长期定位连施化肥的增产培肥效应研究

Effects of Long-term Located Chemical Fertilizer Application on Yield and Soil Fertility

河西走廊灌区质地中壤的灌漠土上,21年的长期定位试验表明,化肥在作物增产中起主导作用。无有机肥条件下连年施用化肥比无肥处理增产粮食19.6%～300.5%,比有机肥增产16.2%～101.6%;生产力水平为90.9%～97.9%;对粮食增产贡献率平均达50%。连续平衡施用化肥对土壤养分的直接影响不均衡,土壤有机质含量连续19年下降了24.9%～27.4%;土壤全N比初始年提高13.7%～46.1%,速效N含量稳中下降的动态;土壤全P含量增效甚微,比初始年提高4.4%～5.1%,速效P含量稳中有增,提高了16.3%～19.1%;土壤K素库处于长期亏缺状态,速效K含量稳步降低的动态。化肥养分具有明显地间接培肥效应,在生物循环中以有机肥为载体下年输入土壤的N、P、K化肥养分分别占当年投入量的27.1%～31.3%,23.8%～27.0%和33.2%;化肥增产的秸杆有机C输入下年土壤的达567.3～626.7kghm-2。证明有机肥中相当一部分养分来自化肥及其化肥的生产物。

The long-term located experiment for 21 years was carried out on an irrigated desert soil in Hexi corridor, Gansu province. The results showed that the yield-increase effect of chemical fertilizer was the most significant in all treatments. The effect of long-term balanced chemical fertilizer application on soil nutrients was different. The content of organic matter in soil declined by 24.9%-27.4% but the content of soil total nitrogen was （TN） increased by 13.7%-46.1%. The content of available N declined, but the content of soil total phosphate （TP） and available phosphate were increased by 4.4%-5.1% and 6.3%-19.1%, respectively. The K content in the soil was deficient, so the content of available K decreased gradually. The effect of indirect developing soil fertility of chemical fertilizer was very significant. The proportion of N, P and K in soil came from organic manure was 27.1%-31.3% ,23.8%-27.0% and 33.2% of total inputs through biocycle.