摘要
为了探明不同轮耕方式对以生土为构建材料的新增耕地的土壤团聚体粒径分布及稳定性的影响,于2018年10月对免耕—深松—免耕、免耕—深松—翻耕、深松—深松—深松、深松—深松—翻耕四种不同的轮耕方式下0~20cm土层土壤进行采集,分析轮耕方式对土壤团聚体粒径、数量及其结构稳定性的影响。研究结果表明:在新增的可耕作土地中采取不同的轮耕方式,其中深松耕作的次数越多,>0.25mm风干团聚体含量越高,土壤团聚度越高;免耕次数越多,>0.25mm的水稳性团聚体含量越高,水稳性团聚度越高,团聚体破坏率越小;翻耕则会降低土壤团聚体含量。相关分析表明,影响土壤团聚体平均质量直径(MWD)的主要限制因素为大团聚体含量,容重、孔隙度、团聚体破坏率等因素对其影响不显著。综上,免耕—深松—免耕模式下,土壤水稳性团聚体含量较高,团聚体稳定,形成的土壤结构良好,为新增耕地可采用的优化轮耕方式。
In order to investigate the effects of different rotation tillage methods on the size distribution and stability of soil aggregates in newly-added cultivated land constructed with raw soil,the soil aggregates in 0-20 cm soil layer under four different rotation tillage modes were collected in October 2018.The tillage modes were namely no-tillage-subsoiling-no-tillage,notillage-subsoiling-tillage,subsoiling-subsoiling,subsoiling-subsoiling-tillage,respectively.And the effects of rotation tillage methods on particle size,quantity and structure stability soil aggregates were analyzed.The results were as follows:The content of air-dried aggregates of>0.25 mm and degree of soil aggregation were higher with more times of subsoiling tillage in the newly cultivated land;The content of water-stable aggregates of>0.25 mm and degree of waterstable soil aggregation were higher with more times of no-tillage and the destructive rate of aggregates were lower.However,the macro-aggregate content reduced with the tillage.The analysis correlation showed that the main limiting factors affecting the mean weight diameter(MWD)of soil aggregates were the macro-aggregates content.But the factors such as bulk density,porosity and aggregate destruction rate had no significant effect on it.In summary,under no-tillage-subsoiling-no-tillage mode,the soil water-stable aggregates content is higher,the aggregates are stable.Formed the well soil structure,which is the optimal rotation tillage mode for new cultivated land.
作者
马建业
何靖
杜宜春
MA Jianye;HE Jing;DU Yichun(Institute of Land Engineering and Technology,Shaanxi Land Engineering Construction Group Co.,Ltd.,Xi’an710075,China;Key Laboratory of Degraded and Unused Land Consolidation Engineering,the Ministry of Natural Resources,Xi’an710075,China;Shaanxi Land Consolidation Engineering Technology Research Center,Xi’an710075,China;Shaanxi Land Engineering Construction Group Co.,Ltd.,Xi’an710075,China)
基金
陕西省土地整治重点实验室开放基金“不同未利用地有机重构土体微形态特征以及质量演变规律”(2018-JC15)
重点科研平台开放基金项目“黄土高原治沟造地下垫面变化对小流域水文过程的影响”(300102279502)
关键词
轮耕方式
新增耕地
风干团聚体
水稳性团聚体
rotation tillage
new cultivated land
air-dried aggregates
water-stable aggregates
