Enhancing fertilizer efficiency in high input cropping systems in Florida

During the last century, a number of strategies have been used to determine optimal N-fertilizer rates and to develop appropriate N-fertilizer recommendations for intensively-managed cropping systems. However, these strategies lack a system-based approach and the precision needed to warrant high yields while addressing environmental concerns in a cost-effective manner. Therefore, a more holistic approach is required to enhance fertilizer use efficiency (FUE) in high input agricultural systems that pose both large environmental and economic risks. This article presents a physiological basis for improving FUE in these systems by linking physiological crop nutrient requirements with nutrient uptake efficiencies as affected by root characteristics, crop N demand, and production management practices. Starting at the crop and field level we outline key processes affecting crop N demand and uptake efficiency. For this purpose we reviewed key scientific papers that describe yield response and fertilizer uptake efficiencies with special reference to pepper (Capsicum annuum L.), potato (Solanum tuberosum L.) and tomato (Lycopersicon esculentum L.) crops in Florida production systems. This because such systems are especially prone to N leaching. Based on this review it is evident that yield response to fertilizer for most crops tend to be inconsistent both within and across locations. Therefore, use of standard recommendations may not be appropriate since they pose substantial economic and environmental risks.