Improving the efficiency and sustainability of fertilizer use in drought- and submergence-prone rainfed lowlands in South-East Asia.
Improving the efficiency and sustainability of fertilizer use in drought- and submergence-prone rainfed lowlands in South-East Asia.
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提高东南亚易发生干旱和淹没的雨养低地肥料使用的效率和可持续性。
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
J. Basnayake
中科院分区：
文献类型：
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作者：
R. Bell;C. Ros;V. Seng;S. Fukai;J. Basnayake
在东南亚多雨的低地，水稻产量低，对化肥的反应往往很弱。对柬埔寨和泰国东北部土壤的研究表明，由于土壤水分饱和度的丧失，一系列复杂的因素限制了水稻产量和养分吸收。两个重要且密切相关的制约因素是可行的降雨量和缺乏土壤养分。即使在供水充足的情况下，土壤的间歇性淹水和干旱也会抑制某些养分的可获得性。此外，土壤水位的极端波动可能会削弱根系的活力，进一步限制养分的吸收。由此产生的低效吸收显然会导致对化肥、氮和磷的反应较弱。因此，制定管理策略以优化干旱易旱的旱地水稻的矿质营养，特别是在铝毒和缺钾的情况下，取决于了解水稻根系在养分吸收中的功能及其对水分和土壤性质的时空变化的反应。这一需要对于采用水稻直接播种特别相关，这会导致根系最初在好氧条件下发育，然后暴露在淹水条件下，并在生长季节期间恢复到好氧状态，在极端情况下又回到干旱条件下。随着未来化肥使用的潜在增加，从而可能造成地下水污染和水体富营养化，新的管理战略也需要评估此类污染的风险，并寻找预防方法。
In the rainfed lowlands of South-East Asia, rice yields are low and often respond weakly to fertilizers. Studies of soils in Cambodia and North-East Thailand suggest that a complex combination of factors restrict rice yield and nutrient uptake in response to loss of soil-water saturation. Two significant and closely linked constraints are viable rainfall and lack of soil nutrients. Intermittent flooding and drying of soils depresses availability of some nutrients, even when water supply is adequate. Moreover, extreme fluctuations in soil-water levels may impair root activity, further restricting nutrient uptake. The resulting inefficient uptake apparently leads to weak responses to fertilizer nitrogen and phosphorus. Developing management strategies for optimizing the mineral nutrition of rice in drought-prone rainfed lowlands, particularly in the presence of aluminium toxicity and potassium deficiency, thus depends on understanding the function of rice roots in nutrient uptake and their response to temporal and spatial variation in water content and soil properties. This need is particularly relevant for the adoption of direct sowing of rice, which results in a root system developing initially in aerobic conditions, then being exposed to flooded conditions and, during the growing season, returning to aerobic and, in extreme cases, to drought conditions. With the potential increase of fertilizer use in the future, and thus potential pollution of groundwater and eutrophication of water bodies, new management strategies also need to assess risks of such contamination and seek ways of preventing it.
DOI：
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发表时间：
1996-03
期刊：
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影响因子：
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作者：
O. Ito;R. Matsunaga;K. Katayama;S. Tobita;J. Adu-Gyamfi;J. Kashiwagi;T. P. Rao;G. Devi
通讯作者：
O. Ito;R. Matsunaga;K. Katayama;S. Tobita;J. Adu-Gyamfi;J. Kashiwagi;T. P. Rao;G. Devi