Yield Increase Effects Of Potassium In Several Crops In Paddy Soils Of Jingmen City

Potassium is one of the necessary nutrients for plant growth. Because of the shortage of potassium fertilizer application during the long term, the soils in Jingmen city have a serious decrease of K contents, thus it limits the crops yield increase. Therefore, K fertilizer application is an important topic both in Jingmen city and in the whole country for agriculture sustainable development. A series of field increase effects of potassium fertilizer. Our aims are to demonstrate the soil K statues and provide the foundation of K application in Jingmen city.The main results indicated: (l)under the current K levels of Jingmen city soils, K application to the crops tested (rice, wheat, cotton and wormawood) has a significant yield increase effects. When nitrogen, phosphorus were the same application amount, kg/hm2 K2O application made 27.4% (rice), 22.3%(wheat) increase compared with the controls, respectively. The effects of K fertilizer application increased with the contents decreasing of soil available K. (2) in the 90kg/hm K2O application, the rice yield increased with the soil gleyed degrees increasing. (3) in the rotation of rice and wheat, the yield of two crops in the I application twice was greater than the application once. Moreover, the yield increase of rice was better than that of wheat. (4)for the same K application kevels, K fertilizer imported from Russia had a similar yield increase with Qinghai K fertilizer. For rice, wheat and cotton, the yield increase percentages were 27.4%, 21.1% and 22.3%, separately. (5)The K application amount that we suggested are 90 kg/hm2 for rice, wheat and cotton, and 150 kg/hm2 for wormwood. There was obvious decrease of available K, nonexchangeable K and total K contents in all soils tested when K was not used.Based on the results, the K contents had a decrease even when K fertilizer was applied. The use of K fertilizer could only to inhibit the rapid reduction of soil available K. From the viewpoint of yield increase of crops, long term K application has been advised.