水肥耦合对小麦/玉米系统根系分布及吸收活力的调控

Regulation of water-fertilizer coupling on root distribution and absorbing ability in Triticum aestivum-Zea mays intercrop system

设计内径为30 cm的PVC管作为试验装置,模拟大田生长状况,在不同的水肥条件下,研究了间作条件下小麦和玉米的产量及其根系的生理生态特征.结果表明,适当的干旱(W2:60%～65%)有利于根系的下扎和产量的提高,严重干旱(W1:30%～35%)大大地降低了带田小麦和玉米的根量和产量,并增加了作物根系和叶片的质膜透性,同时根系活力也降低;供磷提高作物产量,增加下层根量,提高根系活力,供磷与不供磷相比,0～30 cm土层,小麦根系活力提高65.9%,玉米提高65.0%;小麦根系总量平均增加94.66%,玉米增加67.67%;小麦叶片细胞质膜透性平均下降8.33%,根系下降7.96%,玉米叶片平均下降1.62%,根系下降2.50%.不同处理之间比较,产量均以W2P1水平较高,说明其水肥耦合性最好.究其原因,其细胞质膜透性最低,根系活力、根量、根长均为最高.

Formulating field condition, the experiment was conducted by using the 30cm diameter PVC tube to investigate the effect of water-fertilizer coupling on crop yield and physiological and ecological character in Triticum aestivum-Zea mays intercropping system. The result showed that the root grew deeper and the crop yield increased with light water deficit. Under the condition of serious water deficit, both root fresh weight and root oxidation-reduction activity reduced significantly while the relative penetrability of cell membrane of root and leaf increased obviously. The result also indicated that phosphorus have high positive effect on root oxidation-reduction activity, root fresh weight and root length, which conduced to the yield increase. As opposed to no phosphorus treatment, phosphorus increased root oxidation-reduction activity of Triticum aestivum and Zea mays by 65.9% and 65.0%,respectively. In phosphorus supply, the root fresh weight of Triticum aestivum and Zea mays also increased by 94.66% and 67.67%,respectively. Contrarily, the average of relative cell membrane penetrability of root and leaf of Trticum aestivumdropped by 7.96% and 8.33%, those of Zea mays decreased only 2.50% and 1.62%, respectively. All these positive effects resulted that Triticum aestivum seed yield increase by 239.56% in phosphorus supply. In all the treatments,W 2P 1 was the best one.