Zroznicowanie nadwyzki bezposredniej w produkcji krzewow zywoplotowych zywotnika zachodniego [Thuja occidentalis L.] w zaleznosci od powierzchni szkolki i sposobu uprawy

Gross margin is the difference between the annual value of production from 1 ha of crops and the variable costs incurred in their production. One of the points of this study was t o record individual variable costs for hardy nursery stock, especially consumption and labour costs. It should be mentioned that the gross margin includes just the main variable costs. It is often very difficult to split the other smaller variable costs, e specially between the crop categories. The gross margin evaluated for hedge cultivars of Eastern arborvitae plants grown in containers varied with the area of the nursery, from 95,75 PLN/ha in small nurseries to 125,687 PLN/ha in big ones. For plants grown in the field, the margin was much lower, from 47,217 PLN/ha to 65,527 PLN, respectively.