How Farmers Affect Natural Resources 405
Total Page:16
File Type:pdf, Size:1020Kb
How Farmers 404 Affect Natural Many of our natural resources are either owned or influenced by farmers. Our 2.4 million Resources farms occupy over 900 million acres. Use of these lands influ- ences the appearance of our Na- By Sandra S. Batie tion's rur£d landscape, the qual- ity of our water and air, as well as the amount and tjrpe of our wildlife. In short, farms are an impor- tant part of the ecosystem we depend on. Not only do farmers influence our natural resources; the quality, quantity, and price of natural resources influence farmers' profits and ultimately their ability to continue in farm- ing. The farm sector is extremely diverse. A tobacco farm in the Virginia Piedmont bears little re- lationship to an irrigated vegeta- ble farm in California's Imperial Valley or to a dryland wheat farm in the Palouse country of Wash- ington State. A 65-cow dairy farm in New York may scarcely resemble a corporation-owned drylot enter- prise with 10,000 cows in Ari- zona. Still, each of these farms influ- ences and uses our Nation's re- sources: Agricultural land, water, energy, and wildlife. Beliefs and Practices To a farmer, agricultural land is an input in a production proc- Sandra S. Batie is As- ess; land is needed to produce sociate Professor of crops or graze animals. Yet the Agricultural Econom- meaning of land to many farm- ics, Virginia Polytech- ers—perhaps most—transcends nic Institute and its production capacity. The land State University, Blacksburg. is a storehouse of wealth, a heri- How Farmers Affect Natural Resources 405 i|l||MS^H ^^m fl^feK:^^«» ^ "^^^^Çv""^ itJat.-- —,..- . , W^^ilhVi«^ ^ I „.•■«¿Sji» âii^''- VH'^^^^■H ^H^H^^^^^I k" ' M, ■ .*z^i Plfe- ^T^^^^^^V ^^^^^^^H |t<kSg:'|>sWc ^ ^''„---^^^ ^^Si^^K "■-' ■^.vjj^if^ê li £^^^^ Mfliraj 1 ■ Farming in the little relation- culture estimates that cropland United States is ship to an irri- erosion still occurs at an esti- gated vegetable extremely di- mated rate of 2 billion tons of verse. A dry- farm in the Im- land wheat perial Valley of soil a year. Although measuring farm, here in the California or to soil loss is difficult, widely used Palouse of a tolKLCCofarm tools show that four regions Washington in the Piedm.ont have severe water-caused ero- State, Jor in- of Virginia. stance, bears sion problems: 1) The Palouse and Nez Perce tage from the previous genera- areas and the Columbia Plateau tion, and a bequest to the next of western Idaho, eastern Wash- To many farmers, land is some- ington, and north-central Oregon thing special and precious. 2) The cropland soils of Ne- But farmers have to be busi- braska, Kansas, Iowa, and Mis- ness-minded to succeed. Thus souri farmers may hold strong beliefs 3) Uplands of the southern on the wisdom of land steward- Mississippi Valley, and ship and also farm in such a way 4) Cultivated areas in Aroos- as to cause considerable soil took County, Maine. erosion. Furthermore, almost 70 per- Erosion remains a national cent of the erosion exceeding 5 problem despite a half-century of tons per acre is on less than 8.6 government programs to combat percent of the total cropland it The U.S. Department of Agri- acreage. 406 Managing Natural Resource Systems Erosion Can Cut Yields Erosion reduces the depth of topsoil, impairs the soil's capac- ity to retain water, and thwarts infiltration of water and air into the soil. As a result, soil erosion can ultimately reduce crop jàelds. But measuring yield reduc- tions due to soil erosion is diffi- cult because, over time, farmers may substitute increasing amounts of fertilizers or use other technologies to enhance the soil's natural fertility. Also, erosion effects on crop yields differ by soil type, crop, and management practices. Studies indicate, however, a re- lationship between erosion and reduced yields on many soils. If erosion has reduced the soil's water-holding-capacity, the root- ing depth available to the plant, or the water infiltration rate, adding fertilizer may not offset the yield-reducing effects. Erosion also affects air and water quality. Agriculture is con- sidered the main source for that part of the Nation's water pollu- tion that comes from diffuse (nonpoint) sources. Sediment in water runoff carries along fertil- izer residues, pesticides, dis- solved minerals (such as salts), and animal wastes (with associ- ated bacteria). Excessive sedimentation can clog navigation channels and can dirty drinking water, adding costs to rectify both, and can re- duce recreational opportunities. Also, in some areas, sediment is Soil erosion is timately reduce considered a crop yields. The rapidly filling inland lakes and problem be- sedim.ent in reservoirs. cause it can ul- water runoff is How Farmers Affect Natural Resources 407 no Less uj a Nation's water problem—con- pollution tributing sub- problems. stantially to the 408 Managing Natural Resource Systems The Profit Factor For some tracts of land, con- If erosion reduces yields, servation may be economiced for water, and air quidity, why don't the farmer when the land is first all farmers practice conserva- cultivated. This might be true on tion? A major reason is many fairly flat land where the topsoil conservation practices do not is shallow but highly productive, pay for themselves. However, and the subsoil of substantially this is not because the practices poorer quality. In this situation, are ineffective. losing an inch of topsoil could Farmers can choose among reduce yields dramatically. Ero- many soil conservation tech- sion could be reduced inexpen- niques such as changing the sively if, for example, contour characteristics of a field's topog- plowing or residue retention raphy with terraces, planting were used. only the least erosive lands, ro- On other tracts where conser- tating crops, stripcropping, vation requires major land-mov- planting on the contour, retain- ing technologies to form terraces ing crop residues on the field and where straight-row, highly surface after harvesting, con- erosive cropping patterns can structing waterways, or using bring a high dollar return, pri- methods such as no-till. vate economics may dictate min- No-till is a technique that ing the soil. This is particularly eliminates almost all tillage, and true where the original topsoil is chemicals—rather than conven- very deep. tional plowing—are used to con- Other financial factors also in- trol weeds. On some croplands fluence the farmer's decision on this can reduce erosion rates 60 conserving soil. The lower the to 95 percent price of soil substitute, such as Many of the techniques are not fertilizers, the less likely the profitable, however, or not per- farmer is to conserve. Also, the ceived to be so. A business- lower a farmer's current net in- minded farmer—who must be come, the less likely he or she is competitive to remain in farm- to conserve, since substituting ing—is not interested in prac- future income for present in- tices that don't pay. Even a come is financially impossible. farmer with a strong land ethic While many soil conservation and a desire to practice soil con- practices may not be economical servation may find it financially investments for farmers, there impossible to do so. are exceptions, such as conser- vation tillage, contour plowing, Mining the Soil or Not and leaving residue on the field For the business-minded after harvest In some areas farmer, a decision to maintain, these practices are effective in improve, or deplete soil is largely reducing erosion and may even an investment decision. increase profits. How Farmers Affect Natural Resources 409 Farmers can choose among m.any soil con- servation tech- niques. On this cropland in southwestern Iowa, the farmer has cho- sen to plant on the contour and use conserva- tion tillage. These practices are effective in reducing ero- sion and in some areas of the Nation may even increase profits. The Nation's policjmiakers 1962 low of 331 million acres, currently are considering mainly due to tremendous ad- changes in conservation pro- vances in yields per acre during grams to make them more effec- the I950's. tive in reducing soil erosion on Next there was a relatively sta- croplands. If incentives are pro- ble period when land used for vided so farmers will conserve crops averaged about 330 million the soil when and where it is ap- acres until 1972. Then the land propriate, substantial progress used for crops began to increase, can be made in both retaining reaching a new high of 391 mil- soil for future production and lion acres in 1981. improving water and air quality. Considerable regional shifts occurred in the use of cropland. Cropland in Use Over a third of the cropland de- Erosion influences the quality cline took place in the North- of our farmland. Another dimen- east, Southeast, Appalachia and sion is the quantity of farmland. the southern Plains. Other re- The amount of land in crops gions increased their cropland was relatively stable from 1920 acres. Recent rises were mainly through 1950, varying between in the Mississippi Delta States, 360 to 380 million acres. That the northern Plains and the was followed by a decline to a Com Belt 410 Managing Natural Resource Systems Cropland in Actual Production Land used for crops (millions of acres) 400 380 360 340 320- 300. 1910 1920 1930 1940 1950 1960 1970 1980 Source: USDA Land Shifts Too Big? First, many communities enjoy These trends and changes the visual, cultural and financial have led many to question benefits from a viable agricul- whether too much land is being tural industry.