Until recently, it was generally believed that seeds must be in direct contact with soil to obtain liquid water with which to germinate. From various experiements using wheat seeds at the ARS Centre at Pendleton, soil scientist Stewart Wuest has discovered that it is water vapour that really counts. With a relative humidity in the soil of close to 99%, seeds do not need to be in contact with soil particles or liquid water. Seeds separated from the soil by crop residues or artificially by a layer of fibreglass cloth or even suspended in the air above water, germinated just as well - in a sufficiently high relative humidity. Seeds are able to absord the moisture they require from the water vapour in the soil and liquid water accounts for only about 15% of the water taken up by germinating seeds. This discovery will no doubt change the configuation of some seed germinating equipment with the object of retaining water vapour near the seed. (It should be noted however that seeds of some plants need water to eliminate natural chemicals produced to inhibit germination). Stewart Wuest works for the ARS (Agricultural Research Service) which is the chief scientific research agency for the USDA (US Department of Agriculture). See the Journal: 'Soil Science Society of America'. www.agriworld.nl www.ars.usda.gov