ObjectiveThe aim was to increase farmers’ income and reduce the waste of fertilizer by exploring effects of N, P and K fertilizations on vegetable yields and the accumulation of N, P and K in vegetable and soils. Met...ObjectiveThe aim was to increase farmers’ income and reduce the waste of fertilizer by exploring effects of N, P and K fertilizations on vegetable yields and the accumulation of N, P and K in vegetable and soils. MethodThe fertilization tests were conducted on tomato, cauliflower and celery in greenhouses. ResultWhen N, P and K were not applied in tomato, cauliflower or celery, the yields reduced in 6.0%-13.8% and total annual income reduced by 39 220, 36 902 and 22 023 yuan/hm 2 respectively, suggesting that N, P and K are limiting factors of yield. The absorbed N amounts of tomato and cauliflower were higher compared with celery; the absorbed P amount of cauliflower was higher compared with tomato and celery; the absorbed K amount of tomato was the highest, followed by celery and cauliflower. The absorbed N in tomato fruit was lower than that of cauliflower and the absorbed N amount of other parts of tomato was also lower. Furthermore, the absorbed amounts of P and K by tomato and cauliflower fruits were higher than it absorbed by the other parts, especially the absorbed of K was significantly high. Total absorbed amounts of N, P and K from high to low were cauliflower, tomato and celery. After harvesting of tomato, cauliflower and celery, N, P and K in soils were all higher compared with soils before planting. Influenced by fertilizers, residual N content in soils grown with tomato and residual P content in soils grown with celery both doubled compared with base soils. Cauliflower plants were not applied with organic fertilizer, and residual N and K contents in soils were lower compared with tomato and celery. ConclusionResidual P content in soils is higher, which is a kind of waste and would cause pollution on soils. It is necessary to improve the proportion of organic and inorganic fertilizers in fertilization.展开更多
Dynamic changes of soil pH as influenced by ammonium sulfate (AS),monocalciuin phosphate (MCP), potassium chloride (KCl) and their interaction in soils were evaluatedin incubation experiments. Applying these fertilize...Dynamic changes of soil pH as influenced by ammonium sulfate (AS),monocalciuin phosphate (MCP), potassium chloride (KCl) and their interaction in soils were evaluatedin incubation experiments. Applying these fertilizers significantly reduced soil pH values in allcases and followed sequences of AS > MCP > KCl, MCP > KCl > AS and KCl > AS > MCP for the paddy,calcareous and red soils, respectively. The AS-induced reduction of pH in the three soils followedthe sequence of red soil > paddy soil > calcareous soil, while in MCP and KCl systems the reductionof pH followed the sequences of calcareous soil > paddy soil > red soil and red soil > calcareoussoil > paddy soil, respectively. The interactions of the NPK fertilizers on pH were significant. MCPplus KCl or MCP plus AS reduced pH values more than the fertilizers applied solely in the paddysoil, but AS partly counteracted the effect of MCP on pH in the 1 d sample of the calcareous soil.The effect of MCP on pH was trivial when MCP was applied in combination with KCl or AS in the redsoil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed thereduction of pH at the later incubation stage, which was related to inhibition of nitrification byKCl in the soils.展开更多
基金Supported by Tianjin Municipal Science and Technology Commission Program(07ZCGYNC00800)International Plant Nutrition Institute Program(Tianjin-2008,Tianjin-2009)Agricultural Eco-protection Program of Ministry of Agriculture(2110402-201258)~~
文摘ObjectiveThe aim was to increase farmers’ income and reduce the waste of fertilizer by exploring effects of N, P and K fertilizations on vegetable yields and the accumulation of N, P and K in vegetable and soils. MethodThe fertilization tests were conducted on tomato, cauliflower and celery in greenhouses. ResultWhen N, P and K were not applied in tomato, cauliflower or celery, the yields reduced in 6.0%-13.8% and total annual income reduced by 39 220, 36 902 and 22 023 yuan/hm 2 respectively, suggesting that N, P and K are limiting factors of yield. The absorbed N amounts of tomato and cauliflower were higher compared with celery; the absorbed P amount of cauliflower was higher compared with tomato and celery; the absorbed K amount of tomato was the highest, followed by celery and cauliflower. The absorbed N in tomato fruit was lower than that of cauliflower and the absorbed N amount of other parts of tomato was also lower. Furthermore, the absorbed amounts of P and K by tomato and cauliflower fruits were higher than it absorbed by the other parts, especially the absorbed of K was significantly high. Total absorbed amounts of N, P and K from high to low were cauliflower, tomato and celery. After harvesting of tomato, cauliflower and celery, N, P and K in soils were all higher compared with soils before planting. Influenced by fertilizers, residual N content in soils grown with tomato and residual P content in soils grown with celery both doubled compared with base soils. Cauliflower plants were not applied with organic fertilizer, and residual N and K contents in soils were lower compared with tomato and celery. ConclusionResidual P content in soils is higher, which is a kind of waste and would cause pollution on soils. It is necessary to improve the proportion of organic and inorganic fertilizers in fertilization.
基金Project supported by the National Natural Science Foundation of China (No.40071051)and the National Key Basic Research Support Foundation of China(No.G1999011802).
文摘Dynamic changes of soil pH as influenced by ammonium sulfate (AS),monocalciuin phosphate (MCP), potassium chloride (KCl) and their interaction in soils were evaluatedin incubation experiments. Applying these fertilizers significantly reduced soil pH values in allcases and followed sequences of AS > MCP > KCl, MCP > KCl > AS and KCl > AS > MCP for the paddy,calcareous and red soils, respectively. The AS-induced reduction of pH in the three soils followedthe sequence of red soil > paddy soil > calcareous soil, while in MCP and KCl systems the reductionof pH followed the sequences of calcareous soil > paddy soil > red soil and red soil > calcareoussoil > paddy soil, respectively. The interactions of the NPK fertilizers on pH were significant. MCPplus KCl or MCP plus AS reduced pH values more than the fertilizers applied solely in the paddysoil, but AS partly counteracted the effect of MCP on pH in the 1 d sample of the calcareous soil.The effect of MCP on pH was trivial when MCP was applied in combination with KCl or AS in the redsoil. When applied in combination with AS, KCl did not affect soil pH initially, but suppressed thereduction of pH at the later incubation stage, which was related to inhibition of nitrification byKCl in the soils.
