Nitrogen fertilization strategies to reduce the risk of nitrate leaching in open field cultivation of spinach ( <i>Spinacia oleracea</i> L.) ^#

Background Spinach is a nitrogen (N) demanding crop with weekly N uptake of up to 60 kg ha–1. Consequently, high supply required, which can temporarily lead quantities nitrate (NO3–) being at risk leaching. Aims The objective this study was develop fertilization approach reduce the NO3– leaching in field-grown spinach production without adversely affecting yield and quality an early late harvest stage. Methods Ten trials were conducted compare different base rates splits top dressings. For dressings, granulated fertilizers or foliar sprays used. In further treatment, reduced by withholding second dressing 50–70 ha?1. Results Nitrate concentration considerably decreasing fertilizer rate as well splitting dressing. However, stage, total aboveground dry mass by, on average, 6% these measures across all seasons. contrast, later less affected schedule. Urea proved be insufficient promoting plant growth caused leaf necrosis. A led impaired yellowish leaves both spring winter. Conclusions Base only required spring, but not other Despite slight reduction, should split NO3? after harvest.