开垦对科尔沁沙地土壤团聚体分布及稳定性的影响  

Effects of tillage on distribution and stability of soil aggregates in Horqin Sandy Land

作　　者：曹立悦 李玉霖 詹瑾 石丽娜 Cao Liyue;Li Yulin;Zhan Jin;Shi Lina(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730000,China;Naiman Desertification Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]西北师范大学地理与环境科学学院,甘肃兰州730000 [2]中国科学院西北生态环境资源研究院奈曼沙漠化研究站,甘肃兰州730000 [3]中国科学院大学,北京100049

出　　处：《中国沙漠》2021年第2期212-220,共9页Journal of Desert Research

基　　金：内蒙古自治区科技计划项目(201601052);国家重点研发计划项目(2016YFC0500907)。

摘　　要：选取科尔沁地区不同开垦年限玉米田,以沙质草地为对照,采用湿筛法测定了0-40 cm土壤各粒径团聚体分布状况,以大于0.25 mm水稳性团聚体的含量(W_(0.25))、平均重量直径(MWD)、几何平均直径(GMD)、分形维数(D)和土壤可蚀性因子(K)为稳定性评价指标,研究随着开垦年限和土层深度变化下土壤水稳性团聚体的含量变化及稳定性差异。结果表明:(1)开垦对土壤水稳性团聚体含量产生了显著的影响,在不同土层呈现出一致性规律,整体上表现为随开垦年限增加大,团聚体含量呈现"N"型态势;(2)开垦15-20 a土壤团聚体的W_(0.25)、MWD和GMD值均高于其他开垦年限,D、K则相反,且上层团聚体稳定性优于下层;(3)相关分析表明,大于1 mm粒径的土壤团聚体含量与W_(0.25)、MWD、GMD极显著正相关(P<0.01),而与0.5-0.25 mm、<0.25 mm粒径团聚体含量、D和K极显著负相关(P<0.01)。开垦活动提高了科尔沁地区土壤团聚体稳定性,开垦15-20 a的土壤抗侵蚀力较强,大于20 a的开垦可能会导致土地退化,应考虑通过采取保护性耕作措施等方式实现该地区土壤可持续健康发展;大于1 mm的水稳性团聚体含量可以作为评价该区域土壤质量的重要参数。In order to find out the effects of tillage on the composition and stability of soil water-stable aggregates,this study analyzed distribution of aggregates with different particle sizes of corn fields with different tillage period and the sandy grassland nearby in the 0-40 cm soil layer by wet sieving method in Horqin area.The content of soil aggregates of>0.25 mm(W_(0.25)),mean weight diameter(MWD),geometric mean diameter(GMD),fractal dimension(D)and soil erosibility factor(K)were studied to explain the distribution and stability characteristics of water-stable aggregates under different tillage period and soil depth.The results showed that:(1)tillage exerted remarkable effects on the content of soil water-stable aggregates,the content of macro-aggregates presented an"N"type trend with the increase of tillage period,which was consistent in different soil layers.(2)W_(0.25),MWD and GMD of soil aggregates in 15-20 years were higher than the others,while the D and K were opposite,the stability of the upper layer aggregates was better than that of the lower one.(3)Correlation analysis showed that soil aggregates content of>1 mm was significantly positively correlated with W_(0.25),MWD and GMD(P<0.01),but was negatively correlated with the aggregates content of 0.5-0.25 mm,<0.25 mm,D and K(P<0.01).In summary,tillage activities enhanced the stability of soil aggregates in Horqin area,15-20years of tillage has strong anti-erodibility,and tillage of more than 20 years may lead to land degradation,conservation tillage should be considered to achieve sustainable and healthy development of soil.The water-stable aggregates content of>1 mm can be used as an important parameter to evaluate the soil quality in this area.

关 键 词：水稳性团聚体 开垦年限 粒径分布 团聚体稳定性 

分 类 号：S152.3[农业科学—土壤学]