Trace elements in fertilizers

OTHER COMMENTS replaced radium in experimental medicine and cancer research used as a trace element in fertilizers principal use is in alloys, especially cobalt steels for permanent and soft magnets. 

Precaution Dust is flamm. attacked by dil. hydrochloric and sulfuric acids corrodes readily in air explosive reaction with ammonium nitrate + heat ignites on contact with bromine pentafluoride incandescent reaction with acetylene, nitryl fluoride Uses In alloys oxidizing agent lamp filaments in mfg. of cobalt steel, cobalt salts electroplating ceramics catalyst (sulfur removal from petrol., Oxo process, org. synthesis) trace element in fertilizers drier in inks, paints colors cermets in porcelain, glass, pottery, enamels pigment in paints food processing aid cemented carbides jet... 

The transfer of trace elements in phosphate rocks to P fertilizers is dependent upon the manufacturing processes. Triple superphosphate fertilizer contains 60-70% of the Cd present in phosphate rocks (Wakefield, 1980). The transfer coefficients may be similar for most other elements and heavy metals even though there are little data on the transfer of other elements from phosphate rocks to P fertilizers. In general, based on some long-term (> 50 years) soil fertility experiments in the U.S., annual Cd rates from the application of phosphate fertilizers are estimated to range from 0.3 to 1.2 g per ha. The addition of Cd to soils as a contaminant from P fertilizers... 

The Association of Official Analytical Chemists is utilizing atomic absorption spectroscopy for the determination of several trace elements. McBride 274>27s), has conducted collaborative and ruggedness studies for a number of elements in fertilizers. He dissolves the sample in hydrochloric acid, filters, and dilutes to vo-... 

Consumption data for micronutrients are not available, but amounts sold for fertilizers in the U.S.A. during fiscal year 1975—1976 are shown in Table 9.11. The range of concentrations of micronutrients usually found in soils is shown in Table 9.4. Commonly used micronutrient fertilizers are shown in Table 9.12. Data for trace elements in a wide range of fertilizers have been compiled by Swaine (1962). 

Shortly after postulating the need for fertilization of plants with the basic nutrients nitrogen (N), phosphorus (P), and potassium (K) by Justus von Liebig, it was determined that, if solid fertilizer materials are applied, the availability of these elements depends to a large extent on solubility. In most cases a high solubility is desired requiring large surface area which is synonymous with small particle size. It was also found that, additionally, micronutrients are necessary and, because of the small amount of these trace elements in a fertilizer formulation, they had to be added as fine powders. 

Agriculture demands vast quantities of fertilizers to supplement soil nutrients this is critical when the same land is used year after year for crop production. Essential nutrients are N, P, K (the three required in largest amounts), Ca, Mg and S plus trace elements. In 2002, in the US, direct use and its conversion into other nitrogenous fertilizers accounted for 88% of all NH3 produced. In addition to NH3 itself, the nitrogen-rich compound C0(NH2)2 (urea) is of prime importance, along with... 

The chemical composition of soils is diverse and governed by many different factors, of which parent materials and climatic factors usually predominate. Although trace elements (both cationic and anionic forms) are minor components of the soil, they play an important role in soil bioactivity and fertility. Behavior of trace elements in soils depends upon complex reactions between their ionic forms and various components of the various soil phases solid, aqueous, and gaseous. This relationship is closely related to the main features of the soil biogeochemical system, which are (i) seasonal and spatial alteration of major soil variables (ii) heterogeneous distribution of compounds and components (iii) transformation of element species (iv) complexa-... 

The correlation of the trace elements in the indicator plants is much higher than that of the macro elements contained in the fertilizers (Table 6.6). 

A novel corn seed coating agent (NCSCA) was prepared by modifying chito-san, a natural nontoxic biopolymer, trace elements and fertilizer seed treatment which resulted in a high germination percentage and yield in corn, and also showed high resistance to head smut caused by Sphacelotheca reiliana stress both under laboratory and field conditions [48]. 

There are three primary elements in fertilizers that require analytical determinations nitrogen (N) available phosphate (AP) for plant uptake expressed as P2O5 and water-soluble potassium expressed as K2O. Procedures are examined to determine values based on the best methods available for the primary elements, secondary elements, micronutrients in fertilizers, and other trace elements. Uniform methods can eliminate problems associated with fertilizer analyses, resulting in agreement between laboratories on a given sample. By following the exact procedures as outlined in an acceptable method, one can expect a reliable and reproducible chemical analysis. 

Molybdenum, recognized as an essential trace element for plants, animals, and most bacteria, is present in a variety of metaHo enzymes (44—46). Indeed, the absence of Mo, and in particular its co-factor, in humans leads to severe debility or early death (47,48). Molybdenum in the diet has been impHcated as having a role in lowering the incidence of dental caries and in the prevention of certain cancers (49,50). To aid the growth of plants. Mo has been used as a fertilizer and as a coating for legume seeds (51,52) (see FERTILIZERS Mineral NUTRIENTS). 

EEC Directive amending Directive 76/116/EEC in respect of the trace elements contained in fertilizers... 

For the most part, the zinc materials recovered from secondary materials such as slab zinc, alloys, dusts, and compounds are comparable in quality to primary products. Zinc in brass is the principal form of secondary recovery, although secondary slab zinc has risen substantially over the last few years because it has been the principal zinc product of electric arc furnace (EAF) dust recycling. Impure zinc oxide products and zinc-bearing slags are sometimes used as trace element additives in fertilizers and animal feeds. About 10% of the domestic requirement for zinc is satisfied by old scrap. 

---