基于最小数据集的生草覆盖对吉县苹果园土壤肥力质量的影响评价

Effect of Grass Covering on Soil Fertility Quality of Apple Orchard in Jixian County Based on a Minimum Data Set.

为研究生草覆盖对山西省吉县苹果园土壤质量的影响并探索限制吉县苹果产量的土壤因素,选取人工草、自然生草和清耕3种覆草方式的苹果园,对果园土壤物理、化学和酶活性特性进行研究。采用典型对应分析和主成分分析方法,并通过全体数集、最小数据集和灰色关联度方法评估土壤肥力质量。结果表明:(1)自然生草显著提高土壤含水量和土壤pH;(2)人工草种植显著提高土壤有机质、全氮、全磷和全钾含量;(3)土壤过氧化氢酶活性在自然生草条件下最大,多酚氧化酶和脲酶活性在人工草条件下最大,蔗糖酶活性在清耕条件下最大;(4)研究区土壤肥力质量评价的最小数据集为土壤容重、土壤含水量、有机质、速效钾、全磷和脲酶6个指标,3种覆草方式的土壤肥力质量评价结果表明覆草显著提高了土壤肥力质量,且人工种草效果优于自然生草,灰色关联度分析结果与之一致。吉县土壤肥力质量限制因素为土壤含水量、有机质和蔗糖酶,土壤有机质含量和蔗糖酶活性是影响苹果产量的主要制约因素,增加土壤有机质含量和提高土壤酶活性是提高果园土壤肥力的主要途径。

In order to investigate the influence of grass covering on the soil quality of an apple orchard and explore the soil factors that limiting the apple yield in Jixian County of Shanxi Province,three grass-covering methods(planted grass RC,natural grass ZC and clear farming QG)were selected to study the physical,chemical and enzymatic activities of the orchard soils.Soil fertility quality was assessed by canonical correspondence analysis,principal component analysis,total data set(TDS),minimum data set(MDS)and gray correlation degree(GRA).The results show that:(1)the soil water content and soil pH of the field covered with natural grass significantly increased;(2)soil organic matter,total nitrogen,total phosphorus and total potassium concentration of the field covered with artificial grass significantly increased;(3)catalase activity was highest under natural grass,polyphenol oxidase and urease activities were the largest under planted grass,and sucrase was the largest under clear farming.(4)there are six indicators(soil bulk density,soil water content,organic matter,available potassium,total phosphorus,urease)in the MDS for soil quality assessment in the study area.The results of soil quality evaluation show that grass covering significantly improved soil quality,and the effect of planted grass cultivation was better than natural grass cultivation.Similar conclusion was found by using the method of GRA.The limiting factors of soil fertility in Jixian County are soil water content,organic matter,and sucrase activity.Organic matter and sucrase activity are the main limiting factors for yield.Increasing organic matter content and soil enzyme activity are the main ways for improving soil fertility in orchard soils.