Nutrient State And Characteristics Of Accumulation And Translocation Of Salt In Greenhouse Soil Profiles

On the basis of distribution of greenhouse cultivation in china, some research about greenhouse soil of Shouguang in Shandong province, Liaoning and Beining in Shenyang province, Changzhou in Jiangsu province and Shuangliu in Sichuan province were studied. By investigating the greenhouse cultivation of these different region in China and analyzing both the greenhouse and open field soil samples, nutrients banlance of greenhouse cultivation system and nutrient state were studied under typical greenhouse cultivation.In the same way, the ion composition of salt and its accumulation and translocation of greenhouse soils in different regions were studied. The main results were as the belowing:1. A large amount of chemical fertilizers and manures were used in order to get more yields in typical greenhouse cultivation in China. By investigation, in Shouguang, Shandong province, the annual application rate of Nitrogen (N) , phosphorus (P₂O₅) , kalium (K₂O) to greenhouse vegetables were 4088.2 kg/hm², 3655.5 kg/hm² and 3437.5kg/hm² and respectively, 63%, 61% and 66% of these nutrients were from chemical fertilizer. Under the greenhouse cultivation, the rate of nutrients was higher than that actual demand of greenhouse vegetables. Only 24%, 8%, 46% of the application of Nitrogen(N), phosphorus(P₂O₅), kalium (K₂O ) respectively were absorbed by vegetables. Moreover, the proportion among nitrogen (N) , phosphorus (P₂O₅) and kalium (K₂O) 1: 0.89: 0.84 was also quite different from the proportion of actual nutrient demand 1:0.3:1.43. So it led to accumulation of many nutrients of nitrogen, phosphorus and potassium in soils, especially in accumulation of phosphorus and nitrogen.2. As a result of fertilization, nutrient state of the greenhouse soil was more different...