Recently I came across an interesting book that Steve purchased online called ‘Organic growing with worms’ by David Murphy. It was sitting on the coffee table and I had a few minutes between the dishwasher finishing and hanging out a load of washing. (This is what I do on my days off as a part time domestic goddess!!)
One of the few challenges we’ve found in our vineyard is the imbalance of nitrogen. Why do grapes need nitrogen? Grapes with balanced ‘goldilocks’ nitrogen produce higher quality, flavoursome and stable wines that age well. Too much nitrogen is not a good thing as vines push to create canopy rather than fruit shading out bunches. This can produce unripe fruit characters with poor age-ability. One of the reasons Grand Cru wines are planted on hillsides rather than the valley floor is because hillsides have soils of less vigour and are generally warmer (less clay), and also can be of a higher PH. When we purchased our Granton vineyard over 30 years ago it was planted to a market garden producing mostly brassicas best suited to an alkaline soil type. The previous owner ran the market garden conventionally and, as a result, we inherited soils like concrete, which is a habitat uninviting to worms. Over the past 30 years we’ve set about reversing the harm done through the introduction of compost, compost teas, 500, 501, gentle cultivation and cover crops. We monitor our progress through soil testing. We’ve come a long way and we’ve increased the carbon content immensely but there is still some more work to be done. Worms can help us as they work around the clock with no overtime converting the carbon to nitrogen.
If you’re mad about gardening and want to do something to help the environment, especially if you’re keen to grow food, this is an essential book. What I learned was that worms deposit nitrogen in the soil through their burrowing and urine (wee). When worms burrow they shore up the walls of the burrows with their mucus. This is full of nitrogen that is excreted through the digestion of carbon, minerals and bacteria. Their wee is also full of nitrogen. When it rains, or irrigation is applied, this washes all the nitrogen through the burrows to the tip of the root system that is then taken up by the vine. Not only do the worms deposit nitrogen but their burrowing allows for oxygen to enter the soil. Along with carbon this is a key requirement for bacteria to flourish. ‘bacteria is agriculture’s richest source of nitrogen on the planet’ p112. Oxygen in soil feels squidgy underfoot, not like concrete. ‘Organic growing with worms’ explains how to start a worm farm, attract worms, keep them and increase their numbers. It’s an easy read full of great ideas. I give it 5 stars out of 5.