green manures

As the summer and autumn crops are cleared we are sowing green manures to protect the soil and conserve the nutrients through the winter. Though air temperatures are dropping quickly, the soil is at its warmest and most active in the autumn. This means that all the invertebrates and microbes are busy breaking down the remains of previous crops. Eventually the nutrients end up in simple, soluble forms that plants can absorb through their roots.

We can expect almost a metre of rain between now and April. There is very little evaporation at this time of year so most of that water will percolate through the topsoil, taking anything that is soluble with it. To save our precious nutrients we need a crop that will grow vigorously through the autumn and early winter, soaking up, in particular, any soluble nitrogen and potassium. This is then held in the plants tissues until we mow, chop and incorporate it as green manure in the spring.

Any bare ground on the farm has been sown to rye, which, with its origins in Northern Europe, grows vigorously at low temperature and light levels. It will quickly smother out any competing weeds and has the added benefit of being slightly allelopathic. This means that it releases chemicals from its roots that inhibit the germination of seeds and other species. The result is that we tend to have fewer weeds in crops following a rye green manure.

We are in the process of harvesting the squash. They have to be handled like eggs and laid carefully in their boxes if they are to store well. On Saturday October 30th we will have our annual pumpkin sale and open day with all the proceeds going to Oxfam. So if you can make it, come and select your Halloween pumpkin, have a meal in the restaurant and take a farm trailer tour. There will also be apple pressing and a few other activites going on. More details later in the month or check our website www.riverford.co.uk. In the meantime, if you are a squash fan, you can order an 8 to 10kg box of mixed sqaush for