Response of Corn Growth in Salt-Affected Soils of Northeast China to Flue-Gas Desulfurization By-product
2007
Chun, S. | Nishiyama, M. | Matsmoto, S.
In semiarid and arid regions, plant growth is limited by high pH, salinity, and poor physical properties of salt-affected soils. A field experiment was conducted in the semiarid region of Kangping in northeast China (42 degrees 70' N, 123 degrees 50' E) to evaluate a soil-management system that utilized a by-product of flue-gas desulfurization (FGD). Soil was treated with 23,100 kg ha(-1) of the by-product. Results of corn growth were grouped into three grades (GD) according to stages of corn growth: GD1, seeds did not germinate; GD2, seeds germinated but corn was not harvested; and GD3, plants grew well and corn was harvested. The pH, electrical conductivity (EC), bicarbonate (HCO3(-)), carbonate (CO3(2-)), exchangeable and soluble calcium (Ca(2+)), chloride (Cl), and sulfate (SO4(2-)) in surface soils of the three grades (> 20 cm) was measured to assess the correlation between corn growth and soil properties. Vertical differences in subsoil properties (0-100 cm) between GD1 and GD3 were compared to known benchmark soil profiles. The FGD by-product significantly increased EC, exchangeable and soluble Ca(2+), and SO4(2-) and decreased CO3(2-), exchangeable sodium (Na(+)), and soluble Na(+). pH, EC, HCO3(-), CO3(2-), and Cl(-) were higher in surface soils of GD1 than GD3. Soil hardness, soil moisture content, Cl(-), and calcium carbonate (CaCO3) were higher in GD1 than in GD3, whereas the amount of available P was lower in GD1. Interestingly, the concentration of Cl(-), a toxic element for plant growth, was 2.5 and 1.5 times higher in GD1 than in GD3 and control soil, respectively. In the comparison study of subsoils, GD1 and GD3 were classified as having typical characteristics of saline-alkali soil (pH > 8.5; exchangeable-sodium-percentage ESP > 15; EC > 4.0) and alkali soil (pH > 8.5; ESP > 15; EC < 4.0), respectively.
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