基于BaPS系统黑土硝化、反硝化和呼吸作用研究

Study on Nitrification, Denitrification and Respiration in Black Soil Based on BaPS System

利用BaPS系统测定了不同施氮量（0，240，312 kg/hm2）、不同采样深度（0～20，20～40，40～60，60～80 cm）及作物不同生育时期等条件下黑土的硝化、反硝化和呼吸速率。结果表明：BaPS系统能够用于测定黑土硝化、反硝化和呼吸作用；随着采样深度的增加，黑土硝化速率和呼吸速率降低，而反硝化速率升高，各土层间差异极显著（F值分别为85.5＊＊，791.3＊＊，220.2＊＊）；评价黑土硝化、反硝化及呼吸速率以0～20 cm土层监测数据为宜；随着施氮量的增加，黑土硝化、反硝化及呼吸速率均呈现增加的趋势；黑土硝化、反硝化和呼吸速率随季节的变化呈先升高后降低的趋势，三者约在7月上旬出现最高峰；适宜施氮量下（240 kg/hm2）黑土硝化速率最高为161.85μg/（kg＆#183;h），反硝化速率最高为325.23μg/（kg＆#183;h），呼吸速率最高为63.45 mg/（kg＆#183;d），施氮量增加，反硝化速率和呼吸速率升高。

In this study,a BaPS （Barometric Process Separation）technique was used to determine nitrifi-cation,denitrification and respiration rates in black soil of northeastern maize field under different nitro-gen fertilizer application rates （0,240,31 2 kg/hm2）at different soil depths （0-20,20-40,40-60, 60-80 cm）and in different growth periods .The results showed that BaPS could be used in determining rates of nitrification,denitrification and respiration in black soil .With the deepening of the sampling depth,rates of nitrification and denitrification decreased while that of respiration increased,and the dif-ferences between different soil layers were extremely significant （F values were respectively 85.5＊＊, 791.3＊＊ and 220.2＊＊）.To evaluate nitrification,denitrification and respiration rates in black soil, monitoring data of 0-20 cm soil layer were most suitable;With the increase of N application amount, rates of nitrification,denitrification and respiration in black soil showed a strengthening trend;Dynamics of seasonal variations of gross nitrification rate,denitrification rate and respiration rate were first increas-ing and then decreasing and the highest peak appeared around early July .Under suitable nitrogen appli-cation amount （240 kg/hm2）,the highest nitrification rate was 1 61.85μg/（kg＆#183;h）,the highest denitrifi-cation rate was 325.23μg/（kg＆#183;h）,and the highest respiration rate was 63.45 mg/（kg＆#183;d）.With the in-crease of N application amount,nitrification and respiration rates increased .