| Water and fertilizer are two indivisible factors for crop growth, and the most important factors for restricting the agricultural development of semi-drought aera in western Liaoning. Under dry shed rain and drip irrigation fertilizer conditions, with "311-B" D optimized saturation design field micro-plot trials were conducted to study effects of water and fertilizer coupling on spring maize in order to establish wate-fertilizer regression mathematic mode. The results showed that the same trend was found in the changes of plant height, stem diameter and aboveground biomass of different treatments at entire growth stage, the degree of tested factors influencing plant height and stem diameter was in order to N> water> P, and the effects of water-fertilizer coupling is N-water coupling> N-P coupling> P-water coupling indicating the positive effect of three factors coupling. The effect of water and N fertilizer on dry matter accumulation was not obvious at initial stage of spring maize, and after jointing stage this effect increased with the most obvious positive-effect of N fertilizer. At the same N application rate, dry matter accumulation was higher in high irrigation amount treatment than in low irrigation amount treatment, however, P application rate had no significant effect on dry matter accumulation. Under test conditions, the most important factor influencing spring maize yield was N application rate, next was irrigation amount and P application rate. The synergistic effect of test factors on yield was N-water> N-P> P-water. N-P coupling and N-water coupling were stimulative interacton, and P-water coupling was fungible interaction. Marginal yield decreased in the order of water> N> P. Considering of the yield, it was suggested that the combination of high N application rate (256.92 kg·hm-2), high P application rate (133.64kg·hm-2) and abundant irrigation amount (irrigation threshold was 64.4% of water holding capacity) would be the best. |
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