双氰胺对不同质地红壤中碳酸氢铵的硝化抑制作用研究

通过室内好气培养试验,研究了双氰胺(DCD)对施入不同质地红壤中碳酸氢铵的硝化抑制作用。结果表明,添加DCD明显提高了相应处理的铵态氮含量,降低了硝态氮含量。无论加入DCD与否,砂壤土中碳酸氢铵的硝化时间大约都需7周;轻粘土中碳酸氢铵的硝化时间为35.d,加入硝化抑制剂后硝化时间可延长2周;而中壤土中至培养结束时仍有较高的铵态氮,故铵的硝化时间有待进一步研究。DCD对碳酸氢铵的硝化抑制效果中壤土优于砂壤土、轻粘土;在砂壤土和轻粘土中,DCD对低浓度铵态氮处理的硝化抑制效果好;而在中壤土中对高浓度的抑制效果好。

Nitrification inhibition effect of dicyandiamide on ammonium bicarbonate in red soils with different textures

This experiment was conducted using aerobic incubation to study the nitrification inhibition effect of dicyandiamide(DCD) on ammonium bicarbonate in red soils with different textures.The results indicated that adding DCD significantly increased ammonium content and decreased nitrate nitrogen content at the same time.The nitrification of ammonium bicarbonate took 7 weeks in sandy loam soil and 5 weeks in light clay soil.These processes were 2 weeks longer if dicyandiamide was applied in light clay soil.However,the content of ammonium was still high after aerobic incubation was over,no matter DCD was added or not,so more studies were needed to study the transformations of ammonium bicarbonate in light clay soil.Nitrification inhibition of dicyandiamide on ammonium bicarbonate in medium loam soil was better than that in sandy loam soil and light clay soil.It was concluded that DCD could significantly inhibit the nitrification of treatments with less NH 4-N rate in sandy loam soil and light clay soil,but had better effect on treatments with high NH 4-N rate in medium loam soil.