Background Papers: (International) 21. HISTORICAL REVIEW OF NO-TILLAGE CULTIVATION OF CROPS R. Derpsch Abstract 

No-tillage and reduced tillage have been used since ancient times by indigenous cultures, simply because man has not the muscle force to till any significant area of land to a significant depth by hand. The ancient Egyptians and the Incas in the Andes of South America for example, used a stick to make a hole in the ground and put seeds by hand into unprepared soil. In modern, mechanised agriculture no-tillage cultivation of crops was tried a long time ago, but it was not until the advent of modern herbicides that the technique could be put into practice. Back in the 40ies Edward Faulkner induced a change to go away from the plough and reduce tillage with his famous book „Plowman’s Folly" (1943). 

According to Phillips and Phillips (1984) attention turned to reduced tillage in the late 1940s with the introduction of plant growth regulators developed during World War II. Klingman, in North Carolina in the late 1940s reported no-tillage work. In 1951, K.C. Barrons, J.H. Davidson and C.D. Fitzgerald of the Dow Chemical Co., reported successful application of no-tillage techniques. In the 1960s M.A. Sprague, in New Jersey, reported pasture renovation using chemicals as a substitute for tillage. L.A. Porter, New Zealand, reported on strawberry production without tillage in the early 1960s, followed be A.E.M. Hood, and R.S.L. Jeater at Jealott’s Hill, England, with small grain (Phillips and Phillips, 1984). 

The invention of Paraquat in 1955 and its commercial release in 1961 led the Imperial Chemical Company, ICI, and others, to start intensive no-tillage research in the UK, the USA and elsewhere. In 1961 and 1962 demonstration trials where run on several farms in the United States. These demonstration plots led Harry and Lawrence Young from Herndon, Kentucky, to try the novel technology on their farm and turned them into one of the first mechanised farmers in the world to use modern no-tillage crop production. 

First no-tillage trials in Latin America were started in 1971 by the Instituto de Pesquisas Agropecuarias Meridional, IPEAME, in Londrina, Paraná State, Brazil, in co-operation with a GTZ (German aid) project. This project installed demonstration plots at the farm of Herbert Bartz, a Brazilian farmer of German descent, in Rolandia, Paraná. After seeing the results of these plots, Herbert Bartz made a trip to the UK and to the USA, researched about the advances of this technique, visited ICI in Fernhurst and Harry Young in Kentucky, bought a no-till planter in each country, and started seeding his first no-till soybeans in 1972. Thus Herbert Bartz became the first farmer to try the technology in Latin America and to use it continuously until the present. 

Compared to the Americas, much less no-tillage is practised in Europe, Africa and Asia, and in many countries this soil conserving sustainable production system is virtually unknown. Despite a wealth of research information generated at IITA, Nigeria, since the seventies, the total area under no-tillage in Africa is still very small. 

Introduction 

No-tillage is defined in this paper as the operation of planting crops in previously unprepared soil by opening a narrow slot, trench, or band only of sufficient width and depth to obtain proper seed coverage. No other soil preparation is done (Phillips and Young, 1973). We also refer here to permanent no-tillage rather than not tilling the soil occasionally. No-tillage is the term used in North America while direct-drilling or zero tillage is used in the United Kingdom and Europe. Aerial seeding is of course the ultimate form of zero tillage. 

When I have been invited to present this paper on „Historical review of no-tillage cultivation of crops" at the 1^st JIRCAS Seminar on Soybean Research I thought that I could accept the task, since I have lived an important part of this history by myself. But when trying to get information on what has happened outside the main no-till countries, information gets very scarce and given the short time frame to prepare this paper, I have not been able to gather enough information to give a comprehensive picture on the historical development of this production system. Therefore I am obliged to reduce this paper to the countries where data was more readily available or where colleagues and friends provided me with information. It has to be recognised, that it is very difficult to be always fair to all who have contributed over the years to the history and development of no-tillage farming over the world. Therefore I would like to apologise to those not mentioned in this paper. Also, at this point I would like to thank everybody that took his time to provide me with facts and figures on the history of no-tillage cultivation in different parts of the world. Despite the difficulties , the task of writing this paper has been a worthwhile experience and has opened my eyes to the fact that probably about 95% of the practical application of no-tillage by farmers world-wide takes place in the Americas. Therefore, a greater effort has to be made to transfer this truly sustainable production system mainly to the tropics and warmer areas of Africa and Asia. The reason for this, is that „no technique yet devised by mankind has been anywhere near as effective at halting soil erosion and making food production truly sustainable as no-tillage" (Baker, et al., 1996). 

The ploughing system is considered to be an inefficient use of time and fuel and causes much „wear and tear" to the machines (Waydelin, 1994). Power requirements for soil tillage are considerable. In modern agriculture this may be a technical challenge or an economic problem, but formerly this meant hard, long lasting labour for a large percentage of all the people that ever lived on earth. Forces required are so great that animals were used very early to make the physical stress endurable (Kuipers, 1970). But a small farmer ploughing his field with animal traction has to walk 30 to 40 km behind his plough for each hectare he is preparing the soil. Therefore, the reduction of tillage to the minimum necessary to produce a crop, has probably been in the minds of many farmers for a long time. But when the tractor appeared, where effort is reduced because the operator is sitting, the tendency went the other way and farmers started believing that the more tillage you do, the more yield you get. Truth was, that the more tillage you do the more erosion and soil degradation you get, especially in warmer areas. 

A Short History Of Tillage 

The plough has been developed in early days of agriculture and was first pulled by man and later by animals. The use of the plough is often mentioned in the Bible and one of the best known citations is „they shall beat their swords into plough shares" (Isaiah 2. V. 4.). But the plough of biblical times had nothing to do with modern ploughs of the 19th century. In those days a plough was nothing else than a branch from a tree that scratched or scarified the soil surface without mixing the soil layers. Ploughs that inverted the soil layers and thus had a better weed control where not developed until the 17th century. Only in the 18th and 19th century ploughs became more and more sophisticated. But it was not till the end of the 18^th century that German, Dutch and British developments of this tool led to an almost perfect shape of the mouldboard, that turned the soil by 135° and was very efficient in weed control. It is this plough that avoided famine and death at the end of the 18^th century, since it was the only tool that could effectively control quack grass (Agropyron repens), a weed that than spread all over Europe and could not be controlled with „conventional" tools. Because the modern plough saved Europe from famine and poverty it became a symbol of „modern" agriculture and is used as such by many agricultural research institutes, Universities, agronomy schools, etc. One of these early ploughs of 1884 is shown at the agricultural museum of the University of Hohenheim, at Stuttgart, Germany, and in a festival is taken around the city of Hohenheim each year, to commemorate the invention of this implement. By knowing the history of this tool, it becomes understandable why Europeans and especially Germans are often such fervent defenders of the plough, which has turned to be the most often used symbol of agriculture world wide. 

As a consequence of this history, the colonial powers took the plough to America, Asia and Africa, where it became an important tool for the development of newly cultivated land. But it took many decades to discover that the same tool that brought food and wealth to Europe, would bring soil erosion and degradation to the warmer environments. 

Often the experts mainly from Europe have spread the idea that tillage makes the soil fertile and therefore cannot be overdone. They have not understood the significance of soil erosion, as well as intensive weathering under hot, humid conditions. This has resulted in the widespread distribution of poor, badly eroded, infertile soils all over the tropics and subtropics. Economic interests and the lack of experience of some of the expatriate experts have led, first the colonial countries and later the aid donor countries, to spread the culture of the plough in developing countries, while the so called „primitive technologies" have been classified as backwards and unproductive. 

Early Cultivation Without Tillage 

No-tillage and reduced tillage has been used since ancient times by the so called „primitive cultures" for the cultivation of crops, simply because man has not the muscle force to till any significant area of land to a significant depth by hand. 

The Incas in the Andes of South America and probably also most indigenous cultures around the world, have used a stick to make a hole in the ground, put seeds in the soil by hand and cover the seeds with the foot. Even today hundreds of thousands of farmers in Central and South America seed their crops using the same technology. Moreover, millions of hectares of land have been (and are today) traditionally sown with a hand jab planter without tilling the soil, after burning, in the shifting cultivation system in Brazil and neighbouring countries, long before the term no-tillage was introduced into modern vocabulary. The slash mulch or „tapado" system in Central America and Mexico is another example of small farmer developed no-tillage which has been used for centuries (Thurston, et al., 1994). In this system the seed is thrown after a rain on top of the soil underneath a dense stand of Mexican Sunflower (Thithonia diversifolia) or other voluntary (or seeded) vegetation. Then the plants are cut and left on top of the seeds. After a few days the plants dry out and seeds germinate. In this case there is absolutely no tillage performed at all. 

The first possibility of cultivating crops without tillage on large scale farms occurred when 2,4-D, a broadleaf weed killer, was made available to farmers in the 1940s. Later, also Atrazine and Paraquat became available, these being the only herbicides accessible to early no-tillers. 

Development In Europe 

The invention of the herbicide Paraquat in 1955 in the UNITED KINGDOM was the start of modern no-tillage development in Europe and also world-wide. This discovery led the Imperial Chemical Company, ICI, to initiate research without tilling the soil. In 1973/74 the area under no-tillage in Great Britain grew to 200.000 ha and 10 years later to 275.000 ha (Table 1), thus the UK had the second largest area under no-tillage in the world after the USA (Derpsch, 1984). Field experiments in England showed that, if well managed, direct-drilling and reduced cultivation could give similar yields of winter cereals as after ploughing, when straw residues were burnt. However, when restrictions on straw burning were introduced and problems occurred from the build-up of weeds and volunteer cereals many farmers who used these methods returned to using the plough and direct drilling almost ceased to be used (Christian, 1994). 

In the NETHERLANDS research on minimum and no-tillage started in 1962, aimed at simplification of field work, saving of time and energy and improvement of farm economy. W.A.P. Bakermans and C.T. de Wit of the Institute for Biological and Chemical Research of Agricultural Crops in Wageningen, were among the first Scientists to try the novel technology. Wind and water erosion are not real incentives for no-tillage practices in this country. From the early experiences, gained in the period 1962-1971, Ouwerkerk and Perdok (1994) concluded that in Dutch arable farming no-tillage is not feasible. 

Stimulated by successful trials abroad, investigations into direct drilling systems started in GERMANY during 1966 (Bäumer, 1970). Despite intensive and long term research by Bäumer in the Institute of Plant Production of the University of Goettingen (the early experiments are still under way), by Czeratzki in Braunschweig and by Kahnt at the University of Hohenheim (Kahnt, 1969, 1976) that started in the late sixties, it is estimated that not more than 5.000 ha of permanent no-tillage were practised in Germany in 1997 (Friedrich Tebrügge, personal communication 1998). On the other hand occasional no-tillage is being increasingly practised by farmers in this country. In long term research (18 years) carried out at the University of Giessen (Tebrügge and Böhrnsen, 1997) the authors conclude that no-tillage is a very profitable cultivation system compared to conventional tillage because of the cost savings from lower machinery costs and lower operating costs. No-tillage decreases the purchase costs, the tractor power requirement, the fuel consumption, the amount of required labour as well as the variable and fixed costs. At the same time no-tillage increases the campaign performance so that it is a very powerful cultivation system. On average the same crop yields are possible by no-tillage compared to plough tillage. So the profit will increase. On the other hand lower yields can be accepted without any loss of profit in comparison to the conventional system. Calculating the total process cost the relative superiority of no-tillage systems would increase further, if we took the positive environmental effects of no-tillage (e.g. less erosion, less pollution by agrochemicals) into account (Tebrügge and Böhrnsen, 1997). 

In FRANCE a long term experimentation with different minimum tillage techniques (including no-tillage) was started by INRA and ITCF in 1970, mainly with cereals (Boisgontier, et al., 1994). The authors conclude, that a comprehensive range of technical and economic data is now available in France in relation to where minimum tillage can be developed and how it can be implemented. 

In PORTUGAL, Carvalho and Basch (1994) conclude that for most of the crops direct drilling is a feasible technique. 

No-tillage research in SPAIN started in 1982 and on the clay soils of southern Spain it is advantageous in terms of energy consumption and moisture conservation, as compared to both conventional or minimum tillage techniques (Giráldez and González, 1994). In 1996 there were 500 no-tillage machines in use and it is possible to advance as a conservative estimation that the area direct drilled in Spain amounts 300.000 to 350.000 ha (Gonzáles, et al., 1997). These areas represent only a small proportion (below 5%) of the area under annual crops. Although the references cited mention no-tillage, it is doubtful if no-tillage under the proposed definition in this paper is meant. Costa (1996), writes: „It is somewhat disappointing that conservation tillage (no-tillage with 30% of soil covered by crop residues) has received so little public support". Is no-tillage being understood as synonymous of conservation tillage? 

First no-tillage trials in ITALY were carried out in 1968, but only in the last 5 or 10 years the technology has experienced a substantial growth. This is due to the necessity of reducing crop costs and the greater availability on the Italian market of equipment capable of sowing on untilled soil, as well as progress in the availability of adequate herbicides. In 1994, it was estimated that this planting system was used on a surface area well above 30.000 ha for cereals and around 3.000 ha for soybeans (Sartori and Peruzzi, 1994). More recently the no-tillage area has grown to 100.000 ha, this is 2% of the agricultural land used for extensive cropping (Sandri and Sartori, 1997). 

In BELGIUM Frankinet and Rixhon compared ploughing to direct drilling over a 15 year period from 1967 to 1982. Yields after direct drilling were slightly greater for winter beans, similar for winter wheat and spring oats, 15% less for spring barley and maize, and 20% less for sugarbeet (Cannel and Hawes, 1994). 

In SWITZERLAND Vez started research on direct drilling in 1967 showing 15% yield increases in winter wheat as compared to ploughing (Cannel and Hawes, 1994). 

Development In The United States 

Research on conservation tillage with early versions of a chisel plough was started in the Great Plains in the 1930s, looking at solutions to the damage caused by wind erosion, after the occurrence of the famous „dust bowl". Stubble mulch farming was developed in the great plains, being a forerunner of no-tillage. 

Edward Faulkner’s Boock Plowman’s Folly, first published in 1943, is probably a milestone in changing agricultural tillage practices. He questioned the wisdom of ploughing. Some of his statements are: „No one has ever advanced a scientific reason for plowing"; „There is simply no need for plowing in the fist instance. And most of the operations that customarily follow the plowing are entirely unnecessary, if the land has not been plowed"; „There is nothing wrong with our soil, except our interference"; „It can be said with considerable truth that the use of the plow has actually destroyed the productiveness of our soils". The statements were questioned by both farmers and researchers, because alternatives to ploughing at that time would not allow farmers to control weeds or plant into the residue. According to the Reader’s Digest, „probably no book on agricultural subject has ever prompted so much discussion in the United States, at the time it was written. Five editions were printed in the first year of publishing. 

Klingman, in North Carolina in the late 1940s reported no-tillage work. In 1951, K..C. Barrons, J.H. Davidson and C.D. Fitzgerald of the Dow Chemical Co., reported successful application of no-tillage techniques. In the 1960s M.A. Sprague, in New Jersey, reported pasture renovation using chemicals as a substitute for tillage. (Phillips and Phillips, 1984). 

More intensive research on chemical seedbed preparation is started in the United States in the early sixties. In 1960, experiments were begun in Virginia, killing bluegrass sod with Paraquat, using Atrazine for residual control and 2,4-D for post planting cleanup. These experiments were soon repeated in Ohio, Illinois, and Kentucky (Thomas and Blevins, 1996, Blevins et al., 1998). 

In 1961 and 1962 demonstration trials where run on several farms in the US. These demonstration plots led Harry and Lawrence Young from Herndon, Kentucky, to try the new technology on their farm in 1962. This turned them to be one of the first mechanised farmers in the world to use no-tillage crop production. A metal plate at the site remembers the date: „First practice of no-tillage crop production in Kentucky occurred on this farm in 1962. Harry and Lawrence Young of Christian County were among first in nation to experiment with no-tillage techniques which use herbicides in providing seed bed in residue stubble. Conserves soil and water, saves time, labour, fuel and often produces higher crop yields". 

Harry Young earned his B.S. and M.S. degrees at the University of Kentucky, and worked for the University before returning to the 500 ha family farm in 1954. He began experimentation with no-tillage on about 1/3 ha in 1962. Soon thousands of visitors went to his farm to learn about the new technology (Phillips and Young, 1973). Other farmers joined Harry Young and his brother later and began testing no-tillage corn production. At this time also machinery manufacturers started developing adequate equipment and in 1966 Allis Chalmers introduced the fluted coulter no-tillage planter. As no-tillage made it possible to seed immediately after harvest, no-tillage soybeans started to be double cropped after wheat in 1967 (Phillips and Young, 1973). 

Shirley Phillips, one of the pioneer researchers of no-tillage in Lexington, University of Kentucky, wanted to prove that no-tillage was unsuited for adequate crop production. But after seeing the results, he turned into one of the strongest defenders and most successful disseminators of no-tillage, not only in the US, but abroad as well. Because of his commitment to the system and his scientific as well as extension and lecture work, Shirley Phillips can be regarded today as the father of no-tillage technology. 

Among the earliest research publications on no-tillage crop production we can cite Moody et al., 1961, Free el al., 1963, Triplett et al., 1963, Triplett et al., 1964, Lillard and Jones, 1964 and Jeater and McIlvenny, 1965. A six year comparison of no-tillage was published by Shear and Moshler in 1969. 

In 1973 Phillips and Young published the Book „No Tillage Farming". This publication was a milestone in no-tillage literature, being the first one of its kind in the world. It led other people to try and research the technology and was later translated into Spanish. 

The area under no-tillage in the United States experimented a steady growth and went from 
2.2 million ha in 1973/74 to 4.8 million ha in 1983/84 (Table 1) to almost 20 million ha in 1997 (Table 2), but this is only 16% of the total cropping area of the country. 

The new farm laws of 1985 and 1990, which pushed conservation compliance, recognised the vital role of no-tillage as a major means of meeting conservation requirements on highly erodible soils (Thomas and Blevins, 1996) and contributed to a faster adoption of no-tillage. 

Despite an impressive growth of no-tillage in the USA, expansion has been much slower than anticipated. In 1975 USDA predicted that in the year 2000 about 82% of planted cropland in the United States could be under conservation tillage and 45% under no-tillage (USDA, 1975, 1985). This forecast will be impossible to meet. 

The growth of the no-tillage area in the USA, Canada and the other main no-till countries from 1987 to 1996 is shown by Hebblethwaite (1997) from CTIC (Figure1). 

Development in Latin America 

BRAZIL: The first attempt to try the no-till technology was made by the Faculty of Agronomy of the University of Rio Grande do Sul, in Não-Me-Toque, in 1969 (Borges, 1993). With the help of USAID a Buffalo no-till planter was imported from the USA, and one hectare was direct drilled with sorghum the same year. Unfortunately this machine was destroyed by fire putting an end to this early development. 

First no-tillage trials in Latin America were started in April 1971 at the Instituto de Pesquisas Agropecuarias Meridional, IPEAME (later EMBRAPA, Empresa Brasileira de Pesquisa Agropecuaria), in Londrina, Paraná State, in co-operation with a GTZ (German aid) project (Derpsch, 1984). This project installed demonstration plots at the farm of Herbert Bartz, a Brazilian farmer of German descent, in Rolandia, Paraná. After seeing the results of these plots, Herbert Bartz made a trip to the UK and to the USA, researched about the advances of this technique, visited ICI Fernhurst and Harry Young in Kentucky, bought a no-till planter in each country, and started seeding his first no-till soybeans in October 1972. This is how Herbert Bartz became the first farmer to try the technology in Brazil and Latin America and to use it continuously until present. Another farmer, that imported an Allis Chalmers no-till machine together with Bartz, abandoned the system a few years later, after having problems in controlling weeds. The beginning of no-tillage had many ups and downs in terms of area, since the first machines build in Brazil in 1975/76 based on the rotary hoe (Howard Rotacaster) were slow and the only herbicides available were 2,4-D and Paraquat. Hand hoeing saved many crops from failure at this stage. Despite the difficulties at the beginning, the area under no-tillage grew from 1.000 ha in 1973/74 to 400.000 ha in 1983/84 ( Table 1) and reached 6.500.000 ha in 1996/97 (Table 2). The Federation of No-till Associations in Brazil FEBRAPDP, estimates that in 1998 the no-till area in Brazil has expanded to 8,4 million hectares (Figure 2). 

ICI promoted no-tillage in Brazil from the early days with Terry Wiles starting applied research in Rolandia, Paraná in 1972. First experiences in the State of Rio Grande do Sul were started by ICI in 1973. More intensive and systematic research on no-tillage was initiated at IAPAR, Fundação Instituto Agronomico do Paraná, Londrina in 1976, in a co-operative research effort with ICI. This resulted in the first comprehensive research publication on no-tillage in Brazil in 1981 (IAPAR, 1981). Another co-operative research project started in 1977 between IAPAR and the German Agency for Technical Cooperation, GTZ, focusing on cover crops and crop rotations in no-tillage. The results were published in German in 1988 and later translated into Portuguese (Derpsch, et al., 1991). At present, some research institutions of Brazil as EMBRAPA (CNPTrigo), in Passo Fundo, Rio Grande do Sul, have determined, that all research programs (varieties, rotations, cover crops, etc.) should be done in no-tillage and the goal is to work (together with the extension service and the private sector) towards a 100% adoption of this farming system by farmers. 

The first National No-till Conference was held in Ponta Grossa, Paraná in 1981 organized by the „Cooperativa Central Agropecuária Campos Gerais". Two other National conferences in 1983 and 1985 at the same site boosted the no-till area in the „Campos Gerais" of Ponta Grossa to about 200.000 ha in 1986, this being the first big region to be completely no-tilled in Brazil. Here the pioneer work of Frank Dijkstra and Manoel Henrique Pereira (President of the Federation of No-till Farmers FEBRAPDP, from 1992-1998), both farmers and leaders in their community, played a major role in the development and diffusion of this method of farming, not only in Brazil, but in all Latin American countries and abroad. From here the technology spread mainly to the States of Santa Catarina and Rio Grande do Sul in the South of the country where great advances have been achieved with the use of cover crops and crop rotations, thus reducing fertiliser and herbicide costs. In the 1990s the biggest expansion of no-tillage in Brazil (Figure 2) occurred in the Cerrados (savannas of North Central Brazil with only one growing season per year), thanks to the important work of APDC (No-till Association of the Cerrados), which organised the fifth and sixth national no-till conference in Goiania, the last one with more than 2500 participants. 

As more, better and cheaper herbicides appeared on the market in the 1990s no-tillage became easier to manage and this together with the development of more diverse and better no-till seeding machines, has had a tremendous impact in adoption rates by farmers (Figure 2). Among the chemical companies, probably Monsanto has been the one that has invested more in the diffusion of no-tillage, because of its interest in marketing the herbicide Gliphosate. Among the no-tillage seeding equipment manufacturers, Semeato has been the leading Company in developing seeding machines and supporting no-till related activities. In 1985 already, thirteen no-tillage seeding machine manufacturers were on the market in Brazil (Derpsch, et al. 1991). 

Main crops under no-tillage in Brazil are soybeans, maize, wheat, barley, sorghum, sunflower, beans and green manure cover crops in rainfed agriculture. Irrigated rice is also increasingly being no-tilled in southern Brazil. About 110.000 ha of irrigated rice (13% of total area) is being no-tilled in the State of Rio Grande do Sul (Juliano Busato, personal communication, 1998). Not only traditional crops are now being no-tilled in this country, but also onions, tomatoes, vegetables, tobacco, etc. 

ARGENTINA: First farm experiences and also research with no-tillage were started in Argentina in 1974. At this time some pioneer farmers began trying no-tillage while looking for a better way to grow soybeans after wheat in a double cropping system (two crops in one year). Several farmers started with the system and than gave up mainly because of the lack of adequate herbicides and machinery which constituted the main bottleneck for the early adoption of the system. Duperial (ICI) was one of the first private companies to get involved with the diffusion of the system by promoting research activities, meetings and field days. This company also arranged a co-operation project with INTA (Instituto Nacional de Tecnologïa Agropecuaria) (Marelli, 1995). Among other outputs of this project, a National No-tillage Conference was held at the INTA experiment station Marcos Juarez in1977 (INTA, 1977). From that time, INTA developed research and extension no-till projects targeting some productive areas of the country. Heri Rosso from Marcos Juarez was one of the first farmers to try the technology in Argentina in 1978 and is now using it with increasing success. In 1979 the second National no-till Conference was held in Rosario, Santa Fé. 

In 1986 AAPRESID (Argentine Association of No-till Farmers) was formed, being a milestone in Argentine diffusion of no-tillage technology. In 1992 AAPRESID organised its first national conference „Congreso Nacional de Productores en Siembra Directa" which is visited yearly by more than 1000 farmers. While in 1987/88 not more than 25.000 ha were no-tilled in Argentina, the technology has expanded to 4,4 million hectares in 1996/97. The availability of machines was the main bottleneck in early adoption of no-tillage, but today almost 30 different manufacturers from Argentina, and a few from Brazil, are selling no-tillage seeding machines in this country. Soybeans, maize, wheat and other small grains, as well as sorghum and sunflowers are the main crops being no-tilled in Argentina. 

CHILE: Carlos Crovetto is Chile’s no-till pioneer. In 1978, he bought an Allis Chalmers planter and planted Chile’s first no-till corn on his Chequen farm near Concepción. Today, Crovetto has virtually eliminated erosion, by leaving about 14.300 kg/ha of corn residue and 6.200 kg/ha of wheat residue on the surface. On land with 15 to 18 percent slope he produces remarkable yields, such as 19.600 kg/ha irrigated corn and 10.800 kg/ha dryland wheat (No-Till Farmer, 1997). Through 19 years of continuous no-till Carlos Crovetto has added one inch of topsoil, boosted the organic matter from 1.7 to 10,6% in the first 5 centimetres of soil, improved bullk density from 1.7 to 1.4 g/cm³, jumped his soil’s water holding capacity by more than 100 percent, increased phosphate from 7 to 100 ppm and potash from 200 to 360 ppm in the top 5 centimetres of soil, improved the soil’s cation-exchange capacity from 11 to 26 milli-equivalents per 100 grams of soil and raised the soil’s pH levels from 6 to 7 (No-Till Farmer, 1997). As a farmer and researcher, Crovetto is also author of the book „Rastrojos sobre el suelo" (1992), which was later translated into English with the title „Stubble over the soil" (1996). 

First research reports on no-tillage were published by INIA in 1981 (Del Canto and Ormeño, 1981; Martinez and Novoa, 1981). Despite 20 years of successful no-till farming in Chile, the system has not expanded to more than about a 100.000 ha in this country, and many farmers still burn the straw and no-till into ashes. Wheat, oats and Rapeseed are the main crops under no-tillage in Chile (approximately 95%). Other crops are barley, triticale, lupins, lentils, and maize. 

PARAGUAY: Before any research on no-tillage was performed, farmers from the Cooperative Colonias Unidas, in Itapua, the South of Paraguay, tried the new production system in the beginning of the 1980s. Because of lack of knowledge on how to handle the new technology and because they imported machines of lower quality based on the rotary hoe, as well as because of lack of appropriate herbicides on the market, the first experiences failed and soon they returned to conventional tillage. Later, Japanese farmers from Colonia Yguazú, Eastern Paraguay, gave the technology a new try with the backing of the Centro Tecnológico Agropecuario en Paraguay (JICA-CETAPAR). This centre, which was established for extending technical assistance to Japanese immigrant farmers in Paraguay, together with farmers, succeeded in making the system work. Akinobu Fukami, a Japanese immigrant, president of the local co-operative and leader in his community was the first farmer in this country to practise no-tillage successfully and continuously since 1983. With the support of JICA, all the farmers of this co-operative were using the technology 10 years later and also many farmers of other Japanese colonies. Initial growth was slow, and in 1992 only 20.000 ha were no-tilled in Paraguay. After the Ministry of Agriculture of Paraguay with the assistance of the German Agency for Technical Cooperation, GTZ, started a Soil Conservation Project in 1993 that concentrated on no-tillage development and diffusion, the technology expanded rapidly to about 500.000 ha in 1998 (mainly soybeans). About 65% of soybean growing farmers in mechanised agriculture were using no-tillage on all or part of their farms in 1998. 

BOLIVIA: After visiting Brazil and Argentina, Dr. Jean Landivar started no-tillage on his 2000 ha farm in the lowlands of Santa Cruz in 1986. He started no-tilling sorghum and maize and also some soybeans. Research started at about the same time but without positive results. In the summer of 1996/97 102.000 ha were no-tilled in Santa Cruz mainly with soybeans but also maize, rice and some cotton. In the winter of 1996 35.000 ha of wheat (35% of total area) and also sunflowers were sown in no-tillage (Patrick Wall, personal communication, 1997). 

MEXICO: At the end of 1997 about 490.000 ha were being no-tilled in Mexico, 100 - 200 thousand hectares of which was practised by small farmers (Ramón Claverán, personal communication, 1997). 

Most other countries in Latin America have started to work with the technology more recently and have no-tillage areas below a 100.000 ha. 

CAAPAS: An important milestone in the development of no-tillage in Latin America was the foundation in 1992 of CAAPAS, the Federation of American No-tillage Associations for Sustainable Agriculture. Victor Trucco has been the first president from 1992-1998. At first only Latin American countries joined, but in 1998 CTIC (Conservation Tillage Information Centre) has become a member too. 

Development in Africa 

Earliest research on no-tillage in Africa was performed in the late sixties in Ghana (Kannegieter, 1967, 1969, Ofori and Nanday, 1969, Ofori 1973). Research work at the IITA (International Institute of Tropical Agriculture) in Ibadan, Nigeria started in 1970 (FAO, 1993). Rattan Lal has been one of the most prominent researchers and prolific writers on this subject at IITA. First publications by Lal were written in 1973 (Lal, 1973 a, b). Forty one of his publications are listed as references in the IITA Monograph N° 2, which summarises 12 years of work at this Institute (Lal, 1983). Other scientists working in national research institutes and universities in Nigeria also started studies on a range of soils in the 1970s to compare the effect of different tillage methods on soil properties, crop growth and yield (Agboola and Fayemi, Aina, Wilkinson, cited by FAO, 1993). Similar studies were also initiated in other African counties including Liberia by Lal and Dinkins, Ivory Coast by Roose and Senegal by Nicou and Chopart (FAO, 1993). Despite a great wealth of research information on no-tillage and mulch farming in Africa, the technology has not spread to a great extent among farmers. Also, there is only little information available on the development of no-tillage in this continent. A study on the potential use of no-tillage in Africa made by GTZ (Köller et al., 1998), indicates, that the technology is already being used to some extent in the following countries: Angola, Benin, Ghana, Ivory Coast, Kenya, Mozambique, Niger, South Africa, Tanzania Zambia and Zimbabwe. In most countries in Southeast Africa some work on conservation tillage practices (either at research stations or on farms) is being done and no-tillage is practised successfully on larger farms. The most common crops being used in no-tillage are maize, sorghum, wheat and cotton. 

On mechanised farms no-tillage seeding machines are often imported from Brazil, New Zealand or from the USA, but in Zimbabwe there is also a local production. No-tillage seeding equipment for small farms is manufactured in South Africa for experimental purposes and in some cases imported from Brazil. Also hand jab planters are imported from Brazil (Köller et al., 1998). 

On the other hand according to the Conservation Tillage Handbook in Zimbabwe (Vowles, 1989) many farmers have modified their planters to enable them to plant row crops directly through crop residues with no previous tillage operation. Although experimentation with zero tillage in many cases began with irrigated crops, it is believed that under dryland conditions the potential benefits of zero tillage are the greatest. 

It should also be mentioned, that permanent zero tillage is practised only in regions with higher rainfall patterns or when irrigation is available. Minimum tillage is used widely and is the most common form of soil preparation on small farms (1-2ha). 

According to Köller et al. (1998), traditional land tenure, uncontrolled or communal grazing and lack of sufficient soil cover, as well as socio-economic constraints are the mayor problems in spreading no-tillage in Africa. Research and development as well as diffusion strategies have to be directed towards solving these problems before no-tillage will be an attractive alternative for farmers in this continent. On the other hand labour constraints at the time of seeding in many regions of Africa may be an opportunity for this system to be accepted among farmers. 

Development in Australia and New Zealand 

Before no-tillage of crops pastures were direct drilled in Australia and New Zealand. In 1964 Plant Protection Ltd and ICI Australia Ltd undertook a joint programme of work with the bipyridiyls for crop establishment without tillage in Australia (Barret et al., 1972). First experiments were conducted in the Eastern States (Rowell, 1968). Besides this, little information could be obtained on the development of no-tillage in Australia other than that the technology is practised on about 1 million hectares (Hebblethwaite, 1997). Australia has serious erosion problems and this is an important reason why no-tillage is being increasingly used. 

In New Zealand Taylor (1967) from ICI Christchurch, reports that satisfactory yields of winter wheat were obtained by Arnott and Clement in 1962 following the application of chemicals in uncultivated soil. At Massey University in New Zealand many papers have been published in the 1950s and 1960s by M.W. Cross on reseeding, oversowing and overdrilling pastures. In the 1970s more profound investigations start with direct drilling of crops (Baker, 1970, Dixon 1972). Intensive research on no-tillage has continued at Massey University until the present days. In the book „No-tillage seeding" (Baker, et al., 1996) many references of research on direct drilling carried out in New Zealand are listed. 

Development in Asia 

It has been difficult to get information on the development of no-tillage in Asia. According to Table 1 there was some no-tillage being practised in Japan, Malaysia and Sri Lanka. There is some information that conservation tillage is practised in India, Indonesia, Korea, Philippines, Taiwan and Thailand. A little bit more information could be gathered from Japan. 

JAPAN: (Personal communication by Makie Kokubun, 1998) There have been many studies and experiments on the no-tillage system in Japan, from the viewpoint of soil properties, crop performance and labour cost. The advantages and benefits from this system were in many cases observed in terms of labour cost/time, and in sometimes in terms of crop performance. 

Several types of no-tillage seeding machines have been designed, built and tested by experimental stations and private companies and some of them have proved to be practical. A few of the machines are ready for commercial sale 

Despite the considerable research effort for the development of no-tillage, farmers have not been keen to adopt this technology, so that the acreage under this system is statistically negligible in Japan. This is mainly because soil erosion, which is a strong driving force to introduce no-tillage in South and North America, is not a serious problem in Japan. 

There is an effort to develop the no-tillage system in rice-based cropping system in paddy field. In this system, weed control is done by water management rather than herbicide application. Similar system was used in rice-pasture cropping system in Australia. 

In some Asian countries where JIRCAS is carrying out collaborative research, the situation is similar to Japan. Despite the research efforts to confirm the advantages of the no-tillage system, the prevalence among farmers is still at a starting point. 

Final Remarks 

1. Although there were many early attempts to cultivate crops without tillage, modern no-tillage research started in the 1940s and adoption by farmers in the early 1960s.

2. First conceived as an efficient soil conservation method, no-tillage has evolved to an economic and sustainable production system that not only improves soil physical, chemical and biological characteristics, but also improves the environment for all, by reducing the emission of greenhouse gases.

3. The historical development of no-tillage cultivation of crops and the successful application on mechanised farms has been intimately related to the following factors:

• the availability of appropriate knowledge (research results and farmers experiences) for the different agro-ecological and socio-economic conditions
• the availability of a variety of efficient low cost herbicides
• the availability of appropriate machines at adequate prices
• the practice of adequate crop rotations including green manure cover crops (this has been the basis of successful application especially in Latin America)

4. The greatest diffusion of no-tillage has happened in the Americas, while only a small proportion is found in the rest of the world.

5. Latin America has achieved adoption on more than 14 million hectares virtually without any subsidies.

6. Despite a wealth of research information in Africa showing the benefits of no-tillage, this farming system is practised very little in that continent.

7. The historical development shows, that industry and farmers have had a major influence in the diffusion of the no-tillage production system

8. Research, development and diffusion of no-tillage has been accomplished almost exclusively on mechanised medium and large sized farms. Research on small farms in Brazil started only in 1982, and in most parts of the world is none existent.

9. Adoption of no-tillage on small farms (that do no have tractors) is still very little on a world wide basis. Greatest adopters are Brazil with less than 50.000 ha, Paraguay with 4.500 ha, and the countries in Central America that use the „tapado„ system.

10. Reduced costs of production under no-tillage is probably the main driving force in achieving high adoption rates. Production costs per acre of soybeans in no-tillage are reduced by US$ 27,00 in Argentina, by US$ 14,18 in the USA and by US$ 11,50 in Brazil. Similar reductions in the production costs are also achieved with maize (Hebblethwaite and Towery, 1997).

11. No-tillage accounts for less than 50% of conservation tillage practices in the USA, but is almost the only form of conservation tillage practised in Latin America.

12. It has been generally understood that no-tillage is not a fashion or a transitory trend, but it is a production system that is spreading increasingly because of its evident advantages and also because of ecological and economic pressures.

Acknowledgements 

The author gratefully acknowledges the help received from many colleagues, friends and farmers in the preparation of this paper, without which this report would not have been possible. It would be a too long list, to mention all who have contributed in one way or another in making available information requested by the author. The major contributors to this paper have been Dr. Grant Thomas, University of Kentucky, USA; Dr. Friedrich Tebrügge, Justus-Liebig-University, Giessen, Germany; Dr. Kurt Steiner, GTZ, Eschborn, Germany; Dr. Theodor Friedrich, FAO, Rome; Maury Sade, FEBRAPDP, Ponta Grossa, Brazil; Dr. Roberto Peiretti, AAPRESID, Rosario, Argentine; Dr. Makie Kokubun, JIRCAS, Tokio, Japan. 

References 

Rolf Derpsch, Proyecto "Conservación de Suelos" MAG-GTZ, Casilla de Correo 1859, Asunción, Paraguay. Fax: 595-21-582451, E-mail: rderpsch@quanta.com.py