Effect of Organic Fertilizers on Gas Emission from Lettuce-growing Soil in a Solar Greenhouse

Emission flux of greenhouse gases (GHGs) and global warming potential (GWP) of asolarlettuce-greenhouse using organic fertilizers were studied. A decomposed chicken manure (H), a sheep manure (S), a chicken manure/straw combination (HSt), a sheep manure/straw combination (SSt), a sheep manure, or a chicken manure/straw combination (SHSt) wasapplied on the soil. The atmospheric conditions in the greenhouse with each fertilization were monitored using the static chamber-gas chromatograph techniques. The results showed that (1) throughout the entire fertilization period, the N₂O emissionsfrom H, S and HSt were in a V-shapemathematicfunction, whileCK, SSt and SHSt, an inverted V-shape function; the CH₄ emissionsfrom S, SSt and SHSt were inan inverted V-shape trend; and, the CO₂ emissionsfrom all, except SSt, were in aV-shape; (2) during the early stage of the fertilizations, the N₂O emissionsfrom HSt, S, H, SHSt and SSt were 2.89, 2.32, 1.48, 1.17 and 0.95 times, respectively, greater than that of CK; the CH₄ emissionsfrom S and H, 1.91 and 1.11 times, respectively, greater than that of CK; and, the CO₂ emission from H, 3.88 times lower than that of CK; and, in the middle of the fertilizations, the N₂O emission from HSt was 1.93 times lower than CK; the CH4 emission from SHSt, 1.34 times greater than CK; and, no significant differences onthe CO₂ emissionsbetween CK and all other treatments; whereas, at the late stage of the fertilizations, the N₂O emission from H was 1.10 times greater than CK; the CH₄ emissionsfrom SHSt, SSt and S, 3.76, 5.25 and 5.58 times, respectively, lower than CK; and, the CO₂ emission of HSt, 8.61 times greater than CK; and, (3) GWP for the various fertilization treatments decreased in the order of S > SHSt > HSt > SSt > CK > H. Consequently, H, SSt, orHSt was recommended for farmingapplicationsin light of their potentials in GHG emission reduction.