The BBC (again) this morning has a report (http://www.bbc.co.uk/news/science-environment-26682750) on an investigation by Lancaster University, which claims that wetter winters could cause more river pollution from increased fertiliser run-off especially in warmer summers with cracked dry soil! Are we talking about winter or summer?

I would have thought that more rain would flush the fertiliser out faster, either leaving it at a lower level in both soil and river (though not the sea). If farmers replace the lost fertiliser quickly, the levels might stay the same.

Am I naive? And if so please correct me.

When I read the headline I thought they were talking about something other than farmers fertiliser. The pollution that first came to my mind was sewage, industrial chemicals and solvents, oil and general detritus. I would have thought that sewage was just as likely to cause toxic algae problems. In fact more likely in the Thames in the Home Counties.

The BBC report was specific. They only mentioned fertiliser; "A research team from Lancaster University concluded that increased, more intensive winter rainfall is likely to wash more fertiliser out of soil and into rivers"

Soil cracking occurs (in my gardening experience) in clay soils.

With a lot of these stories there's an element of truth to them but it doesn't consider innovation or what is an ideal climate any way. That's even before you consider the science might be wrong. Fertilizer washing off? Create slower release versions. Create plants that need less any way. Recycle runoff to put the fertilizer back... whatever. We don't have to sit here and watch stuff fail, forever lamenting our 'perfect' climate from the past.

What were the research team looking for, all pollution or just fertiliser?

When reports of flooding they always make a point that the water contains raw sewage; they do the same when warning people about the dangers of wading in flood water.

I agree that cracks are more likely in clay based soils. From historic news reports I thought that run off in summer after heavy rainfall initially at least, doesn't penetrate the soil surface more than a couple of mm. In that situation the pollution is more likely to be insecticides.