The Effect of Chemical and Organic Straw Fertilization on the Content and Properties of Soil Organic Matter

The result of long-term experiment conducted on fluvo-aquic soil indicated that:different fertilizations had marked effect on the content and properties of soil organic matter(OM).Both chemical and organic straw fertilizers increased the soil OM content,but differed in the effect on the OM properties.Chemical fertilizer tended to increase all fractions of OM and promote the ratio of(loose+stable)/fastened OM fractions,this might lead to the consumption of soil fertility.The effect of organic fertilizer on the OM fractions was not stable.Both chemical and organic fertilizers increased the soil humus content,but the former stimulated the accumulation of humic acid(HA),and showed little effect on the fulvic acid(FA),thus decreased the HA/FA ratio;on the contrary,the latter stimulated the FA,but showed little effect on the HA,and promoted the HA/FA ratio.Chemical fertilizer degraded the soil OM quality and the organic fertilizer improved it,therefore,the combined application of chemical and organic fertilizers was much benefit in practice.