Microorganism Quantity and Enzyme Activities in Wheat Field Subjected to Different Nitrogen Fertilizer Rate

Field experiments are described involving nitrogen fertilizer in wheat field to research its effect on microbial quantity and enzyme activity. The results showed that 250 kg N hm applied in wheat field (1) can increase bacteria, fungi, actinomycetes quantity by 39.9%, 56.7% and 70.5% compare to 0 kg N hm. (2) Similarly, the activities of soil urease, catalase and FDA expressed 60.8%, 18.3% and 49.1% of the improvement variation compared to 0 kg N hm, respectively. (3) Shannon-Wiener diversity index (H) and Evenness index (E) reached the peak (H=0.37, E=0.33). Correlation analysis microbial quantity with enzyme activity indicated they were related to each other. These findings suggested that soil microbial quantity and enzyme activity were significantly influenced by nitrogen fertilizer and application of 250 kg N hm in wheat field was the best. Keyword: Microorganism quantità, enzyme activity, nitrogen fertilizer, wheat field.