三种牧草对三峡库区旱坡地氮磷养分流失的影响

发布时间：2018-02-05 22:11

本文关键词： 三峡库区旱坡地牧草养分流失小流域　出处：《草业学报》2017年04期 　论文类型：期刊论文

【摘要】：本研究以三峡库区王家沟小流域为对象,通过田间试验和室内分析相结合的方法,以种植常规玉米为对照(T_1),利用2015年5-8月自然降雨采集的地表径流样品,研究了黑麦草(T_2)、墨西哥玉米草(T_3)、大力士甜高粱(T_4)三种牧草对三峡库区旱坡地氮磷流失的影响,为三峡库区种植结构调整及面源污染防治提供科学依据。结果表明,3种牧草均能显著减少径流及泥沙中的氮磷养分流失量,以墨西哥玉米草效果最佳;降雨造成的氮磷养分流失以泥沙为载体为主要流失途径,占总氮、总磷流失量的76.34%~79.97%和81.69%~83.90%;黑麦草、墨西哥玉米草的生物量及干物质积累量最高,分别为玉米处理的4.45、1.52倍和4.89、1.53倍,种植4种植被的养分截存效果表现为T_2、T_3T_4T_1。考虑到养分截存效果及饲用经济效益,三峡库区旱坡地应优先选择种植墨西哥玉米草,其次选择黑麦草,代替传统的玉米种植模式。
[Abstract]:In this study, the Wangjiagou small watershed in the three Gorges Reservoir area was used as an example, and the conventional corn cultivation was used as the control by combining the field experiment with laboratory analysis. Based on the surface runoff samples collected by natural rainfall from May to August of 2015, the ryegrass T _ 2 / T _ (2) and Mexican corngrass (T _ 3) were studied. The effects of three kinds of forage on nitrogen and phosphorus loss in dry sloping land of the three Gorges Reservoir area provide scientific basis for the adjustment of planting structure and the prevention and control of non-point source pollution in the three Gorges Reservoir area. The loss of nitrogen and phosphorus in runoff and sediment was significantly reduced by the three forages, and Mexican corn grass had the best effect. The nitrogen and phosphorus nutrient loss caused by rainfall is mainly through sediment as the carrier, accounting for the total nitrogen, and the loss of total phosphorus is 76.349.97% and 81.69%, 83.90% of the total phosphorus loss. The biomass and dry matter accumulation of ryegrass and Mexican corn grass were the highest, which were 1.52 times and 4.89 times of maize treatment, respectively. The nutrient interception effect of planting 4 was T _ 2C _ 2T _ 2T _ 3T _ 4T _ 1. In view of nutrient interception effect and forage economic benefit, priority should be given to planting Mexican corn grass on dry sloping land in the three Gorges Reservoir area. Secondly, ryegrass was chosen to replace the traditional maize planting mode.
【作者单位】：西南大学资源环境学院;
【基金】：十二五国家科技支撑计划课题(2012BAD14B18)资助
【分类号】：S158

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