不同侵蚀程度对土壤质量及作物产量影响的模拟研究

Effects of soil erosion of different degrees on soil quality and crop growth

为了探讨不同侵蚀程度对土壤质量和作物生长的影响,采用野外盆栽试验,将红壤表层剥离0、5、8、15cm以分别模拟无明显侵蚀、轻度侵蚀、中度侵蚀和强烈侵蚀,分析不同侵蚀程度对土壤物理、化学、生物特性及花生生长、产量的影响。结果表明:随着土壤侵蚀程度的增加,土壤容重增加,总孔隙度、>0.5mm水稳性团聚体下降;土壤碳、氮、磷等养分含量随侵蚀强度的增加而逐渐减少;微生物类群总量减少,土壤酶活性下降;土壤质量指数(SQI)随侵蚀程度的增大显著下降,其中无明显侵蚀的SQI与其他侵蚀程度的SQI差异显著(P<0.05);无明显侵蚀等级下的花生产量和生物量显著高于其他侵蚀处理(P<0.05)。土壤侵蚀程度显著影响土壤物理、化学、生物特性以及作物产量,SQI可表征土壤侵蚀影响下的土壤综合质量及土地生产力水平。

The effects of different erosion degrees on soil quality and crop growth were discussed to provide a theoretical basis for in-depth understanding of the relationship between soil erosion processes and soil functions.The tested soil was obtained from removing different levels below the surface layer to simulate no obvious erosion,mild erosion,moderate erosion and strong erosion.Meanwhile,the effects of different levels of erosion on the physical,chemical and biological properties of the soil and on the growth and yield of peanuts were analysed.The results showed that soil erosion thickness had a significant influence on many important indicators of soil quality.With the increase of the erosion degree,the soil bulk density increased,the total porosity and the water-stable aggregates(WSA)over 0.5 mm decreased;nutrient contents of soil carbon,nitrogen and phosphorus decreased gradually with the increasing erosion intensity;total microbial taxa decreased and soil enzyme activities decreased;soil quality index(SQI)decreased significantly with the increasing erosion,in which the difference between the SQI of the no-significant-erosion and that of the other erosion levels was significant(P<0.05);peanut yields and biomass under the no-significant-erosion class were significantly higher than that of the other erosion treatments(P<0.05).The degree of soil erosion significantly affected the physical,chemical and biological properties of soil and crop yield,and the SQI can characterize the comprehensive quality of soil and the level of land productivity under the influence of soil erosion.