为了给改良盐碱地果园土壤和推广果园生草制提供理论基础,以山东东营市孤岛镇12年生黄金梨[Pyrus pyrifolia (Burm.f.).cv.‘Nakai’]种植园清耕梨园土壤为对照,设生草2年、生草3年和生草4年3个处理,分别测定株间和行间各层土壤pH值、有机质和氮磷钾含量,分析其随生草年限的变化,并分析pH值与有机质和其他矿质营养的相关性.结果表明:与清耕梨园相比,生草能显著降低株间和行间各层土壤pH值,株间降低1.2％～3.4％,行间降低0.6％～4.08％,且随生草年限的增加逐年降低;生草能提高株间各层土壤有机质含量,能显著提高行间各层土壤有机质含量,尤其在生草4年后,行间有机质含量比清耕梨园土壤提高64.6％,有机质含量随生草年限的增加逐年升高;生草后株间和行间各层土壤碱解氮、速效磷、速效钾含量均升高,除行间20～40 cm土壤速效钾增加不显著外,其他均呈显著增加,且随生草年限的增加逐年升高;相关性分析表明,不同生草年限梨园土壤pH值与有机质、碱解氮、速效磷、速效钾含量均呈负相关关系.

The soil calcium,magnesium,iron,zinc,manganese content change in different grass years of pear orchard was studied.The surface(0-20 cm) and sub-surface(20-40 cm) soil in the orchard with golden pear[Pyrus pyrifolia(Burm.f.)‘Nakai'] grown with grass for 3,4 and 8 years,respectively,were compared with that of the clean cultivated pear orchard.The items were measured including soil total Ca,Mg,Fe,Zn,Mn by ICP-OES-Optima 8x00.Inter-row and inter-plant soils were both measured.In pear orchard with grass growing,the total Ca,Mg,Fe,Zn,Mn of inter-plant surface soil were increased 25.35%-58.00%,8.83%-24.73%,15.30%-40.55%,17.93%-57.94%,11.86%-28.12%;the inter-plant sub-surface soil were increased 11.44%-39.08%,3.17%-38.53%,6.69%-38.25%,24.34%-55.81%,3.31%-34.00%;the inter-plant surface soil were increased 24.36%-53.05%,31.70%-63.81%,33.58%-66.05%,24.34%-55.81%,35.79%-73.21%;the inter-plant sub-surface soil were increased 18.29%-52.92%,27.77%-69.69%,27.45%-72.19%,19.02%-62.75%,32.70%-81.69%.Sown grass significantly increased the total Ca,Mg,Fe,Zn,Mn in different layers of the inter-row and inter-plant soil,and the content of both elements show that 8 years>4 years>3 years> clean cultivated,and sub-surface soil higher than surface soil,inter-plant higher than inter-row.

【Objective】 To provide a theological basis and the basic data on improving saline-alkali soil by natural grass growing techniques in orchard,the effects of this new grass management system on total soluble salt,organic matter,mineral elements concentration,enzyme activity in the soil,and fruit quality in pear orchards in the Yellow River delta were studied.【Method】 The biochemical attributes of surface(0-20 cm) and sub-surface(20-40 cm) soil in the orchard with golden pear [Pyrus pyrifolia(Burm.f.).cv.Nakai] grown with grass for 2,4,and 7 years,respectively,were compared with that of the clean cultivated pear orchard and their way of change was analyzed.The items were measured including soil total soluble salt,organic matter,minerals and enzyme activity.The quality of the fruits produced by those orchards was also compared.【Result】 The results demonstrated that the naturally grown grass significantly increased the organic matter in different layers of the soil from the surface down to 40 cm while effectively decreased the total soluble salt.In pear orchard with 2 years grass growing,the nitrate nitrogen,available phosphate and potassium,exchangeable calcium and magnesium,effective zinc,copper,and ferrous in soil layer of 0-20 cm was significantly lower than that of the clean cultivated orchard,and 7 years grass growing made nitrate nitrogen,ammonium nitrogen,available phosphate and potassium,and effective zinc in the soil layer of 0-20 cm significantly higher than that of the clean cultivated orchard,while nitrogen,available phosphate and potassium,exchangeable calcium and magnesium,effective zinc,copper,and ferrous in the sub-surface soil layer was significantly lower than that of the control.And in the 7 years grass growing orchard,the urease activity in soil layer of 0-20 cm was 0.79 mg.g-1and alkaline phosphatase was 1.25 mg.g-1,which was 3.8 times and 1.5 times of that of the control,respectively,but the two enzyme activities showed no difference in the layer of 20-40 cm.The fruit fracturability,soluble solids,total aroma,sugars,sugar-acid ratio of pear produced by the orchard with natural grass growing for 4 and 7 years were higher than those from the orchard that had natural grass orchard for 2 years.Correlation analysis indicated that the urease,phosphatase,sucrase,catalase and protease activities mostly showed very significant correlation with N,P,K,Mg and Zn in soil layer of 0-20 cm.The soil enzyme activity mostly showed no significant correlation with all the soil nutrients in layer of 20-40 cm,except the catalase.【Conclusion】 Natural grass could reduce the total soluble salt and increase the organic content obviously in 0-40 cm soil layer of pear orchards in the Yellow River delta.With year increasing,naturally grown grass could improve surface soil enzyme activity,content of mineral nutrition elements and enhance fruit fresh eating quality.

黄河三角洲是黄河入海沉淀填海形成的平原,属盐化潮土亚类.上世纪60～80年代中期,果树栽植采用内地传统定植法,即挖长、宽各60 cm、深80 cm的定植坑,将有机肥和表土混合均匀回填后进行栽植,栽植深度一般为40 cm左右.此法在上世纪60～70年代初期,果树定植成活率87%～95%,树体长势正常.