This Sustainable House

Recently I have been reading a number of books around transgenic foods (also known as genetically modified foods), and the dangers/benefits they produce. Whilst this topic is highly decisive, it did highlight for me another area of concern… the twindling number of species grown in our agricultural systems.

For example, over the 20th century, the US Department of Agriculture’s seed storage bank reduced the varieties of fruits and vegetables held. For example 544 varieties of cabbage became just 28; 287 varieties of carrot was reduced to 21; and most staggeringly of all, 2,683 varieties of pear was reduced to approx 300.

Of course the practical upshot of these losses is the fact that the majority of our food crops, both in agriculture & the home garden, are genetically narrow.

What is the risk of sameness??

Well the most publicized risk is the fact that many of our pests and diseases may find ‘chinks’ in the armour of these crops leading to massive losses. This, due to the lack of genetic diversity, then leads the need to apply prodigious amounts of fertilisers and ‘cides (herbicides & pesticides) to keep production up. Of course, as we apply more of the ‘cides, the pest species (which are genetically diverse) begin to adapt making themselves resistant. This creates a feedback loop requiring more ‘cides, creating stronger bugs, more ‘cides, stronger bugs, more ‘cides… etc.

The alternative, which according to Darwinian theory worked for almost all of earth’s history, is to utilize genetic diversity to beat the bugs. This works because not all plants in the population will have the same chink that the bugs find. Those that do are destroyed/damaged, but those that don’t survive. The survivors then become the forefathers of the new generation, and in time the bugs ability to exploit the chink is lessened.

Of course as all this is going on the bugs are also evolving and trying to outwit the plants.

This is evolution at work!!

For this positive feedback loop to work, evolution only needs a single tool… diversity!

Which leads us back to the concerns around the increasing lack of diversity amongst our food crops.

What can we do?

Well the simpliest thing we can do, whether we are a farmer or a gardener, is to encourage genetic diversity. For example, instead of planting only ‘Derwent Globe’ beetroots in our gardens this year we might plant Derwent Globe, Chioogga, Bulls Blood, and Burpees Golden. In this way we have increased the genetic diversity in our gardens by 4, as well as making for much more interesting salads due to colour, taste and texture.

As we do this we are also encouraging the seed houses to hold more varieties, and the growers to grow the seeds.

For the home gardener there are a number of really good suppliers of heritage seeds (see the links page) but for the farmer things are a little more difficult.

Things are more difficult for the farmer as most of the seeds that can be purchased in bulk are not available in a ‘wide range’ of varieties. In fact, the established agricultural systems discourage planting a range of varieties, and encourage the planting of vast monocultures.

However even farmers can make a difference. You could for example;

• encourage your seed supplier to provide you with greater diversity
• encourage more cross pollination on the farm, and save seed wherever possible
• encourage weeds and other endemic species (tricky one due to laws around weed control)

The key point is that we need to start considering the genetic diversity of our food crops, and doing whatever we can to increase that diversity.

Our future depends on it!!