| During 2002~2004, we studied the changing of soil environmental characteristics with fertilization problems in vegetables greenhouse at FANYAO village and WAWANG village in JINGYANG county . We adopted the methods of field investigation and soil sample analysis lab., synthesized some documentary materials. The used for references were concerned with achievement of studying the changing of soil environmental characteristics with fertilization of unenvironmental vegetables cultivation interior and overseas. It was showed as follows. (1)The soil environmental changed in greenhouse. The soil secondary salinization, P and K accumulation were obviously showed. The condition was more serious along with ages. The contents of organic matter, the total N and available N were low, the contents of nitric N were a little high. But the change of them were irregular with the age of the vegetables greenhouse. (2)The vertical variation of soil environmental characteristics in soil profile. The soil salt accumulation and acidulation of topsoil were rather obviously showed. The average total salt contents of topsoil were 3.2g/kg, 2.8g/kg of 20-40cm-depth-of soil, almost 2.0g/kg of 40-60cm and 60-80cm depth of soil layer; both pH-value of topsoil lower 0.61 and 60-80cm soil layer lower 0.27 than the comparable samples. The average NO3--N contents were 6.3 mg/kg,which was 5.5 times of the comparable sample, and NO3--N down-ward migration can be found in all total soil layer profile, the average 27.3 mg/kg of 60-80cm soil layer of NO-3-N content. The average contents of organic matter were 16.0 g/kg of topsoil. The salt contents were increasing and pH value was down and NO-3-N was leaching to deep level more and more seriously with cultivated ages. (3)The results of investigation of fertilization current status and problems. not only organic fertilizer was poor but the types were not rich. The standards of fertilization were different, which over-fertilized and the composition of fertilizer were unreasonable, whose nutrition was disorder, whose methods were out-to-date , whose minor element and foliage fertilizer were less, which the degree of socialization service was lower. (4) The obstacles of soil environmental to vegetables growth in greenhouse were the soil nutrient out of balance, the soil salinization and culture without rotation etc. (5)The recondition measure of obstacles of soil environmental. To fertilizer and limit scientifically, to select suitable fertilizer, desalination with elutriation, creature, engineering or cover. To rotate, fallow, soil disinfection and select succession cropping-ensuring and pest-resistance species, soilless culture etc. (6)The measure of soil breed and management in greenhouse. Taking organic fertilizer as chief and fertilizer as assistant. Taking compound fertilizer as chief and simplex fertilizer as secondary place. Taking basal manure as chief and after manuring as assistant. Promoting friendly fertilizer to environment. We suggest to increase the input of organic manure, limit fertilizer; practice the soil testing fertilization to balance the nutrition, apply the new types of fertilizer, improve the methods and use efficiency fertilizer, popularise the technique of CO2 fertilizer , irrigate and drain scientifically, crop rotation etc. (7)The fertilizer problem of unenvironmental vegetables. In order to settle the problem we should be carried out by practice soil testing fertilization and precision fertilization. |
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