|
 |
|
|
Chapter 3
Basis of Fertility FarmingI cannot expect any farmer to believe that my results are other than the result of luck, good land, and perhaps the special Providence that looks after fools, much less try them on his own farm, without giving the scientific principles on which they are based. Justifications for the greatly increasing numbers of organic farmers, those who in this country and all over the world are now eliminating the plough (see Plowman's Folly by Edward Faulkner), and the many farmers and authorities who have abandoned artificial fertilizers as a snare and a danger to health, in favour of entirely organic methods, will be found in the next chapter.
Here I am concerned only with the strictly orthodox explanations, established by research stations, mainly Rothamsted; it makes no difference to my results which are the right reasons. It is even possible that both are entirely wrong, but far more likely that each is correct in some places and not in others.
In theory, by not using artificial fertilizers, and not importing feeding stuffs to my farm, I am exhausting its fertility. Even if I return the straw to the land, a crop of wheat of 2 ton 2 cwt. to the acre takes off 50 lb. nitrogen (roughly as much as 4-1/2 cwt. of sulphate of ammonia contains), 28-3/4 lb. potash, 21 lb. of phosphoric acid (phosphorus) and 9.2 lb. of calcium. (Manures & Fertilizers, Sir Daniel Hall, p. 22, John Murray.) Grass makes even heavier demands: a 1-1/2-ton crop of hay removes 49 lb. of nitrogen, 32.1 lb. of lime and 12.3 lb. of phosphoric acid.
All these elements, in natural form, available to plant life, are going off my farm with everything I sell. Every gallon of milk and every animal I market removes calcium and phosphorus, yet despite the additional losses from 'plant foods' washing out in drainage water, I still have more than I started with.
The explanation is known to every agricultural student; the amount of the heaviest dressing of any artificial fertilizer we can apply to balance the income and expenditure of the land is tiny compared to the vast reserves which lie in the top nine inches of all but the most infertile soil, and in the air above the soil, provided the soil bacteria are adequate to gather it to the soil. The famed Broadbalk field at Rothamsted, after bearing wheat for 100 years, with no manure of any kind and an average crop of 12-1/2 bushels an acre, still contains in its top soil 2,500 lb. nitrogen, 2,750 lb. phosphoric acid and 6,750 lb. potash. The next nine inches probably has nearly as much, and a deep-rooting herb or a tree root going down as far as six feet or more can tap untold reserves.
There is no possible doubt, that what matters in the growing of crops for ourselves and our stock, is the amount of the essential elements which are available for use, including the trace elements which have the importance of vitamins, and the plant hormones about which we are now beginning to know more and which are present only in the living humus of the soil. Not only does this prove that it is possible to farm as I farm on the fertility of my soil, and the provisions of the air above my soil made available by the surface organic matter, it proves that even the poorest soils can be farmed in this way if the system of cultivation is designed to build up the amount of available plant foods near the surface, and keep the land in that same condition which allows nature to grow healthy oak trees for hundreds of years in the same place without importation of fertilizers. The only manures that come on to my farm are sewage sludge and sawdust, and though there may only be 1-1/4 lb. of phosphoric acid in 1 cwt. of sewage sludge, the organic matter must supply more and obtain more from its surroundings, and by returning to my land what should rightly go back to it, I am saving my sons, and the men who will farm my lands 500 years in the future, from the disaster of soil exhaustion.
I am therefore clearly justified, in theory, by high authority. But I don't believe a word of it. I was justified before I started my 'unorthodox' methods, yet my land suffered. The reserves in the soil are the amounts which will dissolve in hydrochloric or sulphuric acid, but crops don't use either of these acids. In theory it would be equally possible to get all the essential elements to support the human body into several pills a day, with results as serious to health as the ease with which the chemical substitute for the real thing is produced.
I can disc in weeds and green manure crops, and use sawdust, without a fall in yield from lack of nitrogen, as the cellulose and carbohydrate decomposing bacteria increase and take it out of the soil and the air to make up their bodies, because I have in my topsoil unlimited natural nitrogen in the forms which plants can use.
This, apart from legume nitrogen bacteria, is fixed by azotobacter croccoceum and other free nitrogen fixers, the bacteria to which almost all the combined nitrogen in the world is owed -- sulphate of ammonia was originally fixed by coal-measurage bacteria. Firstly we gain this in the compost heap. Up to 40 per cent of the nitrogen in normal farmyard manure is lost in making and storage; yet the compost heap gains up to 26 per cent from the air through the activity of azotobacter and its allies which cannot work in the anaerobic conditions of the orthodox dung heap. The compost heap, then, not only adds the additional plant foods gathered by weeds as well as straw; the power of the sun, stored in the carbohydrates in the heap, sets the azotobacter fixing nitrogen, till there is more in the finished article than there was in the original dung. (See The Waste Products of Agriculture by Sir Albert Howard and K. Wad.)
Further, when compost is spread on the surface of the soil, and not ploughed in, it has the ability of increasing not only the nitrogen content of the soil, but also the phosphorus and calcium and potash. My knowledge of science is insufficient to explain why. As far as I know they do not exist in the air, though that would seem to be the only source from which the organic matter can absorb them. Maybe dust particles in the air carry phosphorus, potash and calcium, or maybe some scientist will discover that even the air in conjunction with organic matter is able to create them. The fact is that they appear in abundance where surface organic matter is adequate and they benefit the crop in a way which is not evident when organic matter is ploughed down or when these elements are applied in artificial form.
Compost is to-day, in terms of labour, relatively costly, though not more so than the practice of yarding bullocks for dung. But compost is of far greater value than dung as applied from a normal heap, and my methods greatly increase its effectiveness without increasing labour costs.
The surface of the soil is the natural place for humus; all decayed vegetation starts there, and with ample air and the high pH, it makes a bacterial hotbed; decay is almost all aerobic. The azotobacters supply unlimited nitrogen, and the compost is thus almost as quickly available as an artificial fertilizer, but it is instead a perfect diet. Further, any kind of organic matter applied direct to previously composted land, so rich in bacteria and nitrogen, is attacked as readily as in a compost heap, making what is known as sheet composting almost as effective, though not quite so quick, as the application of mature compost.
The darkening of my soil by humus also helps. The sun warms it up quicker, and azotobacter work best between 50 deg F. and 60 deg F [10 deg C. and 15.5 deg C]. Underground it takes longer to warm up, and there is less oxygen. The lime still in the compost keeps the pH about neutral, which the azotobacter need. There are a host of bacteria in any fertile soil, of equal or greater importance than the fungi; a Rothamsted direct count1 showed 3,733,000,000 per gram of soil from a farmyard manure plot, 1,766,000,000 per gram on complete artificials, 1,000,000,000 per gram no manure. (Soil Conditions and Plant Growth, Sir John Russell, Longmans.)
Rothamsted showed, therefore, that by using artificials nearly 2,000,000,000 unpaid helpers are discarded from every gram of soil (about a saltspoon full), and instead the fertilizer maker and the chemist are paid to do their job far less efficiently; for as with all bad workmen, it costs even more to repair their mistakes.
The plant foods from this humus layer are available at root level, and the quick growth of weeds between crops acts as a storehouse for the excess, particularly in late summer. Nature will not tolerate bare ground, because it wastes this store. The bacteria have a peak of late summer activity, and if the ground is clear it will wash away. If weeds are used, as I describe in a later chapter, they catch this surplus nitrogen for the subsequent crop.
Nitrogen is important firstly because, unless there is enough in the land, no other elements can be taken up. Artificial nitrogen fertilizers are the most lethal destroyers of soil organisms and fungi -- sulphate of ammonia even being sold as a worm killer -- and because they are plentiful, they are pushed by commercial undertakings and, sad to say, even by the Ministry of Agriculture; but in artificial form they are pure disease creators. At Goosegreen we have got nature's nitrogen supply taped; that is one of our great key advantages.
Bare land, under arable cultivation by ploughing from virgin prairie (Saskatchewan), lost 1,400 lb. more nitrogen than was recovered in the crop in twenty-two years. In the same period, at Rothamsted, land allowed to run completely wild gained 2,200 lb., 91.7 lb. a year (see Soil Conditions and Plant Growth). Fertility farming adds far more, but does not allow any waste.
Goosegreen is a worms' paradise, and moles also help with the drainage without causing any damage. On a farm under full cropping rotation molehills don't cause any trouble. They merely aerate the soil and improve its friability.
It may be argued that when, in the Middle Ages, we farmed with wooden ploughs which did not invert the soil, on the open-field system, grazing our weedy fallow strips and using no artificials, but returning all animal and human excrement to the soil, our crop yields were rather less than half those of the present day.
But there are very important differences, apart from improved breeds of stock and crops. Then, grain crops were weeded by hand and the weeds carried off; hoeing was practised, the disc harrow not invented, and the true compost heap, with its balance of biological activity, still not known. The modern compost heap is as important as any agricultural discovery of recent years. Though there is evidence of disease in both crops and stock in early manuscripts, it is likely that, as these have increased so greatly within living memory, on the whole, agriculture was healthier even though more people on the land produced far less. Even in the reign of Queen Anne, we exported wheat to America, to such parts as were colonized.
Next: 4. Farming Without Plough or Chemicals
Back to Contents
Back to Small Farms Library index
Community development | Rural development
City farms | Organic gardening | Composting | Small farms | Biofuel | Solar box cookers
Trees, soil and water | Seeds of the world | Appropriate technology | Project vehicles
Home | What people are saying about us | About Handmade Projects
Projects | Internet | Schools projects | Sitemap | Site Search | Donations | Contact us