Friday, March 2, 2012

The Skinny on Fertilizers (And why to go Organic)

Because providing extra nutrients to crops to furnish healthy growth will always be a necessity, fertilizers are considered an intelligent investment in agricultural industries all over the world (Ashman & Puri, 2009). With the dangers of pollution making headlines in the past decade, due to leaching, run off and global warming, bodies governing agriculture as well as the environment in developed countries have concocted guidelines and regulations for type, timing and amount of fertilizers applied during a growing season (Sample, 2004). Commercial farming is fingered in the battle to balance ecological effects with maximum yield, and in the U.S. the EPA (Environmental Protection Agency) provides literature on “BMPs” or best management practices that local farmers claim are the practices of any learned, seasoned farmer (Griffith). The U.S Department of Agriculture provides guidelines for organic farming and test produce against them to label said produce “USDA Organic (U.S.EPA, 2011).” The EPA suggests that farms self-compost when viable, make use of agricultural wastes such as biosolids, manures, and yard trimmings when applicable, and apply fertilizers as a kind of last-resort supplement (U.S EPA, 2011). However, applying any materials, organic or other, in excess can cause severe damage to surrounding waters, plant life and the ozone layer of our atmosphere that blocks harmful ultra violet rays (Ashman & Puri, 2009).

Most literature suggests that timing is essential in effectiveness as well as contamination prevention. Plant growth at the start of a growing season is vulnerable to nutrient deficiency due to the rapid growth and development of roots, therefore an extra supply of nutrients is almost always beneficial (Ashman & Puri, 2009). The application of organic as well as commercial fertilizers for the rest of the growing season must depend on frequent testing of soil and plant tissue, most beneficially, before crops begin to show any sign of deficiency (Griffith).

Analyses should also be conducted annually for residues, rotation and crops grown (Griffith). Close attention need be paid to the temperature and rainfall before application of both organic and commercial fertilizer (Griffith). In addition to supplementation, nitrification and urease inhibitors can be applied in conjunction with fertilizers to preserve necessary compounds (such as those created by ammonia synthesis) and stretch their use, limiting application (Griffith).

The key components to nutrient supplement practices consist of nitrogen (nitrate), phosphorus (phosphate) and potassium, and are the basis of the commercial “NPK rating” which is based on the levels of each within a fertilizer (Office of Solid Waste, 2007). The U.S EPA’s Office of Solid Waste provides a list of organic components suggested for compost and fertilizer and their estimated NPK ratings for efficient self-fertilizing.

In the U.S, indoor cattle facilities (Animal Feeding Operations [AFOs] and Concentrated Animal Feeding Operations [CAFOs]) are estimated to produce 335 million tons of dry matter annually (Office of Solid Waste, 2007). Biosolids, which consist of the “end product” of raw sewage treatment that is then further chemically and thermally treated for use, were estimated at 8.2 million tons in 2010 with an impressive estimation of 70% of which that was applied to crops in the U.S (Office of Solid Waste, 2007). In 2004, the U.S produced a whopping 5 billion tons of poultry feather waste (Office of Solid Waste, 2007). Feather waste is the most common agricultural waste, rich in slow-releasing nitrogen, and an estimated NPK range of 13-0-0 to 15-0-0 (Office of Solid Waste, 2007). Other suggested materials for organic and commercial fertilizers and composting include alfalfa meal (2.5-1-1 to 2.5-0.5-2), blood meal (12.5-1.5-0.0 to 12.5-1.5-1), cottonseed meal (6-2-1 to 7-2.5-1.5), fish meal (10-5-0 to 10-3.7-0), meat and bone meal (2-28-0), poultry litter (4-2-3), soybean meal (7.5-0.7-2.4 to 6.5-1.5-2.4), and wood ash (0-1-3 to 0-1.5-5) (Office of Solid Waste, 2007).

A farm which makes smart use of agricultural wastes, being yard wastes (trimmings), food wastes (composting), municipal wastes and construction and demolition debris, as well as animal manures may never need a commercial fertilizer if practices are managed properly (U.S. EPA, 2011).

For the home farmer and gardener who wants to start out with nutrient rich soil or continuously add nutrient rich soil throughout the growing season, try a compost heap. They are great for the environment, economically viable, easy to maintain and can be done indoors or outdoors.

Outdoors, check it out:



Indoors, check it out:



Cold Weather farmers, check it out (thermophilic):



Need to know more about worms? Check it out:



Resources:

Ashman, M. R., & Puri, G. (2009). Essential soil science- a clear and concise introduction. (pp. 136-150). Hoboken, NJ: Wiley-Blackwell.
Griffith, B. (n.d.). Efficient fertilizer use manual. Mosaic.
Organic fertilizer recipe (2009, January 12). Youtube. (2009). [0]. Retrieved from http://www.youtube.com/watch?v=7p9ckLg1-W0
U.S Environmental Protection Agency, (2011). Compost and fertilizer made from recovered organic materials. Retrieved from website: http://epa.gov/osw/conserve/tools/cpg/products/compost.htm
U.S Environmental Protection Agency, Offices of Solid Waste. (2007). Comprehensive procurement guidelines appendices

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