Abstract: Long-term field experiment with K fertilization and straw recycling was conducted since 1992 to 2012 in a Fluvo-aquic soil of Hebei Province.The soil total K content,soil available and slow release K content,and the soil K balance were examined in the long term experiment to find the effects of K fertilization and straw recycling on soil K status change.The results showed after 20 years continuous treatments of no K fertilization and straw recycling,there was no significant change in soil total K content;The treatments of NPSt,NPK and NPKSt significantly increased the soil available K content than the initial of about 44.2%-79.1%.And the NPK and NPKSt treatments significantly increased the soil slow release K content of about 7.66%-37.3% than the initial.There was no significant change for NP treatment in soil available K content,but the slow release K content for NP and NPSt treatments decreased about 20.8,9.8 mg/kg respectively.Only the NPKSt treatment got soil K surplus in the 4 treatments,and 100 kg/ha surplus will increase 2.71,24.4 mg/kg,for soil available K and slow release K content,respectively.The experiment showed the positive effect of K fertilization and straw recycling on soil K fertility improvement.

Key words: Long term in-site experiment, Potassium fertilizer, Fluvo-aquic soil, Straw recycling, Soil potassium status

CLC Number: 

• S143.3