Organic Fertilizer

Farmyard manure (including dried and/or composted manure) - 

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Problems associated with excessive levels of nutrients and unwanted nuisance species have already been mentioned. There are cases in which intentional fertilization is used by aquaculturists in order to produce desirable types of natural food for the species under culture. Examples of this approach include inorganic fertilizer appHcations in ponds to promote phytoplankton and zooplankton blooms that provide food for young fish such as channel catfish, the development of algal mats through fertilization of milkfish ponds, and the use of organic fertilizers (from Hvestock and human excrement) in Chinese carp ponds to encourage the growth of phytoplankton, macrophytes, and benthic invertebrates. In the latter instance, various species of carp with different food habits are stocked to ensure that all of the types of natural foods produced as a result of fertilization are consumed. 

Deeper contamination may be remedied with bioventing, where air is injected through some wells, and extracted through others to both strip volatiles and provide oxygen to indigenous organisms. Fertilizer nutrients may also be added. This is usually only a viable option with lighter refined products. 

The suggestion frequentiy is made that substitution of organic fertilizers, namely manures and composts, for chemical fertilizers would be of ecological benefit. The reaUty is, however, that the supply and logistics of such materials could never be adequate for the present-day level of agriculture. Furthermore, iatensive appHcation of such materials to the soil would itself present ecological problems, such as mn-off pollution and steady buildup of toxic heavy metals. 

Manure is often recycled as a solid organic fertilizer or mixed with water and sprayed as a liquid fertilizer. If the manure is repeatedly used upwind of populated areas, complaints are sure to be filed with the air pollution control agency. 

Environmental and economic implications must be considered in order to make well-informed decisions on the management of soil treatments, i.e. how many, how often and what kind of organic fertilizer should be used in order to improve crop production and simultaneously limit soil deterioration and greenhouse gases production. 

Mortvedt J.J. Heavy metal contaminants in inorganic and organic fertilizers . In Fertiliers and Environment, C. Rodriguez-Barrueco, ed. Netherlands Kluwer Academic Publishers, 1996. 

Nonghyup (2007) The list and application guideline for the production companies of composts and organic fertilizers. Nonghyup, Seoul... 

There are several studies on the effect of fertilization on product composition. However, they were of limited scope because they do not provide clear answers on the effect of farming systems on composition. Bourn and Prescott (2002) made a comprehensive review on this subject and, overall, the studies suggested that the use of organic fertilizers may result in lower nitrate concentration for some crops and some cultivars than when using more soluble mineral fertilizers. Based on the observed large variations, they emphasized the strong influence of climatic conditions on nitrogen, nitrate and mineral content, as well as fertilizer treatments. 

Leclerc J, Miller M L, Joliet E and Rocquelin G (1991), Vitamin and mineral contents of carrot and celeriac under mineral or organic fertilization , Biol Agric Hort, 7, 349-361. 

The risk of viral contamination in plant-based medicinal products, and requirements for strategies to ensure that the product is consistently free of contaminating viruses, is discussed in detail in the EMEA document, while it is not addressed by the FDA. In addition to contamination by insect, bird and animal excreta or carcases, organic fertilizer, production personnel and equipment, the EMEA document lists plant virus infection as a source of contamination and claims that "... freedom from contamination with all types of viruses, irrespective of natural tropism, should be demonstrated. ... 

Although further study needs to be conducted to determine the effect of other soil properties, the influences of organic matter and pH on rice s BAC provide an important pathway to predict heavy metal risk on the safety of rice and other agricultural products. This may mean that as soil contamination continues soil properties such as pH may need to be adjusted using products such as lime and organic fertilizer. 

Mozafar A (1994) Enrichment of some B-vitamins in plants with application of organic fertilizers. Plant Soil 167 305-311... 

NprbaskR, Aaboer DB, Bleeg IS, Christensen BT, Kondo T, Brandt K (2003) Flavone C-glycoside, phenolic acid, and nitrogen contents in leaves of barley subject to organic fertilization treatments. J Agric Food Chem 51 809-13... 

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