Effect Of Interaction Between Manure And Inorganic Fertilizers On Soil Nutrient Characteristics And Salt Content And Ion Composition In Greenhouse Soil

Absorption of crops, nutrient efficiency and salt accumulation of soils were great influenced by interaction of different nutrition or soil salinity ion. Under greenhouse cultivation, a large amount of chemical fertilizers and manures were used in order to get more yields, the rate of nutrients was higher than that actual demand of greenhouse vegetables. Excessive fertilization in greenhouse were the main causation of low fertilizer use efficiency, nutrient state, and secondary salinization. It is very important to study the influences of interaction of several fertilizers concurrently in soils on salt content and ion composition for enhancing fertilizer use efficiency, regulating nutrient balance and salt content, and sustainable development in greenhouse cultivation system. On the basis of the investigation of greenhouse cultivation in Shandong, Liaoning and Sichuan province and the study of nutrient state, ion composition of salt and its accumulation and translocation of greenhouse soils in these different region, in this research, the effects of amide nitrogen(CO(NH₂)₂), ammonium nitrogen(NH₄HCO₃), calcium nitrate(Ca(NO₃)₂) and interaction between manure and inorganic fertilizers on soil nutrient efficiency and salt content and ion composition in greenhouse and open field soil of Shuangliu in Sichuan province were studied in an incubation experiment. The results showed that:1 In the treatments of different nitrogen fertilizers, manure, and different proportion of nitrogen, phosphorus, and potassium fertilizers, the content of NH₄⁺-N, NO₃^--N, available K, and slow-available K changed in a same way as it in each different treatment. The NH₄⁺-N was transformed into NO₃^--N, nitrification lasted 60 days. The content of available K and Slow-available K were transformed in a balance. When available K content decreased to 26.43%-54.22% or increased to 59.10%-85.40% of that before incubation, the potassium could be released or fixed. The content of available P was decreased in the treatments of combined application of phosphorus, and potassium fertilizer with different nitrogen fertilizers, or different proportion of nitrogen, phosphorus, and potassium fertilizers during the incubation days, but it increased in the treatments of combined application of nitrogen fertilizers and manure at the middle stage of the incubation, then decreased after 60 days.2 Compared with no nitrogen fertilizer, combined application of phosphorus, and potassium fertilizer with different nitrogen fertilizers could increase NH₄⁺-N, NO₃^--N, available K content, enhancing potassium fertilizer use efficiency, except that Ca(NO₃)₂ had no effect to the content of NO₃^--N. The content of NH₄⁺-N, NO₃^--N was increased with nitrogen fertilizers amount. A significant relationship was found between available K content and ammonium or amide nitrogen fertilizer amount. Nitrogen fertilizers application could reduce potassium fixation, potassium fertilizer fixation rate in two soils was: ammonium nitrogen < amide nitrogen < nitrate < no nitrogen fertilizer. Ammonium nitrogen was more benefit to potassium fertilizer use efficiency. The content of available K were increased 26.88%, 18.28%, 11.07% by ammonium nitrogen, amide nitrogen and nitrate. However, slow-available potassium and nitrogen fertilizers amount did not show much as the same as available P and nitrogen fertilizers amount.3 The content of NH₄⁺-N was not effected by nitrate, it was mainly effected by manure in the treatment of combined application of nitrate and manure; In the treatment of ammonium nitrogen or amide nitrogen and manure combined application, the content of NH₄⁺-N was same as it in single nitrogen fertilizer or single manure treatment. The content of NO₃^--N was changed by the double effects of nitrogen fertilizer and manure, but the content of NO_<sup>3--N in the treatment of manure and nitrate was higher than other treatment. Soil available K and slow-available K were significantly correlated with manure amount. Responded than single application of manure, combined application of nitrogen fertilizers and manure could increase the content of available K, decreased available P especially combined application of manure and ammonium nitrogen, but not significant effect to slow-available K and NH₄⁺-N.4 In the incubation experiment of interaction between different amounts of fertilizers, the contents of NCV-N and NH₄⁺-N were effect by nitrogen fertilizer, they increased with the amount of nitrogen fertilizer increasing from 0.3 g N/kg soil to 0.8 g N/kg soil, and same as the nitrification time, it increased from 15 days to 60 days, but phosphorus and potassium fertilizer had no much effect to NO₃^--N and NH₄⁺-N content. Nitrogen and potassium fertilizer didn't show much effect to the content of available P. There were much different of the content available K in 15 or 30 incubation days in different treatments. Phosphorus fertilizers application could increase available K and reduce potassium fixation.5 Salt content and EC in greenhouse soil changed in a same way as that in open field, EC were significantly related to salt content. A significant relationship was found between salt content and manure amount, potassium fertilizer amount; however, salt content and nitrogen, phosphorus fertilizer amount did not show much. EC were significantly correlated with both manure amount, nitrogen, potassium fertilizer amount, but EC and phosphorus fertilizer amount also did not show much. K⁺, Na⁺, Ca²⁺, Mg²⁺, NO₃^- content were differently increased after nitrogen application, K⁺, Na²⁺, Cl^- content were significantly increased after manure application, and K⁺, Ca²⁺, Mg²⁺ were increased by potassium fertilizer. There were no significant difference between salt content and ion composition in greenhouse soil and that in open field soil. The change of HCO3" content was opposite to the change of salt content; it decreased in the beginning 15 days. Both salt content and EC correlations with K⁺, Ca²⁺, Mg²⁺, SC₄^2-, Cl^-, NO₃^- content were also discussed, results were significant, and SO₄^2-and Ca²⁺ were the main factor of salt content and EC either.