With costs of conventional fertiliser rising, farmers are turning to a new way to fertilise their crops. Many have now started using human waste in the form of treated human sewage. Water companies are no longer allowed to dump this into the sea but appear to have a ready market in supplying farmers. In fact Severn Trent Water have said they are struggling to keep up with demand. Human fertiliser costs farmers around a fifth of the price of the more expensive alternative but does have the disadvantage of being more smelly. However, farmer Jonathan Barrett says the smell can be reduced once it is incorporated into the soil and turned regularly. He also said it is best to take into account the wind direction when using it. Human sewage is currently allowed to be used on grassland and crops but not on salads, fruit and root crops.