| Abstract/Contents: | The efficient utilization of nitrogen is a prime concern. Nitrogen is more often found to be deficient in soils than any other nutrient. It must be easily converted to the fixed forms of NH4 (or ammonium) and NO3 (nitrate) for the turf to readily absorb it. External factors which exert a strong influence on the fertilizer efficiency include: soil types and texture, pH, moisture, temperature, organic matter and content, thatch accumulation, microbial activity, and turfgrass species and variety. A table showing 4 categorizations of nitrogen fertilizers, (synthetic inorganics, natural organics, synthetic organics, and contained organics to inorganics) as well as source examples, degree of solubility, and the rate of nitrogen availability for each is given. Turf fertilizers are ideally economical, efficient, easy to handle, and non-phytotoxic. A table giving a salt index, which determines a fertilizer's tendency to burn, is included. Another table, synthetic organics, gives the product's release mechnism, fractions, approximate residuality, advantages and disadvantages. The longer the polymer chain, the less burn potential in urea reaction product. Granular products have a shelf life of longer than a year, while liquid products have a potentially very short shelf life. A recently formed company whose charter is the development of new nitrogen sources has developed a water dispersable urea reacted powder which combines the positive aspects of both liquid and dry urea reacted products: contains Fractions I, II, and III which provides a good initial release and a variable residual release dependent upon the degree and type of reaction, a low salt index, very low to no burn potential, long shelf stability, tank mix compatibility, and the ability to utilize various pesticides as an integrated part of the fertilizer. Other areas of development are the utilization of nitrification inhibitors, and microencapsulation, where complete fertilizer blends (N-P-K and micronutrients) are found in one discreet particle. |
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