干旱区生态环境知识资源中心

Air pollution, desertification and crop failure are serious problems in China. In order to solve these problems simultaneously, amelioration of desertified soil with gypsum, a by-product of the desulfurization process, has been investigated in northeast China since 1996. With the expansion of the trial area in 1998, an area of no amelioration (ANA) was found where corn could not grow despite 1.0 wt% application of desulfurization gypsum. Additional application of desulfurization gypsum to the ANA in the following year resulted in improvement in germination rate, ratio of growth strain, height of growth strain, thickness of stem, and corn production. Corn production increased with the increase of gypsum application rate and increased year by year, while soil pH and Na concentration decreased. Next, we evaluated the correlations among corn production, gypsum application rate, and ion concentrations in soil solution and found a slightly positive correlation between the increase of corn production and gypsum application. Lastly, the change in water movement in the soil resulting from gypsum application was compared between the area of amelioration (AA) and the ANA. A remarkable amelioration effect of hydraulic conductivity with the increase of gypsum application rate and the decrease of dry density of soil was found in both areas, indicating that the change in water movement in the soil was not the main reason that corn could not grow in the ANA.