The soil aggregate and micro-aggregate of fixed fertilization plots in Qia nxian county

Shaanxi province are studied. The results showed that the disparities were remarkable in content of soil organic

matter

the quantity and proportion of each grade of aggregate and micro-agg regate in different fertilization

levels. Compared with the contrast

raising the level of fertilization

soil organic matter

10-250μm microag

gregate and > 0. 25mm aggregate increased constantly

and the quantity of < 10μm micro-aggregate had the decreasing trend. Soil coefficient of disperse decreased and that of the soil structure increased.Analysis showed that the content of organic matter was positively linear corelated to quantity of > 0. 25mm aggregate and 10-250 μm micro-ag g reg ate respectively

and was neg atively linear corelated to < 10 μm microag gregate. Raising fertilization

especially raising quantity of organic fertilizer or blending organic fertilizer and in organic one

it is benefited for forming the bigger diameter aggregate.