核桃不同套种模式对土壤养分、微生物数量及酶活性的影响

Effects of Different Walnut Intercropping Patterns on Soils Nutrients, Microorganisms and Enzymatic Activity

【目的】分析核桃不同套种模式对土壤养分含量、微生物数量和酶活性的影响,为石漠化地区生态恢复及其核桃产业的可持续发展提供理论依据。【方法】在石漠化地区广西河池市巴马县东山乡设核桃/红薯、核桃/玉米、核桃/火麻、核桃/黄豆和核桃/花生套种模式(套种处理),以核桃单种为对照(CK),测定分析各处理林地的土壤养分含量、微生物数量和酶活性,并采用Pearson相关系数评价三者间的相关性。【结果】与相应的CK相比,核桃/黄豆、核桃/红薯和核桃/玉米处理林地的土壤碱解氮、有效磷和速效钾含量分别显著提高19.92%、63.45%和102.98%(P<0.05,下同),核桃/花生处理的有机质含量提高14.32%,但差异不显著(P>0.05)。核桃/黄豆、核桃/花生和核桃/黄豆处理林地的细菌数、真菌数和放线菌数分别较相应的CK提高40.24%、100.00%和42.16%,其中核桃/花生处理林地的真菌数显著高于CK。核桃/玉米、核桃/红薯和核桃/玉米处理林地的土壤纤维素酶、脲酶和酸性磷酸酶活性分别较相应的CK显著提高118.15%、21.50%和137.94%。相关分析结果表明,土壤酶活性与土壤速效养分含量间具有相互促进作用,其中,酸性磷酸酶活性与速效钾含量呈极显著正相关(P<0.01),与有效磷含量呈显著正相关,脲酶活性与有效磷含量、纤维素酶活性与速效钾和有机质含量呈显著正相关。【结论】在广西河池市巴马县,核桃/黄豆、核桃/红薯、核桃/玉米和核桃/花生套种模式分别对提高核桃林地碱解氮、有效磷、速效钾和有机质含量的效果最佳,核桃/黄豆、核桃/花生和核桃/黄豆套种模式林地的土壤细菌、真菌和放线菌数最高,在生产中可根据核桃园的实际土壤状况选择适宜的作物进行套种。

【Objective】In order to provide theoretical support for ecological restoration and sustainable development of walnut industry in rocky desertification area,effects of different walnut intercroppings on soil nutrient content,microbe quantity and enzyme activity were studied.【Method】Six different interplanting modes including walnut(CK),walnut/sweet potato,walnut/corn,walnut/cannabis,walnut/soybean and walnut/peanut(treatment 2-6)were designed in Dongshan,Bama,Guangxi.Soil nutrient content,microbe quantity and enzyme activity in different treatments were analyzed and Pearson correlation coefficient was used to evaluate the correlation among the three.【Result】Compared to the corresponding CK,the content of alkali-hydrolyzed N,available P and available K in soil of walnut/soybean,walnut/sweet potato and walnut/corn were significantly increased by 19.92%,63.45%and 102.98%,respectively(P<0.05,the same as below).Organic matter content of walnut/peanut treatment increased by 14.32%,but the difference was not significant(P>0.05).Compared with the corresponding CK,the number of bacteria,fungi and actinomycetes in walnut/soybean,walnut/peanut and walnut/soybean treatments increased by 40.24%,100.00%and 42.16%,respectively.Fungi amout of walnut/peanut was significanly higher than CK.Compared with the corresponding CK,the activities of soil cellulase,urease and acid phosphatase in walnut/corn,walnut/sweet potato and walnut/corn treatments were significantly increased by 118.15%,21.50%and 137.94%,respectively.The results of correlation analysis showed that soil enzyme activity and soil available nutrient content promoted each other,among them,acid phosphatase was extremely positively correlated with available K(P<0.01)and significantly positively correlated with available P,while urease activity was significantly positively correlated with available P,and cellulase activity was significantly positively correlated with available K,cellulase activity and organic matter.【Conclusion】In Bama,Hechi,Guangxi,the available N,available P,available K and organic matter in walnut/soybean,walnut/sweet potato,walnut/corn and walnut/peanut treatment groups were the highest.The number of bacteria,fungi and actinomycetes in the walnut/soybean group,walnut/peanut and walnut/soybean treatment group were the highest among the whole groups.In the production,suitable crops for interplanting should be selected according to soil condition.