Studies on the Weeds of Vegetable Crops: III. Effect of Different Primary Cultivations on the Weed Seeds in the Soil

Abstract

Annual determinations were made over a 6-year period of the numbers of viable weed seeds present in the soil of an experiment carrying a rotation of vegetable crops. Deep ploughing (14-16 inches), shallow ploughing (6-7 inches) and shallow ploughing with subsoiling had little differential effect on the size or species composition of the weed seed population. Where primary cultivation was carried out with a rotary machine (6-7 inches), however, greater numbers of seeds, especially of Poa annua, were found, leading to higher weed populations in the crops.