三峡库区新建柑橘园间作的截流保肥效果分析

Analysis of Effects on Water Interception and Nutrient Conservation from Citrus Intercropping in Hilly Area of Chongqing City

针对三峡库区水土流失严重、土壤肥料利用率低的现状,利用模拟降雨条件下的田间小区试验,研究幼龄柑橘、柑橘间作马铃薯、柑橘间作甘薯、柑橘间作大豆、柑橘间作白菜、柑橘周年间作6种处理对土壤水分涵养功能,作物吸收N、P、K,土壤有机质和水土保持效果的影响。结果表明：柑橘周年间作具有良好的水分涵养作用,其平均土壤含水量显著最高,较幼龄果园增加41%。柑橘周年间作的上、中和下坡土壤含水量显著高于其他处理,是幼龄果园的1.5-1.9倍。雨后柑橘周年间作的土壤含水量随天数的增加表现为缓慢下降且下降幅度较小;与其他间作方式相比,柑橘周年间作柑橘产量显著提高1.4-8倍,N、P、K养分吸收量分别显著提高40%-280%,20%-220%,40%-240%;有机质增加量表现为柑橘周年间作〉柑橘-马铃薯〉柑橘-白菜〉柑橘-大豆〉幼龄果园〉柑橘-甘薯,柑橘周年间作的有机无机复合度最高,达88.7%;随降雨强度的增大,6个处理的平均水土流失量逐渐增加,其中幼龄果园和柑橘-大豆水土流失量的增加达到显著水平。在不同雨强下,柑橘周年间作水土流失量较幼龄果园减少约52%,达差异显著水平。综合分析认为新建柑橘园周年间作具有良好的截流保肥效果。

According to the unreasonable tillage measures and the serious erosion of soil nutrient on sloping land in Chongqing city,the simulated rainfall and a field experiment was conducted to study the effect of young orchard,citrus-potato,citrus-sweet,citrus-soybean,citrus-cabbage and citrus anniversary intercropping treatments on the effect of the water conservation,the absorbing of N,P,K,the soil organic matter and the water and soil conservation.The results showed：The average water content in soil under citrus anniversary intercropping was 41% higher than that of young orchard and was the significantly highest one with good water conservation effect.The water content under citrus anniversary intercropping was significantly higher than those of other treatments,was 1.5times to 1.9times higher than those of the young orchard in upper,middle and downhill.With the days after rains increasing,the soil water content of citrus anniversary intercropping slowly declined with the diminutively declined range;compared with other intercropping systems,the harvest of crops in citrus anniversary intercropping increased from 1.4times to 8times,N,P,K nutrient uptake in citrus anniversary intercropping were respectively increased by 40% -280%,20% -220%,40%-240%;the sequence of increase in organic matter showed that citrus anniversary intercropping〉citrus-potato〉citrus-cabbage〉citrus-soybean〉young orchardcitrus-sweet,and the multiplicity between organic and inorganic of the citrus anniversary intercropping was 88.7% and reached the highest;with the increased rainfall intensity.The average soil and water erosion amount of six treatments increased by degrees,those of young orchards and citrus-soybean increase was increased significantly.The average total water and soil erosion volume under citrus anniversary intercropping was less 52% than that under youngorchard with significant difference at different rainfall intensity.In a word,it suggested that citrus anniversary intercropping had better effect of water interception and nutrient conservation.