This image is in the public domain because it contains materials that originally came from the Agricultural Research Service, the research agency of the United States Department of Agriculture.
Bone and meat meal.

Spring is here and it’s nitrogen’s time to shine. Farmers and gardeners the world over are well acquainted with the effects of nitrogen, or N, on their plants. Lush, green growth is the most visible effect of N applications. Over applying N leads to stunted growth, burned tissue and, in extreme cases, plant death.

Proper levels of N are essential to healthy plants. It is the most frequently applied nutrient, in part because plants take it up so readily and they need it at every stage of plant growth. Monitoring your levels through regular soil testing will help avoid issue of over or under applications. Due to it’s soluble nature, it is also an extremely mobile nutrient, both in the plant tissue and in the environment.

Stop Wasting Money & Keep Excess Nitrogen Out of Waterways

In addition to tissue burn, excess applications of N have a tendency to run off into the environment, leading to pollution of waterways. Once this N has found it’s way into the water, it encourages algal blooms. This explosive growth of algae reduces oxygen levels in the water resulting in the suffocation and death of aquatic life.

The infamous “dead zone” at the mouth of the Mississippi River is an unfortunate example of this. Excess fertilizer applications of nitrogen (and to a lesser extent phosphorus) are washed into the water during winter and spring rains causing a large swath of the Gulf of Mexico to be devoid of life.

Water quality issues are a growing concern in Emerald Triangle farming communities. The ongoing drought conditions coupled with the increasing number of farms along with an increase in farm size is putting a strain on local watersheds. Lower flowing rivers are at greater risk of N pollution — there is simply less water to dilute the excess, runoff N. While this is a large, complicated issue there are some simple steps farmers can take to mitigate these risks.  It all starts with getting to know your nitrogen source!

Options for Nitrogen Application To Strengthen Plants All Season

Whole agronomy courses can be taught on the different forms of N and their effects on plant growth but let’s get down to basics. A leading cause of N pollution is through the use of chemical-based fertilizers.  Ditch the chemicals and you are well on your way down the path of sustainable agriculture.

Even without considering chemical fertilizers, there are many options. Almost any farm supply store will be stocked with blood meal, feather meal, fish meal or soy meal — commodity products commonly used as N sources for organic crops. Understanding these products interaction in the soil will help you understand which ones to apply.

Even amongst organic nitrogens all forms are not created equal. One indicator of this can be found on the product label. Total N content is mandated to be listed on all fertilizer labels along with the percent of Soluble and Insoluble forms. Soluble nitrogen is N that is immediately available to the plant in the presence of water. Chemical fertilizers, for the most part, are completely, immediately available.  Insoluble nitrogen is N that is bound up with organic matter that needs to break down before it becomes available to the plant.

What Happens to the Plant When You Overapply Soluble Nitrogen

Plants require adequate N through all stages of growth. By understanding the N release rates, one can ensure healthy, lush growth while avoiding the wasted time, costs and environmental damage associated with over use of N. Oh, and your plants will be healthier! Over applying N, soluble N in particular, can lead to weak, leggy growth or “stretched” plants. These weakened plants are more susceptible to pests and diseases resulting in the unnecessary costs of pesticide and fungicide applications.  It really pays to know your N.

Recommended Sources of Nitrogen for Farmers (Organic or Not)

Through trials conducted over the last few years, a few N sources have presented themselves as being particularly useful to the local farmers. Three favorites are feather meal, soy and neem, organically certified is best. In combination they provide a fast, medium and slow release of N while stimulating soil microbial populations.

Of particular interest are the plant-based forms of N.  It has been hypothesized that plant based materials feed a greater variety and number of soil microbes. Plant life exists in a greater volume than animal life — it seems logical to assume that soil biology has evolved to breakdown and digest this greater volume at a more efficient rate.

Now is the time, prior to planting, to apply these time released N sources and avoid the costly applications of liquid and chemical fertilizers thought the growing season. Organic forms of N  truly are the gift that keeps on giving.


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