| 化肥减量配施生物炭对紫色土坡耕地磷流失的影响 |
| 摘要点击 2492 全文点击 721 投稿时间：2019-09-24 修订日期：2019-10-22 |
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| 中文关键词 生物炭 坡耕地 磷流失 地表径流 壤中流 |
| 英文关键词 Bio-charcoal sloping land phosphorus loss overland flow runoff |
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| 中文摘要 |
| 磷是农作物生长所必需的营养元素，但过量磷的投入是造成水体富营养化问题的重要原因.探究实际生产中施肥方式与磷素流失之间的关系，为科学施肥和合理减施化肥提供理论依据.本试验采用野外径流小区对紫色土坡耕地2017~2018年度多次降雨产流产沙进行定点监测，研究了不施肥处理、常规施肥处理、优化施肥处理和减量施肥配施生物炭4种不同方案对紫色土坡耕地壤中流、地表径流和泥沙磷素流失的影响.结果表明：①各处理的产流总量表现为：优化（20737.23 L） > 常规（18513.17 L） > CK（18134.58 L） > 生物炭（13594.85 L），各处理的产沙总量表现为：CK（1998kg·hm-2） > 生物炭（1884 kg·hm-2） > 优化（1681kg·hm-2） > 常规（910kg·hm-2）.壤中流是紫色土坡耕地雨季产流的主要类型，占到总产流量的60.14%~87.34%，各处理的产沙总量除常规外，其他处理不存在显著性差异（P>0.05）.②各处理的全磷流失通量均表现为泥沙 > 地表径流 > 壤中流.通过壤中流流失的磷素最少，只占全磷流失通量的2.63%~12.91%，而泥沙磷素流失通量占比可达63.74%~78.74%，是紫色土坡耕地土壤磷素流失的主要输出途经.③配施生物炭可以有效减少紫色土坡耕地土壤的壤中流产流量，以及壤中流的正磷酸盐的流失通量，较常规处理分别减少49.94%和56.45%.但是对地表径流的截留效果不佳，对颗粒态磷的流失通量无明显影响，同时增加了地表径流与泥沙中的全磷流失通量，较常规处理显著增加73.28%和123.53%（P<0.05）.因此，为控制西南地区紫色土坡耕地磷的流失，应着重减少土壤泥沙流失的发生.而生物碳在农业生产实际应用中也应进一步优化与化肥磷素投入配比. |
| 英文摘要 |
| Phosphorus is an essential nutrient for crop growth, but the input of excess phosphorus is a significant cause of eutrophication. This study explored the relationship between fertilization methods and phosphorus loss in actual production, providing a theoretical basis for scientific fertilization and rational reduction of fertilizer application. In the experiment, a wild-type OD flow plot was used to monitor the occurrence of multiple rainfall runoff and sediment yield in purple soil sloping farmland in 2017-2018. Four different schemes of non-fertilizer treatment, conventional fertilization treatment, optimized fertilization treatment, and reduced fertilization combined with biochar were studied. The effects of soil flow, surface runoff, and sediment phosphorus loss on purple soil sloping farmland were analyzed. The results showed that:①The total yield of each treatment was optimized (20737.23 L) > conventional (18513.17 L) > CK (18134.58 L) > biochar (13594.85 L), and the total sediment yield of each treatment was CK (1998 kg·hm-2) > biochar (1884 kg·hm-2) > optimized (1681 kg·hm-2) > conventional (910 kg·hm-2). The middle stream of soil is the main type of runoff in the rainy season, accounting for 60.14%-87.34% of the total output flow. The total amount of sediment produced by each treatment was not significantly different from that of the conventional treatment (P>0.05). ②The flux of total phosphorus loss in each treatment was characterized by sediment > surface runoff > soil middle flow. Phosphorus lost through the middle stream of soil is the least, accounting for only 2.63%-12.91% of the flux of total phosphorus loss, while the flux of sediment loss of phosphorus can reach 63.74%-78.74%, and thus is the main output route of soil phosphorus loss. ③The application of biochar can effectively reduce the abortion flow in the soil of purple soil sloping land, and the loss flux of orthophosphate in the middle stream, which are 49.94% and 56.45% lower than the conventional treatment, respectively. However, the interception effect on surface runoff is not good, and there is no significant influence on the flux loss of particulate phosphorus. At the same time, the flux of total phosphorus in surface runoff and sediment is significantly increased by 73.28% and 123.53%, respectively, compared with conventional treatment (P<0.05). Therefore, to control the loss of phosphorus in purple soil sloping farmland in southwest China, we should focus on reducing the occurrence of soil sediment loss. Bio-carbon should be further optimized in the practical application of agricultural production with the phosphorus fertilizer input ratio. |
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