长期滴灌棉田土壤盐分演变趋势预测研究
《水土保持研究》[ISSN:1005-3409/CN:61-1272/P]
卷:
20
期数:
2013年01期
页码:
186-192
栏目:
出版日期:
2013-02-28
- Title:
- Study on the Evolution Trends of Soil Salinity in Cotton Field under Long-term Drip Irrigation
- 关键词:
- Keywords:
- 分类号:
- S156.4+1
- 摘要:
- 膜下滴灌节水增产高效的表现使其成为我国西北干旱区绿洲农田普遍使用的灌溉方式。然而，长期滴灌下土壤盐分的变化趋势亟待研究。于2010年在新疆玛纳斯河绿洲进行微咸水灌溉试验，校验Hydrus 2D模型，并模拟预测长期滴灌下土壤盐分积累的变化特征。结果显示：Hydrus 2D模型可以有效模拟滴灌土壤盐分分布与积累特征；滴灌根区土壤盐分主要受灌溉输入土壤盐分与深层淋洗作用影响，随着滴灌年份的增加，根区盐分逐步增加，作物蒸腾受限，下渗淋洗量加大，最终根区的输入盐量与淋洗盐量相当，根区盐分处于相对平衡状态。以矿化度分别为4.8，3.2，1.6，0.8 g/L的灌溉水质为例，在420 mm灌溉水量下，分别在10，15，20，35 a后土壤盐达到平衡，根区盐分分别稳定在4.2，3.8，3.2，2.8 mg/cm3，作物的蒸腾满足率分别为72%，80%，85%，91%，为保证研究区内作物的正常生长，需要的灌溉量至少应分别为495，470，425，395 mm。
- Abstract:
- Drip Irrigation under film is a prevailing irrigation method in arid area of northwest China due to its outstanding efficiency of water saving and production increases. However, issue on rise of salt accumulation in crop field under long-term drip irrigation should been dealt with as soon as possible. In this paper, the Hydrus 2D model was calibrated and validated by using the observed data of dynamics progress of soil salt obtained from field experiment which was conducted in Manasi river irrigation district, Xinjiang Uygur Autonomous Region. The result showed that Hydrus 2D model was a useful tool to simulate soil salt distribution and accumulation under drip irrigation. Then soil salt accumulation in different quota brackish water under long-term drip irrigation was simulated and analyzed. We found that soil salt increased with the irrigating years, but it finally reached a stable equilibrium for its increasing speed got slower which was chiefly due to salt leaching increase while transpiration was suppressed by increased soil salt. The equilibrium times were 10, 15, 20 and 35 years, respectively, while then contents of irrigated water salinity were 4.8, 3.2, 1.6 and 0.8 g/L and with irrigation water rate of 420 mm, contents of soil salt at root zone were 4.8, 3.2, 1.6, 0.8 mg/cm3, respectively, and corresponding guarantee rate of transpiration requirement were 72%, 80%, 85% and 91%, respectively. In order to maintain soil salt below the tolerance of crop, contents of irrigated water salinity were 4.8, 3.2, 1.6 and 0.8 g/L, rates of irrigation water should be more than 495, 470, 425 and 395 mm, respectively.
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更新日期/Last Update:
1900-01-01