论文部分内容阅读
采用好气恒温培养法,通过一次和分次供氮的方式,研究不同尿素施用量对黑土土壤无机态氮浓度的短期效应。结果表明:CK处理(不供氮方式)在培养期间,NH4+-N的浓度始终保持较低水平,而NO3--N浓度则呈稳步上涨的变化态势;pH值稳定在6.0～6.3之间;硝化率则稳定在90%左右。一次供氮方式各处理NH4+-N的浓度,在施氮后第3d时达到最大,第20d后趋于稳定;NO3--N的浓度则呈稳步增长的态势;土壤的pH值与NH4+-N的浓度的变化规律相似,在培养后的第3d达到峰值,而后开始下降,在培养第10d时,各处理的pH值趋于稳定,且明显低于CK;而硝化率则随着培养时间的延长,呈逐渐增加的变化趋势,在第20d时已与CK无显著差异,趋于平缓。分次供氮各处理在第1次施氮1d后,NH4+-N浓度达到峰值,之后开始呈下降的变化趋势,另外3次施氮后NH4+-N浓度变化与此类似,且每次施肥后第3d和第10d土壤NH4+-N浓度之间差异不显著;NO3--N浓度在第1次施氮1d后,各处理差异不明显,第3d达到最大,但整体上是呈稳步增长的变化趋势;各处理的pH值的变化情况与一次供氮的情况相似;土壤硝化率硝化率呈先下降后上升的趋势,整体呈逐步上升的变化趋势。
The aerobic culture method was adopted to study the short-term effects of different urea application rates on the concentration of inorganic N in black soil by one and several times of nitrogen supply. The results showed that the concentration of NH4 + -N remained low while the concentration of NO3 - N changed steadily during the CK treatment (without nitrogen). The pH value was stable between 6.0 and 6.3. Nitrification rate is stable at about 90%. The concentration of NH4 + -N was the highest at the third day after nitrogen application and tended to be stable at the 20th day. The concentration of NO3 - N increased steadily. The pH of the soil was positively correlated with NH4 + -N , And reached its peak on the third day after the culture, and then began to decline. At the 10th day after culture, the pH value of each treatment tended to be stable and obviously lower than that of CK; while the nitrification rate increased with the incubation time Prolonged, showing a gradual increase in the trend of change in the first 20d CK had no significant difference, tends to be gentle. After the first nitrogen application, the concentration of NH4 + -N peaked at 1 day after the first application of nitrogen, and then began to decline. The change of NH4 + -N concentration after 3 times of nitrogen application was also similar to that after each application of nitrogen fertilizer There was no significant difference in soil NH4 + -N concentration between the third and the tenth day. The NO3 - N concentration did not show significant difference after 1 day of the first application of nitrogen, and reached the maximum on the third day, but it showed a steady increase The change of pH of each treatment was similar to that of one nitrogen supply. The nitrification rate of soil nitrification rate firstly decreased and then increased, and the overall trend showed a gradual increase.