红壤不同含水量对尿素氨挥发的影响

Effects of Red Soil Moisture on Ammonia Volatilization of Urea

根据第四纪红壤水分特征设计160、200、240、280、320、360g/kg6个土壤含水量处理,通过温室模拟,研究了红壤不同含水量对尿素氨挥发的影响。结果表明,等量尿素施入红壤后,氨挥发通量与土壤含水量之间无显著相关性,而高含水量(280、320、360g/kg)处理氨挥发通量峰值较低含水量(160、200g/kg)处理提前10天。氨挥发过程可分为快速-慢速2个阶段,氨累积挥发量(y)与对应时间(t)符合Elovish动力学方程(y=a+blnt)。第1～10天,氨挥发累积量随红壤含水量的增加而递增;第11天后,以含水量为240g/kg处理的氨挥发累积N量最低。试验期间,氨挥发累积总N量,以含水量240g/kg时最低(0.90gN),含水量320g/kg时最高(1.16gN),分别占尿素施入N量的9.0%和11.6%。

The effect of quaternary red soil moisture on ammonia volatilization of urea was studied by greenhouse simulation. The results showed that there was no significant correlation between ammonia volatilization flux and soil moisture, but the peak of ammonia volatilization flux at the higher moisture treatments （280, 320 and 360 g/kg） appeared 10 days earlier than at the lower ones 060 and 200 g/kg）. Ammonia volatilization of urea in red soil could be divided into two stages, namely, rapidly and slowly increasing stages. The relationship between the cumulative ammonia-volatilization flux （y） and the corresponding time （t） followed Elovich equation （y = a ＋ b lnt）, y increased with soil moisture increased from the first day to the tenth day, then it decreased to the lowest （0.90 g, accounted for 9.0% for urea applied） when soil moisture was 240 g/kg. The highest y was 1. 16 g and accounted for 11.6% for urea applied when soil moisture was 320 g/kg.