Nitrogen budget and gaseous nitrogen loss in a tropical agricultural watershed
Nitrogen budget and gaseous nitrogen loss in a tropical agricultural watershed
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DOI：
10.1007/s10533-007-9164-5
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发表时间：
2008
期刊：
影响因子：
4
通讯作者：
N. Yoshikawa;S. Shiozawa;Ardiansyah
中科院分区：
文献类型：
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作者：
N. Yoshikawa;S. Shiozawa;Ardiansyah
尽管亚洲热带季风区的农业系统在全球氮循环中起着重要作用，但该地区流域尺度氮循环的细节仍不清楚。本研究量化的N预算在热带流域的221 km 2爪哇岛，其中稻田覆盖28%的土地，进行实地调查。大气中的净生化气态氮损失量（XGB），这是通常难以确定的，被计算为N平衡的剩余。假设NH3挥发平衡了沉积，因此从氮输入中减去NH 4-N和大气沉积，发现流域内每年氮的平均输入和输出总量为46.5 kg ha− 1 year − 1。其中，71%是作为肥料（MF）进口的，29%是大气沉降（MAD）。在出口方面，42%的损失来自XGB，37%来自焚烧大米残渣和木材燃料（XGI），13%来自河流排放（XD），9%来自大米剩余出口（XR）。大部分的XGB，因此，一小部分的XD可以解释由高温和潮湿的气候造成的高速率的反硝化作用，并被认为是常见的特征，热带流域的稻田被发现。
Although agricultural systems in tropical monsoon Asia play a central role in the global nitrogen (N) cycle, details of the N cycle in this region on a watershed scale remain unclear. This study quantified the N budget in a tropical watershed of 221 km2on Java Island, where paddy fields cover 28% of the land, by conducting field surveys. The amount of net biochemical gaseous N loss to the atmosphere (XGB), which is generally difficult to determine, was calculated as the residual of the N balance. Assuming that NH3volatilization balances deposition, and hence subtracting NH4–N from the N import with atmospheric deposition, the average total import and export of N per year was found to be 46.5 kg ha−1year−1over the watershed. Of this, 71% was imported as fertilizer (MF) and 29% with atmospheric deposition (MAD). On the export side, 42% was lost asXGB, 37% with incineration of rice residues and wood fuel (XGI), 13% with river discharge (XD) and 9% with rice surplus export (XR). A large portion ofXGB, and consequently, a small portion ofXDcould be explained by the high rate of denitrification resulting from the high temperature and humid climate, and are thought to be common features of tropical watersheds where paddy fields are found.