| Studied on the extraction of ammonium nitrogen from three kinds of fertilizer (urea, ammonium sulphate and ammonium
chloride) and five acidity black soil by cation exchange resin membrane. The results showed that the ammonium nitrogen-release rates of three kinds of fertilizer slower increased during the first 35 days,but it increased fastest in 35-49 day. The ammonium nitrogen-release rates of urea were slower than ammonium sulfate and ammonium chloride.The release accumulation of ammonium nitrogen in black soil was slower in the fist 35 days, increased rapidly in 35-42 day,and increased fastest after 42 days. The minimum release accumulation of ammonium nitrogen in acidity black soil was urea application and the maximum was ammonium sulphate application except in ph 5.5 black soil. The release accumulation of ammonium nitrogen decreased with the increase of soil ph with urea application. |
