淋溶条件下土地利用方式对土壤有机碳含量及其理化性质的影响

Effects of Land Use Types on Soil Organic Contents and Physical and Chemical Properties Under the Leaching Conditions

为探讨土地利用方式对土壤有机碳含量及其理化性质的影响,选择不同含盐量的土壤(耕地土、混合土和原生荒漠土),分别种植水稻和棉花,进行1个生长期的淋溶试验。结果表明:淋溶前后土体的有机碳含量均呈下降趋势,其值范围为1.09～4.73g/kg,淋溶后期小于淋溶前,有机碳含量与电导率(EC)呈极显著负相关;淋溶前后原生荒漠土EC值均大于耕地土,耕地土各处理pH在0-50cm各层土体中变化不大,混合土和原生荒漠土均是先增大后稳定;淋溶前CO23-含量要明显高于淋溶后土体(p<0.01),而淋溶前后土体HCO3-含量无明显差异(p>0.05),CO23-含量与EC值呈极显著正相关。

In order to explore the effects of land use types on soil organic carbon contents and physical and chemical properties,a leaching experiment was carried out in Fukang station of desert ecology in Xinjiang.This study chose different soil salinity（farmland soil,composite soil and native desert soil） with rice and cotton growing with different irrigation in the saline-alkali soil of arid zone.The leaching experimental reasons with a growing season showed that soil organic carbon contents before and after leaching were downtrend,the values’ range was 1.09～4.73 g/kg and the values before leaching were higher than that after leaching.There was a significantly negative correlation between organic carbon contents and electric conductivity（EC）.The EC values before and after leaching in native desert soil were higher than that in farmland soil,the values of pH at each layer of 0-50 cm depth in farmland soil had a little change.pH initially increased and then stabilized in composes soil and native desert soil,the CO32- contents before leaching were significantly higher than after leaching（p0.01）,but the HCO-3 contents between before and after leaching had no significant differences（p0.05）.The CO32- contents were very significantly correlated with EC values.