黄土缓坡耕地粟株不同生育期土壤的抗冲性特征  

Soil anti-scourability of sloping farmland under millet cultivation relative to growth stages

作　　者：谢欣利 王计磊 路培[1] 吴发启[2] XIE Xin-li;WANG Ji-Lei;LU Peii;WU Fa-qi(Institute of Soil and Water Conservation,Northwest A＆F University,Yangling 712100,China;College of Resources and Environment,Northwest A ＆ F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《泥沙研究》2018年第5期52-57,共6页Journal of Sediment Research

基　　金：国家“973”重点基础研究项目(2007CB407201-5);国家自然科学基金项目(41271288)

摘　　要：采用典型黄土,基于原状土冲刷法,测定并分析了粟株不同生育期土壤抗冲性变化特征及其与根系生长的关系。研究结果表明：粟株各生育期土壤含沙量随冲刷时间延长逐渐降低,除苗期外均在3 min后趋于平稳,苗期在9 min后保持稳定,且前3 min内苗期的流失量最大（5.92 g/L）。随着粟株生育期推进,土壤抗冲指数及其增强效应呈现出先增强后减弱的趋势,苗期均最弱,分别为1.19 min/g和0.59。各土层,土壤抗冲指数与除根系平均直径以外的其他根系特征参数显著相关,相关系数介于0.64-0.91之间,其中根长是影响土壤抗冲性的主要因素,通过线性拟合进一步分析,发现土壤抗冲性与根长〈0.5 mm指标相关最紧密。因此,在缓坡耕地上种植粟株有利于增强土壤抗冲能力,保持水土。On the basis of washing experiment by undisturbed soil sample,soil anti-scourability variation characteristics and influencing factors were studied under millet cultivation. Characteristics of soil anti-scourability can be primely reflected by soil anti-scourability index,which was selected to evaluate soil anti-scourability.Soil anti-scourability index refers to runoff detach a gram of soil in a unit time（ g/min）. The effect of millet roots on enhancing soil erosion resistance was evaluated by measuring soil anti-scourability is improved by the root system at different growth stages of the crop. Results show that with the prolonging of scouring time,the sediment concentration at different growth stages of millet,decreased first and then gradually become a balanced developing state,the sediment concentration of seedling stage reaches the highest（ 5. 92 g/L） in the first 3 minutes. Soil anti-scourability and its enhancement effect varied with the crop growing,showing a similar trend,soil anti-scourability index increased gradually from seedling stage to beginning heading stage,peaked at beginning heading stage,and then decreased to maturation stage,while seedling stage was the minimum.Soil anti-scouribility positively correlated with root weight density,root volume,root surface area and total root length,also millet with 〈0. 05 mm root system plays an important factor to affect the soil anti-scourability.Hence,planting millet on gentle slope land can enhance soil anti-scourability,and conserve water and soil.

关 键 词：坡耕地 抗冲性 粟株 

分 类 号：S157.1[农业科学—土壤学]