与磷源、施用方法和施用量相关的皮埃蒙特土壤径流磷流失情况

Tarkalson David D, Mikkelsen Robert L

Department of Agronomy and Horticulture, University of Nebraska-Lincoln, West Central Research and Extension Center, 461 West University Drive, North Platte, NE 69101, USA.

J Environ Qual. 2004 Jul-Aug;33(4):1424-30. doi: 10.2134/jeq2004.1424.

Land application of animal manures and fertilizers has resulted in an increased potential for excessive P losses in runoff to nutrient-sensitive surface waters. The purpose of this research was to measure P losses in runoff from a bare Piedmont soil in the southeastern United States receiving broiler litter or inorganic P fertilizer either incorporated or surface-applied at varying P application rates (inorganic P, 0-110 kg P ha(-1); broiler litter, 0-82 kg P ha(-1)). Rainfall simulation was applied at a rate of 76 mm h(-1). Runoff samples were collected at 5-min intervals for 30 min and analyzed for reactive phosphorus (RP), algal-available phosphorus (AAP), and total phosphorus (TP). Incorporation of both P sources resulted in P losses not significantly different than the unfertilized control at all application rates. Incorporation of broiler litter decreased flow-weighted concentration of RP in runoff by 97% and mass loss of TP in runoff by 88% compared with surface application. Surface application of broiler litter resulted in runoff containing between 2.3 and 21.8 mg RP L(-1) for application rates of 8 to 82 kg P ha(-1), respectively. Mass loss of TP in runoff from surface-applied broiler litter ranged from 1.3 to 8.5 kg P ha(-1) over the same application rates. Flow-weighted concentrations of RP and mass losses of TP in runoff were not related to application rate when inorganic P fertilizer was applied to the soil surface. Results for this study can be used by P loss assessment tools to fine-tune P source, application rate, and application method site factors, and to estimate extreme-case P loss from cropland receiving broiler litter and inorganic P fertilizers.

在农田中施用动物粪便和肥料，增加了径流中磷过量流失到对养分敏感的地表水的可能性。本研究的目的是测量美国东南部皮埃蒙特地区一块裸露土壤在施用不同磷施用量（无机磷，0 - 110 kg P ha⁻¹；鸡粪，0 - 82 kg P ha⁻¹）的情况下，施用鸡粪或无机磷肥（采用混施或表施方式）后径流中的磷流失情况。降雨模拟的降雨强度为76 mm h⁻¹。每隔5分钟采集一次径流样本，共采集30分钟，并分析其中的活性磷（RP）、藻类可利用磷（AAP）和总磷（TP）。在所有施用量下，两种磷源的混施导致的磷流失与未施肥对照相比无显著差异。与表施相比，混施鸡粪使径流中RP的流量加权浓度降低了97%，TP的质量流失降低了88%。鸡粪表施时，施用量为8至82 kg P ha⁻¹时，径流中RP含量分别为2.3至21.8 mg RP L⁻¹。在相同施用量下，鸡粪表施径流中TP的质量流失范围为1.3至8.5 kg P ha⁻¹。当无机磷肥施用于土壤表面时，径流中RP的流量加权浓度和TP的质量流失与施用量无关。本研究结果可被磷流失评估工具用于微调磷源、施用量和施用方法等场地因素，并估算施用鸡粪和无机磷肥的农田极端情况下的磷流失量。