基于隶属函数法的不同生草栽培模式下澳洲坚果果园土壤理化性质综合评价

Comprehensive Evaluation of Soil Physico-chemical Properties in the Macadamia Orchard under Different Sod-cultural Practices Based on Membership Function Method

为明确生草栽培对澳洲坚果果园土壤理化性质的影响,筛选出适宜当地的生草栽培模式。本研究选择5种果园常见生草草种(光叶紫花苕子、白三叶、一年生黑麦草、鼠茅草、肥田萝卜),以清耕为对照,分析不同处理间果园土壤含水量、温度、物理性质、养分及肥力差异,并运用隶属函数法进行综合评价。结果表明,生草栽培能有效增加表层土壤含水量,相较对照增加8.7%~24.0%。同时,生草栽培能降低果园表层土壤温度,降低幅度达7.6%~16.8%。与对照相比,生草栽培区土壤容重平均降低11.7%。在土壤养分方面,生草栽培区显著提升了土壤有机质含量,其中白三叶土壤有机质含量最高,达到32.0 g/kg,豆科草种与十字花科草种能显著增加土壤速效养分含量,禾本科草种则表现不明显。光叶紫花苕子、白三叶、肥田萝卜生草栽培模式的土壤综合肥力系数表现最好,分别比对照增加了51.5%、49.2%、45.4%,果园土壤肥力评价可达肥沃级别。利用隶属函数法对各处理的果园土壤的含水量、容重、温度、肥力共4个理化指标进行综合评价,光叶紫花苕子栽培模式表现最佳。

To clarify the impact of sod-cultural practices on the soil physico-chemical properties in Macadamia orchards,suitable local grass cultivation models were selected.Five common grass species in orchards(Vicia villosa,Trifolium repens,Lolium multiflorum,Vulpia myuros,and Raphanus sativus)were selected in the study with clear tillage as the control to analyze the differences in soil moisture content,temperature,physical properties,nutrients,and fertility among different treatments in orchards.The membership function method was used for comprehensive evaluation.Sod-cultural practices could effectively increase the surface soil moisture content,which was 8.7%~24.0%higher than that of the clear tillage control.Meanwhile,sod-cultural practices could reduce the surface soil temperature of orchards by 7.6%to 16.8%.Compared with tillage,the average soil bulk density in the sod-cultural practice areas decreased by 11.7%.In terms of soil nutrients,sod-cultural practice areas significantly increased the soil organic matter content,with T.repens having the highest soil organic matter content,reaching 32.0 g/kg.Leguminous and cruciferous grass species could significantly increase the soil available nutrient content,while poaceae grass species showed no significant im-provement.The soil comprehensive fertility coefficient of the cultivation modes of V.villosa,T.repens,and R.sativus showed the best performance,increased by 51.5%,49.2%,and 45.4%respectively compared to the clear tillage control.The evaluation of orchard soil fertility could reach a fertile level.The optimal grass cultivation mode obtained using the membership function method was V.villosa.Comprehensive evaluation of the four physical and chemical indicators of soil moisture content,bulk density,temperature,and fertility in each treated orchard by the membership function method revealed the cultivation mode of V.villosa performed the best.