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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 250
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
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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
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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
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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 254
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 255
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 256
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 257
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.
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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 259
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.
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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 farms—cultivating
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 261
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 262
262
ECOLOGICAL RISKS
Acknowledgement
Partial financial support for this research was provided by Ministry of
Education of Poland.
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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~.
Representative terms from entire chapter:
plant cover
