不同覆膜方式对杨树林下土壤物理性状及呼吸速率的影响

在大田条件下,研究了白膜覆盖和黑膜覆盖对欧美I-107杨林下土壤0—40cm土层的温度、含水量、容重、孔隙度和土壤呼吸速率的影响。结果表明,在两种覆膜方式中,白膜覆盖的增温效应优于黑膜覆盖,而对土壤含水量的影响无显著差异。0—20cm土层白膜覆盖和黑膜覆盖处理均显著提高了土壤总孔隙度、毛管孔隙度和非毛管孔隙度,而土壤容重却明显降低,分别比对照降低15.44%和9.56%;此外,白膜覆盖的土壤呼吸速率与对照差异不显著,而黑膜覆盖显著低于对照。20—40cm土层与0—20cm土层表现出基本一致的变化规律,但两种覆膜方式与对照之间的差异均变小,表明随着土层的加深,覆膜的影响作用减弱。说明白膜和黑膜覆盖均可明显改善表层土壤的物理性状,但黑膜覆盖明显抑制了土壤呼吸。在两种覆膜方式中,白膜覆盖的作用效果明显优于黑膜覆盖。

Effects of Different Plastic Film Mulching on Soil Physical Properties and Respiration Rate of Poplar Forest

A field experiment of three treatments, i.e., traditional cultivation without mulching(CK), white plastic mulching(WM) and black plastic mulching(BM) was designed and performed to determine the effects of film mulching on soil temperature, water content, bulk density, and porosity and respiration rate in the 0-40 cm soil layer under Populus euramericana. Results indicated that the WM treatment had better warming effect than the BM treatment, but had no significant difference in the soil water content. In the 0-20 cm layer, the WM and BM treatments significantly increased the soil total porosity, capillary porosity and non-capillary porosity and however, the soil bulk density was visibly decreased, which was reduced by 15.44% and 9.56%, respectively. Besides, the soil respiration rate in the WM treatment had no significant difference as compared with CK, but the soil respiration rate in the BM treatment was obviously decreased. The 20-40 cm soil layer showed the variation trend similar to the 0-20 cm soil layer, while the differences among CK, WM and BM were decreased in the 20-40 cm soil layer, demonstrating that the effects of plastic film mulching on poplar weakened with the increasing of soil depth. In conclusion, the two plastic film mulching treatments significantly ameliorated the physical property of topsoil, while the black plastic mulching treatment evidently inhibited the soil respiration. Therefore, the white plastic mulching was obviously better than the black plastic mulching.