生物炭与膨润土对辽西北风沙土理化性质的影响研究

Effect of biochar and bentonite on physicochemical properties of sandy soil in northwestern Liaoning province

农田土壤沙化造成其生产力低下,急需对土壤进行改良,提高其保水保肥性,进而促进作物增产。以辽宁省西北地区风沙土为研究对象,选取水稻稻壳、玉米秸秆和竹子3种生物炭与膨润土作为改良剂开展土壤培养试验,研究不同用量改良剂单施及混施对风沙土土壤理化性质的影响。结果表明:单施及混施不同用量生物炭和膨润土,均可显著改善风沙土土壤理化性质。与CK相比,单施及混施不同用量改良剂可有效降低土壤容重,提高土壤含水量和孔隙度,混施处理中施用相同量的膨润土,其生物炭含量越高,效果越显著;2%膨润土显著提高了风沙土中粉粒的占比;改良剂提高了风沙土pH、有机质、阳离子交换量(CEC)、全氮、全磷、全钾、碱解氮、有效磷和速效钾的含量。与CK相比,改良剂混合施用的效果优于单施,膨润土用量相同处理下,土壤中生物炭含量越高,其改良效果越显著,以2%生物炭和2%膨润土混合施用的效果最佳。

The soil desertification of farmland causes its low productivity,so it is urgent to improve the water conservation and fertilizer preservation of soil,and thus promote crop yield increase.With sandy soil in the northwest of Liaoning province as the object of research,soil culture experiments were conducted with three kinds of biochar and bentonite(rice husk,corn straw and bamboo)as modifier to study the effect of singled and mixed application of different amendments on the soil physicochemical properties of sandy soil.The results show that single and mixed application of different dosage biochar and bentonite significantly improved the physicochemical properties of sandy soil.Compared with control,different dosage amendments effectively decreased the soil bulk density,improved content of soil water and the soil porosity.When applying the same amount of bentonite in the mixed treatment,the higher the biochar content was,the more significant the effect was;2%bentonite significantly increased the proportion of powder particle in sandy soil;the modification improved the pH,organic matter,cation exchange capacity total nitrogen,total phosphorus,total potassium,available phosphorus,alkaline nitrogen and available potassium.Compared with control,the improvement effect of mixed application was better than alone.With the same amount of bentonite treatment,the higher the biochar content was in the soil,the greater the improvement effect was.Application of 2%biochar and 2%bentonite were the best.