I recently completed some research regarding the relative availability and uptake of applied plant nutrition. Time was spent looking through research papers and results posted on the Internet. I mistakenly thought the pickings would be slim and I would have to search far and wide to get some background.
How wrong I was! It appears every research paper, whether academic or industrial, amateur or professional, doctorate or undergrad are all posted in some form or another somewhere on the Web. Many of them are posted in multiple places. At first this was a bit overwhelming, but it turns out to have made the task at hand a little easier. The only limit was my time and patience.
I was looking for evidence of the nutrient release time from manure products from any third party source. I found plenty, but ended up citing six. They were from Clemson, University of Florida, University of Hawaii, Purdue, N.C. State and the University of Georgia. The exact findings varied somewhat from each institution depending on their overall climate. But the evidence showed that manure releases nitrogen at the rate of 50-90% of total applied N over the period of 12 months. Low was in Purdue (Indiana), high was in Hawaii. The difference in average daily soil temperature was the main factor in the difference.
The fact is, compared to Nature Safe, any manure, sludge or compost product releases much more slowly — 50-90% in 12 months — compared to Nature Safe which is 85-100% release in three to four months! Right away this shows you have to take into consideration many factors other than simple N content.
There was a term that was used in some of the papers that pinpointed the real crux of the issue when figuring how much fertilizer to use and, even more importantly, the REAL cost of the nutrients you apply. That term is PAN. This was originally used to signify Plant Available Nitrogen, but is now in customary use as Plant Available Nutrition. It signifies how much nutrition is actually used by, and usable to, the plant. It is becoming the standard measure of the efficacy of any fertilizer, whether chemical or organic. Some of the facts I gathered in my readings regarding a fertilizer’s potency:
Leaching: Soluble fertilizers readily mix with water and are carried through the soil profile before plants can use them. Leaching has been measured at highs of 20% of soluble nitrogen loss, although 8-12% is considered normal. This is mostly because plants cannot absorb nitrogen as fast as soluble nitrogen is available, so it passes through the root zone without doing any feeding.
Runoff: Soluble fertilizers combine with water and are carried off into streams, rivers and lakes. Organics can be physically moved, but to a much lower extent. Runoff is such a huge problem that the US Department of Agriculture and and the Department of Environmental Quality are starting to implement restrictions on fertilizer application in order to limit the occurrence. The state of Florida was most recently put under orders to limit sales of fertilizer because of runoff into groundwater. This is under litigation.
Volatilization: This happens when nutrient chemicals take on a gaseous form of the chemical and is lost in the atmosphere. Think of smelling ammonia while applying NH4NO3 or urea. If you smell ammonia, you are losing nitrogen.
Solariation: A chemical reaction to exposure to sunlight can render fertilizer elements to an unavailable form. Solarization has seldom been measured, but most superintendents know to water in applications not only to prevent leaf burn but also to maximize the impact of their fertilizer. In greenhouse and nursery situations, where many soluble liquid feeds are used, the rapid decline in a fertilizer’s effect has been acknowledged for years, even if not quantified.
Any of the above processes eats into your fertilizer budget. You end up paying for chemicals that the grass can’t use. No matter how low the price, if the turf doesn’t get anything from it, it can be very expensive. Do you have money to waste on fertilizers that don’t feed the plants? As much as 25% of a fertilizer’s ammoniacal nitrogen content can volatilize during application. This includes organic fertilizers with ammoniacal nitrogen content too.
All of these factors can dramatically diminish the amount of nutrition that a plant can utilize. Yet, applicators are paying for all of it. One of the most striking characteristics of Nature Safe is that what you pay for is delivered in a form and rate that is most efficiently used by the plant. In fact, due to the need for biological release through the action of microorganisms, if the plant growth rate is slowed by temperature, then so is the action of the microbes. This keeps the nutrition in the soil until the plant demands it.
If Nature Safe looks expensive due to the relatively lower analysis compared to chemical fertilizers, try factoring in 10-15% loss due to volatilization, 10% loss due to leaching, maybe 5-10% in runoff and who knows how much in solarization. And if it’s a coated fertilizer, remember that part of each 50 lb. bag is inert coating, usually 3-5% of total weight.
So, if you are tired of the expense of labor to put out fertilizer that the turf can’t use, are tired of paying for fertilizer that can lose 20% or more of it’s potency and are tired of the expense of having fertilizer wash away because it’s ready when the plant isn’t, then realize that the PAN, the Plant Available Nutrition in Nature Safe, is the wise buy. Homogenous, organic, stable and biologically activated, Nature Safe is there when you (and your turf) need it.