Abstract:
Abstract: There is still a great uncertainty of nitrogen conservation and greenhouse gas reduction from farmland soil due to lack of data of the soil properties change and greenhouse gas emissions from the land application of compost and sewage sludge. In this study, tomato plants were cultivated in the greenhouse in treatments of 1) 800 kg/hm2 fresh sludge (S-H), 2) 400 kg/hm2 fresh sludge (S-L), 3) 800 kg/hm2 straw composting product (VM-S), 4) 800 kg/hm2 swine manure composting product (VM-M), and 5) no fertilization (CK). The soil properties, inorganic nitrogen forms and N2O emission characteristics were investigated. The results showed that, compost treatments significantly increased the soil EC value (P<0.05), and the VM-M treatment exhibited the largest soil EC value. With the addition of sludge and compost products, soil pH value increased significantly (P<0.05) and soil pH tended to be neutral. The inhibitory effect of VM-M on soil acidification was better than VM-S. Under the treatments of sludge and compost, concentration of soil NO3--N was significantly higher (P < 0.05) than the CK, and the NO3--N concentration of each treatment decreased gradually with time. Most of the NO3--N was absorbed by tomato plants, and part of the nitrate was leached from the upper to the lower soil layers. Most of the NH4+ was oxidized to NO3--N, but some were absorbed by plants. With the application of organic nitrogen, the shoot biomass in the VM-M, VM-S and S-H treatment was 1 515, 1 383 and 1 103 g/plant, respectively, each corresponded with the plant height of 56.8, 54.5 and 51.3 cm, respectively. The positive effect of the treatment on the tomato growth was VM-M > VM-S > S-H. In addition, the excess application of organic nitrogen fertilizer from S-H compared to S-L did not promoted growth of tomato markedly (P>0.05). Compared with the CK, N2O emission from soil was significantly improved by sludge (P<0.05). The N2O emission from the all treatments were focused on the first 20 days after fertilization, and the amount of emission of soil N2O was S-L (0.76 kg/(hm2·a)) < VM-M (0.95 kg/(hm2·a)) < VM-S (1.19 kg/(hm2·a)) < S-H (1.71 kg/(hm2·a)). Therefore, the types and the amount of manure should be considered when the sludge or compost was applied in farmland, so that, the yield of crops can be improved and the emission of greenhouse gases could be reduced at the same time, and it's better to compost using sludge and animal manure.