ABSTRACT
This chapter aims to summarize the enhanced efficiency fertilizers (EEFs) types and the state of knowledge on each product's ability to improve yields or nitrogen use efficiency and reduce nitrogen (N) losses. In general, polymer-coated urea (PCU) will have the best return on investment on sandy or waterlogged soils, especially if fertilizer can only be applied early in the growing season. Use of PCU on sandy soils can also reduce the need for split application. The N stabilizer products reviewed here, specifically nitrapyrin, dicyandiamide, 3, 4-dimethyldimepyrazole phosphate, and N-(n-butyl) thiophosphoric triamide (NBPT), are all well-studied products with clear inhibitory effects. The use of NBPT should be considered for all surface applicants of urea. Nitrification inhibitors use ensures against N loss in years when weather conditions promote faster nitrification and leaching. Stabilized fertilizers are those that incorporate substances, in small quantities, which stabilize the N in urea and ammonium-based fertilizer by inhibiting their transformations by chemical or microbial action.
