Science (1979–1986 magazine)

Transcription

P A thank you very much indeed for being with us this morning. I'd like to start by possibly investigating a point of view that I think many many of our listeners will be a little bit hazy about. I know when I was at school myself, we learned that the soil we've got is a precious resource and once it's been eroded away, and we see all the erosion galleys around the place, that topsoil is virtually lost forever. Now your own experiments have shown that in fact you can grow, literally grow topsoil, on previously very very barren areas. Perhaps you'd the like to discuss this. How actually do you go about doing this, growing topsoil on previously very barren areas? Well first of all I'd like to give an opposite view to the general one and say that the most valuable deposit of chemical and mineral wealth on earth is the subsoil, because as much of it as is required, and I'm not limiting that to a few inches but to several feet, can be made quite quickly, not slowly. This subsoil is actually the deposit below the top soil as we know it. Is that right? Yes that is exactly it. It's gone through the process of soil formation, the aging process, so you not dealing with some solid rock that you've got to turn into soil in a couple a million years. The million years have passed. So the only stage that's left is the very rapid stage of soil life. Making the soil. All you got to do is feed the microbes. Now you've virtually perfected that method of feeding the microbes. Tell us about it? Well originally we had poor soil or no soil. So we aerated the soil and planted pasture with it. To produce a pasture. Every now and again we got a good pasture that would disappear. So once when we had a really good pasture, it only lasted about a year, we tore it to pieces. We got a better one next year. Then we tore it to pieces a bit deeper with a chisel plow in those days and we got a better pasture but we had seven or eight inches of soil in three years instead of no soil or just the skin of soil. So what we're doing of course was allowing the grasses and the clovers to grow to nearly the flowering stage they're grateful for the young because the roots would not have gone down far enough. You allow them to get up to near flowering stage, the roots will have gone as deep as they can, and if you've aerated a bit of the subsoil the roots will go down into the subsoil because it will be moist and aerated. As soon as the grass is mown or eaten off by stock it suffers a shock and to get over the shock it calls on the nutrients in the dead, in the roots that were in reserve for the great reproductive event of flowering and setting seed, and a few days later a new set of roots will start downwards but the old set of roots, that newly dead roots of mixed grasses and clovers. That is the perfect food for soil life and it's the perfect means of introducing organics into the soil. I think we've got to really emphasize here this aeration technique. Now use a chisel plow. Just how does the chisel plow vary from the vast acreages of paddocks that we see plowed today? Well the chisel plow, which we introduced to Australia 1951 or 2 has, seems to have led to enormous numbers of them being sold and also influencing other types of cultivators and farmers to use the scratch type implement instead of the moldboard, of course went out when the disc came in and the disc plow now is on its way out with the various versions of the chisel plow with the scratch plow. It's like the old Egyptian stick plow of course. What I'm trying to get at here is that the chisel plow actually does not turn the soil over, does it? No it doesn't turn the soil over but we designed another implement in 1974. We got the Prince Philip prize for it, which leaves the horizon of the soil more in place than a chisel plow does. Actually you can run it through eight inches through a pasture and you look back and hardly seen that you've been there. With sort of plow was that? It's called the Bunyip Slipper Imp with Shakaerator. The Bunyip Slipper Imp with Shakaerator. Alright tell us about that, that sounds pretty tremendous. Well it arose very early in the piece when we struck trouble with the chisel plow in certain types of clay. No matter how much weight you put on them it just wouldn't get down deep enough to give you a reservoir of moisture down there. I was really inspired to do something about it when I wrote The City Forest in 1971. And we got on with it then but it has a easier entry into the ground and it splits and shatters upwards. The vibrator greatly assists it do that. This vibrator is just a sort of an off center weight on the PTO part of the plow is it? Well its inspired by a wobbly wheel on the front of a motor car, was the idea and it's one of those things that, if you have a bit of luck with it, it worked right first time. Almost most first time. Usually these thing come after a lot of mistakes. They're the foundations of any successes usually but this one came very easily and we had luck with the plow in that we designed it to do certain things and through accident and a little bit of luck we got it to do lot better than we ever anticipated. P A you mentioned that the new plow, the Bunyip etc, keeps the soil profiles intact. I wonder if you could explain to us why that's important? I can tell you of a incident that happened many years ago when I was mostly connected with tin mining. I was out on a property and the owner told me that he'd employed a young Englishman and the weather was good for plowing and he was going to town so would he plow up this twenty-acre paddock. He showed me the paddock twenty years later and it hardly grew a weed. What the Englishman had done is what they do in England he turned it over with the moldboard plow. So he'd turned the dead top soil, the little bit of soil underneath a body of dead topsoil and nothing happened. But by keeping their horizons in place you have the fertility and the microbes aerated and in place and they'll move downwards. And you don't want to go too deep in the first instance. It would be like trying to make beer with not enough of the ingredients. It would be too watery so you limit the depth to about what you can aerate right through, that is from shank to shank. P A I once heard someone say that if they did nothing else, with a little bit of money that they had, and this person was one of your Keyline proponents, someone who had a farm, if there was no money for a dam, no money for a gate valve, if they did nothing else but chisel pattern plow their land, that they would increase the water absorption and the water storage on that property. Would you care to comment on that? By aerating the soil properly we put it in a condition to take in moisture and if the whole of Australia was aerated just another three or four inches deep, it would hold more water than the Snowy Mountain Scheme. So water becomes in Keyline the basis of planning because of the natural factors of climate, the heat and light of the sun, the air and the water and its various movements. There's only one of those factors that can be planned for that will improve the use of all the others. You improve the sun, you improve the air by controlling the water and taking water into the soil when it's needed. So the basis of Keyline planning is the natural landscape with it's own water lines the new water lines that control all the water when those lines are in they position the roads, the roads automatically give you the subdivisions and within the subdivisions you start your soil treatment. These man made lines or water control together with the water lines of the landscapes that the water lines of the small valleys and the little creeks and streams and rivers form a pattern of water lines which are channels to transfer water perhaps to dams others to transfer it from the dams for irrigation other lines usually up the gentle ridges are offered transfer of water to a lower area or sometimes from pumping from a source that's low down for use higher in the landscape. That gives you the pattern. We called it the Keyline grid and all planning, it's based on a grid system because it has to be. You subdivide the land so you've got to get at it so it's always agreed, it's not the grid that can be wrong as a grid, it's the manner of the grid. So our grid is a natural water line grid plus the control line grids. So you then have a patten for the landscape and the landscape imposes itself on the planner. The planner doesn't put geometrical patterns on the land in Keyline. I'm a little bit confused about how ongoing this process is. How regular it has to be. Do you plow once a year or more often than that P A? Well there are various circumstances that arise for instance pasture, a mixed pasture is probably the quickest means of improving soil. Now under irrigation conditions you can cultivate five or six times in the one year if you wanted to we've done that to see if we could destroy the soil by over cultivation, with a chisel plow it was in those days, and we found that we don't destroy the world the thing by cultivating, the soil by cultivation, you just make it happen. But that's in irrigation conditions in the summertime. Now if it's ordinary rainfall conditions and your most reliable rain is in the autumn, then for the first three years you cultivate each autumn, so it's a process for three years. But then you have to watch the soil because everything that happens in farming is tending to compact soil. The implements, the cattle all tending to rob the soil of its air. So you watch the soil. When you see some of the grasses that like sourish conditions start to come in. Alright you need air, so you do it again, maybe five years later. But all the time you have to watch soil and read the soil. Now under the conditions where they're cropping. Well nature make can't make soil without legumes, whether its a rainforest soil or natural pasture. And by legumes you mean what sort of crops? Any legume but to the clovers in the tree falls and that sort of thing, so we would never plant a wheat crop. It would always have its companion legume, because there's something magical about the dead roots of legumes that seems to trigger everything off rapidly. I think that you should just repeat that. I think that's a very important point. You don't just planted a wheat crop on its own. You have another crop with it. Is that right?. That's correct. In fact the big thing to decide then is to select the companion legume or you may have two varieties of legume to plant with every grass crop. That includes all your grains as well as your sugar cane. They're all grass crops. So you plant always a legume with the wheat. You just pick a legume that's not going to interfere with the planting or the harvesting of the wheat. The soil will continuously improve then with the companion legume. Not quite as fast as with a mixed pasture. That's the best to the lot. But soil will improve and deepen, as deep as you want it, as long as you keep your companion legume going. The earth is sufficient. Can you use any legume with any crop or do you have to match a particularly legume with a particular crop? Any legume, just about any legume, will suit the growing of the crop but the important thing is it mustn't interfere with harvesting. For instance, one farmer friend grew a barley crop with Dolichos Lablab. He was a Keyliner, this man, and doesn't use fertilizers, artificial fertilizers, and he doesn't use sprays. He spends most of his spare time, he's a beach buggy fan running round on Flinders Island I think it is. However he grew with barley, Dolichos Lablab, which is a vine type tropical legume. He had a look at it some time before it was ready to strip and he found that the legume had climbed up the storks through all the barley and it was just a mess and he didn't think he would take anything off it. But just as, just before the crop was due to harvest, the Dolichos Lablab set seed and died and broke up into little pieces about half an inch long and all dropped down to the ground and he took a crop that was 50 percent higher in the one year from the Dolichos Lablab and the combination of barley. He also has a another crop he grows with snail clover, which most people haven't heard about. So the important thing is the practical, practical one of being able to harvest and sow the legume that goes with whatever grass and barley's a grass. So do those people who for say to you that it's virtually impossible to grow large crops of any of our staple grasses like wheat, without the use of fertilizers and chemicals and herbicides, you would say that this is completely wrong? It is completely wrong. There's a difficult period of changing over because you can't just stop using fertilizer and do nothing else. You won't get a crop. So the little difficult part is just the changeover but if you have someone else's experience of having done it and made a mistake and found the right one of course it's a big help. But no crop should be planted without a legume. That's a very very important point. I'm sure that many of our listeners will not have realized this. I find it fascinating myself and I'm sure that a lot of people will be interested to hear that. Well P A Yeomans, you're going to be actually addressing a seminar on Thursday the 26th of April. This is being organized by the Murray Valley League and it's in Albury and I believe that we've got another very very distinguished guest from overseas. Some of us may have seen a story about him in Thursday morning's Age (Melbourne newspaper) but part of your own speech, which I'd like you to read to us here, gives a nice succinct, very concise view of what Keyline is and perhaps we can say a little bit about Dr Sopper after this, but just read us a little bit if you're your summary what you maintain Keyline really is. Briefly the foundation of Keyline is a planning medium, the same as those for the natural landscape, namely the shapes the shapes and form of the land and the particular climate that have been applied, that have applied the finishing touches, smoothed it off you know. These are the more permanent things. Of the factors that determine climate, such as the heat and light of the sun, with the air and water and its various movements, one alone can best be manipulated to gain greater landscape value from the others. Of course it's water, The control of water for its beneficial use thus becomes the supreme basis of planning. The first objective of planning has to be the enhancement and enrichment of the land. Since all planning interrupts the natural tree like branching and joining pattern of the little valleys, the small creeks, the streams and the rivers, planning also interrupts the pattern of water for rain flowing over the land. It has to. But it's not the interruption that's wrong, but the manner of it. Planning of the land can lead either towards it's enhancement and the enrichment of the environment or to its degradation. I think very very true words. Planning I think, as we well know here in Melbourne, is sometimes a little bit out of control. Tell us here. We've been very fortunate to have in Australia a visit by Dr William Sopper. Perhaps you can tell us why he is such an eminent person in his own field and what he's going to be talking about up in the Marray Valley League on the 26th of April. Well Dr William E Sopper is professor of forest hydrology at the University of Pennsylvania, near a city called State College in that state. I've had the pleasure touring with him and talking to him, over a few days last week, and I think I'm also going to introduce him as the principal speaker at the symposium that's being held on the 26th at Albury. It goes all day. Is this open to the public by the way? It's open to the public and you just have to bring along forty-five dollars, but if you only want the papers afterwards, it's twenty-five dollars. Why he's so famous in America is because of experiments that have been conducted at State College where they had two great problems. One, the stream through the city had became badly polluted and second the aquifers from which they do they draw their water were rapidly depleting and getting deeper and deeper and less and less. So the problem was to purify the effluent and return it to the groundwater for reuse. Its been so successful that the United States government now pay eighty-five percent towards this type of treatment as opposed to any other treatment. You must understand that the normal first and second stage of treatment goes through but this replaces the tertiary treatment which is very very expensive and from the accounts of Dr Sopper, not too successful. So I'll be introducing Dr Sopper on Thursday. Now they're going to be trying to solve a problem which I consider to be very very major one and that is pollution from a major industry up in the Albury area. I think this has very strong local significance. Perhaps you could tell us a little bit about this? Well the new newsprint mill that Australian Newsprint Mills are putting in at Albury. The construction's already started. It will be discharging about twenty-two megalitres of water per day. That's around between 4 and 5 million (imp. gallons per day), which incidentally is about what you get from a city of sixty to seventy thousand people. They'll be taking that water from the river and discharging it back into the river. With pollutants? With the pollutants. It wont be a bad polluting plant in that it's a mechanical and thermal process for the paper making, not a highly chemical one and but still there will be materials in it that we believe should be taken out of it. The Murray Valley League's principle aim now is the purity of the Murray waters. They were behind the irrigation water and Sir William Hudson (Commissioner of the Snowy Mountains Scheme) said there wouldn't have been any Snowy Mountain Scheme except for the Murray Valley League. But their principle aim now is purity of the waters and the Murray Valley League, of which I've got, I am on the executive. I'm quite proud of it, is making this their project to see if we can persuade the powers that be and the mills to put in a City Forest which is the Keyline version of land treatment for sewage effluent. Just very very briefly here. What we're doing is going to be using the effluent and we're going to be distributing it over the land along the principles of Keyline. Is that right? The aim is to put a City Forest according to the Keyline book of 1971, which was called The City Forest, and return most of the water back, because it doesn't take a lot of water to maintain the forest, although they are typical of high rainfall areas, so it will go through the forest and the forest soil and come out like mountain spring water. Well thank you very much indeed Mr P A Yeomans. And if anyone would like to know any more about this seminar which is being held on Thursday the 26th of April in Albury, with two very prominent speakers at least, I'm not certain of the other speakers, they can get in touch with me Bruce Hedge via 3CR here in Melbourne 419 2569 (no longer current). Thanks very much indeed Mr Yeomans and we'll be hearing more from you on future programs hopefully.