Do the Right Thing - Prevent Pollution When Fertilizing
Spring is just around the corner and soon the cold and snow will give way to warmer temperatures and thoughts of fertilizing to ensure lush green lawns and crop fields. As you plan for the growing season don't forget to plan for protecting the environment as well. Whether you're a farmer or urban homeowner, you can play a part in protecting water quality for Ohio's tomorrow. If you've heard of the algae blooms in lakes across the state of Ohio, you know how important water quality is to the quality of life of all Ohioans.
First, think about water and how it cycles. All the water on earth exists in different forms and different places: in the atmosphere; in icebergs; in oceans, lakes and ponds; in plants and animals; and in soil.
Water falls as precipitation, which either runs off hard surfaces or soaks into the porous soil. The water that runs off the surface usually enters a body of water. The water that soaks into the soil becomes ground water. Ground water feeds our lawns, crops and trees, and we can draw it up through wells for our personal use. It all gradually seeps into our bays, rivers and other waterways.
This water cycle will carry pollutants from our land surface into our waterways and water supply if we aren't careful in how we manage the land and the nutrients or fertilizers we apply to it. While nutrients are good for plants in proper amounts, applying too much fertilizer will result in a surplus that inevitably follows the flow of water as it cycles.
Fertilizer Use Depends On Plant Type, Purpose
Most fertilizer is applied to turfgrass and crops grown for food and fiber. However, turfgrass and crops are fertilized and managed differently. Nutrient losses are dependent on amount, type and timing of fertilization and irrigation.
- Food and fiber crops are almost always fertilized and sometimes irrigated.
- Urban turfgrass is frequently unfertilized and unirrigated.
- Recreational turfgrass (greens, tees, athletic fields) is regularly irrigated and fertilized where it receives steady use; therefore, it presents a greater potential pollution risk.
The primary nutrients that contribute to water pollution are nitrogen and phosphorus. Nitrogen (usually in the form of nitrate) is the nutrient that produces the greatest growth response in plants. But if we put too much nitrate fertilizer on our lawns and crops, the excess nitrogen not taken up by plants will leach downward, entering the ground water supply that we use for drinking water. Nitrate contamination is most commonly caused by animal manure, pet wastes, improperly designed or improperly maintained septic tanks and over application of nitrogen crop and turfgrass fertilizers.
Phosphorus Promotes Algal Blooms
Phosphorus is an important nutrient necessary for plant growth, but when an excess enters into our lakes and ponds, it causes rampant algae and weed growth. The overabundance of decaying algae depletes the water's oxygen supply, which can kill fish and desirable vegetation. Also, some algae are toxic to humans.
Phosphorus exists in the soil in several forms which can be transported to surface water bodies. Since very little runoff occurs from turfgrass or pasture systems due to their capacity to retard overland flow and allow high rates of infiltration, most losses occur in runoff when vegetative debris (leaves, yard waste) or surface-applied fertilizer and composts are carried by large volumes of water over impermeable surfaces to storm drains and streams.
In agricultural areas, the major routes of phosphorous loss are from erosion of soil and washing away of excess manures or synthetic fertilizers from exposed crop fields or when water infiltrating soils leaches excess phosphorous out and flows into sub-surface drainage systems which outlet into ditches and eventually into streams, rivers and lakes.
However, commercial fertilizer as well as organic and manure fertilizers are easily controlled by practicing the Four R's of Managing Fertilizer: Right source, Right rate, Right time and Right place.
Use these 4 R tips for managing your fertilizer applications:
- Do not fertilize or apply manure on frozen ground or if a heavy rainfall is expected.
- Match the product to the situation. All fertilizers can cause pollution if allowed to escape the root zone, so avoid both leaching into groundwater or subsurface drainage and surface runoff.
- Become knowledgeable in soil testing procedures and soil test interpretation so that your fertilizer buying and application decisions are made based on facts.
- Correct other deficiencies first. Soil pH, shade, overwatering or other stresses may be at fault; be sure fertilizer is the correct response before applying.
- The rate and timing of Nitrogen (N) fertilization depends on species, season, level of maintenance desired, source of the N applied and location.
- Limit Phosphorous (P) application to soils that require additional P based on soil or tissue testing.
- At lawn installation, amend the soil as needed with lime or organic matter. Limit N & P fertilization to one time 30 days after seeding/sodding.
- Always leave a 10-foot or more "ring of responsibility" or buffer strip near water bodies or impervious surfaces. Use deflector shields on broadcast or rotary spreader when applying fertilizer near water or sidewalks, driveways & streets.
- Sweep any fertilizer or grass clippings from impervious surfaces, such as driveways, streets and sidewalks, back into the vegetated area.
- Know size of the application area and make sure the spreader/ application equipment is properly calibrated and set to deliver the correct amount of fertilizer.
- Apply fertilizer only when plants are actively growing. For example turfgrass goes dormant in the summer heat, so fertilizing then won't help growth.
Through the 4R Tomorrow program, Ohio's soil and water conservation districts are bringing together farmers, homeowners and businesses to take active roles in better fertilizer management. By using Backyard Conservation and Nutrient Management Stewardship principles, together - we can keep our soils productive, our waters clean and our future bright! To learn more about how you can do RIGHT today, for our tomorrow, go to www.4RTomorrow.org or contact your local county soil and water conservation district