Cover Image

PAPERBACK
$35.00



View/Hide Left Panel
Click for next page ( 250


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 249
Ecological Guidelines for Management of Rural Areas in Poland LECH RYSZKOWSKI Institute of Agrobiology and Forestry Polish Academy of Sciences - Increasing environmental degradation in various areas of Poland re- flects neglect or disregard of environmental structures and processes in the pursuit of the economic development of the country. Rural areas com- prise 60% of the total land area of Poland, and they are not excluded from widespread environmental degradation. From these failures one may conclude that some changes are needed in our attitudes about agricultural environments. We must stop treating each individual farm, industry, or landscape as though it were isolated from other aspects of the environ- ment, economy, or social system. A larger, systemic approach is needed in decision-making regarding rural areas so that the long-term, functional effectiveness of the biological, economic, and social aspects of the system can be achieved and sustained. Direct productive or social outcomes and the constraints involved in natural and managed environments should be recognized in formulating programs for agriculture, agricultural industries, and services for the agri- cultural sector as well as for recreation and other functions in rural areas. Realization of these goals requires: understanding the relationship between structures and levels of agricultural production with respect to conditions of the natural environ- ment; changing the methods of planning for agricultural development to consider the costs of environmental degradation from traditional forms of economic development; stimulating the introduction of new technologies which are sup- portive of longer-term functioning of agroecosystems; and 249

OCR for page 249
250 ECOLOGICAL RISKS changing the rules of spatial planning to include greater concern for the ecological balances of natural and cultural environments. ENVIRONMENTAL HAZARDS IN RURAL AREAS OF POLAND The area in Poland used as arable land, grasslands, and orchards has decreased continuously since World War II. Agricultural area per capita decreased from 0.85 hectares in 1946 to 0.50 hectares in 1987 due to industrialization, urbanization, and growth of the country's population. At the same time, improvements in agriculture have led to increased yields. According to data from the Main Statistical Office (1986), yields per hectare of major crops increased as follows between the years 1946-1950 and 1981- 1983: four cereals by 237%, potatoes by 132%, sugar beets by 171%, and rapeseed by 230%. Although agricultural productivity has increased, still larger yields are possible. For example, the average yield of the four cereals could be increased from the present level of three tons per hectare to about four tons per hectare; this is the average yield in East Germany and Czechoslovakia where soils and climatic conditions are similar to those in Poland. Environmental hazards for rural areas give rise to several problems interfering with sustainable development of farming. The severity of the situation is reflected by the March 4, 1983, resolution of the Polish Cabinet in which 27 "areas of ecological hazard" were identified. Pollution and degradation of the environment threaten both the public health and the future economies of these areas. Areas of ecological hazard cover 11.2 55 of Poland's total area, ac- cording to the Main Statistical Office (1984~. In 1983, these areas were inhabited by 35.5% of the nation's population. Agriculturally, 9.7% of these areas are devoted to cereals, 9.6% to potatoes, 9.5% to beets, 9.5% to fodder crops, and 11.8% to orchards. These areas also produce 82% of the total emissions of dust and gas pollutants in Poland, which amount to 5,464,000 tons per year. This figure includes 1,065,0()0 tons per year of fly ash which carries various heavy metals; these areas were responsible for 77% of the total fly ash emission in Poland. Emission of sulfur dioxide in these areas is also very high (1,987,000 tons per year) which is 81% of the SO2 emission for the whole country. Obviously, these data indicate that the safety of food produced in these areas is much lower because of the heavy deposition of different pollutants. Acid Deposition Lack of effective means for limiting industrial emissions of sulfur and nitrogen oxides leads to progressive acidification of soils. The National

OCR for page 249
AGRICUL17JRAL IMPACTS TABLE 1 Mg and Ca leaching in watersheds with different amounts of sulfur dioxide air pollution. Concentration Rate of leaching Arable of so2 Kg ha-1 ye) Area Land in air Watershed Dun) (percent) (ug m3) S-SO4 Mg Ca 1 425 66 50 4.8 3.8 19.8 2 694 71 20 3.3 2.1 13.2 SOURCE: Unpublished infomlaiion obtained from B. Karlik, ~shtute of Agrobiology and Forestry, Poman. 251 Program for Natural Environmental Protection through 2010 estimates that by the year 2010, the SO2 concentration in air will not be lowered below the officially accepted air quality standard value of 32 fig m~3 (Ministry of Environment and Natural Resources Conservation, 19883. Because of acid rain, about 50% of Polish soils are expected to have a pH value of about 4 (Stigliani et al., 1988~. The gradually changing chemical composition of soil, including leaching of calcium, magnesium (Table 1), and other elements like phosphorus, potassium, and aluminium, will likely eliminate some plant communities and related microorganisms and soil animals (Cook 1983~. A decline of soil bacterial biomass is expected with considerable increase of fungi. The amount of biologically inactive or even dead fungal hyphae is also expected to increase with rising acidity. The biomass and variability of earthworms and enchytraeids is expected to decline which, together with changes among microorganisms, will lead to slower decomposition of plant residues and regeneration of humus. Many invertebrate species living in soil water may be threatened with extinction. On the other hand, a quantitative rise in some groups of insects should be expected, e.g., springtails (Coleman, 1981~. Although the role of animals and microorganisms in formation of humus is still not fully known, changes from acid deposition are likely to unfavorably affect the soil humus by decreasing the rate of decomposition of plant residues. This will be most dangerous in light, arable soils which are widespread in Poland and in which we have observed increased leaching of organic matter with more intensive farming practices (Zycynska-Baloniak, 1980~. Intense farming contributes to decreased amounts of humus because of increased mineralization of organic matter, intensified erosion, or the leaching of water soluble organic compounds. Increased soil acidity will result in changing patterns of nutrient cy- cling. For example, soil acidity will gradually limit the activity of bacteria responsible for Vitrification or even denitrification processes, which will

OCR for page 249
252 ECOLOGICAL RISKS considerably lower the rate of nitrogen cycling (Cook, 1983). Soil acidity will also decrease symbiotic nitrogen fixation by legumes (Aleksander, 1980) and will change conditions important to the formation and the functioning of mycorrhizae (Domanski et al., 1987~. Air Pollution Agricultural production in Poland is limited by air pollution. Even though evaluation of losses in plant production have not been conducted for the whole country, air pollution limits crop yields in areas of ecological threat (Wartesiewicz, 1978~. Also, the concentration of heavy metals in soils has increased, which leads to concerns about food contamination. The report of the Committee for Food Technology and Chemistry of the Polish Academy of Sciences indicated that the amount of mercury and cadmium in average diets is close to the health hazard limit (BaryLko-Piekielna et aL, 1985~. Groundwater Degradation Increased applications of nitrogen fertilizers have increased crop yields, but also have led to increased leaching of nitrogen into underground and surface waters. According to data from the Main Statistical Office (1987), the seriousness of the situation is illustrated by the fact that as much as 63% of household wells, 45% of factor wells, and 52% of public wells were classified as unhealthy by the National Sanitary Inspection. Contamination of these rural wells was caused by nitrogen compounds leached from fields and contamination by farm sewage. Water Shortages Water deficiencies are a significant threat to all living organisms. Man- agement of water resources in Poland is made difficult by both unfavorable climatic conditions and past management errors. Natural water regimes in Poland, particularly in the central areas, are the least favorable among all European countries. Annual precipitation ranges from about 500 mm in central Poland to over 1,000 mm in the mountains. Water shortages are common in the Polish lowlands, where the amount of transpiration exceeds total rainfall during the vegetative period and results in the lowering of the groundwater table (Niewiadomski, 1979; Maciak and Zawadzki, 1981~. Drainage projects have also lead to excessive drying of considerable areas of land and have lowered groundwater tables. Increasing needs for water by industry, agriculture, and municipalities have lead to further

OCR for page 249
AGRICULTURAL IMPACTS 253 increases in water deficiencies. The area of excessively dried land in Poland amounts to about 4 million hectares, including a dramatic deficit area of 0.6 million hectares (Partyka et al., 1979~. Cropland has been augmented over time by conversion of grasslands, pastures, and even marshes which have been drained for agricultural use. However, reclamation projects based exclusively on technological criteria, and which neglect ecological considerations, have decreased water storage capacities in Poland. The channelization of rivers and construction of levees have lead to increased water flow rates and deepening river beds, resulting in a lower groundwater table in adjacent areas (Palys, 1985). The elimination of small ponds in fields and the drying of marshes also reduces water holding capacities and increases wasteful surface runoff. Because of a poorly developed network of water reservoirs (only 6% of the mean annual outflow can be stored in Poland), considerable quantities of surface runoff waters are typically lost to the sea. Thus, water manage- ment errors often actually result in reductions of water from watersheds. The role of non-systematic drainage~rainpipes open to small ponds which are unconnected with river system is neglected, particularly in areas with steep slope. Water retention is greater on the areas which are drained non-systematically. The processes of self-purification of water are also more effective in these areas, especially when whole watersheds are considered (Kosturkiewicz, 1988). Increased drying of the central region of Poland (i.e., Konin, Wloclawek, Plock, Ciecha now, Lodz, Skierniewice, and Lublin districts) is also associated with high degrees of deforestation in those areas where forest cover is below 15%. Water shortages also limit economic activity and the conservation of some organisms in Poland. This situation is aggravated due to contami- nation of surface waters by industry and municipal sewage discharges as well as by agricultural sources, e.g., fertilizers and pesticides leached from fields, farm sewage, and discharges from small food processing plants lo- cated in agricultural areas. The result is that pollution of surface waters is increasing. About 40% of all rivers in Poland carry water which is below established standards for use, even for industry. The inflow of pollutants into lakes leads to severe degradation. About 60% of Polish lakes are strongly polluted. Problems of solid waste disposal in rural areas is also leading to the filling-in of small ponds. Unfortunately, it is common prac- tice to dump solid wastes into small ponds located in rural areas, turning them into scrap heaps over time. According to research carried out by the Institute of Agrobiology and Forestry, about 30% of the small ponds in the studied area (400 km2) disappeared within the last 30 years (Karg and Ryszkowski, 1984).

OCR for page 249
254 ECOLOGICAL RISKS Soil Erosion Another environmental hazard associated with agriculture involves water and wind erosion of soil. More intensive agricultural technologies can accelerate erosion processes because they are often accompanied by elimination of shelterbelts and hedgerows as fields are made larger to accommodate increased mechanization. Changing crop rotations may also have significant impacts on erosion processes. For example, an increased proportion of row crops in crop rotation often increases erosion (Szumanski, 1977~. Three regions of Poland are particularly threatened by wind and water erosion (Ziemnicki, 1978~. The northern region of Poland, the lakelands, is mildly affected by erosion. The southern uplands region has loess soils which are very strongly threatened by water erosion; as a result, many gullies have been formed there. In about 0.3% of the region, gully density is above 2 km per k=2 (Jozefaciuk and Jozefaciuk, 1988~. The third region prone to erosion is the mountain area; here, slopes are steep, and annual rainfall often exceeds 1,000 mm per year. Jozefaciuk and Jozefaciuk (1988) estimate that surface water erosion hazards exist on 39.3 of the country's area, and that wind erosion threat- ens an additional 10.8%. These estimates of erosion potential are based on the assumption that climatic conditions favoring erosion are uniformly distributed over the whole country. However, actual erosion hazards occur on about 1~15% of the country's area. In addition, increasing concentra- tions of carbon dioxide in the atmosphere (which could stimulate increased rainfall) as well as air pollution by sulfur and nitrogen oxides (which could destroy plant cover) could directly or indirectly enhance water erosion in the future. Potential for wind erosion is also increased when soils are dried out as a result of drainage projects in many regions of Poland. NEED FOR ECOLOGICAL GUIDELINES FOR AGRICULTURAL DEVELOPMENT Many of the sources of environmental degradation in rural areas mentioned above appear to be negative side effects of efforts to increase agricultural production. Such efforts include increased use of agricultural chemicals, greater intensity of mechnization, and introduction of other el- ements of "modern" technology for intensive plant and animal production. Negative effects of these efforts often result from an inadequate under- standing of ecological processes in agroecosystems, suggesting that current economic development guidelines are too simplistic and do not address natural laws of ecosystem function. Therefore, ecological guidelines for agriculture need to be developed

OCR for page 249
AGRICULTURAL IMPACTS 255 on the basis of sound ecological knowledge and joint optimization of agri- cultural production and nature conservation. Such an approach or program must design waste-free technologies for plant and animal production which would incorporate recycling by-products (e.g., using slurry, food industry wastes, etc.) and would also take advantage of previously unused produc- tion factors. For example, a portion of applied fertilizers remains in the environment and may result in eutrophication of water bodies or pollu- tion of drinking water. Modern ecology provides the means to control these negative environmental side effects and, at the same time, to develop sustainable agriculture. ECOLOGICAL GUIDELINES FOR CONTROL OF ENVIRONMENTAL HAZARDS IN RURAL AREAS Intensive cultivation prevents development of more complex plant communities. Animal communities in agroecosystems are more impover- ished than in natural ecosystems, and bacteria start to predominate among soil microorganisms (Golebiowska and Ryszkowski, 1977; Kaszubiak and Kaczmarek, 1985; Ryszkowski, 1979, 1981~. In addition, agricultural activity often leads to decreased amounts of humus in the soil. These phenomena result in the development of a less complex network of interrelationships among the components of an agroecosystem. As a consequence of this sim- plification, relationships among ecosystem components are altered so that there is less tie-up of local cycles of matter. This leads to increased leach- ing, blowing off, volatilization, and the eventual escape of various chemical compounds and materials from agroecosystems (SIDAlFAO, 1972; Frissel, 1977; Clark and Rosswell, 1981~. As an illustration of the above, research carried out in Poland by Borowiec et al. (1978) showed that landscapes with a higher proportion of arable fields had increased leaching of elements from watersheds Able 2~. On an average, there was 2.5 times more nitrogen, almost 3 times more phosphorus and potassium, and over 1.5 times more calcium and magnesium leached from a unit of agricultural watershed than from a unit of forest watershed. Fields were intensely fertilized in both types of watersheds. These results indicate lowered retention of various chemical compounds in arable fields. The same study also indicates that increases in watershed plant cover can also control migration of nutrients. An important conclusion for both agriculture and environmental pro- tection can be drawn from investigations on matter cycling in cultivated fields: short-term increases in crop yield can be achieved in simple agroe- cosystems, but such systems lead to decreased retention of chemical com- pounds in the long run. Such long-term losses can be prevented by better

OCR for page 249
256 TABLE 2 Influence of plant cover of watersheds on ion leaching. ECOLOGICAL RISKS Type of No. Percent of area OutElowof elements curing two years (am ) Watershed of (WS) WS grass- + 2 + 2 arable forests land N-NO3 P-PO4 K Ca Mg Larger contri- 1 53 12 35 1.63 0.03 3.32 37.66 2.89 button of 2 62 8 28 1.43 0.04 2.99 35.42 3.30 cultivated 3 53 32 13 1.13 0.04 2.57 30.95 2.98 fields 4 51 21 27 0.71 0.02 2.91 39.40 2.70 MEAN 55 18 26 1.22 0.03 2.36 34.13 2.78 Smaller 1 38 44 17 0.60 0.02 1.58 23.33 1.80 contribution 2 29 45 26 0.48 0.01 1.00 25.63 1.44 of cultivated 3 21 65 14 0.39 0.01 0.91 22.54 1.56 fields 4 39 47 21 0.44 0.01 0.91 15.26 1.20 MEAN 30 50 19 0.48 0.01 1.10 21.69 1.50 SOURCE: Borou~ec, SI;rzyczynski, and Kucharska, 1978. management of the agricultural landscape structure through use of shelter- belts, grasslands, and small water reservoirs to better control dispersion of various compounds from arable fields. MANAGEMENT OF AGRICULTURAL LANDSCAPE Agroecosystems are characterized by openness of matter circling. This means that parts of the materials used in intensification of production are spread outside the boundary of the ecosystem. Thus, the management of material migration could be improved if agricultural regions include structures such as grasslands and small forest plots and ponds which could direct the cycles of matter and thus retard the accumulation or spread of harmful compounds or materials. Interfield stretches of grassland and shelterbelts are biological barriers which can modulate the dispersal of venous chemical compounds or ma- terials from arable fields. Analyses of the concentration of various ions in groundwater flowing from arable fields through adjacent forests or shelter- belts show a considerable decrease in nitrates and a smaller decrease in concentrations of calcium, magnesium, and phosphorus Able 3~. Decreased concentrations of nitrates in groundwater flowing under adjacent forested areas result not only from direct adsorption by root systems, but probably indirectly by denitrification as well (Peterjohn and Correll, 1984~. Paliukevicius (1981) has also noted the importance of tree

OCR for page 249
AGRICULTURAL IMPACTS TABLE 3 Mean element concentration (ma dm 3) in ground rater under cultivated fields, forest, and shelterbelts adjancent to the fields, August 1982 - September 1986. 257 AREA 1 Elements Cultivated Fields Forest AREA 2 Cultivated Fields Shelterbelt Nitrate 22.2 1.0 37.6 1.1 nitrogen Calcium 158.0 82.0 198.0 116.0 Magnesium 15.8 8.6 41.1 18.4 Phosphate 0.21 0.11 0.8 0.06 phosphorous SOURCE: Bartoszewicz and Ry~zkowski (in press). stands in controlling water-based migration of various chemical compounds from fields. Experimental defoliation and various methods of logging in watersheds have shown significant relationships between plant cover and the chemistry of surface waters (Likens and Borman, 1972; Likens et al., 1977~. Nitrogen cycling in forests is relatively closed because of the high affinity of soil organisms and plants for this element. Thus, only a small amount of nitrogen is lost from forest ecosystems (Rosewall, 1976~. Even so, the input of nitrogen often exceeds output, indicating that nitrogen is stored in forest ecosystems (Likens et al. 1977~. When the system of interrelationships between soil, plants, and heterotrophs is broken due to human intervention, large quantities of organic nitrogen are mineralized and nitrates are leached from soil (Margowski and Bartoszewicz, 1976; Margowski, 1979; Ryszkowski, 1979~. Grasslands also provide barriers to prevent spreading of different compounds in agricultural landscapes. At a distance of 15 to 25 meters from the edge of a field, there are reductions of nitrates from 10.4 mg dm~3 to 2.4 mg dm-3 in groundwater flowing under grasslands (Bartoszewicz and Ryszkowski, in press). Different kinds of cultivated plants also influence element leaching rates. In an analysis of water drained from fields having different cultivated plants, Borowiec (1986) showed high leaching rates of various elements under fields planted with row crops and maize, whereas lower leaching rates were associated with cereal cultivation (rIbble 4~. Because Borowiec used as the base reference value the mean for each element calculated from all samples (including row crops and cereals), his analysis indicates only relative rates. Nevertheless, the conclusion is that the pattern of plant rotation influences the leaching of elements from soils of cultivated fields.

OCR for page 249
258 ECOLOGICAL RISKS TABLE 4 Idfluence of winter cereals, row crops and maize cultivation on concentration of nutrients in drain water. (:hange of concentration percent from mean due to cultivation Mean concentration during 9 years Row Crops Winter Nutrients (ma dm~3) and Maize Cereal N - NO2 8.7 + 37 - 21 P - PO4 0.14 + 57 43 K 5.0 + 22 - 30 Ca lS7.0 + 19 - 18 Mg 26.0 + 3 - 6 + = above mean - = below mean SOURCE: Borowiec (1986). . _ '~S5 4-8h Rain Fall 107% Snow Cover 115% (1h) ............ > 1 Oh Rainfall 100% Wind 100% - - Wind 60% ~S Potential 75% ``Evaporation ~ - Yield 105% ,. , , ., .. ,. ., L Potential 100% _ Evaporation Yield 100% , ~ ~ Il~l~llllll)~n~ ,, ~ Distance from the shelterbelts 4h 8h 1 6h expressed in units equal to their height (h) FIGURE 1 Effect of shelterbelts on microclimate adjoining fields (Ryszkowski, 1975~. Higher proportions of legumes, grasses, and cereals are associated with decreased leaching of chemical elements from agroecosystems. The results of these investigations indicate the possibility of changing groundwater chemistry by manipulating the structure of plant cover by planting shelterbelts, grasslands, forests, and crops. Plant cover also de- creases soil losses by water erosion. Preventing soil loss by wind erosion is another problem for contemporary agriculture. Shelterbelts can help con- trol wind erosion. Long-term research carried out in the vicinity of Crew by the Institute of Agrobiology and Forestry of the Polish Academy of Sciences has provided results which show that shelterbelts can significantly modify wind velocity and consequently affect the spatial distribution of atmospheric deposition and decreases potential evaporation from adjacent fields (Ryszkowski, 1975; Ryszkowski and Karg, 1976~. Figure 1 illustrates the general results from these studies.

OCR for page 249
AGRICULTURAL IMPACTS TABLE 5 Parameters of heat and water balances for vegetation season agricultural landscape components. Parameter Units Shelterbelt Wheat Grassland Intercepted solar energy (Rn) Energy used for evapotranspiration (LE) MJm~ 1,730 1,536 1,494 MJm~2 1,522 1,090 1,250 Evapotranspiration mm 609 436 500 LE: Rn 0.88 0.70 0.8 SOURCE: Ry~zkowski and Kedziora, 1987. 259 Shelterbelts capture large amounts of incoming solar energy (because of low albedo values) and use nearly 90% of intercepted energy for evapo- transpiration Amble 5~. As a result of these thermodynamic characteristics, shelterbelts evaporate about 170 more liters of water per square meter during the growing season than fields with cultivated wheat (Ryszkowski and Kedziora, 1987~. There are at least two reasons for this difference, both of which are connected with the difference in structure of plant cover of these two systems. Tees have much better developed root systems than do wheat and other agricultural crops, allowing them to absorb water from deeper layers of soil. Thus, more water is within direct and indirect (capillary flow) reach of the tree roots. Shelterbelts also have a larger canopy roughness than wheat. Together with higher wind speeds and turbulence in shelterbelt canopies, this canopy roughness results in more intensive vapor exchange over shelterbelts (Ryszkowski and Kedziora, 1987~. In this respect, shelterbelts function as powerful "natural water pumps" and, thus, influence groundwater chemistry when groundwater is within direct or indirect reach of the tree root system. Because of higher albedo values, grasslands intercept smaller amounts of incoming solar radiation (Bible 5~. Managed grasslands are usually located in terrain depressions, often in or adjacent to areas of natural drainage. Here, the roots reach shallow groundwater and the plants use a high proportion of the intercepted energy for evapotranspiration. Thus, grasslands also affect the chemistry of underlying groundwaters. The ion exchange capacities of soils under shelterbelts and under grasslands diner from those under cultivated fields. This also leads to different effects on the chemistry of groudwater. Taken together, these phenomena explain why shelterbelts and grasslands impact groundwater chemistry as discussed above.

OCR for page 249
260 ECOLOGICAL RISKS Ponds and small reservoirs provide another kind of environmental barrier which can prevent the spread of chemical compounds. At present, the role of small ponds is almost totally neglected in development planning. These ponds can be effective in controlling matter cycling in agricultural landscapes. The sediment deposited on the bottom of ponds contains nutrients leached from the fields. Thus, sedimentation of nutrients in ponds decreases the amount lost from the landscape. Fertilizing fields with the sediment from small, shallow field ponds facilitates recovery of mineral plant nutrients otherwise lost from the agroecosystem. Thus, small water ponds or reservoirs located according to terrain relief to create barriers for surface runoffs can play an important role in shaping pathways for matter cycling in the landscape (Golley et al., 1978~. Gliessman (1978) reported a practical utilization of small catchment reservoirs in Yucatan, Mexico. Attempts to intensively cultivate crops on large fields led to a considerable intensification of soil loss by water erosion. Eventually, losses in soil fertility created conditions which led to abandonment of farms. However, a return to traditional farmscultivating smaller fields (15 hectares or less in size) surrounded by shelterbelts and with catchments for collecting sediment carried by water during heavy monsoon rains has lead to a return of a more prosperous agriculture. Soil nutrients collected in catchments are now returned to the fields after the monsoons are over. Natural, compatible structures which assist in controlling matter cycling are of great importance for farming. Arable fields have an open type of matter cycling, with low utilization of mineral fertilizers. Strict agricultural use of applied nitrogen amounts to only 50 percent of input. The rest either escapes to the atmosphere or migrates to ground and surface waters causing various environmental problems. Providing different environmental barriers can reduce the loss or spreading of various chemicals and nutrients from -farm fields. Shelterbelts and small patches of forest or grasslands distributed within the agricultural landscape can influence matter cycling over the entire area, facilitating enhanced environmental protection in rural areas. OPTIMIZATION OF AGRICULTURAL PRODUCTION AND ENVIRONMENTAL CONSERVATION Increased recognition of the natural laws of ecosystem function fa- cilitates more objective evaluation of alternative technologies which seek to optimize agricultural production, nature conservation, and achievement societal needs at the same time. An agroecosystemic method of analysis is

OCR for page 249
AGRICULTURAL IMPACTS 261 useful in developing a better understanding and better control of environ- mental threats in rural areas caused by industry and urbanization of the country, as well as for sustainable agricultural development. A broad, systematic method of analysis of these phenomena helps to overcome the common view that maximum yields can be obtained by intensified farming on a large scale. Use of mixtures of shelterbelts, grasslands, open drainage canals with banks covered with trees or shrubs, and small ponds or catchment reservoirs are often viewed as obstacles to mechanized production. Thus, there is a tendency to avoid them on the part of farmers who want to take maximal advantage of mechanization, albeit at the expense of increased wind erosion and increased surface and subsurface runoffs. This narrow and ecologically harmful point of view can be corrected by introducing a wider agroecosystem perspective. Of course, maintaining appropriate field mosaics shelterbelts, grasslands, hedgerows, small water reservoirs, streams, canals, etc.will require a reorientation in attitudes as well as the development of new and more appropriate agricultural and forest technologies. Agricultural and forest implements and machines should work effectively without destroying environmental barriers. Their designers should consider their maneuvering ability, utility in fulfilling multiple tasks, as well as limit their size, improve speed control, and allow flexibility in changing their area of contact with ground. This ecosystem perspective would enable creation of regional or na- tional programs of agricultural~development with fewer negative env~ron- mental effects. Controlling humification and mineralization processes of soil organic matter is of fundamental importance. Knowledge about par- ticipation of various groups of organisms in energy flows in agroecosystems also can be of great use. Recognition of the laws of matter cycling would facilitate development of so-called '~waste-free" technologies, and min- eral fertilizers might be used more effectively, causing fewer unfavorable changes in water and soil quality. Ecological agriculture does not lead to a refutation of modern means of agricultural production, but to a more rational agroecosystem strategy which seeks to meet the objectives of food production and nature conservation. In conclusion, increased emphasis on ecological farming stems from the societal need to reduce environmental hazards in rural areas, and not from a desire to return to a less productive, traditional economy. Ecological agriculture is an attempt to optimize output and achieve high yields while maintaining the long-term productive potential of soils. Thus, it can be viewed as a farming system which maximizes "social" profits by optimizing agricultural production and environmental conservation, using the laws of ecosystem function to avoid environmental hazards.

OCR for page 249
262 ECOLOGICAL RISKS Acknowledgement Partial financial support for this research was provided by Ministry of Education of Poland. REFERENCES Alexander, M. 1980. Effects of acidity on microorganisms and microbial processes in soil. Pp. 363-374 in Effects of Acid Precipitation on Terrestrial Ecosystems, T.C. Hutchinson and M. Hacas, eds. New York: Plenum Press. Bartoszewicz, A., and L. Ryszkowski. (in press). Influence of shelterbelts and meadows on the chemistry of groundwater. In Dynamics of Agricultural Landscape, L" Ryszkowski, ed. New York: Springer Verlag. Barylko-Piekielna, N., Cz. Kierbinski, and S. Tyszkiewicz. 1985. Estimate of food con- tamination levels as result of environment contamination. Mimeographed text. Polish Academy of Sciences, Warsaw. p. 45 (in Polish). Borowiec, S. 1986. Influence of plant cover in agricultural landscape on nutrient concen- trations in surface waters and nutrient leaching from soils. Proceedings of Conference on Problems of Environment and Landscape Protection in Light of Actual Needs of the Country. Towarzystwo Naukowe Organizacji i Kierowania w Poznaniu. Poznan. pp. 73-79 (in Polish). Borowiec, S., T. Sk~ynski, and T. Kucharski. 1978. Migration der mineralischen Bestandteile aus den Baden der Nizina Szczecinska. Polish Scientific Publishers, Warsaw. p. 68. Clark, F.E., and T. Rosswall, eds. 1981. Terrestrial nitrogen cycles. Ecol. Bull. 33:1-714. Stockholm. Coleman, D.C 1981. The impact of acid deposition on soil biota and C cycling. Pp. 33-53 in Response of Agricultural Soils to Acid Deposition. Proceedings of the Meetings of the Electric Power Research Institute. Columbus, Ohio. Cook, R.B. 1983. The impact of acid deposition on the cycles of C, N. P. and S. Pp. 345-364 in The Major Biogeochemical Cycles and Their Interactions, B. Bolin and R.B. Cook, eds. New York: Wiley. Domanski, S., S. Kowalski, and T. Kowalski. 1987. Industrial emissions and pathogenic activity and biotrophic changes in fungi with special reference to Upper Silesia and Cracow industrial districts. Pp. 281-288 in Biological Reactions of liees to Industrial Pollution, R. Siwecki, ed. ~rdawnictwo Naukowe Uniwersystetu w Poznaniu, Poznan. Frissel, MJ., ed. 1977. Cycling of mineral nutrients in agricultural ecosystems. Agroecopys- tems 4:1-354. Gliessman, S.R. 1978. Ecological processes of traditional agroecosystems in the humid lowland tropics of southern Mexico. 135. Paper Prepared for the Second International Congress of Ecology. Abstracts. INTECOL Jerusalem. Golley, F., O.L. Louks, and L. Ryszkowski. 1978. Role of various elements of agricultural landscape in the functioning of watersheds. 137. Paper Prepared for the Second International Congress of Ecology. Abstracts INTECOL~ Jerusalem. Golebiowska, J., and L Ryszkowski. 1977. Energy and carbon fluxes in soil compartments of agroecosystems. Ecol. Bull. 25:274-283. Stockholm. Jozefaciuk, C., and A. Jozefaciuk. 1988. Strategy of ecosystem and agricultural landscape protection against erosion. Manuscript of Report presented for Strategy of Living Resources Conservation in Poland. Institute of Agrobiology and Forestry, Poznan. Karg, J., and L. Ryszkowski. 1984. Environmental threats in Koscian district. In Stan i Ksztaltowanie Wartosci Krajobrazowych Na Ziemi Koscianskiej, L. Ryszkowski and K. Zimniewicz, edit Towarystwo Milosnikow Ziemi Koscianskiej. Koscian 109-161 (in Polish). Kaszubiak, H., and W. Kaczmarek. 1985. Differentiation of bacterial biomass in croplands and grasslands. Intecol Bulletin 1~29-37.

OCR for page 249
AGRICULTURAL IMPACTS 263 Kosturkiewicz, A. 1988. Program of water reclamations for protection of living resources. Manuscript of Report Presented for Strategy of Living Resources Conservation in Poland. Institute of Agrobiology and Forestry, Poznan. Likens, G.E., and F.H. Borman. 1972. Nutrient cycling in ecosystems. Pp. 25-67 in Ecosystems Structure and Function, J.A. miens, ed. Conrallis, Oregon: Oregon State University Press. Likens, G.E., F.H. Borman, AS. Pierce, J.S. Eaton, and N.M. Johnson. 1977. Biogeochemistry of a forested ecosystem. New York: Springer Verlag. p. 146. Maciak, F., and S. Zawadzki. 1981. Role and development trends of land reclamations in Poland. Zeszyty problemowe postepow nauk rolniczych. 248:13-29. Main Statistical Office. 1984. Regions of ecological threat in Poland. Warsaw, p. 237 (in Polish). Main Statistical Office. 1986. Yearbook 1986 (in Polish). Watsaw. p. 630. Main Statistical Office. 1987. Environmental protection and water management. Department Rolnictwa i Gospodarki Xywnosciowej. Warsaw, p. 363 (in Polish). Margowski, Z 1979. Natural and agronomic factom limiting eutrophication of waters in the agricultural landscapes. Zeszyty problemowe postepow nauk rolniczych 228:65-76. Margowski, Z., and A. Bartoszewicz. 1976. Infiltration of fertilizer components into ground- water. Komitet Ekologii PAN. Matenaly konferencji: Nawoxenie a eutrofizacja wad. 75-97. Zielona Gora. Wyxsza Szkola Inxynierska. Ministry of Environment and Natural Resources Consenration. 1988. The national program for natural environment protection until 2010. Wydawnictwa Geologiczne. Warsaw, p. 122 (in Polish). Niewiadomski, W. 1979. Ecological consequences of the agriculture intensification. Zesyty problemowe postepow nauk rolniczych 228:9-28. Palys, E. 1985. Influence of river erosion on agriculture and water management. W~adomosci melioracy~ne i laka~skie 28:245-248 (in Polish). Partyka, T., B. Szymanska, and E. Suwara. 1979. Changes of spatial structure of the agricultural and forest utilization of soil. Zeszyty problemowe postepow nauk rolniczych 217:45-62. Pauliukevicius, G. 1981. Ecological role of the forest stand on the lake slopes. Vilnius: Pergale, p. 191. Peterjohn, W.T., and D.L. Correll. 1984. Nutrient dynamics in agricultural watershed: Observations on the role of a riparian forest. Ecology 65:1466-1475. Rosswall, T. 1976. The internal cycle between vegetation, microorganisms, and soils. In Nitrogen, Phosphorus, and Sulfur Global Cycles, B.H. Svennson and R. Soderlund, eds. Ecol. Bull. 22:157-167. Stockholm. Ryszkowski, L. 1975. Rewiew of studies carried out in ll~rew on influence of shelterbelts on environment of adjoining fields. Zeszyty problemowe postepow nauk rolniczych 166:71-82. Ryszkowski, L. 1979. Croplands. Pp. 301-331 in Grassland Ecosystems of the World, R.T. Coupland, ed. Cambridge: Cambridge University Press. Ryszkowski, L. 1981. Effects of agriculture intensification on fauna. Zeszyty problemowe postepow nauk rolniczych 233:7-38. Ryszkowski, L., and J. Karg. 1976. Role of shelterbelts in agricultural landscape. Pp. 305-309 in Les bocages: Historie, ecologic, economic: J. Missonnier, ed. CNRS. Univ. dr Rennes. Rennes. Ryszkowski, L, and A. Kedziora. 1987. Impact of agricultural landscape structure on energy flow and water cycling. Landscape Ecology. 1:85-94. SIDA/FAO. 1972. Effects of intensive fertilizer use on the human environment. FAO Soils Bulletin. 16:360. Rome. Stigliani, W. , F. M. Brouwer, R. E. Munn, R.W. Shaw, and M . Antonovsky. 1 988. Future environments for Europe: Some implications of alternative development paths. International Institute for Applied Systems Analysis. I^xenburg, Austria. p. 62. Szumanski, A. 1977. Changes in the course of the lower San channel river in XIX and XX centuries and their influence on the morphogenesis of its floodplain. Studia Geomorphologica Carpatho-Balcanica 11:139-153.

OCR for page 249
264 get H. 1~. Sulfur diode Eric! on planls. ~ p=Nem~e Plea emni~l, S. 1~8. P~le~ion of ails It erosion. Pans=~ Nick ~ln1=e i a. ~-Ba1~b I. 1~. D oxalic maker in waler of law and channel in 1he agd~lluml lanai. alit lit Soda 6:133-1~.