For the plant production used soil's nutrient supplying ability ideally should correspond to the needs of the plants. The aim of our experiment work is to study as precisely as possible, how the dynamics of growth and nutrient uptake of the maize plant develop during the vegetation period. For their determination the basis of our research work was a long-term irrigation and fertilization monoculture maize field experiment that has been set up in 1984 near to Debrecen, Hungary. The soil of this experiment is a medium-heavy, loam texture calcareous chernozem type based on loess. The deepness of humus soil layer is between 70 and 90 cm. Its upper layer has become leached due to the intensive production in the past decades, so it doesn't content any significant lime-amount. Therefore, the soil pH is slightly acidic in the production layer, which is favorable for nutrient-mobilization and -uptake. This field represents the production circumstances of the chernozem soils of Hungary with excellent productivity. Effects of three factors were studied: genotypes of maize (3), fertilizer dosages (6) and irrigation levels (2). The total number of investigated treatments (plots) was 36. Plant samples were collected 7 or 6 times during the vegetation period, and the above-ground dry matter and the nutrient uptake of plants were determined. For characterizing and describing of the plant growth and nutrient uptake dynamics was used the so-called “S-type” (acceleration – saturation) equation as follows: y=A/(1+exp(-k*(x-x0)))*(1-b*x), where “y” is the actual value of the measured (dependent) factor on the day “x” after plant shooting, “A” is the maximum value of “y”, “x0” is the day of maximum growth rate of “y” (point of inflexion) and “b” is the rate of decreasing of dependent value for one unit. According to our results and calculations it can be concluded, that beside the previously used soil and plant nutrientcontent the consideration and calculation of the plant-extracted nutrient-amount – depending on the applied hybrid and other agro-technological measurements – is suggested in order to characterize precisely the nutrient-supply of maize. This parameter informs us not only about the available nutrientamount at the sampling time, but about the supply level of the plants until the sampling time as well. We suggest for sampling times the intensive vegetative growth period, the switch between the vegetative and generative growth phases (silking), just as the grain-filling phase.

For the plant production used soil's nutrient supplying ability ideally should correspond to the needs of the plants. The aim of our experiment work is to study as precisely as possible, how the dynamics of growth and nutrient uptake of the maize plant develop during the vegetation period. For their determination the basis of our research work was a long-term irrigation and fertilization monoculture maize field experiment that has been set up in 1984 near to Debrecen, Hungary. The soil of this experiment is a medium-heavy, loam texture calcareous chernozem type based on loess. The deepness of humus soil layer is between 70 and 90 cm. Its upper layer has become leached due to the intensive production in the past decades, so it doesn't content any significant lime-amount. Therefore, the soil pH is slightly acidic in the production layer, which is favorable for nutrient-mobilization and -uptake. This field represents the production circumstances of the chernozem soils of Hungary with excellent productivity. Effects of three factors were studied: genotypes of maize (3), fertilizer dosages (6) and irrigation levels (2). The total number of investigated treatments (plots) was 36. Plant samples were collected 7 or 6 times during the vegetation period, and the above-ground dry matter and the nutrient uptake of plants were determined. For characterizing and describing of the plant growth and nutrient uptake dynamics was used the so-called “S-type” (acceleration – saturation) equation as follows: y=A/(1+exp(-k*(x-x0)))*(1-b*x), where “y” is the actual value of the measured (dependent) factor on the day “x” after plant shooting, “A” is the maximum value of “y”, “x0” is the day of maximum growth rate of “y” (point of inflexion) and “b” is the rate of decreasing of dependent value for one unit. According to our results and calculations it can be concluded, that beside the previously used soil and plant nutrientcontent the consideration and calculation of the plant-extracted nutrient-amount – depending on the applied hybrid and other agro-technological measurements – is suggested in order to characterize precisely the nutrient-supply of maize. This parameter informs us not only about the available nutrientamount at the sampling time, but about the supply level of the plants until the sampling time as well. We suggest for sampling times the intensive vegetative growth period, the switch between the vegetative and generative growth phases (silking), just as the grain-filling phase.