Young Eric O, Briggs Russell D
Dep. of Plant and Soil Science, University of Vermont, Hills Agricultural Science Building, Burlington, VT 05405, USA.
J Environ Qual. 2008 Jan 4;37(1):69-78. doi: 10.2134/jeq2006.0422. Print 2008 Jan-Feb.
Riparian buffers can be effective at removing phosphorus (P) in overland flow, but their influence on subsurface P loading is not well known. Phosphorus concentrations in the soil, soil solution, and shallow ground water of 16 paired cropland-buffer plots were characterized during 2004 and 2005. The sites were located at two private dairy farms in Central New York on silt and gravelly silt loams (Aeric Endoaqualfs, Fluvaquentic Endoaquepts, Fluvaquentic Eutrudepts, Glossaquic Hapludalfs, and Glossic Hapludalfs). It was hypothesized that P availability (sodium acetate extractable-P) and soil-landscape variability would affect P release to the soil solution and shallow ground water. Results showed that P availability tended to be greater in crop fields relative to paired buffer plots. Soil P was a good indicator of soil solution dissolved (<0.45 microm) molybdate-reactive P (DRP) concentrations among plots, but was not independently effective at predicting ground water DRP concentrations. Mean ground water DRP in corn fields ranged from < or =20 to 80 microg L(-1), with lower concentrations in hay and buffer plots. More imperfectly drained crop fields and buffers tended to have greater average DRP, particulate (> or =0.45 microm) reactive P (PRP), and dissolved unreactive P (DUP) concentrations in ground water. Soil organic matter and 50-cm depth soil solution DRP in buffers jointly explained 75% of the average buffer ground water DRP variability. Results suggest that buffers were relatively effective at reducing soil solution and shallow ground water DRP concentrations, but their impact on particulate and organic P in ground water was less clear.
河岸缓冲带在去除坡面流中的磷（P）方面可能很有效，但其对地下磷负荷的影响尚不清楚。在2004年和2005年期间，对16对农田 - 缓冲带样地的土壤、土壤溶液和浅层地下水中的磷浓度进行了表征。这些样地位于纽约州中部的两个私人奶牛场，土壤为粉质和砾质粉质壤土（潮湿淋溶土、潮湿雏形土、潮湿富铁土、舌状潮湿新成土和舌状新成土）。据推测，磷的有效性（醋酸钠可提取磷）和土壤 - 景观变异性会影响磷向土壤溶液和浅层地下水的释放。结果表明，相对于配对的缓冲带样地，农田中的磷有效性往往更高。土壤磷是样地间土壤溶液中溶解态（<0.45微米）钼酸盐反应性磷（DRP）浓度的良好指标，但在预测地下水中DRP浓度方面并非独立有效。玉米地中地下水DRP的平均浓度范围为≤20至80微克/升，干草和缓冲带样地中的浓度较低。排水条件较差的农田和缓冲带中，地下水中的平均DRP、颗粒态（≥0.45微米）反应性磷（PRP）和溶解态非反应性磷（DUP）浓度往往更高。缓冲带中的土壤有机质和50厘米深度土壤溶液中的DRP共同解释了缓冲带地下水DRP平均变异性的75%。结果表明，缓冲带在降低土壤溶液和浅层地下水DRP浓度方面相对有效，但其对地下水中颗粒态和有机磷的影响尚不清楚。
