NUTRIENTS AND THE ENVIRONMENT
            Days are gradually getting longer. The sun is higher in the sky. With the expectation that spring is coming, gardeners and farmers alike are planning for the next growing season. Choosing and applying nutrients is not only an important part of growing plants, but also of protecting our watershed.
Jim Nelson, Watershed Liaison for the Association of Illinois Soil and Water Conservation Districts, explains the water quality concern: “Why fixate on nutrients when there is oil, grease, silt, PCBs, pesticide, metals, and other pollutants to worry about? One reason is that they are applied every season and we, as citizens who are concerned about soil and water conservation, can actually control the amount of nutrient that enters our local waters. Another reason is that excessive nutrients negatively affect aquatic ecosystems and water quality.”
            Many nutrients and conditions need to be considered in order to enhance plant growth but nitrogen (N) and phosphorus (P) particularly, “are sucked out of the ground and used in the developing plant tissues. This is why anyone who grows plants spends so much time and effort putting these nutrients back into the soil.”
            “Aquatic and marine flora have thrived for millions of years using N and P as well. In fact every organism on earth must have carbon, nitrogen, and phosphorus because of their role in the structure of DNA … In addition, cells use all three in different concentrations to make their structures.”
            Throughout time, water ecosystems have contained a great amount of carbon, also needed for plant growth, while N and P circulated through their respective N and P cycles to a lesser degree. “For the purpose of algal growth we refer to N and P as limiting factors. This means photosynthetic growth in aquatic systems is often times limited by the nutrients available. Other factors influencing this growth include temperature, sunlight, and water movement (all conditions that humans have little or not control over).”
            Without adequate management excessive amounts of N and P are added to our surface waters. The blue-green algae that benefit most from the excess nutrients are indigestible to the natural zooplankton that keep other algae in check. Excessive growth of the blue-green algae forms a “bloom” that shades out the sunlight from penetrating into the water, causing other algae to die, decompose, and consume oxygen. “The result is reduced dissolved oxygen for aquatic organisms such as insect larvae, immature amphibians, and fish. Some areas of the country have experienced blooms of blue-green algae which produce toxins that have poisoned humans swimming in and drinking the water.”
            Plan adequately for nutrient management as you plan for the next growing season. Get help from your Soil and Water Conservation District or University of Illinois Extension.
            Quotes and Information from the AISWCD Conservation Catchall www.aiswcd.org/EventsAndNews/catchall.htm.

Della Moen, Earth Team Volunteer, NRCS/Stephenson Soil and Water
Conservation District, an equal opportunity provider and employer, 12/31/08/ (for publication on 1/10/09 in the Journal-Standard, Freeport, Illinois).
Della can be reached at info@stephensonswcd.org