Transpiration and nutrient uptake dynamics in maize (Zea mays L.)

The study presents a simplified model for estimating nutrient uptake by roots in maize canopies. The results of field studies with a maize canopy grown on silty soil at Trnava site (south of the Slovak Republic) show that the uptake rates of N (nitrogen), P (phosphorus) and K (potassium) nutrients can be described by a linear relationship between a specific ion uptake velocity from the soil and the rate of transpiration. The linear relationships have relatively high correlation coefficients r=0.753 (N), r=0.95 (P), and r=0.849 (K) during the vegetation period of the year 1982. The relationship between nutrient uptake rates and the transpiration rate for the maize canopy was also found for the relatively dry season of 1981 when a loss of nutrients from plants was observed during the second part of the vegetation period. Correlation coefficients for 1981 (r=0.772 (N), r=0.926 (P), r=0.804 (K)) were close to those estimated for 1982.