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DEVELOPING MORE EFFICIENT FERTILIZERS THROUGHFORMULATION, MANUFACTURING, ANDDISTRIBUTION TECHNOLOGYDonald L. McCune, Managing DirectorInternational Fertilizer Development CenterMuscle Shoals, Alabama 35660, USAABSTRACTChemicals are being evaluated for their capacity to improve the agronomicefficiency of urea, the most widely used nitrogen fertilizer. Examples areinhibitors, coatings, metal ions to reduce losses. Solid and liquid forms ofconditioners are reducing losses through improved product quality. New manufacturingroutes, being evaluated for their usefulness in processing rawmaterials, especially phosphate ores, more efficiently include direct acidulationof ore as mined, use of the ore directly as fertilizer on acid soils, andconversion to partially soluble forms without total dissolution. New flotationreagent chemicals are used to upgrade phosphate ores that cannot be used withoutbeneficiation. Improvements in the manufacturing, handling, storage, anddistribution of fertilizers, raw materials, and intermediates are being madethrough better materials of construction, a wider variety of good quality bags,more distribution in bulk, and other means. Thus, chemistry is playing animportant role in providing "cost effective" fertilizers for farmers with theultimate goal of increasing the world food supply.KEYWORDS: Improved fertilizer efficiency, fertilizer manufacturing, fertilizerdistribution.INTRODUCTIONThe need for more intensive agriculture is illustrated by the decline inarable land per person from about 0.41 ha in 1962 to 0.31 ha in 1979 for the worldas a whole. The developing countries had an average of 0.21 ha of arable land perperson in 1979. Although more arable land may be brought into production,population growth is expected to greatly exceed arable land growth. So moreintensive agriculture -- higher yields and more crops per year where practical --will be necessary with intensive and efficient fertilizer use as an essentialcomponent. Modern fertilizers supply one or more of the primary nutrients --nitrogen, phosphorus, and potassium. Scientists now recognize that secondarynutrients -- calcium, magnesium, and sulfur -- may be needed, and many commercialfertilizers are formulated to supply them. Further, small quantities of suchmicronutrients as boron, chlorine, copper, iron, manganese, molybdenum, zinc, andcobalt may also be needed for optimum yields. The chemical form of these elementsis likely to influence their agronomic effectiveness, but fortunately most are21