施用生物质炭10年后对灌耕风沙土物理性质的影响

Effects of Biochar on Physical Properties of Irrigated Aeolian Sandy Soil Ten Years after Application

针对灌耕风沙土存在的土壤贫瘠、保水保肥能力差等问题,采用长期田间定位试验,研究施用生物质炭10年后灌耕风沙土土壤物理性质的变化,探究生物质炭土壤改良的长期效果。试验通过设置空白对照(CK)、22.5 t·hm^(-2)农家肥(牛粪,1%MA)、22.5 t·hm^(-2)腐殖酸(1%FA)和4个梯度的生物质炭(22.5,67.5,112.5,222.5 t·hm^(-2);1%,3%,5%,10%BC),对照比较10年后的土壤物理性质。研究结果表明:与CK相比,施用生物质炭10年后,对灌耕风沙土0~20 cm土层的土壤比重、0~10 cm土层的土壤容重无影响。10%BC处理可以显著降低10~20 cm土层土壤容重6.68%,显著增加10~20 cm土层的土壤含水量、饱和含水量、田间持水量、相对含水量,分别为27.31%,18.60%,15.50%,10.14%;10%BC处理对0~10 cm土层土壤含水量、饱和含水量、田间持水量、相对含水量无显著影响。生物质炭对灌耕风沙土0~20 cm土层水稳性团聚体形成无影响。综上,高施用量的生物质炭在10年后仍能显著改良灌耕风沙土10~20 cm土层的土壤理化性质。

Aiming at the problems of poor soil and poor ability to retain water and fertilizer in the aeolian sandy soil under irrigation,a long-term field positioning experiment was used to study the changes in soil physical properties of the aeolian sandy soil ten years after the application of biochar,and to explore the long-term effect of biochar soil improvement.Experiments passed the settings:blank control(CK),22.5 t·hm^(-2) farmyard manure(cow dung,1%MA),22.5 t·hm^(-2) humic acid(1%FA),and 4 gradients of biochar(22.5,67.5,112.5,222.5 t·hm^(-2);1%,3%,5%,10%BC),and compared the soil physical properties after ten years.The results showed that compared with CK,the application of biochar had no effect on the soil specific gravity of the 0-20 cm soil layer and the soil bulk density of the 0-10 cm soil layer in the irrigated sandy soil after ten years of application.The 10%BC treatment could significantly reduce the soil density by 6.68%in the 10-20 cm soil layer.The 10%BC treatment could significantly increased the soil water content,saturated water-content,field water holding capacity and relative water content in the 10-20 cm soil layer,the content of these layers could be increased by 27.31%,18.60%,15.50%,and 10.14%,respectively.The 10%BC treatment had no effect on the soil water content,saturated water content,field water holding capacity and relative water content of the irrigated sandy soil in the 0-10 cm soil layer.Biochar had no effect on the formation of water-stable aggregates in the 0-20 cm soil layer of irrigated aeolian sandy soil.In conclusion:The high application rate of biomass char can still significantly improve the soil physicochemical properties of the 10-20 cm soil layer of the irrigated sandy soil after ten years.