Abstract
With recent increases in nitrogen (N) fertilizer prices, economic analysis of conventional and alternative N fertilizers has become critical for understanding the factors that drive total production costs and profits. Although fertilizer applications are meant to help reduce marketable yield variability in fresh-market vegetable production, climatic conditions on biomass production are difficult to predict. Still, they can be estimated for a specific physiographic region. A field fresh-market tomato study evaluated the suitability of a one-time preplant application of controlled-release urea (CRU) as an alternate N fertilizer source to the split application of fertigated soluble urea for tomato production using the raised-bed plasticulture system with drip irrigation in coastal plain soils. Marketable yield data from the four tomato production seasons (Fall 2019, Spring 2020, Fall 2020, and Spring 2021) reflected the N treatments that achieved the highest N use efficiencies (i.e., higher or sustained yields with a decrease in N input) from the tested N rates (125, 150, and 200 lb/acre), found that N application above 125 lb/acre did not lead to appreciable improvements in yield across all N sources tested [two CRUs with a 60 (CRU-60) and 75-day (CRU-75) duration and conventional urea]. Therefore, seasonal yields represent the effects of N sources applied up to a 38% reduction of the recommended N rate (200 lb/acre) for Florida tomato production. We conduct an economic analysis to evaluate the effects of the alternative N fertilizer strategies on the economic returns of commercial tomato production in north Florida. Both CRU formulations were roughly three times more expensive than conventional urea ($62.0–$86.1 across seasons), which resulted in N fertilizer costs to total tomato production costs of ≈1.1% to 1.6% for CRUs and 0.4% to 0.6% for urea. Despite the higher costs, CRUs were shown to be profitable, especially in warm spring season tomato production. Marginal return rates for spring were 69.7% to 212.4%, showing that using CRU as the N source helped to almost or more than double the net income compared with using the same N rate of conventional urea. This analysis resulted in positive net incomes in the CRU fertilizer program ranging from $13,541 to $19,246 and $728 to $18,004 per acre for both fall (2019 and 2020) and spring (2020 and 2021) production seasons, respectively. On the other hand, the urea fertilizer program was not successful in Spring 2021.