Nitrogen Fertilization in Snap Bean Following a Legume in the Sandy Soils of North Florida

Abstract

Despite being a legume, snap bean (Phaseolus vulgaris L.) lacks nodulation genes, restricting its ability for nitrogen (N) fixation through rhizobia, making N fertilization essential for maximizing yields. However, conventional fertilizer application may lead to N losses due to a lack of synchronization between plant uptake and N availability. A promising option could be controlled-release fertilizers (CRFs), which can be custom-formulated to synchronize nutrient release with plant growth needs, promoting efficient resource use. Field studies were conducted at the North Florida Research and Education Center-Suwannee Valley (NFREC-SV) in Live Oak, FL, during the spring of 2021 and 2022. The experiments also investigated broadcasting and banding application methods of the University of Florida’s recommended N rate (112 kg·ha−1). The experimental design comprised 10 treatments, including five N rates (0, 56, 112, 168, and 224 kg·ha−1 N) and two fertilizer sources (ammonium nitrate and CRF), applied to ‘Caprice’ in a randomized complete block design with four replications. Results showed a significant yield improvement with N fertilization vs. the zero-N control. However, no yield increase was observed beyond 56 kg·ha−1. This finding could be due to the residual N from a preceding peanut crop rotation in both years. No notable variation in quality metrics (pod length and width) occurred above the 56 kg·ha−1 threshold. The results also revealed that the choice between conventional or CRF did not exert any statistically significant differences in snap bean yield. In addition, fertilizer broadcast and banding treatments yielded the same results.