[Effects of long-term fertilization and fallowing on soil nitrogen mineralization and exogenous NO3(-) -N transformation].
Soil samples were collected from a 17-year fertilization experiment site in southern Loess Plateau to study the effects of different fertilizations and fallowing on the characteristics of soil nitrogen mineralization, and the transformation of exogenous NO3(-) -N in sterilized and non-sterilized soil samples. The results showed that a combined application of manure and chemical NPK and long-term fallowing increased the contents of soil organic matter, total N, and mineralized N, as well as the N mineralization rate significantly, compared with the control. Applying chemical NPK increased soil inorganic N content, but had less effects on the contents of soil organic matter, total N and mineralized N, as well as the N mineralization rate. Autoclaved sterilization resulted in a significant increase of soil NH4(+) -N content, while soil NO3(-) -N content remained relatively constant whether sterilization or not, suggesting that under the conditions of our incubation, abiotic and biological factors had no significant effects on the transformation of exogenous NO3 (-) -N.
Ai
Na
N
College of Resource & Environment Science, Northwest A & F University, Yangling 712100, Shaanxi, China. lovena914129@163.com
Zhou
Jian-Bin
JB
Yang
Xue-Yun
XY
Liang
Bin
B
D000383:Agriculture / Q000379:methods*; D002681:China; D005308:Fertilizers; D009566:Nitrates / Q000032:analysis* / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis* / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D013997:Time Factors
D005308:Fertilizers; D009566:Nitrates; D012987:Soil; D009584:Nitrogen