Buffer strips are useful for mitigating diffuse pollution. As riparian buffers perform their role in sediment trapping, P accumulates with no loss mechanism (as in wetland denitrification for N). Compiled data from buffer retention studies shows limited efficiencies for P trapping and negative budgets (that is, leaching) for dissolved P. So buffer soils can become a near stream source of bioavailable P.
Figure 1 (above) and 2 (below): Engineered buffer strip
We realised that vegetation management (for example, cut and removal) present one of few long term P sinks for buffers. In terms of making buffers pay for themselves and become more acceptable we can economise on this by using plant lines selected for greater P uptake targeted to the P forms we observe in buffer soils. We are now encouraging buffers for biomass for economic returns and as a means of P recycling.
Links:
[1] https://www.hutton.ac.uk/staff/marc-stutter
[2] https://www.hutton.ac.uk/staff/david-lumsdon