三七不同间隔年限种植土壤氮、磷、钾含量动态变化规律研究

目的：研究三七不同间隔种植年限对土壤氮、磷和钾元素的影响。方法：对文山州马白、马塘、古木和盘龙4个三七道地产区新土、间隔5年土和连作土3种种植模式下土壤总氮、磷、钾和有效氮、磷钾含量进行动态测定。结果：土壤全氮、磷和速效氮、磷含量变化均表现为间隔5年土 >连作土 >新土;3种间隔种植模式土壤除全氮含量无显著季度变化外,其他三者均呈倒“V”型,含量峰值出现于2010年4月;土壤全钾含量变化无显著差异,但速效钾含量变化表现为新土 >连作土> 间隔5年土,季度变化规律与速效氮、磷一致;4个监测地3种间隔种植模式下土壤全氮、磷、钾及速效氮、磷、钾含量变化均不同。3种间隔种植模式土壤中全磷和速效磷含量具有显著相关性,但其他2种元素无显著相关性。新土、间隔5年土和连作土速效氮、磷、钾比例分别为1：0.4：2.4,1：0.4：1.4,1：0.4：2.0。结论：连作造成了三七种植土壤磷素的相对富集和钾素的相对亏缺,进而造成的土壤氮、磷、钾比例失衡为产生连作障碍的诱因之一。加强三七种植土壤氮、磷、钾最佳比例研究,从而进行配方施肥为消减连作障碍重要手段。

Study on dynamic change law of N, P and K in Panax notoginseng plant soils with different interval year

Objective: To study effects of different interval year on Panax notoginseng plant soils macro element content. Method: The dynamic change of total N, P, K and available N, P, K in soil from Mabai, Matang, Gumu and Panlong was determined under different planting patterns (new soil, interval 5 years soil and continuous cropping soil). Result: Contents order of soil total N, P and available N, P were interval 5 years soil >continuous cropping soil >new soil. No significant quarter change on soil total N was found, but the other three showed inverted "v" curve, and the peak value appeared on April 2010. Content of soil total K did not change significantly, but the available K content order was new soil >continuous cropping soil >interval 5 years soil, the quarter change was similar as soil available N or P. The soil total N, P, K and available N, P, K were different of the 4 monitoring sites under the 3 interval planting modes. There was a significant correlation between soil total P and available P under all these 3 interval planting modes, but N and K. The propitiation of N-P-K of new soil, interval 5 years soil and continuous cropping soil were 1:0.4:2.4, 1:0.4:1.4, 1:0.4:2.0, respectively. Conclusion: Continuous cropping pattern induce the accumulation of P, but deficient of K. The imbalance proportion of N, P and K was one of the incentives of continuous cropping induced obstacles. Strengthen the research of optimum proportion of soil N, P and K, and then eliminate continuous cropping obstacles by means of formulated fertilization is the future research direction.