9th September 2021
FARMING, THE SOLUTION NOT THE PROBLEM
As the latest Intergovernmental Panel on Climate Change forecast has said "this is a code red for humanity" This means that Farmers and Horticulturists have to realise that major changes have to take place in farming. Many farmers have started to take this message to heart, and it is important that the recent environmental improvements that many farmers have been involved in should first be recognised and applauded – riparian planting, fencing off waterways, tree planting including native plantings etc., but this is far too little. Urgent changes are necessary. Farmers and Horticulturists, rather, than being part of the problem by adding to climate change, can become a large part of the solution. This is the positive message that food growers need to take on board!
ONE OF THE BIGEST PROBLEMS
However, we need to study why farming and horticultural practices are part of the problem. The biggest elephant in the room is the use of chemical fertilisers, chemical pesticides and fungicides. There are several generations of farmers and horticulturist who have never known any other way of growing food. Agricultural collages around the world teach synthetic chemical practices. Indeed, many such establishments are partially, or largely financed by agricultural chemical companies. Although chemical use has helped to maintain crop production over time, they have some serious downsides.
The whole theory of plant nutrition is based on completely outdated and over-simplicated chemical analyses of how plants need certain chemicals to grow and prosper – which is true – apply the right mixture of chemicals and plants will grow. However, this view of plant nutrition misses out the most important part of the puzzle – BIOLOGY! A healthy soil is rich in a huge multitude of micro-organisms and organic matter that ensures that plants get what they need to prosper, as they have for billions of years.
What is not considered in a simple chemical analysis of plant nutrition is the reciprocal co-operative relationship between soil micro-organisms and plants. Plants, through the process of photosynthesis, produce sugars, proteins, cellulous and sugars for themselves, but they produce more than they need. Plants exude the excess through their roots as a mixture of substances known as mucigel which contain simple sugars, simple proteins, carbohydrates, growth factors, organic acids and enzymes; in fact, an ideal high energy food for the bacteria living in the rhizosphere (the area immediately around the root hairs). The excess that plants excrete through their roots encourages billions of micro-organisms to lap them up.
In exchange the micro-organisms access and release locked up plant nutrients for the plants. This amazing mutual co-operation between plants and micro-organisms is the key to understanding all the other aspects of natural plant nutrition and the ‘living soil’.
Nitrogen fertilisers, which encourage leaf and protein growth in crops and grasslands speed up the destruction of soil organic carbon matter (humus), and as no attempt is made to increase soil carbon this trend will continue. It therefore should be our aim to faze out all use of Nitrogen, and other, fertilisers within a reasonable time frame. There is also the problem of nitrogen runoff into waterways and aquifers.
Chemical fertilisers denude soil organic matter and soil micro-organisms over time. As a result, there has been a catastrophic denuding of top soils and the life within them around the world. It has been estimated that the most intensively farmed land in the UK is 30-40 years away from the “eradication of soil fertility”, and “if current rates of degradation continue all of the world's top soil could be gone within 60 years”, a senior UN official said.
This can only be achieved by introducing sustainable methods, that both build up soil organic matter (humus) and the beneficial biology that goes with it – such as Biological, Regenerative and Organic methods of production. Humus is continuously being decomposed by micro-organisms, but with the mentioned methods, it is quite possible to increase soil humus faster than it decomposes. This has been found in many studies of these farming methods, where humus levels were shown to always be more than in soil on conventional farms. Soil carbon content (SOC) in organic systems increased annually by 2.2% on average. Organic farms were found to have 26 percent more long-term carbon storage potential than conventional farms.
A new study from Northeastern University, Boston Massachusetts, run by Geoffrey Davies has said “We already know that [conventional practices] like using [synthetic] fertilizers contribute to climate change – they deplete soil of carbon, which is then released into the atmosphere”. But he and his team at Northeastern University hope their new study might actually provide a roadmap to mitigating it by increasing soil carbon. Even on some upland farms in New Zealand that have adopted Biological methods and cut out chemical fertilisers, especially super-phosphate on their pastures, have found a doubling of soil organic matter within 2-3 years. Super-phosphate destroys beneficial mycorrhizae fungi in soils and the increase in organic matter was largely due to the recovery of mycorrhizae which are largely cellulose containing carbon. The irony is that mycorrhizae fungi are very efficient at accessing unavailable phosphorous in soil and giving it to the grasses and clovers in exchange for sugars (high in carbon C6H1206) released from the plant roots.
In mixed farming and arable and horticultural farming, after eliminating chemical fertiliser use, it is much easier to increase soil organic matter by:
1. Regular making and applications of compost made from crop residues
2. In mixed farms, animal manure can also be used
3. Regular growing and incorporation of green manures
4. Treading in by sheep or cattle, of high grown mixed Regenerative pastures
5. Cover crops
6. Regular use of mulching with organic waste (such as straw, etc.), especially where permanent fruit and nut trees are grown
In permanent pastures the method in 4. can be used to increase organic matter, as well as applying mycorrhizae fungi soil inoculant.
OTHER BENEFITS OF INCREASING SOIL CARBON
• As rainwater enters the soil the humus swells up like a sponge, with 1 part of humus holding 4 parts of water. It swells as it absorbs water and can hold the equivalent of 80-90% of its weight in moisture, releasing it gently to the plants. This greatly increases the soil's, and the plants' capacity to withstand drought conditions. on organic and biological farms where the organic matter content of the soil is 4-5%, 640,000-800,000 litres can be stored in the top 30cm of soil per hectare! That is between 5-8 times the amounts of water stored on conventional farms
• Increased soil carbon holds onto plant nutrients until needed by plants (increased cation exchange capacity). This reduces runoff into waterways and aquifers. To increase this effect, applications of Humates can be used. Humates are carbon-dense, soft coal deposits found near coal mines, which will further the cation exchange capacity of the soil, further decreasing runoff.
• Increased soil carbon also increases beneficial soil micro-organisms
Another cause of soil carbon loss is over cultivation, of course this only applies to arable cropping. Over cultivation releases large amounts of Nitrous Oxide. There has been an increasing understanding of overcultivation in recent years by arable farmers, resulting in an increase in various forms of minimum surface cultivation. There are now specialist seed sowing equipment that can sow through the previous crops residues leaving it as a mulch which the seedling can grow through. There are also similar methods called "conservation tillage" and “no till” being used by small farmers in countries like Argentina and Brazil in the late 20th century. One method is to grow a bean crop and planting through the crop trash with maize – the bean crop leaves nitrogen from its root nodules which feed the Maize.
Monocultures – this practice has become common, growing one crop, often on a large scale and often growing the same species and variety of crop many times on the same land, only made possible by heavy regular applications of chemical fertilisers and pesticides. In this New Zealand there is some arable monocropping in the Canterbury planes and in the Waimea planes, Nelson.
Rotating crops. One example is to have 4-5 years of crop growing, changing the type of crop each year; then 2-3 years of mixed grasses, clovers and herbs grazed by sheep. Then back to arable crops.
Local food growing, and distribution systems are essential! The large-scale supermarket chain system of distributing food is totally unsustainable. It has been estimated that the average content of a supermarket trolley has travelled around 5,000 kilometres to get to the checkout, this is completely unsustainable and add hugely to climate emissions!
Many farmers are starting to realise that selling locally, cutting out the middlemen, and forming a relationship with their clients is the way to go. Farmers Markets, Vegetable Box schemes and schemes like OOOOBY are the way to go. These schemes have many advantages:
• Reduced kilometres that the food travels
• Local food is fresher
• Local foods are seasonal
• Local foods promote variety
• It encourages personal relationships with food producers
• Customers know where their food comes from and who grows it
• Missing out the many middle-men/women in the food chain
• Better financial returns for the producer
• Local foods support your local economy
• Local food distribution enriches local communities