Root growth of potato crops on a marine-clay soil

摘要: In 1982 and 1983 root samples were taken by auger from potato crops grown on marine clay in the Flevo-Polder. The roots increased their penetration depth throughout periods of measurement, ultimately reached depths between 80 cm 100 below hills. Between 50 60 days after emergence, decay commenced, starting upper horizons. hill mean length densities varied 1 2 cm−3. Below hills density rarely exceeded random variation was equivalent to a coefficient 50%. There significant effects position sampling (relative centre plant) density; usually lowest beneath furrow. Depending season date, total 3.4 7.1 km m−2, dry mass 33 77 g m−2. Representative figures for specific 100–120 m g−1 weight. About 90% diameters smaller than 0.44 mm; most frequent class (35%) with 0.12 0.20 mm.