A return to a diversity of breeds
My black grass example is about controlling a weed that is being selected into a resilient variety because of our prolonged use of chemicals. This is of course a very widespread problem, with many other examples. The obverse problem is when we have engineered a single crop strain because of some particularly desirable quality, then we are in equal danger of being hit by a disease that attacks this single strain; then the entire crop would fail (as with the Irish potato blight). Whilst monoculture may seem tempting in the short term, it is a highly dangerous strategy in the longer view. Many crops across the country are grown from seeds from a very limited range of suppliers. Therefore a major disease would not be confined to one region, but would blanket the country very rapidly.
The monoculture concept is not limited to crops—it has also been encouraged for many animal breeds. In the 1960s, the UK government was actively promoting the idea that only two or three breeds of cows, sheep, or pigs should be maintained, as these were high-yield varieties. At the time, there was some immediate logic, but it was extremely short-sighted, as many of the other breeds have qualities and resilience to disease, ability to survive in different conditions, or offer products that are beneficial for different dietary or medical conditions. Again common sense has prevailed to a limited extent, and the value of these less favoured, or rare, breeds has been appreciated and expanded in the last few decades. For me, the message is that there are benefits in a limited range of crops or animals in terms of mass production, but it is essential to preserve a far wider variety as an investment against future diseases and climatic changes. In non-financial terms, it is worthwhile to remind ourselves just how many species we have already brought to extinction and how difficult it is to reverse, or even reduce, such a trend.