**1. Introduction**

An organic fertilizer is a soil amendment produced from plant materials and/or animal manures containing low levels of nitrogen (N), phosphorus (P), potassium (K), and some residues of micronutrients compared with synthetic chemical fertilizers. These plant byproducts include alfalfa meal or pellets (also used as animal feed), corn gluten meal (with allelophatic proper‐ ties), cottonseed meal, and soybean meal (also used as animal feed). Animal byproducts include bat guano, blood meal (slaughterhouse waste product), bone meal, feather meal, enzymatical‐ ly digested hydrolyzed liquid fish, fish emulsion, fish meal, and fish powder. In addition to these byproducts, compost of organic materials (mixture of leaves, food waste, and/or animal manures) and seaweed (valued for its micronutrient contents) are used as organic fertilizers. Contrary to synthetic chemical fertilizers for which nutrient contents are regulated, the term organic fertilizer is not regulated; theses organic fertilizers act as nutrients for plants and soil conditioners that feed soil microorganisms. Biosolids are another type of organic amendment or fertilizer used in agriculture. The United States Environmental Management Agency (USEPA) defines the term biosolids as treated sewage sludge that meets the USEPA pollutant and pathogen requirements for land application as well as surface disposal. As stated early, the term organ‐ ic fertilizer is not regulated and therefore should not be confused with selected organic substances approved by the United States Department of Agriculture (USDA) for its National Organic Program (NOP) for use in organic production. An organic substance to be allowed in certified organic production must be approved by the Organic Materials Review Institute (OMRI) and the Washington Department of Agriculture.

In the southeastern states of the United States, the disposal of vast amounts of organic fertil‐ izers in the form of animal waste can otherwise be used as organic fertilizer. More than 65% of US broiler production is concentrated in the southeastern states. In 2012, Alabama ranks second in the United States in broiler production and produced over 1 billion birds [1]. The litter that results annually from this broiler production averages 15 million metric tons, and its disposal represents a growing problem for the poultry industry.

In 2010, cash receipts in Alabama from poultry operations made up 68% of the total cash receipts for all commodities [2]. Mineralization of C, N, P, and S in poultry litter added to soil is the main cause of groundwater contamination in areas where mineral fertilizer appli‐ cation is limited [3].

In Alabama, there are only a few companies that transform raw poultry litter into organic fertilizers. MigthyGrow, Inc., produces OMRI approved organic fertilizers (4–3–4) as well as an AgBlend all-purpose fertilizer (3–3–3). Denali Organics, LLC, uses catfish byproducts with a proprietary digestive enzyme to produce an organic liquid fertilizer that can be topdressed, banded with seeds, or foliar sprayed. Gulf Coast Organic is a distributor of liquid fertilizers such as Gator Perform SRN (30–0–0) for lawns, turf, and golf courses, and food crops, Primera one green fee super (15–0–0), Turf balance RSN (12–0–12), Medina has a Gro plant (6–12–6), and Medina hasta Gro lawn (12–4–8). It also distributes granular fertilizers such as Primera 3–3–3 crumbles and Primera 4–3–4 crumbles.

Concentrations of 15 trace and nontrace elements (silver, Ag; arsenic, As; barium, Ba; berylli‐ um, Be; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; manganese, Mn; molybde‐ num, Mo; nickel, Ni; lead, Pb; antimony, Sb; selenium, Se; and zinc, Zn) were investigated by the United States Environmental Protection Agency [4] because of their potential toxicity Properties of chicken litter generated in Alabama have been investigated (**Table 1**).


*a n* = 33; pH was determined by a combination glass electrode (broiler litter/water ratio, 1:2.5), organic C by the method of Mebius (1960) (adapted from Kpomblekou A et al., 2002).

**Table 1.** Selected properties of chicken litter generated in Alabama.
