Effects of nitrogen forms on the absorption and N use efficiency in Chinese White Poplar
The present study used stable isotope 15N tracing technique to test the effects of nitrate (labeled N03-15N) and ammonia (labeled NH4-15N) on the absorption and N use efficiency (NUE) of nitrogen and the percentage of N derived from fertilizer (NDFF) in different organs. One-year-old Clone 50 of Chinese White Poplar (Populus tomentosa) seedlings were selected as materials. The results indicated that the total N content and absorptive amount of different 15N labeled ammonium nitrate in P. tomentosa had the same change pattern under different treatments. After applied one week, the total N content and the absorptive amount of 15N labeled ammonium nitrate increased remarkably, and both of them reached the peak on 28 d after fertilization. The maximum absorptive amount of N03-15N and NH4-15N labeled ammonium nitrate was 0.26 and 0.12 g·plant-1, respectively. N derived from soil which accounted for 55％ to 70％ of the total N content was the main N resource in the first week after fertilization. Thereafter. the absorptive amount of nitrogen increased and the percentage of N derived from soil in total N content declined. Compared to NH4-15N labeled ammonium nitrate. P. tomentosa seedlings had a better response to N03-15N labeled ammonium nitrate and the average NUE of N03-15N labeled ammonium nitrate (16.43％) was about two times as much as that of NH4-15N labeled (7.08％). Before 28 d. stem had the stronger competitiveness of absorption to fertilizers. And after 28 d leaf was the main organ to absorb N derived from fertilizers. Moreover. P. tomentosa seedlings had the stronger capacity of absorption to N03-15N labeled ammonium nitrate than NH4-15N fertilizer. It can be concluded that fertilization is one of the most important measures to raise the growth and yield of P. tomentosa seedlings.
N03-15N NH4-15N labeled ammonium nitrate NUE. NDFF Populus tomentosa
DONG Wen-yi QIN Jing LI Ji-yue NIE Li-shui ZHAO Yan ZHANG Zhi-yi
National Engineering Laboratory for Tree Breeding, Beijing 100083, China;College of Forestry, Beijin College of Soil and Water Conservation, Beijing Forestry University, Beijing 100083,China College of Forestry, Beijing Forestry University, Beijing 100083, China;College of Forestry, South C College of Forestry, Beijing Forestry University, Beijing 100083, China National Engineering Laboratory for Tree Breeding, Beijing 100083, China
国际会议
西安
英文
340-344
2010-10-11（万方平台首次上网日期，不代表论文的发表时间）