(*) Agr. Eng.; Ms. of Sc.; Member of the Board of Directors and Technical Committees of AAPRESID. ( No Till Farmers Argentinian Association) and member of the Steering Committee of CAAPAS, ( American Confederation of Sustainable Agriculture Farmers Associations ).
In Argentina, due to strong economics forces mainly derived from a World that quickly globalizes and interacts; the grassland farming developed on alfalfa based pastures alternated with a period of an ultra-conventional " ploughing land agriculture "; was quickly pushed out by a pure cash crop agriculture. This phenomenon was or is also happening in other parts of the world.
Looking back half a century and studing the history of the Argentinian development of this process, some very noticiable things were happening. As a kind of summary of it I tried to graphically represent and somehow summarize it in the next four graphics.
By the fifties, and for the humid and suhhumid " Pampas Region " of Argentina, equivalent to the Corn Belt and some other areas of good soils of the United States, the average land share by the main different agricultural activities were approximatelly as described in the following Graph. N° 1.
ESTIMATED PROPORTION BETWEEN CASH CROPS AND GRASSLAND FARMING FOR THE FIFTIES. ARG. REP.
Around the end of the sixties, the grain and oil seed production started pushing away the cattle farming ,free grazing grassland farming, that mostly had been developed on alfalfa and some other forage crops pastures.
The main reason for this to be so, was an "economic one". At least in the short term, cash crops became more and more profitable compared with catlle grassland activities. The freegrazing grassland activities normally includes the cow-calf, the fattering and dairy opperations.
This phenomenon ended up with a different land share for the two main farm activities; grassland farming and cash crop production. [ GRAPH N° 2].
GRAPHIC N° 2
ESTIMATED PROPORTION BETWEEN CASH CROPS AND GRASSLAND FARMING FOR THE END OF THE SIXTIES AND LATER. ARG. REP.
Within the cashcrops; winter wheat, corn and grain sorghum were the crops that occupied the larger acreages. Few years later soybean appeared as a promisory cash-crop and started to increase its acreage growth. Among other crops, it pushed down the acreage of corn and sorghum. At the same time soybean started to be planted as a second crop of the season, mainly after winter wheat. It showed its ability to produce under this situation and then, either as the main or as a second crop (soybean after wheat) of the season, its acreage steadely grew up and became larger.[ GRAPH N°3 AND N°4].
GRAPHIC N° 3
ESTIMATED PROPORTION BETWEEN SOYBEAN AND OTHER SUMMER CROPS FOR THE FIFTIES. ARG. REPUBLIC.
An old farmers belief rooted or derived from the corn and sorghum crops behavior, shows that the more one moves or cultivates the soils the better the yield to be achieved. Even though they did not had a clear explanation for this phenomenon, this fact behaves as a true hypothesis, unless during those years on which rainfall provides enought water to avoid this production factor, water availability, to became an important yeld level limitation.
As a matter on fact from the farmer short term standpoint and, for the time when the structural condition of the soils were better than it is today, they were somehow right. With an important number of soil tillage opperations they were shifting potential fertility to actual one. Chemically this is achieved trought a relativelly violent oxidation process that encreases the availability of several plant nutrient among which nitrogen was playing a very important role. We can even consider that they were eventually " burning a great proportion of the organic matter and the fertility " stored during the geological development of the soils and somehow kept there when the the soils were occupied by the alfalfa based pasture under grassland activities.
Metaphorically our " High Fertility Argentinian Pampas " were trasformed in a big " Furnace " that using Soil Organic Matter as the fuel, was utilized as an engine to power the strongly agricultural based " relative economic welfare and richnees of my country ". This process lasted for more than half a century and was basically pushed for the govenment absence of a sustainability feeling while regulating and legislating the economic and social activity of the society. In a wide sence they push the farmers and the whole society to" make a living " out of the capital in itself instead of more than out of the profitability or the interest of the capital. During the extent of this period in Argentina, rather than consuming and exporting the products of a rational use of our soils, we were consuming and exporting our natural fertility and in some cases the soils in itself. Due to this attitude, our soils were suffering an unacceptable level of soil erotion and deterioration.
During this period of time, a lot of economic resources were drained from the agricultural activities to the rest of the economic sectors. Succesive governments, belonging to different pollitical tendencies, were sistematically pressing over the different Pampas Agroecosystems from an economic standpoint.
Argentina probably cosntitutes the only example, within the history of the free economies of the world, of " what a governements hasn´t to do at the time of planning the tax policy for the agricultural sector of the economy ". Argentinian farmers never had a friendly nor a subsidize atitude from their governments and from the economic standpoint for almost half a century. Further than this, they put a differential very hight economic taxation on the agricultural activities "taking off" every year a substantial part of the potential farmers annual profits utilizing them or applying them to the different destinations that they consider adecuate acording with the "different pollitical priorities"established for each different period. Most of this policies were somehow not recognizing that after all, what they were doing were to oblige farmers to " virtually sale their soil and soil fertility " along with their grains, meat and milk. This mainly happens by means of a chemical ( nutritional ) and a physical ( anthropogenic erotion ) quite evident deterioration process to which our agroecosistems were strongly pushed by this hight economic pressures.
This type of misshape economic relationship between the Argentinian Society and its Soils lasted for almost fifty years untill after around ten years ago when " fortunatelly and I hope finally" a more " wise and reasonable way to manage this relationships started to be applied ".
What most of the Argentinian farmers pretend from the government policies is not a subsidizing attitude, they know that "worlds winds are not blowing in that direction", but only an igualitary treatment from all the tax and economics standpoints with the rest of the society. The Argentinian farmers are ready ,an actually they are already doing it, to compete and completelly face the free market or free trade rules.
Further than this and hopefully a great number of them are becaming quickly aware about the challenges that the present time, in a world that quiqkly globalizes , is overimposing to the activity. We know that every day we should try to be more efficient to be able to keep on business. From this standpoit; a different governement attitude to the agricultural activities together with the possibility of being utilizing new Systems of Production as the No Till one, constitute the key factors to achieve profitability within a frame of competitiviness and sutentability for our activity.
At the beguinning of the soybean acreage growth previously described, from the soil tillage farmer´s standpoint, this crop was mainly treated as if it were similar to narrow grass summer crops like corn or sorghum. Hence farmers applyied their belief and practical knowledge in regard to the soil tillage strategy.
Now if we look at the whole process from the " soil health standpoint " or even with a wider view from the " Agroecosystem Sustainability and Health Standpoint "; one thing contributed to made the whole situation even worse. Because soybean needed to be planted two to three months later than corn and one to two moths later than sorghum, so, farmers had a lot of more time to do something eiher with weeds or with soils and hence they mostly cultivate or tilled them during that period of time. As Mr. Jim Kimsella said the " Till Gen ", is cousing it´s effect and strongly shows up pushing farmers to till the land when they not find what else to do with it.
All this processes ended up with a very bad conbination for our soils and Agroecosystem future productivity. In some way or another we, the Argentinians, were selling "our jewels" apparently without noticing or showing a concious attitude in front of this reallity.
At the same time this process was taking place in a large area of the Argentinian Pampas including the eastern part of Cordoba Province where I live and farm; new technologies to prevent soil depletion were neither adapted nor applied unless with the necessary speed to be able to avoid the troubles that shortly we will be surelly going to face with.
During this process we lost a good deal of our soil natural fertility, and hence competitiviness, due to the lost of soil nutrients, soil organic matter, soil structure, soil water infiltration and hence water availability for crops, as well as some others desirable soil characteristics.
Besides the phenomenon stated on the previous paragraph; both wind and water soil erosion shortly became a very serious problem that claimed for an inmediately and highly effective solution if the Production System was going to keep been and improving its profitabilitness, competitiviness and Sustainabilitness.
An estimation for the argentinian acreage share between the soybean and other summer crops for the eighties is represented on next graph N° 4.
GRAPHIC N° 4
ESTIMATED PROPORTION BETWEEN SOYBEAN AND OTHER SUMMER CROPS FOR THE NINETIES. AGR. REP.
At the present, the economic reasons that generate the intensification of agriculture activities keep been more or less the same. So, we are somehow expecting a growth of the acreage cropped with grain and oil seed crops; more than expecting a comming back to grassland farming activities as a mean to produce economically and keep fertile soils.
When I think about the role of No-Till System of Production within this process, I believe that No Till is called to bring an adecuate solution to overcame the problem from both the economic and the soil deterioration standpoint. Furthermore I personally feel that today No Till is the most adecuate system of production to stop soil destruction in the shortest possible period of time, at least, for most of the Agroecosystems where agricultural activities are being carried out. My personnal experience as a farmer, as an agronomist and as an advisor; gave me the chance to validate the advantages and benefits derived from the development and usage of the No Till System of Production as an adecuate sollution to this problems.
Quite a large number of Argentinian farmers became aware of this reallity and started the adoption of the No Till System of Production as a way to overcame the arousing troubles they were starting to "face with" when they try to keep farming lands on an intensive manner.
As a result of this farmer attitude, and of the activities of AAPRESID and in some extent Official Institutions and Universities, the Argentinian No tilled acreage had grown at a rather high rate during last years. This phenomenon is shown on Graphic N° 5.
GRAPHIC N° 5
EVOLUTION OF THE ACREAGE CROPPED UNDER NO TILL SYSTEM ARG. REPUBLIC.
( * ) 1997/1998 Preliminary Estimation
With some logical variations and approximately at the same time, similar processes were taking place in different american conutries.
Six years ago, and during one of the International No Till Meetings organized by AAPRESID, representatives of the different countries decided to join efforts and after some deliberations we settle down a new organization which acronime is CAAPAS. The english traslation for its spanish meaning would be: " American Confederation of Farmers Associations for a Sustainable Agriculture ".
The major perpouse of this organization is to enhance the possibilities of interchanging ideas and point of views in regard to the different problems that agricultural activities are facing across the coutries members and at the same time to make a diagnosis and suggest alternative propousal of sollutions to them.
Untill nowadays CAAPAS had six ordinaries and several extraordinary meeting in different countries members of this Institution. Among some other important achievements we had and space to make a presentation at ECO 92 The Worl Ecological Meeting hel in Rio Du Janeiro, Brazil 1992. We also attended as speakers and also had the chance to strongly interact with farmers and to interview with National and State Ag. Ministers and other Pollitical, Technical and Educational Authorities of different CAAPAS s members and non members Countries; among others like: Argentina, Canada, Colombia, Bolivia, Brazil, Chile, Madagascar, Mexico, New Zealand, Paraguay, Spain, Uruguay, U.S.A, Venezuela, and some others. While interacting with the different countries, among many others, we took into consideration a wide range of issues. Among others, some farm economical comparison as well as many different agronomical, technical, farm management and sustainability matters were included on the discussions.
This gave us the chance to made an analysis of the problems and of their possible sollutions from a very wide based background. Ocasionally as a result of all this activities, we concluded this meetins with documents that tried to describe the problems as well as a solution propousal. The similarities brought into by the globallization in most of the cases is a noticeably phenomenon.
SUSTENTABILITY is suggested and considered as a must for any propousal or conclutions derived from CAAPAS activities. We in CAAPAS consider that Sustainability from its more wide sence should be" a must "; more than just one option. This point applies not only for the farm activities - agroecosystem relationships if not for the whole and complex relationships between the human being and their Ecosystems that comprises the Global World Environment.
Even thought the CAAPAS´s farmers goals could be cosidered as too big or high, our thinkings, activities and propousals are allways trying to be strogly tighted to everydaywe farm activities reallity . We are primarilly farmers and then after that we are trying to play some other roles to help the societies of the countries we belong to. We are fully aware of the necessity of developing a Porduction System that should fit properlly within the nowadays necessities. We know and are strogly convinced that amog other characteristics for a new system to be applyable it Should be Profitable for the farmer. This eventually will allow to be able to Compete succesfully. All this should be developed within a Frame of Sustentability and even Improvement of the Natural Resources involved on the Process. We should be willing and wise enought to be able to make the necessary efforts to achieve our goals. If we do so we are insuring to be socially and pollitically accepted and recognized.
Based on the information that the different CAAPAS countries had submitted to me; I built up a Data Base Processing from which I constructed the Graphs Nº 6. Within the CAAPAS´s countries memberships, we can clearly see a possitive trend for the areas cropped under No Till in the CAAPAS s countries , is to increasing every year. I should mention that due to the lack of Mexican datas for the last three years, I used the last ones that this country submitted to CAAPAS; 1995 datas.
GRAPHIC N° 6
PERCENTAGE OF ACRES UNDER NO TILL SYSTEM WITHIN THE LATIN AMERICAN CAAPAS COUNTRIES.
( * ) Preliminary Estimation
Even though the figures included in the previous graph, content a certain degree of " estimation errors "; reallity should not be significantly far from them. A clear tendency for a generalized No Till System growth, can be seen. Eventually it constitutes an indirect validations of the fittness of the system to a wide range of agroecological, economical and to some other kind of reallities found across this countries.
I can add that while travelling this countries, I had the chance to personally visits several operative real farm situations and I had personally seen the system working for a wide range of farm situations including different kind of general agroecosistem limitations as well as a wide range of situations in regard to farm sizes. They ranged from a couple of acres to thousands of them. Whithin all the situations, and basically due to the same group of reasons, the system appears to be equally usefull, but, it should be properly adapted to the local and particularlly to the punctual farm situation and reality in orther to be able to fully express their advantages.
When we look for an explanation of the Argentinian No Till adoption pattern probably they went ahead and adopt the system instead of waiting for a great deal of solutions for their production problems, to be comming from the governements or governements technical or even from the academical institutions. This was especially true on the past and until after a few years ago when a tendency to reverse this situation, hopefully seemed to be arousing and the official institutions as well as the Universities became more and more involved with the idea.
When the adoption of new Systems happens withouth a " full and complete scientific understanding and a subsequent practicall validation ", the whole procees may be assuming a higher level of risk, but, if the right choices are taken, the benefitial results are going to be achieved earlier. On the other hand, when, before reachiing an important level of adoption of a new System the process wait untill science finish up and gets a " convenient and full level " of scientifics explanations and practicall validation; the adoptions risk level will be lower but the neccesary time, for the adoption to reach a significative level, would be longer than in the former situation.
The Argentinian adoption pattern, among others CAAPAS countries ones like, Brazil, Paraguay and so on, mostly followed the first adoption criterion described at the beguinning of the previous paragraph. We as farmers and as professional agronomists were able to "see the tendencies " clearly enought to begun the adoption as quick as possible applying what we considered a reasonable adoption pattern. Been aware of the magnitude of the problem to be solved, this adoption pattern was basically designed from what we tought was an adecuate balance between the risk level to be assumed and the quantity and quakity of the expected achievable benefits. By this mechanism we.went ahead and while shifting to a new System and " Way to Produce " or to " Interact with " our Agroecosystem. We quickly gather all the benefits by taking the full advantages that this new way to look, comprehend and do things were offering to us.
Within the short term among other important benefits , as those I will be explaining later in this paper, we were able to enlarge our profits and enhance our competitiviness and at the same time stoping the soil erotion and deterioration process. Within the medium and long term our main goals are centered in reaching Sustainability in the widest sence than we can attribute to the meaning of this word.
WHAT MAY HAPPEN IN THE FUTURE WITH THE ARGENTINIAN NO TILL ADOPTION PROCESS ?
While looking at the Argentinian No Tilled acreage growing process; and trying to figure out how the future could look, we can consider different hypothetical adoption rates. The one represented in the next graph, could be considered as a resonable one and hence as one of the possible adoption pattern for the coming years. On it, for the year 2010 it is considered that the final no tilled acreage, would be occuping about half of the estimated agricultural cropped area for that time.
GRAPHIC N° 7
HYPOTHESIS OF THE EVOLUTION FOR THE NO TILL SYSTEM ADOPTION PROCESS FOR THE ARG. REPUBLIC.
As it was said in the previous paragraph, this " No Till System Acreage Ceiling Share with other Production Systems "; is assuming that 50 % of the total cropped acreage of the country by the year 2010 will be No Tilled. However, taking into consideration the revolutionary technological tools that Biotechnology and Genetic Engineering are and will be increasingly offering to agriculture, like "herbicide resistant crops", I strongly suspect that, within the coming years, we are going to be seeing a greater adoption pattern of the System as well as greater final acreage for the " higher ceiling" or for the final acreage covered by the No Till System.
Even thought, if we accept the hypothesis included in the previous Graph N° 8 as the true one, it makes sence to compute the first mathematical derivative and get the annual encrease rate for the whole period considered by it. The referred first math derivative computation is represented in Graph N° 9 and it shows us the estimation for the anual acreage increase of the No Till System of Production in the Argentine Republic for the period of years considered.
GRAPHIC N° 8
HYPOTHESIS OF NO TILL SYSTEM ADOPTION AND ITS ANUAL RATE OF GROWTH.
Now; if we make a " close up "of the annual rate of adoption; we may figure out the relationship between the esttimate of the true area of adoption, represented by the anual increase for No Till from the beginning untill the present time( this figure is derived from the annual encrease of the no till cropped acreage), and the estimated potential area of adoption based on the stated hypothesis of annual increase rate expected to the end of the adoption process. This relationship is showed in the next Graph N° 9.
GRAPHIC N° 9
RELATIONSHIP BETWEEN THE REAL AND THE POTENTIAL AREA FOR THE ADOPTION OF THE NO TILL SYSTEM.
By studying this adoption process and comparing it with some other technology adoption phenomenons; we can figure out the different groups into which they could be classified and eventually try to detect where we actually are in the present time. This classification is showed on next Graph N° 10.
GRAPHIC N° 10
ADOPTION GROUPS OF NEW TECHNOLOGIES
Trying to detect into which adoption group the Argentinian farmers are actually in; we can suspect that we may be entering the Great Mayority group. Because of this, and taking into consideration the new " tools " that Biotechnology is offering us, we may expect an important encrease of the annual adoption rate. This fact will surelly couse an steadely and strongly growth of the demand of several kinds of imputs and services to adecuatelly supply the process.
When we take into consideration the adoption status of the others Latin American Countries members of CAAPAS; with the logicall differences between countries, we may expect that a similar processes will be taking place.
While searching for the reasons that could explain this No Till acreage growth, we may consider the next as important ones able to partially explain the phenomenon:
1. ) Economic Group of Reasons. Cost Saving System.
Undoubtelly, one of the main group of reasons are the economic ones.To clearly understand them, we can divide then into two groups a.) the short term and b.) the medium or long term economic reasons
1-a) Economic benefits within the short term:
For a guiven agrecological characteristic and growing season, the No Till System is able to increase the amount of usable water offered to the crops.. Being aware of this fact, and taking into consideration that for the great majotity of the cropped agroecosystems it normally represents the " first limiting production factor "; reality shows us that the system is giving us the possibility of increasing the yield within a crop season and decreasing the variability of it acros the years.
For a better understanding I will define the meaning of the cost terminology that I will be using within this paper. Fixed costs are those derived from the necessary structure for the farm enterprise to operate properly; examples are: land or other type of fixed taxation, farmer living expenses, capital interest; etc. Variable costs are those mainly derived from the necessities emerged from the operative plan like seed cost, fertilizer cost, pesticides cost; fuel costs, etc. Full time employees as well as family member involved in the operation also represent fixed costs.
Some of the economic benefits derived from the utilization of the No Till System are: a better and more consistant return for the money invested in variable costs as for example " superior genetic ", higher yeld target fertilizer strategies, a better fertilizer efficincy use, a better return for the money invested on more effective weed control programs; etc. This advantages usually push us to look for a " higher yield target " keeping the risk level within an affordable one.
A noticeable reduction of the fixed costs can be achieved and constitutes another very important benefit derived form the System utilization. This effect is mainly reached troughout a strong reduction of the necessary operative time to race a crop properly and hence been able to aperate a larger acreage with the same structure or on the other hand reducing it to operate the same acreage
As we can preclude from the phenomenons described on the previous paragraphs of this point, the No Till System help us to reach an improved economic performance within the short term. The System is very effective in allowing us to achieve a decreased total cost, ( fixed + variable ), for a given level of imputs and yield to be obtained. If we look at the thing from a different standpoint, the system allows us to aim to a higher yield for a given level of imputs to be applied. Also the fact of getting a higher yield level for a given level of imputs, or combination of them, is leading us to minimize our per unit cost or per bushel cost. Besides this and since we are getting this without encreasing the risk level to be assumed, we definitelly are improving or srinking, our risk/return ratio.
This " cost reduction effect " allow us to classifiy the system as a "cost saving one".
Finally, and even I may be repeating some concepts I would like to try to summarize the whole short terms beneffitial economic effects derived from the adoption of the No Till System. A somehow different way to look at the economic benefits within the short run could be sumarized trought the occurrence or to the action of the two main mechanism related to the enterprise economic growth. The fist mechanism allow us to produce " more units " with the same level of imputs wether we are referring to the variable or to the the fixed imputs. While refering to the " variable imputs " the encreased production or bigger productivity is basically explained for the improved water resource management that the System is offering us. This improved water management is allowing us to achieve a better performance for the addition of new units of the imputs called variables. When we refer to the "fixed imputs"; the economic advantage is derived from the possibility of increasing the acreage operated with the same level of fixed cost or operational structure. This will quickly result in a significant " Fixed Cost Dilution Effect " that ends up with an important reduction of the per unit production cost for a given yield level. In certain cases, for summer crops, the figure for the operative time reduction, measured on the bases of hand-labor hours by acre by crop, it may reach figures as big as from 1.4 hand-labor-hours per acre per crop to 15 minutes on the same unit base.
GRAPHIC N° 11
COMPARATIVE EVOLUTION OF THE INVESTMENTS IN TECHNICAL IMPUTS, THE HAND LABOR COSTS AND THE PHISICAL PRODUCTIVITY FOR A PULL OF COMMERTIAL SCALE FARM OPERATION.
Most of the phenomenons described within this point, are represented in the above Graph N° 11, that shows a situation personally monitored by myself; where we can clearly see than when we were adopting No Till as the Production System, a big change of the investment share between the technological imputs costs and the hand labor costs; happened. At the same time we can appreciate the big progress that was achieved in regard to the phisical productivity of the system. The information presented within Graphic N° 11, constitutes one of the most valuable personal experience that really allowed me to have an adjusted measure of how this phenomenons are working in a real production situation.
1-b) Economic benefits within the Medium and Long Run
Within the medium and long term, seven years or more, other extra benefits appear. We can see the adecuatelly summarized and represented trought a noticiable yield variability reduction and an important yield encrease. Totis de Zeljcovich et.al.; in a study that already lasted for 16 years, (INTA Pergamino R.Argentina) were comparing the evolution of the productivity as well as some chemical and phisical characteristics of a soil located on the best part of the Humid Pampas Area near Pergamino Buenos Aires Province. Derived form this long term study and from some others runned in Argentina and in Brazil, a clear tendency for the yields to grow while at the same time the interannual variability of them to decrease, could be detected. According to my personnal experience and from the experiences of some colleagues; both of this phenomenon, encreased yield and a decreased variability, are potentiated when we move to the subhumid and even more to the semiarid regions where water shortage are more frequent an intense.
GRAPHIC N° 12
CORN AND SOYBEAN YIELD EVOLUTION UNDER NO TILL IN FAZENDA FRANKANNA, CASTRO, PARANA, BRASIL.
Dr Ramon Rossel and its Group, while working in "Universidad Nacional del Sur ", Bahía Blanca, Buenos Aires Province, Arg. Republic; they were studing the comparative evolution of some chemical and phisical parameters derived from the same soil cropped under "No Till System " and under "conventional tillage". The experience only lasted for three years. Even though the study only lasted for thet relative short period of years, which eventually comprises more a short than e medium or long term, we already can see the possitive trend that these key factors assumed when the soil was cropped under No Till. Some of the results of this studies are shown on the next graphics. It is not my intention nor the perpouse of this paper to deeple analyze this figures. However I consider that they comprise good examples for the explanations of the better soil functioning that allows us to improve the phisical and economical enterprise performance in the medium and long term.
GRAPHIC N° 13
PH EVOLUTION UNDER NO TILL AND CONVENTIONAL TILL.
The soil PH evolution showed on the above Graph N° 13 , allow us to see better values for the no tilled situation. The encreased ammount of organic matter that the No Till Systema allows us to incorporate to the soil and its Buffer Cappacity may probably be responsable for this phenomenon.
On the next two Graphics, N° 14 and N° 15 we can see than either the organic carbon and the organic matter were encreased for the no tilled situation
GRAPHIC N° 14
EVOLUTION OF THE ORGANIC CARBON FOR THE NO TILL AND THE CONVENTIONAL TILLED SITUATION
On the next graph, N° 15 we can appreciate the difference between the No Tilled and the Conventional Tilled situation after three years. Within this graph the average Organic Matter content for both situations is also represented. We can see that the accumulation takes place with higher intensity on the first 1 to 2 inches of soil.
When we go deeper into the soil we are getting further from that surface accumulation of crop stoover deposited there. Within this fisrt two inches of top soil several new things start to happen when we leave the crop leftover to be deposited there withouth significative soil disturbance.
GRAPHIC N° 15
ORGANIC MATER CONTENT AND ITS AVERAGE FOR THE TWO CROPPING SITUATIONS
When we look at the total nitrogen we find a close correlation between the Organic Carbon; the Organic Matter and this Total Nitrogen. This phenomenon is shown on next graph N° 16.
GRAPHIC N° 16
TOTAL NITROGEN FOR BOTH CROPPING SYSTEMS.
On next Graph; N° 17, we can see that the nitrate content is lower under the No Tilled situation. To some extent, and due to a somehow lower temperature for the soil covered with crops stoover, this situation can be expected for the no tilled situation. This factor or phenomenon should be apropriatelly managed and we already developed the technology to overcome this apparent inconvinience. The technologycal strategy developed to overcame this phenomenon, aims more to a different application timing rather than to a higher level of nitrogen application. We already have enough evidences that it works and works properly
GRAPHIC N° 17
NITRATE CONTENT FOR NO TILL AND CONV TILLED SITUATION
For most of the agroecosistem than we have on the main Argentinian Production Area , the Humid Pampas, the climate is maild, we don´t even have snow, so this process is no so strong and "we feel" that along the year the no tilled soils are offerinng us even more nitrogen than those under continous conventional tillage.
In Argentina there are many works that are on the way, trying to encrease or anlarge our knowledge in regard to this aspects of the nitrogen management under the No Till System.
In regard to the phosphorous comparative behaviour under both cropping systems, the results are showed on next graph N° 18. In it also cuold be clearly see that the No Till System offers a much favourable condition than that derived from the conventional Tillage situation. This results contains a hight degrre of coincidence with those finded by Brazilian researchers.
GRAPHIC N° 18
AVAILABLE PHOSPHOROUS UNDER NO TILL AND UNDER CONV. TILLED SITUATIONS.
Similar trends and some aditional findings specially related to the functioning of the soil microbiology were made by Carlos Crovetto in his Chilean Farm named "Fundo Chequen". He was no tilling for a long term and his practical results as well as his soil measurements are of a noticiable coincidence with those included on this paper.
All this chemical and physical positive trends, when adequatelly utilized withing the farm operative system, normally ends up with an improvements of the productivity and usually also the economics results.
My personal experience confirm and enhance this reasoning and, unless for all the agroecosystem evolutions that I had the opportunity to closelly monitor, the more the years under No Till the healthier and more productive the agroecosystem appears: " Erosion and soil deterioration simptoms completelly desapeared and instead we can see evidences of a soil that is encreasing its fertility on its more wide sence ".
This fact is showed in next graph in which I include the productivity growth for a myself close managed productive situation. In the same graphic I also include, with comparative perpouses, the average productivity of Argentina. In this way we can compare a 100 % No Tilled situation for the last three years ( it started with 5% ten years ago and reached 100 % for the last three years), against a national average of a much lower No Till System usage ( between 1 and 20 % of the acreage for the same period).
GRAPHIC N° 19
PRODUCTIVITY EVOLUTION FOR THE MANAGED FARMS AND THE NATIONAL PRODUCTIVITY AVERAGE.
2. ) Water Saving System. A secon very important Adoption Reason.
As it was explained at the beggining of point N° 1, the system is very efficient from the water management standpoint. It constitutes other very important technical advantage that No Till System is offering to us. In central areas of the Sub-Humid Pampas of Argentina, when adecuate ammounts of crop residue are kept covering the top-soil; an average of 4 inches "extra" usable water was anually accumulated whithin the soil profile. This water was measured as the extra water gathered by the No Till System while compared with Conventional Tillage. (Personnal Communication comming from Agr. Eng. Nuñez Vasquez who works at INTA Manfredi; Manfredi, Córdoba Province, Arg. Rep. 1995). According to some other measurements made on this study, it appears to be that credits for this better water management and consecuent extra water should be given to two main facts: a) an increased water intake capacity for the no tilled soils, represented on Graphic N° 20; and b) for a low rate of evaporation from the soil after the water was taken in. A soil well covered will enhance this second benefit. Represented on Graphic N° 21.
GRAPHIC N° 20
DAYLY RAIN VS. EFFECTIVE RAIN FOR A NO TILL AND A CONVENTIONAL TILLED SITUATION
GRAPHIC N° 21
ACCUMULATED WATER EVAPORATION LOSSES FROM THE SOIL UNDER THE TWO DIFFERENT PRODUCTION SYSTEM
This extra water disponibility helps us to improve crops performance basically in two ways:
2 - a.) Helping the crop to easely sort a shortage of water disponibility or Water Stress Period occuring when the soil humidity is approaching the PWP (Permanent Wilting Point).
I had personally experienced situations on which this water help provided by the No Till System was able to keep the crop alive when it partner under Conventional Till died.
2 - b.) Moving up the yield crop ceiling on those areas of production where a non adecuate supply of usable water commonly becames the first yeld limiting factor. This phenomenon also usually happen for the crops raced under rain feed conditions on the subhumid and/or semiarid regions of USA. ( Personal Comunication from Dr. David L. Shertz, Us. Dpt. Of Agr.)
This extra water disponibility, also allow us to push the agricultural boundaries and "gaining new areas" where either the crops didn´t find enought soil humidity to properly develop or due to the same reason, yields were too erratic and hence represented a "nonadecuate risk level" to be taken.
Derived from a combined effect of the phenomenon descripted previously; and as it was said, we may find a noticeable decrease for the interannual yield variability specially when we compare the yield series for different crops raced for several years under No Till and Conventional Till System of Production. This fact would be especially true and valuable for the subhumid and or semiarid Agroecosystems.
L. Totis of Zeljkovich; Zeljkovich V. and Blotta Luis, worked in a long term trial previously mentioned in this paper. This trial had been carried out by them at Pergamino Experimental Station of INTA ( National Institue of Agropecuary Technology ), located at the humid area of the Buenos Aires Province, Arg. Republic. between 1983 and the present time. Among other important things as the yeld evolution and variability, they measured the water efficiency use by corn comparing the performance while raced under No Till and Conventional Tillage.
They came up with datas that showed a highly significant better water efficiency use for No Till Corn than that obtained for Conventional Tilled corn. The figures were 14.5 Kg. of grain produced by each milimiter of Real Evapo Transpiration (R.E.T) under No Till, ( equivalent to 0.368 Ton of grain per each inch of RET water), while they only obtained 10.6 Kg. of grain by each milimiter of R.E.T ( equivalent to 0.269 Tons of grain per each inch of RET water) for conventional tilled (ploughed land). This datas are represented on Graph N° 22
GRAPHIC N° 22
CORN WATER EFFICIENCY USE UNDER NO TILL AND CONVENTIONAL TILL.
This figures mean a 37 % increase of the water efficiency use while measured by means of Kg. of grain obtained by each milimiter of water that was evapotraspirated by the crop. The equivalent figures while expressed in Tons of grain by each inch of water of real evapotranspiration are: 0.362 Tn/Inch for No Till and 0.266 Tn/Inch for Conventional Tillage.
This datas are summarized and included in the following table:
R.E.T YELD WATER EFICIENCY USE.
(Inches) (Tons/Hectar) (Tn.of grain/inch RET)
Conv Tillage 19.04 5.08 0.266
No Till 19.28 6.97 0.362
As a way to summarize the benefitial "Water Saving Effects" that the No Till System is offering to us; I would like to include and offer to the reader my most personnal valuable experience in regard to the practical validation of the close correlation between the No Till Adoption and the improved water management. Since we can increase the soil water intake and later on diminish the evaporation losses, when we approach the water stress limits, PWP Permanent Wilting Point, we can clearly see the differences while comparing with the conventional alternative. This phenomenon can be clearly seen in next Graph N° 23. Again it was constructed with information derived from my personal records derived from the information collection of real operation situation for those farms managed by myself that I mentioned early in this work.
GRAPHIC N° 23
RELATIONSHIP BETWEEN ANNUAL RAINFALL AND PRODUCTIVITY EVOLUTION
For a better understanding of the phenomenon presented in this Graphic n° 23, I should add that the No Till System Adoption Begun during the 1989/1990 production cycle. It started with 5 % of the total acreage and in three to four years ended with 100 % of the acreage managed under the No Till System. If we watch the graph carefully, we can see that during the cycles on which No Till did not occupy a significant acreage, the productivity closelly follow the rainfall pattern; but, when the adoption of the system was important, after 1993/1994 the "System Buffering Capacity" shows up and allow us to overcame the troubles derived from a lower rainfall year. In this case and due to the System ability to gather more water into the soil profile, when the drought period showed up we had some "extra very valuables inches of water" down there ready for the crop to use them. Because of these we can see that even during the last three cycles we had a lower rainfall, crop productivity was able to keep growing up. This situation was not the same at the beginning of the series when No Till were not applied as the production system. As it was said, by this time when the rainfall was lower the
3. ) Soil Saving System.
Another important reason for adoption is that when the No Till System of Production is adecuatelly applied; it normally comprises an excellent way to control water and wind " soil antrophogenic erosion " and hence allow the adopters to give sustainability to their Production Systems.
In many cases, and specially when we are cropping HEL ( Hight Erodible Lands), for each ton of grain produced we are loosing 10 or more tons of soil by means of the erotion processes. From any standpoint we look at this phenomenon it does not appear to be neither an "environmentally and socially affordable" nor an "economic price" to be paid.
When the farmers became aware that the No Till is the system is "easily" allowing us to maximize the ammount of crop stoover that we are able to keep on top of the soil; and that with four tons of it we can reach a soil coverage of 60 % and that with this percentage we can be avoiding as much as 90 % soil water erotion, most of them begun to make efforts to adopt the system as mean to solve such a strong problem like erotion is.
This kind of benefits can be clearly seeb on next Graphic N° 24.
GRAPHIC N° 24
REALATIONSHIP BETWEEN % OF SOIL COVERED BY CROP RESIDUE AND THE WATER EROSION CONTROL
4. ) Availability of Improved Technologies That Make the Adoption Less Risky and "More Easy".
Herbicides and other technological tools that allows to use less costly and very effective weed control programs constitutes an example of this phenomenons. New " Biotechnological Tools " like Crop Resistance to Very Effective and Cheap Herbicides undoubtelly is giving a extraordinary adequate solution to one of the mayor problems that should be adequatelly solved for anyone to be succesfull in racing crops under No Till System " To Properly Control Weeds ".
Another example of this kind of factors are the availability of better fertilizer and improved technology to apply them are also factors that help to push the adoption.
The Availability of better commertial "buyable" genetic, ( also latelly anhanced by Biotechnology and genetic Engineering ), specially adapted to some of the requirements of the No Till System. One example of this could be the better tolerance to cooler soils that have being incorporated to certain Corn Hybrids developed during the last years. The incorporation of resistance to desease, insect and specific herbicides comprise another example on this line of action. Latelly the finding of tolerance to the Aluminium toxicity and the possibilitie of combinig this genetic trait with some other relevant ones trought Biotechnology processes could be of great importance to allow the adoption of this new Systems of Production as the No Till within those "fragile" tropical and subtropical agroecosystems.
5. ) Availability of Improved Planters and Drillers.
The specially No Till designed planters and driller should also be given some credits for a less risky shifting from one system to the other. Some of the new piece of equipments have a very good performance and eventually are able to efficiently and properly operate almost under any reasonable planting or drilling condition. This is very important issue because to get the most out of the No Till System, when we adopt it we have to be able to abandon the constraint of having to get a " good seedbed preparation " to be able to deposit the seed in intimate contact with the soil. Either the planter or the driller should be able to do it for us almost whenever and wherever we decie to plant or drill again within reasonable limits.
6. ) Good Farmers Common Sence.
Credits should be also guiven to the good farmer common sence to detect the economic and other types of conveniences of this System of Production. In most of our countries the adoption process Growed from the Farmers to the Governement and Educational and Research Institutions. This was so, because the farmers were the first in realizing and became aware of the necessity and the tremendous advantages of changing the way to produce. They match this necessity changing conventional system of production by No Till System.
Even though this description does not pretend to include all the valid reasons that push the No Till Adoption precess; it surelly include many of the "Important Ones".
The next facts comprise common concerns specially at the beguinning of the adoption process when farmers are no completelly convinced of the advantages of the systems and normally are looking for some " valid reasons or troubles " to quit the adoption and come back to the conventionall situation. The following situation normally Do Not Constitutes serious or real troubles unless for the most commom CAAPAS Countries Farmer´s realities.
" Even thought, in same cases and in the medium term, some slight encreses in soil bulk density appears, no significant yield problems were detected as derived from this situations. Other clear phenomenon that happens is the a stratification of the nutrients with a distinctive characteristics. Under no till an estratification within the first two to four inches of the topsoil semms to hapens. While under conventional tillage instead of concentrating them on the surface, a tendency "to dillute" them within the first seven to eight inches of the top soil appears as a "visible one". Lower soil temperatures doesn´t seems to be a problem for the Argetinian conditions neither for the Chilean, Bolivian, Paraguayan, Uruguayan and Brazilian conditions. However if it appears in some special situation it looks like than also could be solved by properlly managing the position af the crops stoover. An apropriate crop rotation startegy in many cases resulted in a right answer to this possible inconvenience. In our country we are using the No Till System from the very north; Salta and Misiones provinces, down to the southern part of it , Tierra del Fuego. Even thought it requires to be adapted to the paticular characteristics of each agroecosystems, the system is working properly and offering to the adopters the chance to take the multiple advantages offered by it. As a general rule, it could be said that there is not any recepy to properly adopt the system. Further than this, the use of a wide and wise based criterion are strongly needed to be able to properly adopt it. If we do so, we will be on a good position to take all the advantages that it is offering."
On the other hand, if we look for reasons that probably constitutes " real adoption troubles " that do not allow a faster and generalized adoption and quicker growth of the acreage cropped under the No Till System, among others, we may find the following:
1. ) Absence of Adecuate Goverment Policies and Valid Strategies to Strongly push the Adoption Process.
Taking into consideration the last 30 to 50 years, I personally feel that we, in Argentina, did not have adecuate govermment policies applied to the agricultural economic activities specially if we look at it from a sustainability standpoint. We had a rather high tax pressure and an absence of enough effective lines of action tending to promote the agricultural activities from the economic standpoint; orienting and pushing the process, at the same time, only to Sustainable Agricultural Production Systems.
2. ) A Shortage of Research and Technical Efforts.
Not enough research and technical efforts applied to the development of technologies and Systems that stopped and/or prevent the soil deterioration process by the Governement Official Experimental Stations and University plans. Graphic N° 25 .We should never forget that the greater the technologycal change we are triying to promote the bigger the neccesity of research support we need to be successful.
GRAPHIC N° 25
CONCEPTUAL RELATIONSHIP BETWEEN THE SIZE OF A TECHNOLOGICAL CHANGE AND THE DEMAND OF SCIENTIFIC AND RESEARCH SUPPORT.
An absence of adecuate official campaings trying to help farmers to became aware of the necessity of adopting new technology and Systems to take care of soil, allowing with this the development of Sustainable Agricultural Production System on the widest scence. By achieving this goal we are going to be able to keep the comparative advantages that we already have and eventually to transform them in competitive advantages.
Even thought Governement; Universities and Private Institutions have carried out some actions during the past, many things should still be done and the efforts be doubled in this respect.
The Institutions I represent; AAPRESID (Argentinian Association of No Till Farmers) and CAAPAS (Latin American Confederation of Sustainable Agriculture Farmers Associations), are trying to work as much as they can in this way. Non of them are governement supported institutions; on the other hand they are supported only by the efforts of their own memberships.
As a conclusion of this paper I will add some concepts trying to summarize and wrapping up the main ideas that I tryied to explain while developping it.
Before ending this paper, I would like to include some word in regard to the most recently findings in regard to the No Till System hability to act as a Carbon Sequestration System. These System´s property, recently discovered and recognized as a property of it, will surelly add credits for the Governements, Educational and Finantial Institutions to help to the future development and adoption of it as a valid way to collaborate to mitigate the carbon dioxide emmisions as well as a mean to achieve the other bennefits that the adoption of the system is offering from the environmentall and socially standpoint.As an example, it should also be given credits as a valid way to diminish the water contamination by means of a very important and inmediate reduction of the soil water erotion.
Hopefully nowadays, due to differents reasons, No Till Systems is quickly widespreading and growing and therefore arousing as a way to atemperate the serious soil deterioration process that many areas of our countries and of the whole world are suffering.
While writting this revised and newest eddition of this summary, I feel very happy of being able to inform that U.S.A. throught the CTIC (Conservation Tillage Information Center) had became a member of CAAPAS.
As a foundational member of this Institution, I feel very proud of being able to see that the seed we planted several years ago is growing approaching our goals. From the very beguinning CAAPAS was pushing for the adoption of Sustainable Systems of Production as a mean of keeping the hability of our agroecosistems to remain highly productive so they can keep offering the food that humanity is needing today and is going to be needing on the future.
Agr. Eng. Roberto A. Peiretti. October 1998.
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