affected by different wetting and fertilized zones. Most studies that have been done were limited to the effect of irrigation or fertilization. This study was done to detect the influence of various fertigation (fertilization+irrigation) depths on the growth, dry matter partition, yield and water use efficiency of corn. Corn ( Zea mays L.)plants were established in the growth chamber in soil_filled polyvinyl chloride tubes, 67 cm long and with an outer diameter of 11 cm. Soil was well fertilized and wetted to field capacity at emergence when four treatments were imposed: 1) tubes were fertigated from the top soil (D 0); 2) tubes were fertigated on the depth of 20 cm from soil surface (D 20 ); 3) tubes were fertigated on the depth of 30 cm from soil surface (D 30 ); and 4) tubes were fertigated on the depth of 40 cm from soil surface (D 40 ). Soil moisture profiles, corn height, leaf area, shoot weight, root weight and yield were measured. The results show that the fertigation depths of 20 cm, 30 cm, 40 cm restrained shoot growth in early stages, strengthened the partition of roots in deep soil, and ensured the absorption and application of corn to water and nutrients, then raised water use efficiency. Under experimental conditions, the fertigation depth of 30 cm was optimal for corn. The reasons for these results, which lead to strenghen the absorption and application of corn to water and nutrient under different fertigation depths, and which raise water use efficiency under same conditions, are discussed.