Jan K. Kouwenhoven

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Experiments with planting depths of 10 cm below the top of the ridge and just on top of the unloosened soil, revealed that a deep soil cover of the parent tuber, accomplished by deep planting in a large ridge, increased the yield, increased the size of the tubers, decreased dispersion of the tubers in the ridge, and decreased the number of green potatoes.(More)
Dutch farmers have developed various methods of making the elod-free ridges required for modern mechanical potato harvesting. Measurements showed however, that the ridges were smaller than the optimum 500–600 cm2, although when the seed-bed was prepared 8–10 cm of loose soil was often present. Contrary to general belief ridging operations decreased rather(More)
In order to meet requirements of tractors with large axle widths and wide tyres, the technical feasibility and crop response of increased row spacings for potatoes were checked in the field and in model experiments. Newly developed ridgers performed satisfactorily at a row spacing of 90 cm. but at 105 cm row spacing ridges were usually too wide and.(More)
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