Zinc and iron agronomic biofortification of Brassicaceae microgreens

Insufficient or suboptimal dietary intake of iron (Fe) and zinc (Zn) represent a latent health issue affecting a large proportion of the global population, particularly among young children and women living in poor regions at high risk of malnutrition. Agronomic crop biofortification, which consists of increasing the accumulation of target nutrients in edible plant tissues through fertilization or other eliciting factors, has been proposed as a short-term approach to develop functional staple crops and vegetables to address micronutrient deficiency. The aim of the presented study was to evaluate the potential for biofortification of Brassicaceae microgreens through Zn and Fe enrichment. The effect of nutrient solutions supplemented with zinc sulfate (Exp-1; 0, 5, 10, 20 mg L−1) and iron sulfate (Exp-2; 0, 10, 20, 40 mg L−1) was tested on the growth, yield, and mineral concentration of arugula, red cabbage, and red mustard microgreens. Zn and Fe accumulation in all three species increased according to a quadratic model. However, significant interactions were observed between Zn or Fe level and the species examined, suggesting that the response to Zn and Fe enrichment was genotype specific. The application of Zn at 5 and 10 mg L−1 resulted in an increase in Zn concentration compared to the untreated control ranging from 75% to 281%, while solutions enriched with Fe at 10 and 20 mg L−1 increased Fe shoot concentration from 64% in arugula up to 278% in red cabbage. In conclusion, the tested Brassicaceae species grown in soilless systems are good targets to produce high quality Zn and Fe biofortified microgreens through the simple manipulation of nutrient solution composition. © 2019 by the authors

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