Boron fertilizers

Approximately 5% of the U.S. consumption of is in agriculture. Boron is a necessary trace nutrient for plants and is added in small quantities to a number of fertilizers. Borates are also used in crop sprays for fast rehef of boron deficiency. Borates, when apphed at relatively high concentration, act as nonselective herbicides. Small quantities of borates are used in the manufacture of alloys and refractories (qv). Molten borates readily dissolve other metal oxides usage as a flux in metallurgy is an important apphcation. Other important small volume apphcations for borates are in fire retardants for both plastics and ceUulosic materials, in hydrocarbon fuels for fungus control, and in automotive antifreeze for corrosion control (see Corrosion and corrosion inhibitors). Borates are used as neutron absorbers in nuclear reactors. Several borates, which are registered with the Environmental Protection Agency (EPA) can be used for insecticidal purposes, eg, TIM-BOR. 

After these seminal studies, the use of NHC-Rh systems for the addition of aryl boronic acids to carbonyl compounds became a very fertile area and many groups have reported on variations of this catalytic system [22],... 

McCracken et al. 164) compared atomic absorption with the tetraphenyl-boron method for determining potassium in 1190 fertilizers, and very close agreement was found between the two methods. Hoover and Reagor 16S) also found good agreement between the two methods, and atomic absorption was far more rapid. They reported that the 7665 A potassium line was more subject to interference than the less sensitive 4044 A line. Temperli and Misteli 166> reported far better results for low concentrations of potassium in soil extracts by atomic absorption spectroscopy than by flame emission spectroscopy. 

The recent work of Grimes and his co-workers 14, 26, 84, 96-96b, 98, 119, 191, 192) has shown the smaller carboranes to be particularly fertile sources of metal-boron-carbon clusters, of which a few further examples are shown in Fig. 19. 

In rats the oral LDso values for borates are essentially the same as for boric acid they range from 3.16 to 6.08 g/kg." When borax was fed to dogs and rats for 2 years, 3 50 ppm as boron in the diet had no effect. In a three-generation feeding study in rats, 350ppm had no effect on fertility, litter size, weight, or appearance. 

Borax decahydrate occurs in nature as mineral, borax (tincal). It is one of the most common sodium borate ores. The compound has several industrial applications. The refined material is mostly used in household cleaning products. It is used to make pyrex and other horosilicate glasses. Borax is added to fertilizers in small quantities as a source of boron, as a trace nutrient for plants. High purity grade borax is used in cosmetics, toilet products and electrolytic capacitors. It also is used in fire retardants, adhesives and herbicides. 

Deficiency of boron is a more prevalent worldwide agricultural problem than for any other agricultural micronutrient [62]. Adequate boron supplies are critical for maintaining high crop yields as well as good crop quality. For this reason it is common agricultural practice to apply boron-containing fertilizers in areas where soil boron deficiency is found. 

In addition to borax, which can be applied directly as a fertilizer, special borate products are manufactured for fertilizer use. These include granulated beads for blending with other common fertilizer products and soluble borates for application as liquid foliar sprays. Boron fertilizers are typically applied at a rate equivalent to about one to two pounds elemental boron per acre, depending on the specific crop and soil conditions. As with most fertilizers, excessive application can have adverse results. Borate fertilizers are phyotoxic at high levels and are sometimes used as non-selective herbicides. 

Mitchell, R.J., H.E. Garrett, G.S. Cox, A. Atalay, and R.K. Dixon. 1987. Boron fertilization, ecotomycorrhizal colonization, and growth of Pinus echinata seedlings. Canad. Jour. For. Res. 17 1153-1156. 

Sayli, B.S. 1998. An assessment of fertility in boron-exposed Turkish subpopulations. 2. Evidence that boron has no effect on human reproduction. Biol. Trace Elem. Res. 66 409A 22. 

Most of the world s supply of borax now comes from a gigantic open-pit mine near a California town appropriately named Boron. There are now myriad uses for the material that started its technological life as a gold flux. We use it to make glass for car headlights, enamel for stoves and refrigerators, ceramic tiles, antiseptics, bleach for unbleachables, weed killers, and fertilizers. Thin fibers made from elemental boron reinforce resins destined for aircraft and space-vehicle parts. 

Fertilizers - [AMMONIA] (Vol2) -in bioremediation piOREMEDIATION] (Supplement) -blended [POTASSIUM COMPOUNDS] (Vol 19) -boron in [BORON COMPOUNDS - BORON OXIDES, BORIC ACID AND BORATES] (Vol 4) -cyanamidein [CYANAMIDES] (Vol 7) -lecithin in [LECITHIN] (Vol 15) -molybdenum compounds m [MOLYBDENUM AND COMPOUNDS] (Vol 16) -nitric acid m mfg [NITRIC ACID] (Vol 17) -potassium hydroxide mmfg of [POTASSIUM COMPOUNDS] (Vol 19) -radioactive tracers for [RADIOACTIVE TRACERS] (Vol 20) -role of H2 m production of [HYDROGEN] (Vol 13) -specialty liquid [POTASSIUM COMPOUNDS] (Vol 19) -tanks for [TANKS AND PRESSURE VESSELS] (Vol 23) -use of diatomite m [DIATOMITE] (Vol 8) -use of sulfur for [SULFUR] (Vol 23)... 

Komor S. C. (1997) Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnessota. J. Environ. Qual. 26, 1212-1222. 

Small amounts of boron compounds are also used to control the growth of weeds in agriculture, and as insecticides, fertilizers, and flame retardants. A flame retardant is a material that prevents another material from catching fire and burning with an open flame. 

Spinach requires moderate levels of potassium and phosphorus and high levels of nitrogen. It is also sensitive to low levels of calcium and boron. Have the soil tested and amend as necessary. Fast-acting sources of nitrogen, such as bloodmeal and soybean meal, are good fertilizers for spinach. 

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