Effects of sulfur application on the growth of cole,soil pH and available P in alkaline soil

Pot experiment was conducted to determine the effects of sulfur application on pH,available P content and phosphatase activity of alkaline soil,cole biomass and NO3--N concentration,nitrate reductase activity in plants and P uptake.Results showed that soil pH was remarkably reduced,and an available P content in soil was increased greatly.Comparing to CK,the largest decrease of pH was 0.5.When the amount of the applied sulfur was 120 mg/kg,P content in soil reached the highest value,increased by 68.6% compared with CK.The experiment conducted on the growth status of cole showed that sulfur improved cole biomass,reduced the content of NO3--N,increased the activity of nitrate reductase and P uptake.Compared with CK,the largest biomass increase was 29.64% and the largest decrease of NO3--N was 58.6%.Nitrate reductase activity and P uptake were nearly 1.8 and 1.55 more than those of CK,respectively.When the amount of the applied sulfur was 120 mg/kg,the cole biomass,NO3--N content,nitrate reductase activity and P uptake were all in the optimum range.Meanwhile,high rate of sulfur NO3-Napplication reduced pH value,but hindered the growth of cole.