长期施肥对灌淤土养分状况变化的影响

Influence of Long-term Fertilization on the Nutrient Status in Irrigation Silting Soils

探明灌淤土耕地在常规施肥下土壤养分状况变化及其与施肥关系,为灌淤土培肥及养分资源管理提供理论依据。采取统计分析的方法,阐明灌淤土4个代表性监测点常规施肥20年(1987-2006)来土壤养分含量变化及其与施肥量的关系。灌淤土长期耕作施肥20年后,土壤养分状况变化较为明显。其中,土壤有机质和土壤氮磷养分含量均表现出上升趋势,土壤有机质含量平均累计增加6.16 g/kg,年均增加0.32 g/kg,土壤全氮含量累计增加0.083g/kg,年均增加0.004 g/kg,土壤碱解氮、有效磷含量的年均增量分别为1.98,3.9 mg/kg;土壤速效钾含量呈现出下降趋势,平均累计减少63 mg/kg,年均减少3.3 mg/kg。灌淤土20年施肥监测结果表明,该土壤应采用有机、无机肥料相结合的施肥方式,合理调整化学肥料施肥比例,适当控制磷肥用量,增加氮素和钾素肥料用量,达到施肥平衡,提高耕地生产能力和培肥土壤的目的。

Soil nutrients and the amount of fertilizer under constant fertilization in irrigation silting soils were studied in 20 years. Fertilization and administration suggestion were indicated based on the study in irrigation silting soils. Four long-term experiment sites of irrigation silting soils were monitored in Xinjiang province from 1987 to 2006. The changes of soil nutrients were investigated. The relationship between soil nutrients and the amounts of fertilization application was analyzed on the four sites. The result showed that soil organic matter, nitrogen and phosphor contents increased under long-term fertilizer for 20 years. Soil organic matter, total nitrogen contents increased 6.16 g/kg, 0. 083 g/kg. Averaging increment is 0.32 g/kg per annum and 0.004 g/kg respectively. Moreover, the values of alkali hydrolyzed nitrogen and available phosphorus contents increased per year were 1.98 mg/kg and 3.9 mg/kg. On the other hand, soil available potassium decreased 63 mg/kg for the 20 years, the average annual reduction is 3.3 mg/kg. The results indicated that It is an appropriate way to combine mineral fertilizer and application in this soil. it is suggested that increasing N and K fertilizers and controlling P fertilizer and reasonably adjusting fertilization ratio should be considered. Therefore, the fertility of irrigation silting soils and production capacity would be maintained or improved.