TOWARDS HYPOTHETICAL MODEL OF LEEK PRODUCTIVITY BASED ON LIGHT INTERCEPTION AND N-UPTAKE

The objective of this research work was to determine correlative relationship between interception of photosythetically active radiation (IPAR or light interception, I) and nitrogen uptake(Nu) in order to determine nitrogen (N) status and monitoring N supply, during leek's crop vegetation period. The outset parameters were IPAR and leaf area index (LAI). Based on daily sum of global solar radiation (GS), dry matter production (W) was determined. Nu was defined according to relationship between Nu and LAI. Crop nitrogen demand (ND) and total N, as indicators of crop N-status, were determined. Nitrogen was applied in dose of 250 kg N ha -1 (at once and half-spit dose). Relationships between mentioned parameters and on obtained equations could be used in hypothetical model of leek productivity created. Such model could allow monitoring leek productivity, crop N status and ND during ontogeny using simple and nondestructive measurements.