核桃林下复合种植对土壤培肥效果的影响

Effects of Compound Planting under Walnut Plantation on Soil Fertility

【目的】筛选适宜的核桃林下复合种植模式,对发展核桃林下经济具有重要作用。【方法】以核桃林下不同复合种植模式(包括:核桃+甘蓝+甘蓝(简写为HGG)、核桃+甘蓝+马铃薯(简写为HGM)、核桃+白菜+大豆(简写为HBD)、核桃对照(简写为HCK))和农地对照(玉米+甘蓝,简写为NCK)为对象,研究各模式表层(0~20 cm)土壤物理性质、养分含量、微生物数量和酶活性,采用隶属函数法对各模式土壤肥力进行综合评价。【结果】各核桃林下复合种植模式与农地对照(CK)相比,土壤容重降低4.6%~17.6%,非毛管孔隙、毛管孔隙和总孔隙分别增加2.4%~14.8%、2.8%~29.1%和2.6%~23.1%;有机碳、全氮、碱解氮、全磷和全钾分别增加5.1%~14.9%、3.9%~12.5%、25.1%~112.5%、11.4%~47.1%和0.2%~2.7%;HGG和HGM模式土壤有效磷含量分别增加21.9%和5.0%,而其余模式降低6.1%~28.3%,HCK模式速效钾含量降低17.4%,而其余模式增加20.4%~52.9%;土壤细菌、放线菌、真菌和总微生物数量分别增加21.4%~54.3%、19.2%~58.1%、17.8~58.4%和21.2~54.6%;蔗糖酶、脲酶、磷酸酶、过氧化氢酶、多酚氧化酶和过氧化物酶活性分别增加9.3%~57.8%、16.6%~56.7%、6.2%~30.8%、8.9%~41.1%、4.2%~14.3%和1.4%~38.6%;各模式土壤肥力综合值增加69.6%~431.3%。【结论】核桃林下复合种植均能提高土壤肥力,其中以HGG模式最佳,对发展研究区林下经济和提高土壤肥力具有重要作用。

【Objective】 The selection of optimum compound planting models under walnut plantation plays an important role in the development of economy under walnut plantation.【Method】Soil physical properties, nutrient content, microbe number and enzyme activity of the surface soil(0-20 cm) of each model were determined under different compound planting models(including:walnut+cabbage+cabbage(HGG),walnut+cabbage+potato(HGM),walnut+Chinese cabbage+soybean(HBD),walnut control(HCK))and farmland control(NCK),and used the membership function method to evaluate the soil fertility of each models.【Result】Compared with the CK,soil bulk density decreased by 4.6%-17.6%,non-capillary porosity,capillary porosity and total porosity increased by 2.4%-14.8%,2.8%-29.1% and 2.6%-23.1%,respectively;organic C, total N,hydrolysis N,total P and total K content increased by 5.1%-14.9%,3.9%-12.5%,25.1%-112.5%,11.4%-47.1% and 0.2%-2.7%,respectively;the available P content of the HGG and HGM increased by 21.9% and 5.0%,while the other models decreased by 6.1%-28.3%,respectively,the available K content of the HCK decreased by 17.4%, while the other models increased by 20.4%-52.9%;the number of soil bacteria,actinomycetes,fungus and total microbe increased by 21.4%-54.3%,19.2%-58.1%,17.8%-58.4% and 21.2%-54.6%, respectively;invertase,urease,phosphatase,catalase,polyphenol oxidase and peroxidase activity increased by 9.3%-57.8%,16.6%-56.7%,6.2%-30.8%,8.9%-41.1%,4.2%-14.3% and 1.4%-38.6%,respectively;the comprehensive value of soil fertility of each model increased by 69.6%-431.3%. 【Conclusion】All the compound planting models under wal-nut plantation have obvious improving effect to soil fertility,and the HGG was the optimum model,which is important for the development of under-forest economy and soil fertility improvement in research area.