| In recent years, the greenhouse vegetable cultivation has become important vegetablecropping patterns in the northern region, but the problem of excessive fertilization in thegreenhouse cultivation, not only affect the yield and quality of greenhouse vegetables, butalso the Greenhouse soil degradation, triggering a series of ecological and environmentalproblems. Large amount of organic fertilizer caused the soil nitrogen nutrient inputs in excessand excessive fertilization problems. Although extensive researches have been done on thenitrogen supply characteristics of organic fertilizer, but there were differences in thegreenhouse cultivation and fields on environmental conditions. In addition, many kinds oforganic fertilizers have great differences. It is still an unresolved issue that how to determinethe amount of nitrogen input in organic fertilizer. Objective and accurate assessment of thecharacteristics of nitrogen supply from organic fertilizer in the greenhouse cultivation is animportant matter as to solving the sunlight greenhouse soil nutrient surplus andeco-environmental hazards.Therefore, the main kinds of manures (chicken manure, swine manure and cattle manure)are used in solar greenhouse production in Guanzhong, Shaanxi province were investigated inthis study. In order to effectively evaluate the N supplying properties of manure, based ondetermining the manure nutrient concentrations, indoor incubation experiment, integratedwith pot bio-depletion experiment and field experiment was conducted to investigate the Nmineralization and utilization properties of various kinds of manure. The main conclusionsinclude:1. Nutrient concentrations in more than forty different kinds of livestock and poultrymanures that utilized in solar greenhouses in Yangling, Shaanxi province were analysed. Theresults showed that the mean concentrations of organic carbon in chicken manure, swinemanure and cattle manure were22.80%,14.96%and21.59%, respectively the organic carboncontent of chicken manure and cattle manure were significantly higher than swine manure,and there were no significant difference between chicken manure and cattle manure. Theaverage total N and total P of chicken manure, swine manure and cattle manure were2.47%and1.34%,1.65%and0.85%,1.78%and0.92%, respectively. Total N and P of chickenmanure were significantly higher than those of swine manure and cattle manure; and there were no significant difference between swine manure and cattle manure. There were nosignificant differences in the total potassium among the three kinds of manure. The meanconcentrations of soluble organic nitrogen (SON), NH4+-N, and NO3--N in different kinds ofmanures were1.07g·kg-1,0.49g·kg-1and0.83g·kg-1respectively, accounted for5.03%,2.31%and4.05%of the total N (TN) in those manure. This indicated that SON was the largepart of the manure soluble N.2. Indoor incubation experiment was conducted to study the carbon (C) and Nmineralization characteristics of nine manure samples. The results showed that there weresignificant differences in the C and N mineralization and the mineralization rates (the ratio ofC or N mineralization to total organic C or total organic N) among the different manures. TheC mineralization rates of different manures ranged from22.24%to87.16%, with CV(coefficient of variation) of90.30%, the N mineralization rates of different manures werebetween29.07%and84.87%, with CV of67.36%. The mean amount of C and Nmineralization and mineralization rates of chicken manure were significantly higher thanthose of swine and cattle manures. there was no difference between swine and cattle manures.For the same type of manure, there were also significant differences in the C and Nmineralization and mineralization rates among the manures collected from different places.The amounts of C and N mineralization of manure were linearly related with their total Nconcentrations, indicating that the manure N concentration was a key factor in affecting the Cand N mineralization of manure.3. In-situ incubation experiment was carried out to study the N mineralizationcharacteristics of different kinds of manures (chicken, swine, and cattle manure) in the growthseason of vegetable crops in solar greenhouse. The results showed that there were significantdifferences in the N mineralization rates among the six manures during the incubation period(180days), which ranged from1.06to19.09%with average7.50%. The mineralized N andN mineralization rate of chicken manures were the highest, followed by cow manures, whileswine manures were the lowest. This might results from the higher C/N ratio of the chickenmanure. Although no significant relationship was found between the mineralized N and theaccumulated temperature of soil in each incubation period, the N mineralization tended toincrease with the rising of soil temperature in spring. The accumulated N mineralizationsignificantly linearly correlated to the soil accumulated temperature during the wholeincubation period, indicating soil temperature is a key factor in affecting manure Nmineralization.4. Old solar greenhouse topsoil was conducted for incubation and pot experiment withsuccessive cropping of tomato, which was conducted to investigate the N availability of fourchicken manure samples, two swine manure samples and three cattle manure samples through bio-depletion method. The results demonstrated that all the chicken, swine and cattle manureincreased the aboveground biomass and N uptake of tomato, with the aboveground biomassincreased by28.63%,7.75%and12.28%on average and the mean values of N uptakeincreased by14.06%,6.61%and7.48%, respectively. The average N use efficiency ofchicken manure (41.23%) was significantly higher than those of swine manure (9.17%) andcattle manure (10.81%). The ratio of N uptake in the manure treatment to that in the inorganicfertilizer treatment (being defined as N equivalent weight, MFE-N%) was used to comparethe N availability of various kinds of manure. It was observed that the average MFE-N%ofchicken manure was also significantly higher than those of swine manure (12.39%) and cattlemanure (15.66%). The same kind of manure has a big difference in N availability andMFE-N%among different samples, for example, both the coefficient of variation (CV) of theN availability and MFE-N%for the three cattle manure samples were74.59%.5. Newly-built solar greenhouse topsoil was used for incubation and pot experiment withsuccessive cropping of tomato, which was conducted to investigate the nitrogen availability ofseven chicken manure samples and three cattle manure samples through bio-depletion method.The results demonstrated that the chicken and cattle manures significantly increased thebiomass and N uptake of tomato, with the aboveground biomass increasing by104.01%and92.15%on average and the mean values of N uptake increasing by76.92%and51.88%. Theaverage N use efficiency of chicken manure was32.79%, significantly higher than that ofcattle manure (22.92%).The mean MFE-N%of chicken manure was39.75%, significantlyhigher than that of cattle manure (27.80%). The same kind of manure has a big difference inN availability and MFE-N%among different samples, for example, the CV of N useefficiency for the seven chicken manure samples was23.59%and the corresponding value forthe three swine samples was24.95%.6. Field experiment was conducted to research the effects of manure on tomato yield andsoil nutrient concentration. The results showed that manure significantly increased the tomatoyield. Manure also significantly increased the nitrate-N concentration of the topsoil during thegrowth period of tomato (one month after the application of manure). Topsoil electricalconductivity, organic matter concentration, nitrate-N content and available P contentsignificantly increased with the application of manure as well. N use efficiency of manurewas11.94%for one season of tomato. When the application rates of N, P and K chemicalfertilizer reduced16.03%,23.10%and5.28%, combining with equivalent amount of manure,the tomato yield has no significant change, but soil nutrient and salt accumulation wasmitigated. This indicated that the application of manure could reduce the input rates ofchemical fertilizer.
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