Research On Change Of Carbon Pool Of Soda Meadow Sodic Soil After Biological Rehabiltation

Results of several years' systematical studies in Zhao-Zhou County showed that biologicalrehabilitation might remarkably improve the physical and chemical characteristics and biologicalproperties of soda meadow sadie soil, thus the soil fertility was elevated. Based on the formerstudies, this work studied the changes of carbon pool of soda meadow sodic soil after the biologicalrehabilitation in ,order to supply valuable referential data and basic research documents to thecarbon pool changes and carbon cycling for the rehabilitation of Saline and sodic soils.The study was used the randomized complete block design, of which six treatments and threereplicates were set. Organic carbon changes of soils, carbon dioxide release flux and carbonequilibrium were studied along with the physical-chemical properties of soils. Yet some regularitiesand were summarized. The results showed that:Biological rehabilitation could improve the characteristics of meadow sodic soil by increasingthe total organic carbon content and active carbon content of soil with a better quality of organiccarbon. Liquid and thermal properties were also improved, and the biological activity wasincreased, pH of soil, sodicity and the salinity were all decreased and the chemical properties wereimproved.Light fraction of organic carbon, readily oxidizable organic carbon, and microbial biomasscarbon correlated positively at a significant level with the total organic carbon content. What ismore, there were positive correlations between three organic carbon contents at 0.05 or 0.01 levels,showing that there is an obvious relation between them.Biological rehabilitation could remarkably increase the respiratory intensity of meadow sodicsoil. During the growing season of crops, CO₂ release flux of organic residues' treatments increasedremarkably, especially for the three treatments with poultry manures. Respiratory intensity,correlated significantly and positively, with total organic carbon content and active organic carboncontent and with water content, temperature and microbial quantity, but it correlated inversely andpositively with the pH of soil, total salt content and sodicity of soil.Taking the changes of the physical and chemical properties of soil into consideration,Biological rehabilitation could remarkably increase the biomass in the soil-plant system, thus thecarbon sequestration of soil, and reduce relatively the release of carbon of soil, playing a role ofcarbon sink.The contributions of treatments to the carbon pool of soil were the greatest for the treatment of compost of chicken manure, the treatment of compost of chicken manure and forage residues,followed by the treatment of forage cover.