生物炭和膨润土改良风沙土理化性质及对玉米农艺性状的影响

Improvement of physicochemical properties of aeolian sandy soil by biochar and bentonite and its effect on maize agronomical traits

以辽宁省西北地区风沙土为研究对象,选取3种生物炭(水稻稻壳、玉米秸秆和竹子)和膨润土为改良剂,玉米为种植作物进行野外大田试验,研究生物炭和膨润土单施及混施对风沙土土壤理化性质及玉米农艺性状的影响。结果表明:生物炭和膨润土单施和混施均显著改善了土壤理化性质。生物炭和膨润土的施入降低了土壤容重,提高了土壤孔隙度和含水率;WR>0.25mm(粒径大于0.25mm的水稳性团聚体含量)、MWD(平均重量直径)和GMD(几何平均直径)的变化均表现为拔节期到吐丝期无显著性变化,吐丝期到成熟期变化显著,最大分别增加至1.8、2.0和1.3倍,且膨润土与玉米秸秆生物炭的混施处理效果最佳;生物炭和膨润土显著提高了土壤有机质含量、pH、阳离子交换量(CEC)和速效态氮、磷、钾的含量,其中CEC含量最大增加至2.9倍,膨润土与竹子生物炭的混施处理pH提高至1.2倍,土壤速效磷和速效钾分别增加至5.7和2.4倍,碱解氮增加至6.3倍;玉米产量、株高和叶面积指数也有显著增加。生物炭和膨润土混施优于单施处理,其中施12t·hm^(-2)膨润土和1.9t·hm^(-2)生物炭对风沙土的改良效果最佳。

Taking the aeolian sandy soil in northwest of Liaoning province as the research object,three kinds of biochar(rice husk,corn straw and bamboo)and bentonite as modifiers,and maize as tested crops,field experiments were conducted to study the effects of single and mixed application of biochar and bentonite on the physicochemical properties of the aeolian sandy soil and the agronomic traits of maize.The results showed that both single and mixed application of biochar and bentonite significantly improved the physicochemical properties of soil.Application of biochar and bentonite decreased the soil bulk density and increased the soil porosity and content of soil water.The changes in WR_(0.25mm)(0.25mm water stable aggregates),mean weight diameter and geometric mean diameter all showed no significant changes from jointing stage to silking stage,and changed significantly from silking stage to maturity,with the maximum increase by 1.8,2.0 and 1.3 times,respectively,and that effect of the mixed application bentonite and corn straw biochar was the best.Biochar and bentonite significantly increased the soil organic matter content,pH,cation exchange capacity and available nitrogen,phosphorus and potassium content.The cation exchange capacity increased by 2.9 times,mixed application of bentonite and bamboo biochar increased the pH by 1.2 times.Soil available phosphorus and available potassium increased by 5.7 and 2.4 times,respectively,the soil alkaline nitrogen increased by 6.3 times.Corn yield,plant height and leaf area index also increased significantly.Mixed treatments of biochar and bentonite are better than single treatments,among them 12t·hm^(-2)bentonite and 1.9t·hm^(-2)biochar have the best effect on aeolian sandy soil improvement.