Waste Composting And Fertilizer On Farmland Co <sub> 2 </ Sub>, Ch <sub> 4 </ Sub> Emission Fluxes

City rubbish administration is a important environmental problem that current mankind face with, the agriculture recycling of the urban domestic waste provide anew path to comprehensive harnessing of urban domestic wastes and reduce quantification, harmless melt. The urban waste compost and its compound fertilizer that become with urban domestic wastes have wide application prospect in agricultural production. However the environment influence especially the influence of soil emission CO₂ and CH₄ caused by the use of urban waste compost and its compound fertilizer haven't retrieved related research so far.This paper has studied farmland under the condition of applying urban waste compost and its compound fertilizer, the emission law of soil CO₂ and CH₄ in whole growth issue and the influence of soil moisture and soil temperature and covering for organic quality loss and the emissions of soil CO₂ and CH₄. Experiment is tested with field sub-district fertilizer, set up 3 fertilizer handlings totally, parting is: 1 is compared (do not apply fertilizer); 2 use the waste compost; 3 uses waste compound fertilizer. Every disposal installs 6 repetitions, in which the 3 repetitions cover with straw stalk. Every sub-district around keeps apart with the plastic film of 2 m deep and 2 mm thick, prevent that water and fertilizer seeps by side. In corn and winter wheat entire growth issue, monitor CO₂, CH₄ emission flux and soil in moisture, soil temperature and soil C element in difference application of fertilizer and different growth issue. Studying soil CO₂CH₄ emission law and influencing factor and field manage measure's effect of adjusting CO₂ CH₄ emission, which offers scientific basis for the organic quality loss and emission that reduces farmland soil CO₂ and CH₄.Testing conclusion is as follows:1 The farmland CO₂ emission flux of crop and winter wheat rotation system shows obvious seasonal change law. In general, soil CO₂ emission flux increase with corn grows, in unplugging stage and maturity stage presents obvious CO₂ emission peak. The CO₂ emission of corn field entire growth period concentrates in unplugging stage mainly, this duration, the soil CO₂ emission capacity of control, waste compost disposal h and waste compound fertilizer disposal takes crop respectively to CO₂ 46%, 52% and the 35% of total discharge capacity. Differentfertilizer disposal have different change tendency of CO₂ flux with time change, in different stage emission amount also has great discrepancy. In seedling stage, the CO₂ average flux of the waste compost disposal and waste compound fertilizer disposal are higher than control disposal; During unplugging stage, soil CO₂ flux of the waste compost disposal and waste compound fertilizer disposal be still higher than control disposal, the CO₂ flux of the waste compost disposal is highest; During earing stage, soil CO₂ average emission flux of waste compost disposal and waste compound fertilizer disposal decrease rapidly , soil CO₂ average emission flux of control disposal go up gradually; Mature duration soil CO₂ discharge capacity of different disposal also little range pick up. The CO₂ emission of winter wheat of farmland soil entire growth issue concentrates in seedling stage and unplugging stage mainly: When seedling stage, the soil CO₂ discharge capacities of control disposal waste compost disposal and waste compound fertilizer disposal take respectively to 38%, 39% and the 38% of total discharge capacity; In unplugging stage, the soil CO₂ discharge capacities of control disposal waste compost disposal and waste compound fertilizer disposal take respectively to 33%, 34% and the 32% of total discharge capacity. The CO₂ emission flux of different disposal in wheat field presents identical seasonal change law.2 Under different cover condition, compare CO₂ total discharge capacity of wheat and corn during entire growth period, wheat field > corn field. Major influencing factor is crop growth situation and soil temperature. Wheat growth period is longer, so the period of using soil organic quality is longer; therefore soil CO₂ emission amount is greater. Corn growth period is shorter and in summer, soil temperature is high and rain heat is cooperated with, so during corn growth period, the utilization rate of soil organic quality is higher, CO₂ average emission flux is higher than that of wheat field.3 During Corn growth period, the discrepancy between the soil CO₂ discharge capacity that applies different fertilizer is very notable (P=0.01), the discharge capacity in order: waste compost disposal > waste compound fertilizer disposal > control disposal. During entire growth period, the CO₂ total discharge capacity of the soil of waste compost disposal is the 1.1 times of waste compound fertilizer disposal and 1.3 times of not applying fertilizer. The CO₂ emission amount in wheat has the same law: waste compost disposal > waste compound fertilizer disposal > control disposal. Considering organic quality loss and the emission of control soil CO₂,advocate that waste compound fertilizer after processing waste compost disposal.4 During corn growth period, through the comparison of biomass in different fertilizer disposal to reach: the 100 crop weights and outputs of waste compost disposal and waste compound fertilizer disposal are all higher than control disposal; Waste compound fertilizer disposal has highest output. So consider agricultural economic benefits and crop quality, advocate to use waste compound fertilizer.5 Experiment proves: The major environmental factor that influences soil CO₂ emission flux are soil temperature and soil water content. Soil temperature has promoted the emission of soil CO₂ greatly; the soil influence of water content is not obvious.6 Straw stalk covers make farmland soil CO₂ and CH₄ emission increased, which is a disadvantage for greenhouse gas reduction. Major reason is that straw stalk covers advantage in the maintenance of soil temperature and moisture , for instance in the experiment of winter wheat ,comparing not cover disposal, the soil water contents of control disposal waste compost disposal waste compound fertilizer disposal raise 4%, 2.4% and 2.6% respectively, have so promoted soil organic quality mineralization process. Straw stalk covers can regulate soil temperature, in the experiment of winter wheat, comparing with not cover disposal, in winter soil temperature ( 10 cm )is higher than not cover soil 0.3℃～0.5 ℃; in wheat later stage of growth covers soil temperature is lower than that of not cover soil 0.3℃～0.5 ℃, the balanceable soil temperature advance the active of the microorganism in mineralization process of soil organic quality. The environment formed by Straw stalk covers have promoted soil CH₄ emission on certain degree, the isolation of straw stalk covers disadvantages the absorption of soil for atmospheric CH₄, have weakened soil absorpt effect to for atmospheric CH₄. Therefore, use straw stalk covers, suggest according to local conditions: In the arid region of, if moisture is the major restrict factor of local agricultural development, should cover soil with straw stalk to maintain n soil moisture; In moist half moist region, since straw stalk covers promote role for soil CO₂ and CH₄ emission, considering greenhouse gas reduction and organic quality loss, should use less or avoid using straw stalk covers.7 Corn - winter wheat rotate system farmland soil is a absorption for CH₄ under the most conditions, during entire corn growth period methane average emission flux is negative, when testing methane emission or absorption flux and its seasonal change have no obvious law, andwith soil moisture content and temperature have not discovered direct relation. This may be because of the testing sampling interval too long and have not caught the direct influence of, irrigation and cultivation for its emission or absorption.8 Comparing different fertilizer disposals, the absorpt effect of control disposal and waste compound disposal is stronger, that of waste compost disposal is most weak. In same fertilizer disposal, the straw stalk covers have promoted soil CH₄ emission. Reason is that straw stalk cover have positive role for maintaining soil moisture, cause disgusted oxygen environment in soil, disadvantage CH₄ oxidation occur, eventually, cause the soil discharge capacity of CH₄ increase.Through the study of CO₂ and CH₄ emission law in com and wheat field of North China, offer scientific basis for accurate estimation of annual discharge capacity of CO₂ CH₄ and farmland carbon loss in North China. It has realistic meaning for the popularization of waste compost and waste compound fertilizer.Under condition of straw stalk cover, the application of waste compound fertilizer can reduce CO₂ and CH₄ emission and the carbon loss more effectively than the application of waste compost, Form protecting environment and the angle that keeps soil fertility to see , popularize waste compound fertilizer. Straw stalk cover is important measure that maintains farmland moisture and adjusts soil temperature, If use it should according to local conditions.