水肥处理对辣椒保护地土壤pH值的影响

Effects of water-fertilizer treatment on pH value of protective farmland for capsicum cultivation

探讨辣椒保护地的水肥耦合效应,采用二次回归正交旋转组合设计,建立了灌水定额、氮肥和磷肥对辣椒保护地土壤pH值影响的数学模型。通过模型分析得出:在辣椒保护地土壤养分含量高和施肥量大的条件下,灌水定额、施氮和施磷对辣椒保护地土壤pH值影响的大小顺序为:灌水>施氮>施磷。大量施用氮肥可使土壤酸化,灌水和高量施磷可减弱酸化效应,灌水与施氮、施氮与高量施磷对土壤pH值表现为拮抗作用。维持保护地土壤pH值种植前后稳定的水肥措施:灌水定额为170.71 m3/(hm2.次),施氮量为235.98 kg/hm2,施P2O5为239.38 kg/hm2。合理的施肥和灌水,可以控制土壤的酸化。

In order to study the coupling effects of water and fertilizers,a regression model for the effects of irrigation water,nitrogen fertilizer and phosphate fertilizer on pH value of protective farmland for capsicum cultivation was established by means of the quadratic orthogonal rotatory combination design.The model test results showed that for the protective farmland with high content of soil nutrients and high amount of fertilizers for capsicum cultivation,the effects of the above three factors on the pH value of soil had the descending order of irrigation water,nitrogen fertilizer and phosphate fertilizer. Application of high amount of nitrogen fertilizer urged soil acidification,and their irrigation water and application of high amount of phosphate fertilizer might weaken the effects of soil acidification.The effects of the irrigation water and the application of nitrogen fertilizer,the application of nitrogen fertilizer and the application of high amount of phosphate fertilizer on the pH value of soil were antagonistic.Measures for irrigation water and fertilizers to maintain stable pH value of soil before and after capsicum cultivation were proposed： irrigation water quota of 170.71 m3·hm^-2·t^-1,application of N 235.98 kg·hm^-2 and application of P2O5 239.38 kg·hm^-2.A conclusion is drawn that rational fertilizers and irrigation water may control soil acidification.