荒漠草原区不同粒径土壤理化性质对苜蓿种植年限的响应  

Effect of Soil Physical and Chemical Properties on Alfalfa Grassland of Different Planting Years in Desert Steppe Region

作　　者：陈林[1] 杨新国[1] 宋乃平[1] 肖绪培[1] 王兴[1] 

机构地区：[1]宁夏大学西北退化生态系统恢复与重建教育部重点实验室,西北土地退化与生态恢复国家重点实验室培育基地,西部生态与生物资源开发联合研究中心,银川750021

出　　处：《水土保持学报》2014年第2期105-111,共7页Journal of Soil and Water Conservation

基　　金：国家重点基础科学(973计划)研究前期专项(2012CB723206);国家青年自然基金(41101301)

摘　　要：为了探明宁夏中部荒漠草原区长期种植苜蓿对土壤理化性质的影响，采用时空互代法，选取不同种植年限苜蓿地为研究对象，以天然草地为对照，分析不同种植年限苜蓿地不同粒径土壤颗粒的理化性质。结果表明，种植苜蓿后〈0．106mm的颗粒含量较草地（Oa）的含量高，一定程度上促进土壤的细粒化。不同粒径间的pH值、EC、有机质、全氮、碱解氮、全磷和速效磷在同一种植年限间均无显著差异（p〉0．05），但〉0．5mm和〈0．106mm粒径的土壤活性有机碳含量均显著高于0．106～0．25mm粒径（P〈0．05）。随着种植年限的增加，pH值有所降低，当苜蓿严重退化后（〉22a），pH值略有上升，而EC值则相反。苜蓿种植后对20-40cmpH值的影响要大于0-20cm。土壤有机质含量在各年限间差异不显著（P〉0．05），当苜蓿严重退化后（〉22a），其显著降低（p〈0．05）。0-20cm活性有机碳含量随种植年限增加呈先升高后降低的趋势，而20-40cm则保持不变或略呈降低的趋势。0—20cm中〉0．5mm和〈0．106mm粒径的活性有机碳含量在各种植年限间均显著高于20-40cm（p〈0．05），而0．106～0．25mm粒径在不同土层间则无显著差异（P〉0．05）。0—40cm土壤全磷含量的变化趋势均为先升高（0-22a）后降低（〉22a），而0—20cm速效磷含量呈升一降，20-40cm速效磷则表现为升一降一升一降的“M”型波动。0—20cm全磷含量显著低于20-40cm（p〈0．05）。0—40cm土壤全氮、碱解氮含量属于低和极低等级，且没有表现出豆科植物根系的固氮作用。In order to know the different particles of soil physical and chemical properties in alfalfa grassland of different planting years, by using the method of replacing time with space, an analysis was made on the dynamic changes of top soil （0-40 cm） nutrients and soil particle during the planting years. The results showed that： The particles contents of %0. 106 mm in planting alfalfa plots were all higher than particles contents in the grass, so it could to promote the fine-grained soil particles contents by planting alfalfa. There was no significant difference between the different soil particle diameters （〉0.5 mm, 0. 106-0.25 mm and %0. 106 mm） in the same period of the pH, EC, soil organic matter （SOM）, total nitrogen （TN）, available nitrogen （AN）, total phosphorus （TP） and available phosphorus （AP） （p）0.05）, but the 〉0.5 mm and %0. 106 mm soil particle of soil active organic carbon content were significantly higher than 0. 106-0.25 mm soil particle （p%0.05）. With the increase of years of planting alfalfa, the soil pH values decreased, when al- falfa severely degraded （〉22 a）, pH values increased slightly, and the EC values were opposite. After planting alfalfa, it was effected on pH values of 20-40 cm soil layer greater than that of 0-20 cm soil layer. There were no significant difference between the soil organic contents in each planting year （p）0.05）, when alfalfa severely degraded （〉22 a）, soil organic contents were significantly lower （p〈0.05）, soil organic matter contents of 0-20 cm soil layer were higher than that of the 20-40 cm soil layer. The soil active or- ganic carbon contents of 0-20 cm soil layer increased first and then decreased with the increase of planting years, while the soil active organic carbon contents of 20-40 cm soil layer remain unchanged or slightly de- creased. The soil active organic carbon contents of ）0.5 mm and d0. 106 mm soil particle diameters in 0- 20 cm soil layer in each planting years were significantly

关 键 词：苜蓿 土壤理化性质 种植年限 风沙区 

分 类 号：S158.3[农业科学—土壤学] S344[农业科学—农业基础科学]