This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. Th...This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. The results showed that incomes, residual nitrogen in soil, and the loss of nitrogen in surface water in rice-garlic system were higher than those in rice-fava bean system. There were positive correlations between the nitrogen loss of farmland, nitrogen inputs, residual nitrogen in soil, and incomes of farmland. Economic benefits and environment benefits are both appropriate, if the area of rice-garlic system would be reduced to 53% and the area of rice-fava bean system increased to 36% of total cropping area in the investigated watershed. Adjustment of planting structure and introduction of reasonable rotation systems is considered an effective measure of controlling agricultural non-point pollution in watersheds of Erhai Lake.展开更多
为了阐明氮肥施用量对甜玉米糖分含量及农艺性状的影响,以甜玉米品种‘耘甜8号’为试材开展田间实验,设置5个氮肥施用量处理(即0、100、200、300、400 kg N/hm^(2))。结果表明,氮肥施用量与可溶性糖及还原糖含量的线性模型不显著,只是...为了阐明氮肥施用量对甜玉米糖分含量及农艺性状的影响,以甜玉米品种‘耘甜8号’为试材开展田间实验,设置5个氮肥施用量处理(即0、100、200、300、400 kg N/hm^(2))。结果表明,氮肥施用量与可溶性糖及还原糖含量的线性模型不显著,只是在播种后的第103天,还原糖含量随施氮量的增加而微弱下降。穗重以渐近增长的模式响应氮肥施用量的增加。施氮量超过100 kg N/hm^(2)时,穗重对氮肥施用的正响应程度将显著减弱。每公顷增施100 kg N导致穗长降低0.29 cm。氮肥施用量与穗粗、穗行数及行粒数之间的线性模型不显著。增施氮肥能降低凸尖长度。综上所述,增加氮肥施用量对甜玉米糖分含量、穗粗、穗行数及行粒数无影响,且导致穗长微弱降低。然而,增施氮肥能显著增加穗重,且能降低凸尖长度。展开更多
应用SWAT模型(Soil and Water Assessment Tool),以区域气候复杂的云南省洱海流域为例,研究不同子流域划分数量对径流和泥沙负荷模拟结果的影响,以明确洱海流域合理的子流域划分方案。结果表明,随着子流域划分数量的增加,年均径流深增...应用SWAT模型(Soil and Water Assessment Tool),以区域气候复杂的云南省洱海流域为例,研究不同子流域划分数量对径流和泥沙负荷模拟结果的影响,以明确洱海流域合理的子流域划分方案。结果表明,随着子流域划分数量的增加,年均径流深增加但敏感性较小,相对偏差仅0.89%;年均泥沙负荷减少而敏感性较大,相对偏差达21.21%。经综合权衡年均径流和泥沙负荷对子流域划分响应的敏感性,提出洱海流域合理的子流域划分临界值为137个,相应子流域平均面积占流域总面积的0.73%。在大于该临界值的划分水平下,模拟的年均径流深和泥沙负荷趋于稳定,但对进一步提高模拟精度无明显效果。研究结果对其它地形地貌复杂的流域水文模拟和非点源污染模拟具有重要借鉴意义。展开更多
基金funded by the National Water Special Program of China during 11th Five-Year Plan period(2008ZX07105-002)
文摘This study was designed to find out an optimised planting system of reducing non-point （source） pollution by analyzing the reasons and the factors of influence non-point pollution in farmland of Erhai Lake basin. The results showed that incomes, residual nitrogen in soil, and the loss of nitrogen in surface water in rice-garlic system were higher than those in rice-fava bean system. There were positive correlations between the nitrogen loss of farmland, nitrogen inputs, residual nitrogen in soil, and incomes of farmland. Economic benefits and environment benefits are both appropriate, if the area of rice-garlic system would be reduced to 53% and the area of rice-fava bean system increased to 36% of total cropping area in the investigated watershed. Adjustment of planting structure and introduction of reasonable rotation systems is considered an effective measure of controlling agricultural non-point pollution in watersheds of Erhai Lake.
文摘为了阐明氮肥施用量对甜玉米糖分含量及农艺性状的影响,以甜玉米品种‘耘甜8号’为试材开展田间实验,设置5个氮肥施用量处理(即0、100、200、300、400 kg N/hm^(2))。结果表明,氮肥施用量与可溶性糖及还原糖含量的线性模型不显著,只是在播种后的第103天,还原糖含量随施氮量的增加而微弱下降。穗重以渐近增长的模式响应氮肥施用量的增加。施氮量超过100 kg N/hm^(2)时,穗重对氮肥施用的正响应程度将显著减弱。每公顷增施100 kg N导致穗长降低0.29 cm。氮肥施用量与穗粗、穗行数及行粒数之间的线性模型不显著。增施氮肥能降低凸尖长度。综上所述,增加氮肥施用量对甜玉米糖分含量、穗粗、穗行数及行粒数无影响,且导致穗长微弱降低。然而,增施氮肥能显著增加穗重,且能降低凸尖长度。
文摘应用SWAT模型(Soil and Water Assessment Tool),以区域气候复杂的云南省洱海流域为例,研究不同子流域划分数量对径流和泥沙负荷模拟结果的影响,以明确洱海流域合理的子流域划分方案。结果表明,随着子流域划分数量的增加,年均径流深增加但敏感性较小,相对偏差仅0.89%;年均泥沙负荷减少而敏感性较大,相对偏差达21.21%。经综合权衡年均径流和泥沙负荷对子流域划分响应的敏感性,提出洱海流域合理的子流域划分临界值为137个,相应子流域平均面积占流域总面积的0.73%。在大于该临界值的划分水平下,模拟的年均径流深和泥沙负荷趋于稳定,但对进一步提高模拟精度无明显效果。研究结果对其它地形地貌复杂的流域水文模拟和非点源污染模拟具有重要借鉴意义。
