Waste Composting And Fertilizer On Farmland N <sub> 2 </ Sub> O Emission Flux

Nitrous oxide (N₂O) fluxes from the fields in a maize and wheat rotation system were studied in the North China Plain. Effects of differently treated fertilizers on soil N₂O flux from a maize and wheat field were also studied systematically using static chamber-GC technique. In order to find out the seasonal variation of N₂O emission, a manual sampling system was established to monitoring N₂O emissions from field in a maize and wheat rotation system. The environmental factor such as fertilization, soil temperature, soil moisture, content of N-NO3", content of N-NH₄⁺, straw-mulching, which affect N₂O flux from field was analyzed detailedly in this paper, the results concluded that:1. The seasonal variation of soil N₂O flux was obviously in a maize and wheat rotation system. During growing season, N₂O emission in maize field was fastened on the seedling stage. At the unplugging stage, due to the growth of corn, N₂O emission in maize field under the different fertilization treatments decreased. The higher amount of N₂O released from soil was mainly related to precipitation at earing stage. Similarly, N₂O emissions from winter wheat fields are also concentrated in seedling stage during growing period. It account for about 46%, 48% and 45% of the total emission of N₂O during growing period that the N₂O emissions from control, urban waste compost and its compound fertilizer plots in seedling stage, respectively.2. The total emission of N₂O from wheat field was higher than that from maize field during growing season. But, the opposite result has been found out in straw-mulching. It was the primary reason that straw mulch was of great advantage of water saving, moreover, soil temperature of mulching treatment was much lower than that of un-mulching treatment.3. N₂O emission from field was extremely different and the diversity was significant (P<0.01) among three treatments during growing season. The rank of N₂O average emission in different fertilization treatments from maize field is: compost> compound fertilizer > control. During growing season, the N₂O flux from soil disposed with urban waste compost was higher than that with its compound fertilizer, by about 1.9 and 1.5 times, respectively, higher than that in control. For the sake of mitigation of N₂O emissions, it was necessary to transform urban waste compost into its compound fertilizer.