Only farmers can deliver this.
Only farmers can deliver the following. According to World Bank figures, the global production of urban waste is above 2 billion tonnes and rising. My own experience of composting urban wastes suggests that, technically (if the regulators could come to terms with this) maybe 25% of that could be composted and put to farm land, and possibly more if put to forestry land. If the compost contained only 2% of each of N, P and K, then that would be 10 million tonnes of each. One tonne of N nutrient, made in a modern USA factory, takes 21,000 kWh to make and deliver. So, or the N alone, that would save the use of 210,000,000 kWh of electrical power generation, most of which comes from burning coal and oil. Bearing in mind most N production in the world is several times less efficient than in the USA, and that the rest of the figures err on the side of caution, then recycling urban waste by composting to land would save probably around 1 trillion KWh pa and the associated Carbon dioxide production. As a rough guide, that would save 350,000,000 tonnes of Carbon dioxide being pumped into out atmosphere, every year.
There is a bonus, crops grown on high organic Carbon soils need less irrigation and less crop protection sprays. Cereal crop lodge (fall flat) less. Crops yield a little more. What we need is active, controlled enabling, not ever-increasing suppression and indifference form government.
Bill Butterworth, Land Research Ltd. 18 October 18
Conventional, plough-based cultivations certainly have a place but with a high time and energy cost.
When not to direct drill? Some years, it is wet but the harvest still has to be got in and the result is ruts. They may have to be cultivated out but it is as well to remember that direct drilled soils are less likely to rut because of the resilience of organic matter and a “blocky” structure which distorts less under load, even when wet. Also, some soils naturally form pans which may need to be cultivated out. Last reason is to bury weed seeds – but try not to plough them up next year. Rotational cultivations may be the answer with a progression to long term direct drilling.
Persist with direct drilling next year wherever possible to help build up organic matter. (Actually it is more a question of avoiding the oxidation of organic matter from conventional cultivations which could be 35% pa while direct drilling will be as little as 10% or less.)
Bill Butterworth, Land Research Ltd. August 18
A lot of this, this year. Yields down too. It is largely avoidable.
A sandy soil will hold about its own weight in water. A clay 2 or 3 times. A typical natural peat around 16 times!
A compost made from urban green waste will hold up to 10 times its own weight in water, maybe only 5 times if it is made from woody cuttings in winter (and it would have less N). However, compost made from urban green waste plus industrial wastes will (depending on the wastes used) hold 8 to 14 times its own weight in water and possibly a lot more NPK. Although the Environment Agency will restrict quantities, the truth is that the Fens, when Vermuyden drained them some 300 years ago, were up to 40 foot deep of almost pure compost. (Organic soils do not leak excessive N.) It is also true that high organic, well-composted soils, can halve cultivation energy inputs and reduce chemical spraying.
So, there really should be a national policy of maximizing urban waste recycling to urban farm land. Suggest get a copy of “Survival”, read it and send a copy to your MP.
Bill Butterworth, Land Research Ltd, 1 August 18
The soil mycorrhiza are dramatically assisted by the addition of biosolids, thus reducing crop disease and crop spying.
The Guardian newspaper reported recently that the British museum is exhibiting part of a sewer-blocking fatberg that made headlines last year, weighing 130 tonnes, the equivalent of 11 double decker buses and stretching more than 250 meters, six meters longer than Tower Bridge. Said Vyki Sparkes, the curator of social and working history, “I don’t think you can get much lower than a fatberg … it reflects the dark side of ourselves”.
Fortunately, most of our sewage goes through very efficient sewage treatment works (STW’s) before the water is recycled to rivers and the sea. The STW extracts the organic material and some of that is recycled to land to grow crops (“biosolids” are really good fertilisers which add trace elements and improve the biology and disease resistance of the soil, thus reducing crop disease). The real bogey is the solid plastic which goes to landfill. Yet again, it is hard plastic which is causing intractable environmental problems.
Bill Butterworth, Land Research Ltd, February 2018