5 personal communication with ~rofessorHenry P. Caulfield, Colorado mission on Education in Agricultural and Natural Resources. State University National Academy of Sciences. Washington, D.C. 1971. Head, DeDt. of Recreation and Parks. Texas A & M University. Personal R. L. Kohls. Trends in Agricultural Curricula. M~meo.Summary Pro- communication. ceedings: Reg~onalConfcrence on Undergraduate Education in the Bio- 7 ~uaneAcker. Trends in Agriculture curricula. Mlmeo summary pro- logical. Physical,and Social Sciences. (N.C. Region) 1968-1969. Com- ceedings: Regional Conference on Undergraduate ~ddcationin the Bi- mission on Education in Agriculture and Natural Resources. National ological, Physical, and Social Sciences. (N.C. Region) 1968-69. Com- Academy of Sciences. Washington. 0.C. 1971.

THE BALANCE OF MYTH

Jerry Caulder. .\.Ionsanto Company

On the morning of May 14, 1607, three Xlany plants are able to survive cold could change tlie envirorunent to fit hls ships, the SusnTliompson, Godspeed and weather because they produce seeds that needs. Discovery, sailed up tlie James River from remain dormant during the cold months. Probably man's first significant step to- Cape Henry and put 100 men and four Some sceds, produced by desert plants, on- ward controlling his environment was the boys ashore at a point on a little peninsula. ly germinate when they receive enough use of fire. This enabled him to niove into This swampy, disease-ridden place was water to insure a complete life cycle. the teniperate regions that were formerly named Jamestown by the group of settlers With the animals, we lookat the success too cold. The temperate regions are our who, by 1609, were on the verge of starva- of the crow. Its feeding habits are quite var- most productive ones. but man adapted to tion and death from pneumonia, dysentery ied, so it adapts to many different diets de- tlie cold winters that liad prevented him or malaria. This was the scene when man pending on what food is available. On tlie from inhabiting these areas; man altered first set foot on the eastern coast of North other hand, the Everglade Kite. a bird that his environnient with fire. America and began to upset "the balance feeds exclusively on a giant fresh-water \\it11 the ability to think, man has, of nature". which is often referred to in lit- snail. will become extinct if anything Iiap- througli the ages. been able to perfect erature, but never precisely defined. No pens to the snail. It cannot accept change. means of improving liis environment to student of natural science: particularly of Still other species have learned to avoid contribute to his comfort and health. animal or plant , could ever sub- seasonal scarcity of food by migrating long Early man's thougl~lscentered around scribe to a "balance of n;~ture".Tl~e serious distances. \!later fowl. which nest in Cnna- one simply thing - survival. And to sur- observer knows that animal and plant com- da, winter in the Gulf states and hlexico. vive, he needed two things, food and shel- munities are in a dynamic state. While tc~n- \!'hales, seals and other aquatic animals Icr. He i~eededshelter froni both the ele- porary equilibrium may occur and a given have similar rnigrotion habits. Others ments 311d predators. I-1e needed food for may seem in balance, it is al- choose to avoid adverse conditions by aes- energy. This energy enabled him to gather ways progressing toward a clim;~xcondi- livating during high temperatures. like the more food - he liad no time fo~other tion. For example, if a "balancc" ever ex- bullfrog or box turtle, or hibernating dur- tllirigs ill life. isted, why do not animals and plants of the ing tlie winter like the bear or chipmunk. Men, like other animals. began to estab- pleistocene or tertiary epochs irlllabit the Despite these many adaptations, most lish "territories"or areas in which they felt today? Why are not a few miserable species of animals tllat have existed over safe from predators, but as wild game be- nien and women still huddled in caves the nlillions of years this earth has support- came scarce. they had to move and were cracking bones to obtain every nlorsel of ed life liave lost the battle to change and once again exposed to predators. nourishment from hard-gotten game? If become extinct. Of a11 the animals that Tliis probably led to the first shnple nature were to ever strike its "balance", liave existed on earth, it is estimated that type of farming - nian domesticated ani- this was the time - nian'sintluence on tlie 9Wo are now extinct. NO. and 1 repeat, no mals and planted a few grain crops. Tlus environment was negligible. 50 year period in recorded history is witli- way he had a supply of food with a mini- The date when man first began to con- out numerous examples of animal species mum amount of exposure to his enemies. trol or influence the environnient is one of that passed from the scene - a balance of This is essentially the way the lndians conjecture. nature did not prevail. It is important to were living at the tirne of the Jamestown Early man and most plants and aninlals note that every niche capable of support- settlement. While the Indians in the early had to accept the environment as they ing life has been filled by a differing spe- 1600's had carved small cultivated fields found it and thusreg~~larlybecame victims cies. So the extinction of species is a natu- out of tlie land for corn. squash and tobac- of "change". rally occurring phenomena. Nature is con- co, the nien of Jamestown set into motion The key word here is "change". We've stantly changing. We should look at the a pioneering, organized program of land all heard of the sabcr-toothed tigcr. the di- nlodifications in plant cover or that use (not always tlie best, but man could nosaur, the carboniferous forest? These or- led to the extinction, and these changes learn from mistakes - nature in perfect ganisms could not accept change. If nature should be judged on their merits - not balance would not allow a species to make were "in balance". could tliere be dranlatic what they caused - but what good can mistakes.) and long lasting changes? No, but we know come froni them. Who. among you, would The llistory of agricnlture can be divid- that there is change - frequently abrupt. be willing to live in the so called "natural" ed into rougl~lythree pliases: and sometimes catastrophic. environment that existed at the tirne of (1) nian and animal t~llingthe sod; (2) man, ani- ' Plants and animals, if tlicy ;Ire to sur- Jamestown? nlals and ~a;~chincstilling tl~csoil (1850);and, (3) nlan, milchines ant1 cliemicals(1940). vive. must either adapt to the environment Nature is a difficult and unfeeling task- In the first phasc of farming, man and or adapt the environment to their needs. master if one is wholly dependent on her animal, there was little else in life. A man Many plants and animals can adapt to the whims. could barely produce enough food for his environment, but only Inan has successful- Primitive nian existed. like any other family :~rld aninlals, so most people were ly been able to alter the environaicnt to fit animal, as a part of the environment, exert- farmers. his needs. Most plantsand animals have de- ing very little influence on it. As lime As man moved into the second phase of veloped habits and rnechanisnis to acconi- passed. man found that not only could he agriculture, man and machine, he could modate certain changes. adapt to a hostile environment, but that he

Page 83 produce enough food for himself and five people are no longer Farnicrs, the educa- of the bDA. which protects our food sup- or six orher people. It's easy to grasp the tion of these people is not aseasily accom- ply, the Ilepart~~ientof Interior which con- significance of tlus: if some no longer had plished. They are riot directly involved in cerns itself with our wildlife and environ- to nark to produce food, they could pro- the primary uses or needs of tlicsc cl~emi- ment, and the USDA which judges pesti- duce other needed products, services. This cals. These people. because of fear and lack cide effectiveness and safety. Until 1970, eventually made possible industrialists. sci- of understanding, cry "pollution", a very these agencies operated separately. They entists, doctors. teachers, artists and the popular word today. Unlortunalely. a have now been joined together into one de- niany professions thar make life iiiore en- great deal of rnisinforniation or partial in- partment called the EPA (Environmental joyable. formation is being disseminated. Protection Agency). The scientists, freed from the labors of Let us face the fact that pollution is Clieniical pesticides kill pests because producing food. were now able to supply here and will remaln for some period of they are toxic, and because they are toxic niore arid better equipment at a laster rate time due to the nature of man. his society some are also capable, in excessive doses, to rhc farmer than ever before. The results and technology. Tlle problems can be niini- of causing illness or death to people and of these efforts are nlanifested in the fact mized or overcome ill time, but it will be wildlife. that agricultitre llas advanced more in the impossible to cure all ills overnight. How- Moclern drugs save millions of lives. but last 50 years tlian it had in the first 50.000. ever, let us look at the role of pesticidesas some people have died because of them. It By the turn of the century. tlie aveiage pollutants in the proper perspective. I ndus- wodd not occur to anyone to bar1 penicil- housewife was spending "only" forty per trial waste, automobiles, garbage, and sew- lin because its anmial death rate exceeds cent of the family ir~comefor hod - no- age are the priniary culprits. Do not misun- pesticides by several-fold. Penicillin can tice 1 said only forty per cent - this was a derstand me - pest~cidesmisused are pol- arid will kill even when used according to relatively low amount by world standards. lutants, but whcri properly used. they are prescribed metllods. No death has ever re- Compare with today's seventeen per cent. not a problcni. sulted from a pesticide when directions It is estimated that the United States is the Pesticides are often linked with other west: followed. only count1y that has significantly loiilered pollution problems. when in fact no rela- Tlie autonlobile kills and niairns, but it the per cent of income used for food pur- tionship exists. How niany tinies have you has changed our lives generally for tlie ber- chases. heard of the DDT and mercury residues in ter. Tlie quantity of food being produced fish caught in our Great Lakes, and then in Thus. society is continually t'aced with by the American farmer was unsurpassed the nest breath they say the commercial the task of balancing benefits against risks. by any in the world, yet his food quality fishing industry in Lake Erie is ruined be- The benefit:risk ratio is one that each of us was about the same. The quality of food cause of pollution. This leads one to be- face cvcry day. \Ye must constantly weigh suffered mainly because of three maladies: lieve that pesticides hrtve ruined commer- the benefits of each action we take and de- insects, discase, and weeds. cial fishing in Lake Erie. In filct, it was termine if the benefit is worth the risks Farmers begall to use substances to re- ruined by waste and raw sewage being that we may incur. hlost of us think norh- pel or destroy these pests: they wcle called dumped there by Buffalo, New York; De- ing of getting in a car and driving for hours pesticides. troit, hlichigan; Cleveland and Toledo, to reach a destination, but if an ice storm is Sirn~larsubsla~ices were used by doctors Ol~io.Such unrelated statements linked to- erninent. we then see a cllaiige in the bene- to protect : they were called niedi- gether lead the general public to wrong fit:risk ratio, and may well decide to post- cines. conclusions. pone the trip. Tile use of pesticides quickly b~ouglit11s Agriculture is and will remain this coun- Scientists study pesticide safety by sub- into the third phase of agricultu~e- tlie try's basic industry, whether or not the jecting several species of laboratory ani- chemical age. Tl~echemical age has been by general population wants to accept this mals to feeding tests and even feeding stu- far the most successful: both food quality fact. Evelyone wants and needs to eat a dies that cover three successive genera- and quantity have improved beyond any- balanced, nutritious meal at least twice, tions. The FDA then sets safe residt~ctoler- one's expectations. Tlte farmer can now and preferably three tinics a day.'ihis need ances based upon available scientific evi- produce enough food not only for himself. and desire for food will continue arld there dence. These tolerances are set at 111 00th but for 40 or 50 other pcople.'l'Iiisin turn is only one source - ~griculturc.Teclinolo- (or less) of tlie highest level causing no ef- frees even more people to engage in profes- gy of production and marketing 111~s~be fect. For cxamplc, if it took over 100 ppni sions that wele unheard of 30 years ago. adopted at a laster rate if agriculture is to to cause some effect. the tolerance woilld such as nuclea~physics. niolecula~biology, continue to supply Ihe increased demand be set at less tlian 1 ppm or well over a 100 the space program, and many others. Ke- for food. x safety factor. cently. the Nobel Prize for Peace was The use of pesticides is one of the tech- The same general approach of dosage awarded to an agronomist for his part in nologies enabling agriculture to keep even versus toxicity should be lollowed in stud- what is now called "The Green Revolu- or ahead of demands. All iridica- ies of carcinogenic and teratogenic charac- tion". If man had not significantly changed tions are that the use of pesticides will 3c- teristics of pesticidal cheniicals. Apparent- his cnvirot~rneni to fit Ius needs, there celerate within tlie foreseeable future or iy, they arc not. Some of the more recent, woi~ldbe no "green revolution" because url t il such time tliat substitute co~ltrol highly publicized. 1aboi.ato~investiga- there could be no hybrid crops. tl~erecould means and methods can be proven effec- tions involving the bod additives - cycla- be no chen~icalfertilizers. there could be tive and yet ccorloniical for agricultural mates. the fungicide - captan, arid the no pesticides to protect his crops. practicality. herbicides - 2,4-D and 2,4,5-T, have been Pesticides are tlie newest of the tools Tlie United States Food and D~ugAd- performed with either large to massive, sin- being used by farmers. Let us not forget ministration (FDA) is committed to a safe, gle, oral or injected dosages. The magni- that pesticides are tools, nothing niore - clean. and wholesonle food supply. Regu- tude of tlicse dosagesgreatly exceeded that nothing less. During the course of history lation of pesticides in tile United States has of which our present knowledge would in- most technological advances Ilave been set a standard of excellence the world over. dicate could ever be ingested or accutnulat- criticized because their uses have been mis- This is why the RibicoffConuliittee wrote, ed by animalsor man. This type of research understood. When the metal moldboard "the food supply of the United States is is not a valid test ofwhat a product will do plow was intioduced to our prairie lands, the envy of the world, and the critical as- or cause. To me. this parallels the type re- many people feared that this metal would surance that these abundant crops can be search tliat would result in this conclusion poison the earth: however. most of the profitably grown, harvested, and stored is "rats force fed 20 gallons of distilled water people were farmers and they quickly due to pest conirol, at present la~gelywith per day developed bulgi~igbladders." learned that tliis was not the case. N'ith pes- chemical pesticides." hlonsanto Con~panymakes a herbicide ticides we i'ind these same fears being ex- A pesticide cannot be used in the Unit- called Ramrod. This product is available as pressed; but as ninety-tlve per cent of the ed States until it llns received the approval a wettable powder and as a granule. When we tried to get the granule cleared for use they stopped spraying DDT, in 1968, they stroyed by invasion of man. in corn, we were asked what effects these had over 1 niillion cases of malaria again. In A 1969 report in the pesticide hlonitor- granules would have on pheasants if they 1969. rhey began to use DDT again. ing Jour~ialindicated that pesticides were ate them. Needless to saj-, of the animals Some of the more prominent national the possible - note. I said possible - cause we had run testson, plieasants were not in- niagazines do, on occasions. give tlie devil of only onc ciigle death in 18 states and cluded. We. therefore, mixed granules with its due, however. Backliandedly. National Canada. the pheasants' food - they woi~ld not Geographic, December. 1970. pays thus Repeated rcfcrence is made to the food eat the granules. We told the fctlcral agency complimen~to pesticides. 1 quote: chain and how the loss througll poisoning tliat they wouldn't eat Ranirod grar~ules 'The World fiealth Organization went into Cey- ol' even an obscure species that constitutes wlien given free clmoicc. They I cplicd that lon with pesticides to knock down thc higl~mor- :I link in this clmai~m will Iiave far-reaching this was not good enongh - food pressures tality rate from malari;~.It did a wry good job of and dis;~strousconsequences. may force them to eat the gr;~nules.We it. But ils success - resultcd in Ceylon's severe problem and strained economy." But in the living world there arc scores then put the birds on a dict of Rainrod of food chains and many alternate routes granules and water: thcy still would nut cat It is obvious what they are inferring - for reaching a common goal. Food cliains the granules. Thisstill was not accepted, so don't save lives with pesticides, you upset :Ire not isolated sequences, but are inter- we ended up stuffing granules down tlie the "balance of nature". conneclcd with one another. This inter- pheasants' throats - r~cedlessto say. after a When general statements and conclu- locking pattern is called a . Links week on a diet of 80% clay, 20% ranirod, sions are drawn from highly specific bits of in these webs and chains are repeatedly be- and water, the birds were not a picture of research, the general public is greatly mis- ing broken within a single annual cycle. Na- health, but the Ramrod had no effect, so led. One of the most publicired stories ture is remarkable in the alternate routes we were given label approval. about DDT is how it affects the metabo- she niakesavailable to any one species. hlonsanto does not make DDT. In fhct. lism of calcium in birds - thus causing a The decline or disappearance of species all of our pesticides brcak down rapidly thinning of the egg shells. It is tnle that is not unique to our tinies. It is estimated and harnilesslp in the soil. As a result. thcy some species are affected. These are the that 9%of the species that ever existed on present no hazard to humans, wildlifc or ones we hear about. cart11 arc now extinct. The last example of . But DDT is rhe most popular Research at the University ofWisconsin a bird beconling extinct occurred when the scapegoat for the pesticide rap, so let nie found that DDT-fed pheasants exhibited final passenger pigeon died in 1914 inCin- tell you about how some of the data on no changes in reproduction rates. \Ye cinnati, Ohio. DDT were "derived". would generalize this no-effect data just as A cornmittec of the U. S. Fish and Wild- The National Conmmunicablc Disease well as some have the data on the bald eagle life Service published in July, 1966,aconi- Center at Atlanta, Georgia, did a study of which did show a change in reproduct~on. prehensive study on 129 rare or endan- 35 men with 1 I to I9 yearsof cxposu~ein There are many studies where birds gered spccics of mammals, birds, reptiles a plant that had produced DDT continu- were fed diets containing 1,000 or more :~nd amvhibia~rs.and fish in the United ously and esclusively since 1947. tinies the DDT present in the normal dict States. I':~r;~mount cause mentioned was Medical exaniinatio~lsof tllcsc mcli re- of the birds. DDT causes variouseffects on the loss of habitat and the re- vcalcd no ill effects attributed to a DDT ex- the physiology of tlie bird species at tliese FUI t ing f~om nla~i's~~ctivities. posure rate over 400 times that rcceived by high rates because it is a biologically active Pest icidcs ale often mentioned as a the general population. The overall I;I nge compound. But is it realistic to worry "possible" con1 ributing factor to the de- of storage of DDT in their fa1 was 38 to about such high consumption rates? clir~cof the osprey, b:~ld caglc, pcrcgrinc 647 ppm as conipared to an avcrage of 8 Concentration of DDT in the earth- falcon and Calilsornia condor. However. ppni for the average An~erican. worm from spraying trees for Dutcl~Ehn these species were on the decline a lorrg So charges that the public is being poi- Disease has been shown to cause some time bcfore pesticides were introduced. soned by DDT in its food and drink scc~ii deaths of robins in t11e sprayed area. I low- Reccnt storics have indicated that DDT without foundation. ever. repopulation soon takes place from will destroy our ocean food supply and ox- The FD.4 monitors pesticide content of population pressures in surrounding areas. ygen because it alters the photosyntlletic foods. These market basket surveys show What is happerling to our robin popula- process in the algae, or phytoplankton. that DDT and other pesticide levels arc far tion can be shown b the Audubon Society They painted a real doonisday picture and below the permitted tolerances and they bird counts made each year at Christmas said that long before we would run out of are going down, not up. time. Their reports for 1941 and 1960, be- food. we would die of asphyxiation be- In 1966,1967. and 1968, the total DDT fore and after the widespread use of DDT, cause we depend upon for and metabolites intake was 0.0010. show the following increases for species all the oxygen we breathe. 0.0008, and 0.0007 niilligranms per kilo closely associated with man and his activi- Presumably thex predictions are based body weight. respcctivcly. ties - grackles, 131 times; cowbirds. ?- 1 : on research performed by C. \Yurster. and Such small amountsof DDT intake by a and robins, 12 tinies. published in Science in hlarch, 1968. Five 154 pound man would total 1.28 granis By far the greatest effect of DDT on species of marine algac were studied. (0.148 ounce) of DDT during his lifctime if birds is to kill nlosquitoes that carry seri- He induced the water in which each of tlie DDT concentration in food did not ous diseases of wild birds. including nialar- these algae was grown to accept up to 500 continue to decrease. This is a minute ia, newcastlc disease, fowl pox and enceph- parts per billion of DDT dissolved in alco- amount when you consider that single dos- alitis. hol. TIle natural solubility ofDDT in water es of 5 granis or higher of DDT have been One hears that slnce the chlorinated is only 1.1- parts per billion. This means administered to lmuma~lsfor tllc successful hydrocarbons are co~icentratedas thcy as- 111x1 by mcar~sofalcoholthe algae were ex- treatment of barbiturate poisonitlg. cend tlie , carnivorous bi~dsat posed to concentrations of DDT thar can Pesticides have saved milliot~sof Iluman the top of this pyramid reach the higliest never occur in 11ature. lives. The evidence is ovenvhclmi~lg:pcsti- concentration and face special problems. At tl~e1 parts per billion level of DDT, cides properly used alc a benc1'1t to nian- Tlmc decline of thc osprey and bald eagle pl~otosy~lthcsisin the dgae was either not kind. Research must continue. how eve^, so ;Ire oftcn nientio~ledin [his respect. affected or sl~owedpossible stimulation. that this may continue to be true. However, reports by orr~ithologistsin Photosynthesis in the algae was depressed On the island of Ceylon, in the early the late 1800's indicated that the osprey as D DT concentrat ions were increased 1950's, there were over 2 million cases of was threatened even at that time. In 1962, above 10 parts per billion - a concentr;j- malaria. They began a DDT program to ninety-one per cent of the eagles found tion tl~utDDT cannot reach in the ocean control mosquitoes and by 1963. thcy l~ad dead were killed by violence. seventy-seven because any aniount over 1 .1- parts per bil- so upset the "balance of nature" that there per cent by gunfire. Eagles and osprey lion would precipitate out. were only 17 cases of malaria. In 1964, move out when their are de- Calculations show that if all DDT pro- Page 85 duced in the world cach year were dumped The changes he institutes to survive will teacherbas well. inadvertently affect some species. In this To protect his crops and animals, the farmer in the oceans and there was no breakdown, used substances to repel or destroy insects, di- it would take over 9.000 years to reach 1 regard, rnan is no harsher an administrator seases, and weeds. These were called pesticides. part per billion ofDDT in the oceans. of the environment than "nature", which Similar substances were made by doctors to Do not misunderstand me. Tllc extinc- is totally indifferent to the immediate pres- protect I~unians.These were called medicines. ent, or the welfare of any particular spe- The age of science lad arrived and with it tion of any of our species is to be avoided if came bcttcr diet and longer, happier lives for at all possible. ljowever, the gr:ldual ex- cies. What is farming. but an attempt to more ~l~e~nbersof society. Soon it came to pass tinctions of n species will hardly cause a shift nature in a direction that will help that ccrt;rin well-fed members of society disap- ripple in the living world, so rapidly is the feed and clothe man. 1 cannol help but feel proved of the farmer using science. that there are Inore efficient ways of pro- They spoke I~arsl~Iyof liis techniques for function it sewed taker1 over by others. 1 feeding, protecting, and preserving plants and value. just as much as anyone. the Califor- ducing protein than buffalo grazing on animals. They deplored his upsetting the balance nia Condor. the whooping crane, t1;e 0s- prairie grass and carbohydrates from grains of nature; they longed for the good old days. And prey, the grizzly bear and othzr endan- and berries growing wild. this had emo~ionalappeal to the rest of society. Let me close by reading a short essay Uy tliis time farmers had becomeso efficient, gered species, for these are cherislled by me society gave then1 a new title: unimportant mi- as a biologist. But I also recogrlize that the written by Dr. JohnCarcw: nority. passing of the relatively few individuals, In Balancewith Nature by Dr. JohnCarew ** Uecause society could not ever imagine a which make up these populations and have In ttie beginning diere was earth; beautiful shortage of food, laws were passed abolishing been declining for years. will have no sig- and wild;and then man :me to dwell. pesticides, fertilizers, and food preservaties. At first, he lived like other animals feeding Insects, diseases, and weeds flourished. Crops nificant impact on the environment. himself on creatures and plants around him. And and animals died. Food became scarce. In summary. man must manipulate the thisuas called in balance with nature. To survive. industrialists, artists and doctors environment to survive. His survival will Soon man multiplied. He grew tired of cease- were forced to grow their own food. They were carry with it the survival of most plant and less for food; he built homes and villages. not very efficient. Wild plants and animals were domesticated. People and governments fought wars to gain animal species. In fact, by his interest in Some men became farmers so that others more agricultural land. blillions of people were wildlife, he will undoubtedly prolong the might become industrialists, artists, or doctors. e\teniiinated. The remaining few lived like ani- existence of species that nature would 0th- And thiswascdled society. mals, feeding themselves on creatures and plants erwise have elinlinated. He will significant- Slan and society progressed. \Vith his Cod- around them. and this was called in balancewith given ingenuity, man learned to feed, clothe, pro- nature. ly enhance the population of species that tect, and transport himself more efficiently so he are of economic value to him. niight enjoy Life. He built cars, houses on top of **In 13alance \\'ith Nature is included asa part of On the other hand, man must deliber- cach other, and nylon. And life was more enjoya- this speecl~with permission from Dr. Carew. It ately attempt to minimize the ble. first appeared in print in the Anierican Vegetable The men called farmers became efficient. A Cro\vcr. from pests that endanger his food supply single fanner grew food for over 40 industrialists, or health. artists, and doctors, and writers, engineers, and

Population Supporting Potentials of Agricultural Systems

(;ilbert Lindstrom lns~ructorin Agriculture and Agri-Business, Northeastern Junior College

Ecology includes a study of the interaction of populations. tain food from much of our land area which is best adapted to Food is the primary basic need ofa population for survival arid pasture or forage crops. development. The ultimate size of a population depends primari- The consun~ablecalorie production per acre varies among ly on its food supply. Agriculture is tlle primary basic producer crops. An estimate of this for various crop and livestock systems of food for the highest kind of population, man. is shown by the calculations in Table 1. These estimates are Our objectives in agriculture must focus on production of an based on good production levels on highly productive land and adequate supply of food, both in terms of quantity or total calo- livestock systems that are well managed. hlaximum production rie intake and in quality which includes such factors as protein. levels however are well above these levels but average production vitamin and mineral contents of the food. Thequantity offood levels are well below these levels. Of rhe systems shown, the calo- per capita of population depends on the food producingarea per rie production per acre varies fro111 100,000 to 12 million calo- capita and the yield of consumable calories per unit area. Of ries per acre, a 30 fold difference. these the yield of calories per unit of land area is most important. The average consumption of calories per person in two areas To illustrate this. before 1700 the continental United States pro- of the world is shown in Table 2. As indicated the total calories duced only enough consumable calories to supply an estimated cons~imedper person per day by the North Anlericans is about one to two niillion Indians with levels of food which periodically 50% greater than that consumed by the average Oriental. The left them in Famine. Today this land produces enough food for quality of the diet differs even more as indicated by an eight-fold 200 million people at a level never previously enjoyed by any greater consumption of animal protein by the North American people in addition to vast quantities for export and a surplus. than by the Oriental. Total yield of calories per acle depends on two factors: (1) Table 3 relates the caloric and diet quality difference between the yield of llle crop per acre and (2) the inherent efficiency of the Oriental a11dNortI1Arnclic:ln to the amount of land required the crop or crop-livestock system in converting energy to con- to produce a yearly supply of c:~loriesper person. To simplify sumable calories. hfany crops will convert sunlight, C02. IH20, calculations the diet con~positionis only an estimate. Using and minerals directly into producls I'or llun~anconsun~ption. EX- these values, the basic protluction of 1.23 acres of highly produc- amples of these include potatoes. rice, fruits, and vegetables. tive land would providc the calories for consun~ptionof one Other crop products can be used directly as food or converted to North American whereas the same production potential would food products through animals such as cereal grains. A third provide the diet for nearly nine Orientals. group of plants, which must be p~ocessedinto food by animals. These calculations indicate the following conclusions: include forage crops. and past ure. In general those crops which I. Tllc bazic agricultural production of a country in terms of calories produce consumable food tent1 to yield more food calories per per person deterniines the calorie intake per capita in addition to the quantity and type of aninval products that will be available per capita. acre than those which must be converted to food by livestock. 2. Gross inequalities exist in the basic per capita in dif- However, livestock provides t l~eo~ily means whereby we can ob- ferent areas of the world.The basic production has more influence on the

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