Abstract:

Relying on the national soil quality observation Shanxi (Yuci) experiment platform, we studied the long-term application effects of organic fertilizer, chemical fertilizer, and their combination and non-fertilization on soil physicochemical traits of the grain field, and elaborated the soil quality evolution. Through five years of monitoring, the results showed that the long-term application of fertilizers reduced soil pH, increased the volume weight, and decreased soil porosity. The contents of total nitrogen, available nitrogen and available phosphorus in soil of single application of organic fertilizer increased significantly compared with that of no fertilization, but the effect was not as good as that of chemical fertilizer and organic fertilizer combination. Application of organic fertilizer alone significantly increased soil organic matter content, which was significantly different from other treatments. Organic fertilizers was mainly organic phosphorus, and could increase soil organic matter content, reduce the fixation of inorganic phosphorus, promote the dissolution of inorganic phosphorus; organic fertilizer alone or combined with chemical fertilizer could all improve soil quick-acting potassium content, organic fertilizer was conducive to root growth and extension, and long-term administration of organic fertilizers could reduce soil packing degree, effectively improve the soil tillage conditions, and benefit crops growth. The dry matter accumulation of sorghum at seedling stage was less, and the dry matter accumulation at jointing stage and filling stage increased significantly, and the dry matter reached the maximum at maturity stage. Fertilization methods had little effect on the proportion of dry matter distribution in different parts. The dry matter content of fertilization treatment was higher than that of control, and the effect of chemical fertilizer and organic fertilizer was the best. This experiment revealed the change law of soil fertility under different fertilization conditions for a long term, scientifically evaluated the influence of different fertilization methods on soil characteristics, guiding local agricultural production.

Key words: long-term localized fertilization, grain field soil, soil quality, dry matter of sorghum