Abstract:
Abstract: Songnen plain is the main grain strategy reserve area of China, and it is also one of the three largest soda saline-alkali soil regions in the world. Soil salinization severely restricts the sustainable development of agriculture and the improvement of people's living standards. The land consolidation major projects officially launched in the west of Jilin Province in 2007 provides an effective way for comprehensive controlling salinity land. In the process of land consolidation, one of the most important problems need to be addressed was how to combine land consolidation with soil improvement to realize the purpose of increasing cultivated land areas and improving salinity soil. In order to study the Western Songnen Plain land consolidation effect on improving salinity soil, this paper took the land consolidation project in Zhenlai county of Jilin Province as study area, selected the original cultivated land, saline-alkali land and newly-added cultivated land as plots, adopted the methods of classical statistical analysis and canonical correspondence analysis to comparative study the differences of soil physical and chemical properties and soil ionic composition of different plots. And then we put forward related suggestions for land consolidation and improving salinity soil. The results showed that, in 0-20 and >20-40 cm soil layer, soil electrical conductivity of newly-added cultivated land was significantly decreased by 44.9% and 37.0% than saline-alkali land (P<0.05), but significantly higher than original cultivated land by 35.7% and 58.6%. The total actions and total anions of newly-added cultivated land were significantly lower than saline-alkali land (P<0.05). The exchange sodium percentage of saline-alkali land was around 38% and pH value was close to 10.0, that was classified to severe salinity soil. While the newly-added cultivated land soil exchange sodium percentage was 18.0% and 21.6%, and soil pH value was less than 9.0, that was classified to moderate salinity soil and close to the original cultivated land. Newly-added cultivated soil organic matter was higher than saline-alkali land by 33.4% and 61.3% significantly (P<0.05), but it was significantly lower than original cultivated 21.5% in 0-20 cm soil layer. Newly-added cultivated soil cation exchange capacity was increased by 16.7% and 25.1% than saline-alkali land (P>0.05), and it's slightly higher than original cultivated land. Canonical correspondence analysis results showed that soil physical and chemical properties and ionic composition had significant correlation with plot type distribution. Plot type changed from saline-alkali land to newly-added cultivated land was the process of soil salinization indices decreasing and fertility indices rising in the level of soil physical and chemical properties, and also the process of bicarbonate ion, carbonate ion and sodium ion content reduction in the level of soil ionic composition. Overall, the land consolidation project in Western Songnen Plain could improve salinity soil effectively, but the soil quality of newly-added cultivated land is still lower than the original cultivated land. Therefore, we suggest to improve salinity soil better through improvement of irrigation and drainage system, reasonable land leveling measure and scientific farming.