The large amount of pavement in cities and suburbs provides a direct route for fertilizer nutrients and other surface pollutants to enter bayous and bays. Careful application of fertilizer is one way you can prevent pollution. Follow these tips to make sure the fertilizer you use remains on the lawn and out of the water.
- Try to keep fertilizer off paved surfaces. If granular fertilizer gets onto paved surfaces, sweep or blow it onto the lawn.
- Use a drop spreader instead of a rotary spreader in restricted spaces, especially when near water, driveways or sidewalks. Drop spreaders put materials more precisely in place. Rotary spreaders are best for wide open turf and sling granules over a broader area. Calibrate your spreader to make sure you re not over applying fertilizer. If you must guess at a setting, guess lower; you can always put more out later or come back for the next application sooner. Fill and wash spreaders over grassy areas, not on hard surfaces, or collect the wash water and dispose of it through the sod.
- Avoid getting much fertilizer into natural drainage areas or swales on your property; it will tend to move there anyway.
- Test soil every three years, and then fertilizer and lime your lawn accordingly. Apply only what is needed. The fertilizer 'analysis' is listed as the percent by weight of N, P (as P2O5 ) and K (as K2O). Avoid very high soil phosphorus levels that can build over time from excess application. Mature turf needs only low to medium levels of soil P.
- Leave grass clippings on the lawn. This recycles organic nutrients and can reduce the amount of fertilizer you need to apply by a third. If you remove the clippings, compost them or use as a bed mulch. Do not use as mulch if you applied herbicides or weed-n-feeds until the third cutting. When mowing near the street, direct clippings back on the lawn. You may also sweep or blow them back into the sod.
- If you water your lawn, do not let water run off the lawn surface and into the street. You may need to water in several short cycles to achieve the deep soil wetting with less surface runoff.
- If your soil is sandy, or if you live in an area with a high water table, try to use a slow-release nitrogen source and never apply more than 1 pound of soluble nitrogen per 1000 sq. ft. to any soil in any one application. That application may last a month or two. Better fertilizers have a blend of both soluble N for quick greening and slow-release N for sustained greening.