Phosphorus pollution comes from multiple sources , including fertilizer and manure that enter the water through runoff .
磷污染有多個來源,包括化肥和糞肥通過徑流進入水源。
Differences in brightness in coastal area waters may be due to other factors , including freshwater runoff , strong currents , and water depth and clarity .
沿海水域的亮度差異可能是由于其他因素所導致,包括淡水徑流,強勁的水流,水的深度以及清澈度。
Farmers then began conserving water by moving to drip irrigation and by leveling their fields with lasers to minimize wasteful runoff .
These opinions recognize that current farming methods bring serious environmental problems involving water supplies , fertilizer runoff and energy use .