Interannual Dynamics Of Small-scale Range Of Black Soil Nutrients In Cold Area

Soil nutrients of cold black soil for5years in the field units of singrain northernagriculture development company of northern Nenjiang County were monitoredcombined with previous data and compared with the1980’s second soil survey data inorder to understand the current status of black soil nutrient and to provide guidance forthe scientific management of the farmland. The main results were as follows:(1) During the period of2008~2012, soil pH showed a tendency to increase, butstill was the acid or weak acid. Soil acidification caused by long-term cultivation is stillvery serious. We suggested to improve the soil acidification.(2) During the period of2008~2012, soil organic matter increased first and thendecreased, mostly reached grade A. Long term tillage and fertilization measures canmaintain or increase soil organic matter content. We suggested continue to adhere to thescientific fertilization in farmland, in order to stabilize the organic matter levels.(3) During the period of2008~2012, soil available nitrogen content changed little,mostly reached grade A. This result showed that the soil available nitrogen increase bylong-term fertilization, but also caused waste of the nitrogen and thus soil acidification.We suggested applying nitrogen fertilizer properly in agricultural production in thefuture.(4) During the period of2008~2012, soil available phosphorus content wasdecreased firstly and then increased, and mostly reached grade C. The utilizationefficiency of P fertilizer should be improved in production. We suggest that phosphatefertilizer can be continued to use in farmland, but should continue to monitor.(5) During the period of2008~2012, soil available potassium content wasdecreased firstly and then increased, mostly reached grade A. We suggested toappropriately control the application amount of potassium fertilizer in agriculturalproduction.(6) During the period of2008~2012, the soil nutrients had significant positivecorrelation (P <0.01), soil nutrient factors all play an important role in soil fertility.