The teart pastures of Somerset: III. Reducing the teartness of pasture herbage

Abstract

1. Clovers and Yorkshire fog are outstanding among pasture plants in their ability to absorb molybdenum from teart soils. Many teart pastures contain a fair amount of clover, but Yorkshire fog is only a very minor component of the herbage. Other grasses as well as Yorkshire fog often contain enough molybdenum to cause scouring.2. Acidic nitrogenous fertilizers decrease teartness by suppressing clovers and by reducing molybdenum uptake by grasses.3. Acidification of the soil by regular applications of sulphur would reduce the availability of molybdenum in the soil.4. Basic materials, such as lime and slag, increase molybdenum uptake by grasses on acid soils which contain a fair amount of molybdenum. They also encourage clovers and should, therefore, be used only with the greatest discretion on such soils.5. The percentage molybdenum content of newlysown grasses is low, but it increases with age. A system of short leys consisting largely of grasses would give an increased output of material of low molybdenum content.