In China, the pressure of the shortage of land resources is getting more and more intense gradually, so it is very important to develop sustainable utilization and optimal management of the coastal saline soil resources. On the other hand, climate change is intensifying salinization of the inshore saline soil, thus causing a series of ecological environment problems. However, soil, as an important component of the global carbon pool, plays an important role in regulating the carbon cycle. A field experiment was carried out to study effects of various farming practices on electrical conductivity (EC_e),total respiration, organic carbon (OC),microbial biomass C (MBC),and metabolic quotient (qCO_2) in coastal saline soil. In the experiments, maize was cultivated in rotation with wheat in two tracts of saline soil different in salinity, Soil A (slightly salinized soil) and Soil B (moderately salinized soil),and both tracts were subjected to five different treatments or farming practices, that is (1) CK, conventional farming; (2) OF, application of organic fertilizer at a rate of 1.5 t hm~(-2); (3) NF, application of a higher rate of nitrogen fertilizer, about 150% of that in CK; (4) S, incorporation of straw at a rate of 5.0 t hm~(-2); and (5) NT, no tillage. It was found that after two crops were harvested, ECe varied in the range from 4.57 to 8.20 dS m~(-1) in Soil A, and from 4.89 to 10.13 dS m~(-1) in Soil B, and was the lowest in Treatment S and the highest in Treatment NT, which indicates that in corporation of straw and application of organic fertilizer effectively reduced salt content in the surface soil. Compared to Soil B, Soil A was higher in mean soil respiration intensity, 16% higher during the summer maize season and 18% higher during the wheat season. Treatments OF, NF and S were all higher than CK in soil respiration in comparison with CK, and only Treatment NT was a bit lower. In terms of soil respiration intensity measured in the end of the experiment, the treatments followed an order of S > OF > NF > CK > NT, regardless of soil salinity. When soil ECe got higher than the critical value, soil respiration rate began to slow down. After the crops were harvested, SOC and MBC tended to increase, especially in Treatment OF and S. The treatments varied sharply in SOC and MBC content, which were significantly and positively related to soil respiration. That is to say, with increase SOC content, content of the matrix which soil microbes can decompose into organic carbon increased, thus releasing more CO_2. However, organic carbon did not have any linear relationship with ECe. Soil A was slightly higher than Soil B in qCO_2 and among the treatments, CK was the highest and NT was the lowest. Comparison of the two groups of treatments in the experiment indicates that the soil electrical conductivity and organic carbon content were the two main factors affecting CO_2 release. All in all, though Treatment NT lowers soil respiration intensity and, increases organic carbon and microbial biomass carbon contents, it increases soil salinity too. This study holds that incorporation of straw and application of organic fertilizer are two optimal farming practices that can be adopted to ameliorate coastal tidal flats, improve soil fertility, promote crop growth, alleviate soil salinity and increase crop yield. Therefore, the practices of organic fertilizer application and straw incorporation have a great potential for extension in coastal polders.