平衡施肥对大棚茄子-水稻轮作土壤中作物生产和土壤养分的影响

Effects of balanced fertilization on crop production and soil nutrient status under long-term greenhouse eggplant-rice rotation system

通过田间试验研究平衡施肥对长期大棚茄子-水稻轮作制中2季作物生长和土壤养分的影响。结果表明:N是现阶段土壤的主要养分限制因子,P、K则不成为土壤养分限制因子,连续2季不施用P、K对作物产量、养分含量和吸收量无显著影响;轮作周期内最佳施肥量处理(OPT)的地上部N总累积量为314.2kg.hm-2,其中土壤N供应量分别占大棚茄子季和水稻季N累积量的63.0%和72.9%,N肥的当季利用率仅为10.85%和24.9%;2季地上部P2O5和K2O的总累积量分别为159.5和543.9kg.hm-2,土壤P和K的供应量均超过了90%,P肥和K肥的2季总表观利用率分别为11.5%和8.6%;减少总施N量和N肥后移至水稻季的施肥措施均可增加作物地上部养分累积量,大棚茄子季和水稻季的适宜施N量分别是450和150kg.hm-2,可比常规施肥量分别减少55%和33.3%;水旱轮作可有效地消耗土壤养分,但大棚茄子长期高量施肥累积的养分仍有向下层土壤迁移的趋势。

A field experiment was conducted to study the effects of balanced fertilization on the crop production and soil nutrient status within two crop growing seasons under long-term greenhouse eggplant-rice rotation system. The results showed that N was the main limited factor for soil nutrients at the current stage, while P and K were not the case for crop yields, nutrient absorption and contents in two crop growing seasons. The total accumulation of N overground in optimum treatment （OPT） during the rotation period was 314.2 kg. hm^-2, which accounted for 63.0% and 72.9% of supplying amounts of soil N in the period of greenhouse eggplant and rice respectively, and the corresponding apparent use efficiency of N was only 10.85% and 24.9%. The total accumulation of P2O3 and K2O overground during the rotation period were 159.5 and 543.9 kg. hm^-2, respectively. The supplying amounts of soil P and K both exceeded 90%, and the apparent use efficiency of P and K was 11.5% and 8.6%, respectively. Both decreasing the N application and delaying the N application time to the rice season could enhance the total nutrient absorption. The suitable nitrogen application rates for the greenhouse eggplant and rice were 450 and 150 kg.hm^-2, respectively, decreasing by 55% and 33.3% as compared with the traditional fertilization. The paddy-upland rotation could effectively utilize the soil nutrients which were accumulated by the heavy fertilization in the greenhouse season, but the soil nutrients still had the tendency to move into deeper soil layers.