硫包膜尿素在轻度盐碱土壤中释放特点及肥效研究

应用水中溶出率法和轻度盐碱土壤玉米根下土埋法,研究硫包膜尿素在轻度盐碱土壤的释放特征及其对春玉米氮吸收和产量的影响,并且与腐植酸包膜尿素和普通尿素进行了比较。结果表明,硫包膜尿素在静水中初期养分释放率大,后期明显出现养分"锁定效应"和"尾留效应"现象,仅能释放出59.33%左右的养分;在轻度盐碱土壤中,其释放与静水释放趋势一致,但在玉米收获时养分释放率达87.9%,在玉米全生育期,其累积释放呈现逐渐递增的趋势,与玉米吸氮曲线相吻合;而与之相比较,腐植酸包膜尿素和普通尿素的释放规律与玉米吸氮曲线吻合度较差。硫包膜尿素处理与腐植酸包膜尿素和普通尿素2个处理相比,玉米成熟期氮吸收总量分别增加26.97%和44.32%,产量分别增加8.73%和22.43%,差异均显著;苗期耕层土壤pH值分别降低0.66,0.51。硫包膜尿素处理的穗长、百粒质量分别比腐植酸包膜尿素处理和普通尿素处理高1.33%,4.65%和2.69%,8.41%,硫包膜尿素处理的秃尖和穗粒数与普通尿素处理的差异显著。说明硫包膜尿素在轻度盐碱地上应用可降低土壤pH值、增强玉米植株氮素吸收利用能力,释放特征更符合玉米氮素养分的吸收规律。

Release of Sulfur Coated Urea in Mild Saline-alkali Soil and Study of Its Fertilizer Efficiency

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 coa-ted 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 re-lease rate of nutrient,and ″locked-in effect″and ″tailing effect″in its later period,and the nutrients could be only re-leased 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 0.5 1 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 utili-zation of maize plant,and the release characteristics of the absorption law of nitrogen in maize.