盐渍化改造区土壤有机质变化与培肥系统研究

The changes of soil organic matter and fertilization system in the salt-affected area

本文以曲周试验区为例 ,研究了盐渍土改造区土壤有机质演化的阶段性特征及系统培肥措施。盐生植被归还条件下 ,土壤有机质含量小于 5g·kg-1,近乎贫瘠。随着化肥用量的增加 ,作物生物产量增加 ,以根茬归还土壤 ,从而使土壤有机质含量提高到 8～ 9g·kg-1;加大秸秆还田量 ,土壤有机质含量可提高并维持在 10～ 12g·kg-1。2 0世纪 90年代以后 ,随着高产作物品种的出现、生产条件的改善、物质投入的增加 ,作物产量明显提高 ,无论是以根茬还是秸秆还田都会增加还田量 ,使土壤有机质含量超过 10g·kg-1,有的达到了 12 .5 0g·kg-1;农牧结合 ,以优质的有机物质归还土壤 ,使土壤有机质含量持续提高到 15g·kg-1以上。土壤培肥措施要适应土壤有机质在盐渍化改造区条件下的积累和演化的阶段性和农业 农村发展的阶段性。

This paper describes the phase characteristic of soil organic matter and fertilization system in the salt-affected area of Quzhou Experimental Field. With returning the halophyte plants, the soil was very poor and contained organic matter as low as 5.0 g·kg -1. At the initial stage of clearage soil, the crop biomass increased. The crop roots returned to the soils. The soil organic matter was about 8.0～9.0 g·kg -1. When increasing straw amendment into the soil, the soil organic matter increased to 10.0～12.0 g·kg -1. Since 90s of 20 th century, crop yield largely increased due to introducing high yield varieties and improving agricultural production conditions, the soil organic matter increased to 10 g·kg -1, even to 12.5 g·kg -1, because of the increases of roots and straw returning to the soil. If a large amount of high quality organic matter such as cattle and human manure was returned to the soils, the soil organic matter could be up to 15.0 g·kg -1. Finally, all the measures of fertilizing the soil should adapt to accumulation and phase characteristics of the soil organic matter in the salt-affected area and phase characteristic of farming-countryside development.