Commercial Fertilizer

Physical Properties. The physical form and stabiUty of a fertilizer product is of an importance almost equal to that of its chemical content. Commercial fertilizers of importance include not only soHds, but also fluids, both solutions and suspensions, and even a gas (anhydrous ammonia). 

Oxamide is produced commercially by Ube Industries, Ltd. (Japan) and a pilot process is being operated by Enichem (Italy). It is not produced domestically as a commercial fertilizer, although it was the subject of much research and development activity by the Tennessee Valley Authority s (TVA) National Fertilizer Research and Development Center. It is made in small quantities for industrial use by AUied Chemical, Hummel Chemical Co., and United Guardian, Inc. Oxamide has appHcation as a controlled release nitrogen source for the turf and specialty agricultural markets. 

Calcium phosphate, Ca3(P04)2, is a water-insoluble mineral, large quantities of which are used to make commercial fertilizers. Use the values for Ca3(P04)2 from Table 16.1 to answer the following questions. 

A great many phosphates are used in commercial fertilizers. Perhaps the most important of these is calcium dihydrogen phosphate, Ca(H2P04)2. In relatively pure form, this compound is known as triple superphosphate of lime. A 1 -2 mol mixture of Ca(H2PC>4)2 and gypsum, CaS04 2HzO, is commonly referred to as superphosphate of lime. ... 

A shortage of any of some two dozen chemical elements that are essential for the growth of organisms can reduce ecosystem productivity, but phosphorus and nitrogen are often the most limiting nutrients, which is why these two elements are standard components of commercial fertilizers. Phosphorus is often limiting because it moves through soil pores and aquatic... 

The element phosphorus, like nitrogen, is essential to plant and animal life. Although phosphorus was not identified and isolated until 1669, phosphorus-containing materials have been used as fertilizers since ancient times, usually from bird droppings, fish, and bone. The first phosphoric acid was made by treating bone ashes with sulfuric acid. This marked the beginning of the commercial fertilizer industry. Eventually, mined phosphate rock, a poor fertilizer by itself, was substituted for bones as a raw material for phosphoric acid in the mid-1880s. 

Crop yields can rise dramatically with the use of commercial fertilizers. For example, in 1800 an acre of land in the United States produced about 25 bushels of com. In the 1980s the same acre of land produced 110 bushels. Worldwide, approximately 4 billion acres of land are used to grow food crops. This would probably be enough land to feed the world s population if the entire acreage could be fertilized commercially. It has been estimated that world crop production would increase by about 50% if about 40 per acre were spent to apply modem chemical fertilizers. However, it would cost about 160 trillion to produce this additional food. Furthermore, the use of chemical fertilizers can lead to the contamination of streams, lakes, and bays with phosphates and nitrates. 

Lee K.W., Keeney D.R. Cadmium and zinc additions to Wisconsin soils by commercial fertilizers and wastewater sludge application. Water Air Soil Pollut 1975 5 109-112. 

Stewart WM, Dibb DW, Johnston AE, Smyth TJ (2005) The contribution of commercial fertilizer nutrients to food production. Agron J 97 6... 

Also, remember that nutrients obtained from organic fertilizers will generally be much more expensive than the same nutrients obtained from commercial fertilizers. Rather than broadcasting these expensive materials over the entire garden, they can also be banded near the row or applied only to the area to be planted. 

Phosphorus occurs as rock phosphate [Ca5(P04)30H]. Phosphates are essential to all living things and are therefore important constituents of commercial fertilizers. 

M.8 Urea is used as a commercial fertilizer because of its nitrogen content. An analysis of 25.0 mg of urea showed that it contained 5.0 mg C, 11.68 mg N,... 

It is also likely that nutrient loadings to estuaries have been greatly increased by the use of commercial fertilizers in agriculture. In the United States, the use of inorganic fertilizer has increased approximately exponentially since 1860, with the result that over 500 times more nitrogen was applied to the fields in 1980 than in 1880 (Fig. 1). 

Figure 15.12 Down-core enrichment factors of organic matter derived from phytoplankton, bacterial, and terrestrial sources in Chesapeake Bay. Historical records of commercial fertilizer consumption in the U.S.A (x 10 t y-1), and from the state of Maryland (x6000 t y 1), as well as human population growth (xlO5). (Modified from Zimmerman and Canuel, 2000.)...

Place a small amount (covering the tip of a small spatula) of commercial fertilizer in a test tube (100 X 13 mm). Add 0.5 mL (about 10 drops) of 6 M NaOH to the test tube. Test as above with moist red litmus paper. Record your observation and conclusion (6). 

A commercial fertilizer is a material that contains at least one of the plant nutrients in chemical form that, when applied to the soil, is soluble in the soil solution phase and assimilable or available by plant roots. Most often, this implies chemical forms that are water soluble. However, in the case of phosphorus, solubility in special reagent solutions (citric acid, neutral ammonium citrate, or alkaline ammonium citrate) often is used as a guide for availability to plants. In the case of nitrogen, slow solubility in water may be more desirable from an environmental and efficiency standpoint than easy solubility. 

As mentioned before, these hydrophosphates are used in commercial fertilizers. Hydrophosphates of calcium [Ca(H2P04)2-H20] and ammonium [(NH4)2HP04 and (NH4) H2PO4] are the most commonly used fertilizers, while potassium hydrophosphate (KH2PO4) is also used where the soil needs potash. 

Under the organic guidelines, commercial fertilizers and fertilizers produced by the grower can only be used on the basis of soil analyses and in accordance with the needs of the crops. Only then is it possible to calculate the amount still required and apply it in the form of permitted fertilizers. Well-balanced fertilizer application enables the soil to make nutrients available to the fruit trees in a harmonious ratio and in adequate amounts at the right time, and helps to keep the trees in physiological balance. If fruit producers want to apply fertilizers in accordance with requirements, they need to know the nutrient content of their soil before they start fertilizer application. 

When the soil selenium decrease from the coast to the inland was proved, it was easy to understand that muscle degeneration in domestic animals due to selenium deficiency (Mikkelsen and Hansen, 1967, 1968) was concentrated in the valleys with low precipitation in the eastern part of Norway. Our neighbour country Finland, with a mostly typical continental climate, has from an early stage taken up the problem by adding selenium to the cattle fodder. In Finland, and in other Scandinavian countries as well, there is now a discussion on the possibilities of adding a selenium compound to commercial fertilizers to increase the selenium content in the plants. 

Chlorophenoxy compounds are sometimes mixed into commercial fertilizers to control growth of broadleaf weeds. 

What is the fate of anthropogenic Nr The immediate fate for the three anthropogenic sources is clear NO from fossil-fuel combustion is emitted directly into the atmosphere R-NH2 from rice and legume cultivation is incorporated into biomass NH3 from the Haber-Bosch process is converted primarily into commercial fertilizer applied to agro-ecosystems to produce food. However, httle fertilizer nitrogen actually enters the human mouth in the form of food in fact, most created Nr is released to environmental systems (Smil, 1999). 

Commercial fertilizers have often been touted as magical inoculations for improving poor soils and raising yields extension agents have routinely referred to fertilizers and pesticides as medicine for the soil. The actual results have often been disappointing. Two major reasons for the disappointment are directly relevant to our larger argument. 

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