不同覆盖作物模式对茶园土壤剖面物理性质的影响

Effects of different cover crop patterns on physical properties of the soil profiles in tea garden

为了探究覆盖作物对土壤物理性质的影响,以茶园土壤为研究对象,共设置4个处理组,即2种(EZ)、4种(SZ)、8种(BZ)不同作物覆盖处理以及以自然留养杂草为对照(CK)处理,测量不同覆盖作物模式下0~15 cm和15~30 cm土层的土壤容重、总孔隙度、田间持水量、含水量、机械稳定性团聚体、水稳性团聚体、平均质量直径(MWD)和几何平均直径(GMD).结果发现:与CK处理相比,SZ处理可以显著降低0~15 cm土层土壤容重,增加总孔隙度、田间持水量、MWD和GMD(P<0.05);EZ处理可以显著增加0~15 cm土层土壤田间持水量、MWD和GMD(P<0.05);BZ处理可显著降低0~15 cm土层的土壤容重,增加田间持水量(P<0.05).3种不同覆盖作物模式均有利于2.00~5.00 mm粒级土壤机械稳定性团聚体的形成,尤其是SZ处理.不同覆盖作物模式对土壤物理性质的影响主要集中在0~15 cm土层,对15~30 cm土层影响较小.3种覆盖作物模式中,SZ模式是茶园最适宜的覆盖模式.

In order to explore the effects of cover crop on the physical properties of soil,the tea garden soil was selected as the research object,and four treatments were set up,i.e. two(EZ),four(SZ),eight(BZ)kinds of cover crops and natural vegetation(CK). A series of indexes in 0-15 cm and 15-30 cm soil layers were measured respectively,including the soil bulk density,total porosity,field water holding capacity,water content,mechanical stability aggregate,water-stable aggregate,average weight diameter(MWD)and geometric mean diameter(GMD). The results showed that compared with CK treatment,SZ treatment can significantly reduce the soil bulk density in 0-15 cm soil layer,increase total porosity,field water holding capacity,MWD and GMD(P < 0.05);EZ treatment significantly increased soil water holding capacity,MWD and GMD in 0-15 cm soil layer(P < 0.05);BZ treatment significantly reduced soil bulk density in 0-15 cm soil layer and increased field water holding capacity(P < 0.05). Three different cropping patterns were beneficial to the formation of 2.00-5.00 mm mechanical stability aggregate,especially for SZ treatment. The effects of different cover crop patterns on soil physical properties are mainly concentrated in the 0-15 cm soil layer,and has less effect on 15-30 cm. Among the three cover crop pat-terns,it is preliminarily believed that SZ pattern is the most suitable coverage model for tea gardens.