You may find the thought of drinking fertilizer quite alarming, but in reality, we may all be drinking a bit of fertilizer. When we add fertilizer to our yard or garden, the bag has 3 numbers on the front with dashes between them.
The first number is the percent nitrogen. Excess nitrogen leaches into the soil with water and converts from nitrite to nitrate as it travels downward. In my area of Wichita, about 20-30 feet down it enters our groundwater as nitrates.
The second number is the percent phosphate or phosphorous. Phosphorous is a hazard to surface water since it encourages the growth of algae and more specifically blue green algae. Some strains of blue green algal blooms are toxic, and some are just foul smelling, but neither is desirable. Both are avoidable if we keep the nutrients on our yards where the grass is growing.
The third number is the percent of K or potassium. Potassium does not create as many issues as nitrogen and phosphorous, but it does encourage the growth of algae along with the phosphorous.
The point of writing about this is that none of us really wants to drink lawn fertilizer. For the most part we can avoid drinking lawn fertilizer if we apply small amounts at a time. Not applying right before we irrigate heavily, or a large rain is expected will lower the chance of it leaving our lawn and soaking into the soil or running off with water and entering a stream. The point of buying fertilizer is not to lose much of it to leaching or runoff but to stimulate the growth of plants in our yard or garden. Let’s get a better return on our investment and quit drinking our fertilizer!
The author Howard Miller is the Outreach Coordinator for the Cheney Lake Watershed.