玉米秸秆源有机肥对水稻产量与温室气体排放的影响

Effects of the Organic Fertilizers Made from Maize Straw on Grain Yield of Rice and Emission of Greenhouse Gases from Paddy Fields

以水稻品种扬粳4038为材料,设置玉米秸秆(秸秆,MS)、玉米秸秆制成堆肥(堆肥,MC)、玉米秸秆制成沼渣(沼渣,MR)、玉米秸秆制成黑碳粉(黑碳,BC)还田处理,以不施有机肥为对照(CK),调查了在不施氮肥(0N)和实地氮肥管理(SSNM)两种施肥水平下各有机肥对水稻产量和稻田温室气体排放的影响。结果表明,无论是0N还是SSNM下,施用MS、MC和MR均较CK显著增产,施用MS的产量和氮肥农学利用率(单位施氮量增加的产量)最高,施用BC的产量与CK差异不显著。水稻整个生育期稻田甲烷(CH4)、二氧化碳(CO2)或氧化亚氮(N2O)排放在各有机肥处理间变化趋势一致。施有机肥显著增加了各温室气体的排放(施用BC的N2O排放除外)和全球增温潜势(GWP)。相同有机肥处理,施氮(SSNM)后各温室气体的排放和GWP较0N增加,但单位产量的GWP降低。说明施用有机肥MS、MC、MR可以提高产量,同时也增加了稻田温室气体的排放。采用SSNM和施用沼渣,可以获得较高的产量和较高的环境效益。

A japonica rice cultivar Yangjing 4038 was used and four kinds of organic fertilizers including maize straw （MS）, compost made from maize straw （MC）, maize residue of methane generating （MR）, and black carbon made from maize straw （BC） were applied to the paddy field before rice transplanting, with no organic fertilizer application as control （CK）. Effects of each organic fertilizer on rice grain yield and emissions of greenhouse gases from paddy field were investigated under both no nitrogen （N） application （ON） and site-specific N management （SSNM）. The results showed that, under either ON or SSNM, application of MS, MC, or MR significantly increased grain yield when compared with CK. The MS treatment showed the highest grain yield and agronoNic N use efficiency （kg/kg） among the all organic fertilizer treatments. There was no significant difference in grain yield between the BC and CK. The emission of methane（CH4 ）, carbon dioxide （CO2）, or nitrous oxide （N2 O） from the field exhibited a similar trend during the whole rice growing season under all the organic fertilizer treatments. Application of each organic fertilizer significantly increased the emission of each greenhouse gas and global warming potential （GWP） except the N2O emission which was not increased under the BC treatment, relative to that under CK. Under the same organic fertilizer treatment, SSNM increased emissions of all the greenhouse gases and GWP, whereas decreased GWP per unit grain yield （amount of GWP/grain yield）, when compared with ON. The results indicate that application of organic fertilizers, such as MS, MC, and MR, could not only increase grain yield, but also enhance emissions of greenhouse gases from the paddy field. Both higher grain yield and higher environmental efficiency would be achieved by the adoption of SSNM and the application of MR fertilizer.