Effects Of Desulfurized Gypsum Application On Saline-alkali Soil Physical And Chemical Properties And Growth Parameters Of Oil-sunflower

In this study, soil physical and chemical properties, the diurnal courses curve of photosynthetic parameters, photosynthetic light response curve and crop growth parameters of Helianthus annuus were collected and analyzed on ameliorated saline-alkali soil with different ages. The objective was to investigate the effects of desulfurated waste residue application on saline-alkali soil amelioration and yield of oil-sunflower grown on it. Results show that soil bulk density,electronic conductivity and pH value both decreased while non-capillary porosity,soil organic matter, the concentration of available nitrogen (N), phosphorus (P) and potassium (K) increased with increasing ameliorated ages. When ameliorated ages increased, the netphotosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO2concentration (Ci) increased markedly,whereas the wateruse efficiency (WUE) and stomatal limiting value (Ls) decreased. Meanwhile,as ameliorated ages increased, the dark respiration rate(Rday), the maxmium photosynthetic rate (Amax),the light saturation point (LSP) increased obviously, while the light compensation point (LCP)decreased. A similar dramatic elevatation was found on the height, Stem diameter, biomass,diameter size, plant weight and final yield of Oil-Sunflower. As a sequence, application of desulfurized gypsum can significantly facilitate saline-alkali soil amelioration, enhance leaf photothetic capacity, promote crop growth and ultimately increase crop yield.