the oecd guidelines for good practice set forth a number of options that could be considered to support efforts to move toward the sustainable management of water quality in agriculture the greater use of economic instruments eg water quality trading pollution taxes to address nonpoint source pollution can improve the cost effectiveness of measures while water quality trading has the potential to lower the cost of achieving improved water quality in practice experience w ith such programmes remains fairly limited to date design features eg scale compliance requirements transaction costs have an important bearing on their overall performance in reaching environmental and efficiency objectives current efforts to advance sustainable agricultural practices including for example precision agriculture could be considerably scaledup and provide opportunities for green growth