Response Of Combined Application Of Organic And Inorganic Fertilizer To The Rule And Influence Factors Of Greenhouse Gas Emission From Vegetable Field

In this paper, a field plot experiment was conducted to investigate the effect of six treatments on yield of lettuce and Chinese cabbage, greenhouse gas emission together with corresponding influencing factors. The six treatments included T1(no nitrogen fertilizer),T2(NPK fertilizer),T3(Pig manure and mineral fertilizer), T4(biogas slurry and mineral fertilizer),T5(Pig manure composting and mineral fertilizer),CK(no fertilizer). The primary results were as follows:1. The law of CO2emission flux variation seasonally in each treatment was consistent, and the CO2emission flux was extremely significant positive related to soil moisture content as well as temperature. Organic and inorganic fertilizer could significantly improve CO2emission from vegetable soil. Compared with T3, annual CO2emission of T4, T5reduced by28.98%and25.27%, respectively. Pig manure through retting pile treatment could relatively reduce the CO2emission from soil. In addition, nitrogen fertilizer application could be regarded as an important factor to promote the CO2emission from vegetable soil.2. Vegetable soil could not only be a CH4emission source, but also a sink for its absorption. CH4emission flux among all treatments were minor, CH4was not the major greenhouse gas discharged in vegetable soil. T3and T4exhibited the emission source of CH4, but other treatments less absorption of CH4. Compared with T3, annual CH4emission of T4, T5reduced by80.23%and187.56%, respectively. Annual emission flux of T5reached0.06mg·m-2·h-1, lower than other treatments except CK. Application of pig manure composting could effectively promote CH4absorption of vegetable field, conducible to slow down greenhouse gas emission from dry lands. 3. The law of CO2emission flux variation seasonally in each treatment was consistent, in the order of T3>T2>T4>T5>CK>T1. Compared with T2, the average N2O emission of T4and T5decreased by20.75%and35.33%, while in contrast to T3, they decreased by22.91%and37.09%, respectively. Pig manure through retting pile treatment could effectively decline N2O emission from vegetable fields. There was a negative relation between N2O emission flux and the content of soil nitrate nitrogen and ammonium nitrogen, revealing the exist of competitive relationship among them. That is to say, directions of sink flow were different among N2O, itrate nitrogen and ammonium nitrogen from soil when soil nitrogen source is certain.4. Combined application of organic and inorganic fertilizers could extremely significant enhance the yield of Chinese cabbage and lettuce. Compared with T2, the Chinese cabbage yield of T3, T4and T5increased by28.57%,11.73%and22.09%, respectively. In contrast to T2, the lettuce yield of T3and T5increased by41.95%and50.05%, respectively. The manure composting treatment, to the largest extent, could increase the yield of Chinese cabbage and lettuce.