Abstract: In this experiment, the nutrient release characteristics of sulfur coated urea in mild saline-alkali soil were studied by water extraction and mild saline-alkali soil incubation method, and compared with humic acid coated urea and common urea.At the same time, the trials were conducted to investigate its effects on the absorption of nitrogen and yields of spring maize.The results indicated that in the water, sulfur coated urea had a large initial release rate of nutrient, and "locked-in effect" and "tailing effect" in its later period, and the nutrients could be only released the 60%.It had the same trend in the mild saline-alkali soil with in the water, but the nutrients released rate was 87.9% when the maize was harvest, during the whole growth period of maize, the accumulated release showed a gradual increasing trend, that fitted to the curve of the captured by nitrogen in maize.And compared with the release of humic acid urea and common urea, the difference of the nitrogen absorption curve of the corn was in the degree of the difference.In different fertilization treatments, the treatments of sulfur coated urea was better than the treatment of humic acid urea and common urea, the increment rate of maize nitrogen absorption amount was 26.97% and 44.32%, respectively, the yield of corn increased by 8.73% and 22.43%, respectively;the seedling soil pH value decreased 0.66 and 0.51 units respectively.The spike length and 100 grain weight per treatment in the treatment of sulfur coated urea were significantly higher than those of the humic acid coated urea treatment and common urea treatment, the increment rate was 1.33%, 4.65% and 2.69%, 8.41%, respectively.The treatment of sulfur coated urea had significant difference with the common urea treatment in bald and per spike grain.It can be seen that the application of sulfur coated urea in mild saline alkali soil has lower pH, increasing the nitrogen absorption and utilization of maize plant, and the release characteristics of the absorption law of nitrogen in maize.

Key words: Sulfur coated urea, Nutrient released characteristic, Yield, Nitrogen uptake, Maize

CLC Number: 

• S143.1+5