长期施肥对春玉米耕层土壤养分和肥料贡献率的影响

Effect of Long-term Successive Fertilization on Soil Nutrients and Fertilizer Contribution Rate

为明确连续施氮对耕层土壤养分变化和肥料贡献率的影响,以辽北昌图2007-2016年的长期定位施肥试验为依托,从不同施氮水平和施氮方式两方面入手,共设置9个处理,研究长期连续施肥对耕层土壤养分变化及春玉米产量和肥料贡献率的影响。结果表明,氮肥在提高土壤有机质、全氮等养分方面受施氮量影响较大,而施氮量相同时与施肥方式无明显关系,长期连续不施氮肥使土壤有机质、全氮含量在维持原有水平下略有下降,增施氮肥后,无论哪种施肥方式,都可以增加土壤速效养分含量,有利于培肥地力。氮肥对玉米的增产作用已有研究,但是当化学肥料用量已经能够满足作物正常生长需要时,继续提高氮肥用量不能实现作物产量的持续增加,因此玉米高产应为中氮用量,10 a后肥料贡献率从高到低分别是N2>N3>N常>N1,与10 a平均结果相一致。因此,氮肥是影响春玉米耕层土壤养分变化的重要元素,缺氮使土壤养分贮量和供应能力随种植年限的延续而下降,适量氮肥与磷钾配施可使耕层土壤有效养分维持平稳增加。本试验区域内推荐氮肥用量为241.5 kg/hm^2,拔节中期追施一次的农田操作方式即可达到维持土壤较高肥力水平和粮食增产的和谐关系。

The effects of different fertilization rates and fertilization methods on soil nutrients and yield of spring maize and fertilizer contribution rate under long-term continuous fertilization were studied.Through the long-term fertilization positioning test from 2007 to 2016 for 10 consecutive years in Changtu,Liaoning Province,9 treatments were set up from two aspects of different nitrogen application levels and nitrogen application methods.The results of soil nutrient,spring maize yield and fertilizer contribution rate were systematically summarized.The results showed that nitrogen fertilizer was greatly influenced by nitrogen application in improving soil organic matter and total nitrogen,while nitrogen application had no significant relationship with fertilization methods.Long term continuous non-application of nitrogen fertilizer reduced soil organic matter and total nitrogen content slightly.After adding nitrogen fertilizer,no matter which fertilizer was applied,the content of available nutrients in soil could be increased,which was beneficial to the fertility of the soil.The effect of nitrogen fertilizer on maize yield had been studied,but when the amount of chemical fertilizer had already been able to meet the needs of the normal growth of crops,the continuous increase of nitrogen fertilizer could not achieve the continuous increase of crop yield.Therefore,the high yield of maize should be matched with the amount of medium nitrogen.After 10 a,the contribution rate of fertilizer from high to low was N2>N3>Nnormal>N1,which was similar to average value of those of 10 a.Nitrogen fertilizer is an important element that affects the change of soil nutrients in the soil of spring maize.The nitrogen deficiency makes the soil nutrient storage and supply capacity decrease with the continuation of the planting years.The appropriate amount of nitrogen fertilizer and phosphorus can make the available nutrient of the soil increase steadily,also,the contribution rate of the fertilizer is improved on the premise of ensuring the high and stable yield of the maize.The recommended amount of nitrogen fertilizer in this experiment area is 241.5 kg/ha and a single application in the middle of jointing can maintain the high soil fertility and increase yield.