桑园地和玉米轮作地土壤pH变化的比较研究  

The Changes of Soil p H in Mulberry Plantation and Maize Rotation

作　　者：凌宏文[1] 樊宇红[1] 朴河春[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵州贵阳550002

出　　处：《生态环境学报》2015年第5期778-784,共7页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(4121004)

摘　　要：随着桑园植桑年龄的增加,桑地土壤质量降低,桑树生物量减少,严重制约着养蚕业的可持续发展。这可能与土壤p H降低、营养元素的流失和有害元素的积累有关。选取广西宜州和贵州荔波的桑树(Morus alba)种植园和临近种玉米(Zea mays)轮作地的土壤,分析土壤可交换性盐基阳离子(Ca,Mg,K和Na),可交换性铝(Al)、土壤p H等土壤参数,研究土壤p H在桑树地和玉米轮作地之间的差异,讨论影响土壤p H变化的因素。实验结果表明,相对于玉米轮作地,桑园地土壤p H 5年下降了0.38个p H单位。相应地,桑园地土壤可交换性盐基阳离子(Ca,Mg和K)的含量略低于玉米轮作地,桑地土壤交换性Al的含量(2.35±2.68)mmol·kg-1却显著高于玉米轮作地(1.44±2.13)mmol·kg-1(P=0.002)。因此,桑园地和玉米轮作地土壤可交换性Ca和Al之间呈现出显著的负相关关系。桑园地土壤可交换性NH4+-N含量略高于玉米轮作地。得出结论:随着桑园经营年代的增加,土壤酸化的同时,营养元素(Ca,Mg和K)的流失和有害元素(Al)的积累,土壤质量下降。玉米轮作缓解土壤酸化。显然,不同的经营模式要影响土壤p H变化。导致土壤p H变化的主导因素是碳和氮的循环。在农业生产过程中,我们应该提倡不同作物轮作,以适当的方式将秸秆还田,以保持良好的土地质量。With increasing age of mulberry plantation, soil degradation process enhanced, and leaf biomass decreased, which should be associated with decrease of soil pH, loss of nutrient elements and accumulation of harmful element. The soil samples were collected from Yizhou in Guangxi Province and Libo in Guizhou Province, China. The concentrations of exchangeable base cations (Ca, Mg, K and Na), and exchangeable Al, and soil pH and other soil parameters were analyzed in order to study the differences of soil pH between mulberry (Morus alba) and maize (Zea mays) soils, and to discuss the factors influencing the changes of soil pH. Results show that soil pH in mulberry plantations has decreased 0.38 unit relative to maize soils during 5 years. Consequently, the concentrations of base cations (Ca, Mg and K) in mulberry soils were lower than those in maize soils, though not statistically significant. But the concentrations of exchangeable Al in mulberry soils (2.35±2.68) mmol·kg-1 were significantly higher than that in maize soils (1.44±2.13) mmol·kg-1 (P=0.042). Therefore, there was a significant relationship between soil exchangeable Ca and Al concentrations. The concentrations of exchangeable NH4+-N in mulberry soils were higher than those in maize soils, though not statistically significant. Here, we concluded that soil pH decreased with continuous cropping in mulberry plantation. Correspondingly, soil available Ca, Mg and K concentrations decreased, and soil available Al concentrations increased. Factors causing decrease of soil pH in mulberry plantations relative to maize rotation soils are complex. Among them the cycling of carbon and nitrogen in plant-soil system is the main factor causing the changes of soil pH. Various managements for cropping system also determine the direction and magnitude of pH change. It is suggested that the rotation of cropping plants and return of plant residue into soils should be promoted for increasing soil quality.

关 键 词：土壤PH 交换性盐基阳离子 交换性Al离子 桑园 玉米 轮作 

分 类 号：S153.4[农业科学—土壤学]