The effects of domestic compost upon the germination and emergence of barley and six arable weeds

Summary In a bioassay, leachate from composted household waste was found to decrease both cress germination and the germination of barley and six arable weeds, especially in the light. The effect of compost depth upon the emergence of these species was examined in a glasshouse experiment. Compost had no significant effect on barley emergence. However, weed emergence, particularly of those with small seeds, was reduced greatly by the physical effect of compost and, to a lesser extent, by its chemical effect. The emergence of the large‐seeded species was relatively unaffected by increasing depths of compost, whereas that of the smaller‐seeded weeds steadily decreased, being almost completely prevented by a 3 cm layer. The use of compost to control arable weeds in the field is discussed.