土壤管理措施对紫色土坡耕地侵蚀耕层质量的影响

紫色土坡耕地是我国西南地区重要的耕地类型,为了探讨土壤管理措施对紫色土坡耕地侵蚀耕层质量的影响,以紫色土坡耕地耕层土壤为研究对象,采用铲土侵蚀模拟试验小区,建立不同侵蚀程度(侵蚀年限)的坡耕地定位试验,以不施肥为对照(CK),设置了化肥管理措施(F)、生物炭+化肥管理措施(B+F),对比分析土壤管理措施对土壤理化性质及力学性能影响,采用土壤质量指数法分析紫色土坡耕地侵蚀耕层质量变化特征。对3种土壤管理条件下坡耕地耕层质量及恢复作用进行评价。结果表明:(1)土壤管理措施对紫色土坡耕地侵蚀耕层土壤理化性质影响差异显著。F管理措施不能改善土壤结构,但能提高土壤养分,B+F管理措施耕层土壤容重最小,土壤总孔隙、毛管孔隙及饱和含水量增加,有机质含量最高,为12.45 g/kg,土壤养分状况最好。(2)F和B+F 2种管理措施均能提高0—10 cm土层抗剪强度,使得表层土壤抵抗剪切破坏能力增强,有利于水土流失调控,2种管理措施下土壤贯入阻力下降,能有效促进作物根系生长发育。(3)2种管理措施对紫色土坡耕地耕层土壤质量均有恢复作用,土壤质量指数依次为B+F(0.686)、F(0.625)、CK(0.595),B+F管理措施土壤质量较对照CK(0.595)提升15.3%,较F(0.625)提升9.8%,B+F管理措施对坡耕地侵蚀耕层土壤质量恢复效果最好,能有效提高紫色土坡耕地侵蚀耕层作物产量。B+F管理措施能有效改善土壤结构,增加土壤养分含量,更适合紫色坡耕地侵蚀耕层质量恢复及土壤侵蚀防治,研究结果可为紫色土坡耕地侵蚀性耕层质量恢复提供适宜管理措施,对紫色土坡耕地持续利用具有重要意义。

Effects of Soil Management Measures for the Quality of Eroded Cultivated-layer in Purple Soil Sloping Farmland

Purple soil sloping farmland is an important cultivated land resource in southwest China. In order to explore the influence of soil management measures on the quality of eroded arable cultivated-layer of purple soil sloping farmland,the purple soil sloping farmland cultivated-layer soil is used as the research object,the soil erosion simulation plot was used to establish different erosion degree (erosion years) of sloping farmland location test,fertilizer management measure (F) and chemical fertilizer + biochar management measure (F + B) are set up,taking no fertilizer as a control (CK).Soil quality index method is used to analyze and evaluate the quality recovery effect of eroded cultivated-layer on purple soil sloping farmland and characteristics of indicator change with different management measures. Results show: (1) The effects of the two management measures on the physical and chemical properties of the soil cultivated-layer of purple soil sloping farmland were significant. F management measure can not improve soil structure,but can improve soil nutrient. Under B+F management measure,soil bulk density is minimal,soil total pores,capillary pores and saturated water content increase,and organic matter content is the highest,12.45 g/kg. Soil nutrient status is best. (2) Both F and B+F management measures can improve the shear strength of 0-10 cm soil layer,which makes the surface soil resist shear failure,which is conducive to soil erosion control,and the soil penetration resistance decreases under the other two management measures. Promote the growth and development of crop roots. (3) The two management measures improved the soil quality of the cultivated-layer of purple soil sloping farmland. The soil quality index was B+F (0.686),F(0.625) and CK(0.595),and the soil quality of B+F management measure was higher. Compared with CK (0.595),it increased by 15.3%,which was 9.8% higher than F (0.625). B+F management measure had the best effect on soil quality improvement of sloping farmland. B+F management measures can effectively improve soil structure and increase soil nutrient content,which is more suitable for quality restoration of cultivated-layer and soil erosion control in purple sloping farmland. The research results can provide suitable management measures for quality restoration of eroded cultivated-layer in purple soil sloping farmland. It is of great significance for the sustainable use of purple soil sloping farmland.