As the world’s leading soil scientists gather in Glasgow, we hear calls for a total re-think of how we measure soil health. According to the UN’s Food and Agriculture Organisation, a third of agricultural soil is “moderately” to “highly” degraded, threatening global food supplies, increasing carbon emissions and reducing its capacity to hold water. But how do scientists evaluate the health of soil - and is the way they’ve been using the best one? As the Environment Agency declares July to have been the driest in England on record since 1935, two farmers in Suffolk tell us how their farms are affected. Is planting into dry ground worthwhile, and should they invest in new irrigation systems? And all this week we are talking about the issues faced by tenant farmers. Today we're in Gloucestershire with pig farmer Helen Wade, who would like to share her tenanted land with a new farmer. Presented by Caz Graham Produced in Bristol by Natalie Donovan