.全国土壤养分含量分级标准表级别123456丰缺极高高中上中低极低有机质(g/kg土)40.0030.00-40.0020.00-30.0010.00-20.006.00-10.002.001.50-2.001.00-1.500.75-1.000.50-0.75150.00120.00-150.0090.00-120.0060.00-90.0030.00-60.002.001.50-2.001.00-1.500.75-1.000.50-0.7540.0020.00-40.0010.00-20.005.00-10.003.00-5.0020.0015.00-20.0010.00-15.005.00-10.003.00-5.00200.00150.00-200.00100.00-150.0050.00-100.0030.00-50.00Na2CO3 NaHCO3 NaCl2 CaCl2 MgSO4 Na2SO4;一般情况下土壤中HCO3-达到0.08%，pH为7.79时已明显抑制植物，当达到0.1%0.2%，pH值高达9以上时，则对植物产生致死作用。Cl-含量达0.05-0.1%时，开始明显危害植物生长，达到0.4-0.8%时为致死浓度。.