ENVIRONMENTAL PROTECTION ASPECTS OF AGRICULTURE IN LANDSCAPE REGIONS OF SLOVENIA OKOLJEVARSTVENI VIDIKI KMETIJSTVA SLOVENSKIH POKRAJIN Irena Rejec Brancelj Main business of Slovene stockbreeding is cattle breeding and mountain pasturing is still present in Alpine areas (photography Anton Brecelj). Glavna veja slovenske živinoreje je govedoreja in planinska paša je še vedno prisotna v alpskem svetu (fotografija Anton Brancelj). Abstract UDC: 911:504.05(497.4) 504.05:631.51(497.4) COBISS: 1.01 Environmental Protection Aspects of Agriculture in Landscape Regions of Slovenia KEY WORDS: landscape environment, agricultural pollution, use of fertilizers, nitrates inputs, use of plant protection agents, Slovenia In the paper, several environmental influences of agriculture in 19 selected Slovene landscape regions are described. The investigation focuses primarily on dispersed sources of agricultural pollution, i. e., farms. Based on results of field polls made at over 1000 farms, data was collected and examined on the characteristics of fertilizing agricultural land, the use of plant protection agents, and inputs of nitrogen, one of the most important pollutants of soil and especially of water in agricultural regions. In the central part of the paper, the basic characteristics of these influences, the extent and level of pollution, and the regional differences within Slovenia are described. Izvle~ek UDK: 911:504.05(497.4) 504.05:631.51(497.4) COBISS: 1.01 Okoljevarstveni vidiki kmetijstva slovenskih pokrajin KLJUCNE BESEDE: pokrajinsko okolje, kmetijsko onesnaževanje, poraba gnojil, dušični vnosi, poraba sredstev za varstvo rastlin V prispevku so prikazani nekateri okoljevarstveni vplivi kmetijstva v 19-tih izbranih slovenskih pokrajinah. V ospredju preučevanja so razpršeni viri kmetijskega obremenjevanja - kmetije. Na osnovi terenskega anketiranja preko 1000 kmetij so zbrani in obdelani podatki o značilnostih gnojenja kmetijskih zemljišč, uporabi sredstev za varstvo rastlin in o vnosih dušika, kot enega od najpomembnejših onesnaževalcev prsti in zlasti voda na kmetijskih območjih. V osrednjem delu prispevka so prikazane osnovne značilnosti teh vplivov, obseg in stopnja obremenjevanja in regionalne razlike znotraj Slovenije. The editorialship received this paper for publishing in June 17th 1999. Prispevek je prispel v uredništvo 17.6.1999. Address - Naslov: Irena Rejec Brancelj, M. sc. Inštitut za geografijo Trg francoske revolucije 7 1000 Ljubljana Slovenia Phone- telefon: +386 (0)61 2002711 Fax - faks: +386 (0)61 200 27 34 E-mail - el. pošta: Irena.Rejec.Brancelj@Uni-Lj.si Contents - Vsebina 1. Introduction 97 2. Methods of work 97 3. Basic characteristics of regions studied 99 4. Characteristics of agricultural land use 101 5. Agriculture in the light of environmental pollution 104 5.1. Use of manure and liquid manure 104 5.2. Use of mineral fertilizers 108 5.3. Nitrogen pollution 113 5.4. Use of plant protection agents 117 6. Conclusion 121 7. Bibliography 121 8. Summary in Slovene- Povzetek 123 1. Introduction Previous research shows that the influence of agriculture on landscape pollution can no longer be ignored in Slovenia. In addition to pollution from single-point sources, where until now livestock farms and fish farms in particular have been in the forefront, more attention has recently been devoted to pollution originating from dispersed sources. This is all the more important since one of the basic characteristics of Slovene agriculture is an above-average fragmentation of property and farmland. Modern agriculture, which in regard to cultivation has assumed the characteristics of industrial production, has spread its technology and philosophy onto farms. By using agrochemical agents, today's farms can heavily influence the landscape structure and cause effects beyond their borders; and the effects of such production manifest themselves in the pollution of soil and waters. A consequence of Slovenia's landscape diversity is its diversity of agricultural activity. In the past, this activity has had a primarily self-supplying character and was adapted in great measure to local circumstances (fruit growing in the hilly regions and livestock breeding in the mountainous regions). On farms, processes ensuring the renewal of provisions were in balance with the use of energy and material. Because of modern needs, however, agriculture has been redeployed, e. g., in some places livestock breeding has moved onto flatlands. This caused changes in the structure of farms (in the seeding structure of land, the flow and balance of substances, energy characteristics, etc.). In the past, the amount of manure available on a farm was an important limiting factor on the farm's production. If it was not possible to secure a larger amount of nutrients, production could not be intensified. However, with the advent of mineral fertilizers, the balance of these relationships collapsed. Due to the overburdening of cultivated areas with livestock (excessive livestock density), the manure balance on farms is upset and there is too much manure, which can become an environmental problem. The fundamental landscape diversity in Slovenia is the result of its varied rock structure and relief. By considering pedological features and human influences in the landscape, we have included the factors that are most important in evaluating the influences of agriculture. The landscape diversity of agricultural regions requires research by individual types. The main landscape types are karst, flatland, hilly regions, mountainous regions, and high mountains. Each has certain common traits that are significant from the point of view of their environmental sensitivity. In this study, we will present the agricultural activity typical of each individual type and its environmental characteristics. Since from the environmental standpoint the fertilizing of cultivated areas and the use of plant protection agents are the most polluting processes, we will devote most attention to these factors. 2. Methods of work For studying agricultural pollution in Slovene landscapes, the sampling regions were chosen according to the following criteria: a) every type of landscape unit in Slovenia should be represented, b) their economic characteristics should be considered, c) various agricultural systems should be represented, d) various settlement types should be represented, and e) the settlements chosen in each region should vary from the socioeconomic standpoint. In the process of choosing the sampling areas according to the criteria above, typologies created by Slovene geographers and already established in the literature were used (Gams, Orožen, Kladnik 1995; Vrišer 1994; Drozg 1995; and Ravbar 1995). On this basis, 19 regions were chosen for study (see Figure 1). The settlements polled were chosen from every socioeconomic settlement type, and their numbers reflect the occurrence of individual settlement types in the studied region. We chose settlements with 100 to I. FLAT LANDS 1. Kamniškobistriška ravnina 2. Kranjsko - Sorško polje 3. Krško - Brežiška ravnina 4. Ljubljansko barje 5. Dravsko - Ptujsko polje II. HILLY REGIONS 6. Dravinjske gorice 7. Goriška Brda 8. Kozjansko gričevje 9. Slovenske gorice 10. Haloze III. MOUNTAINOUS REGIONS 11. Brkini 12. Mirnska dolina in Raduljsko hribovje 13. Posavsko hribovje (zahodni del) 14. Posavsko hribovje (osrednji del) 15. Pohorje 16. Škofjeloško hribovje IV. KARST REGIONS 17. Dobrepolje 18. Ribniško - kočevsko podolje 19. Bela krajina Sources: Relief: GIAM ZRC SAZU Regionalizacija: I. Gams, D. Kladnik, M. Orožen Adamič. KLS 1995 Območja preučevanja: ankete IG, 1996 Vsebina: I. Rejec Brancelj Kartografija: I. Sajko Inštitut za geografijo, Ljubljana 1998 200 inhabitants, as they are predominant in the Slovene structure (Perko 1991). In each region, ten socioe-conomically different settlements were chosen where the fieldwork was carried out, and in each settlement, five polls were taken at random. Because additional control polls were done in four regions (Dravsko-Ptujsko polje, Slovenske Gorice, Kranjsko-Sor{ko polje, and [kofjelo{ko hribovje), the number of settlements analyzed and polls in these regions is greater. Altogether, 210 settlements were polled and 1006 polls carried out. Through direct polling of farmers, we tried to establish regional characteristics pertaining to the socioeconomic structure of farms, the land structure, the orientation of individual farms, the marketing of production, the use of farm machinery, the methods of cultivating agricultural land, the quantities and types of mineral fertilizers and plant protection agents employed and their spread of use, the fertilizing routines of farmers, the methods of measuring out the agrochemical agents used, personal protective clothing for using them, observations of the influence these agents have on the environment, the number of livestock, the existence of stables and sewage systems, energy characteristics of farms (use of mineral fertilizers, plant protection agents, rich fodders, fuels, electric energy), and crops. 3. Basic characteristics of regions studied From flatland agricultural landscapes, the following were included in the study: three regions in central Slovenia (Kamni{kobistri{ka ravnina, Kranjsko-Sor{ko polje, and Ljubljansko barje), one in southeastern Slovenia (Kr{ko-Breži{ka ravnina), and one in northeastern Slovenia (Dravsko-Ptujsko polje). Their rock structure is composed primarily of gravel deposits (Kamni{kobistri{ka ravnina and Kranjsko-Sor{ko polje contain as much as 78% carbonate gravel, Kr{ko-Breži{ka ravnina 36%, and Dravsko-Ptujsko polje 76% silicate gravel) and clay and silt (Kr{ko-Breži{ka ravnina 47%, Dravsko-Ptujsko polje 24%, Kamni{kobistri{ka ravnina and Kranjsko-Sor{ko polje each 3% clay and silt) (Preglednice ... 1995). The Ljubljansko barje moor is an exception with 69% clay and silt, 16% carbonate gravel, and 10% siliceous sandstone and conglomerate. Gravel areas are drier and there are more fields on them, while clayey areas are wetter and extensive drainage projects have been carried out on many. Certain other hydrographic characteristics are also common to them, including a location beside a larger river and irrigation possibilities, as well as areas with groundwater. There are also similarities in land use, types of settlements, etc. Five agricultural landscapes in hilly regions were included in the study: one in western Slovenia (Gori{ka Brda), one in eastern Slovenia (Kozjansko gričevje), and three in the northeastern part of Slovenia (Dravinjske gorice, Slovenske Gorice, and Haloze). In the studied regions, the surface lies for the most part below 400 m above sea level, and the altitude belt of200-299 m encompasses their greater part (Dravinjske gorice 51%, Slovenske Gorice 74%, Haloze 47%, and Kozjansko gričevje 38%); the exception is Gori{ka Brda with 40% of its surface at altitudes of 100-199 m above sea level. The bedrock is mainly tertiary sediments (in Gori{ka Brda there is 66% flysch, and elsewhere the most widespread stone is marl: 70% in Haloze, 43% in Slovenske Gorice, 37% in Kozjansko gričevje, and 17% in Dravinjske gorice) along with clay and silt (64% in Dravinjske gorice, 33% in Slovenske Gorice, 21% in Kozjansko gričevje, 18% in Haloze, and 12% in Gori{ka Brda). Kozjansko gričevje differs from others in that it is more karstified: limestone comprises 20% of it, and dolomite 15%. Surface waters dominate and there are numerous small springs, but there are no larger consolidated areas with groundwaters. Due to their location and openness, the studied regions are reached by the influences of the warmer neighbouring submediterranean and Pannonian climates. They have much in common relative to land use, since vineyards and orchards cover a significant proportion of these regions. We included five mountainous regions in our study: Brkini, Mirnska dolina-Raduljsko hribovje, Posavsko hribovje, the Pohorje mountain range, and [kofjelo{ko hribovje. They exhibit great diversity relative to rock structure and climate. In the Brkini region (including the Reka River valley), flysch rock comprises three quarters of the surface. The proportion of flysch is also significant in the Mirnska dolina-Raduljsko hribovje region (30%), while limestone accounts for more than 15% of the surface in both regions. Dolomite accounts for more than a half (55%) of the bedrock in the Mirnska dolina-Raduljsko hribovje region. Figure 2. Vineyards are most intensively spread in hilly areas and there it is typical big use of mineral fertilizers and other chemical plant protection substances. Picture is from Tomaj - Karst area (photography Anton Brancelj). Slika 2: Vinogradi so najbolj raz{irjeni v gri~evnatih pokrajinah in zanje je zna~ilna velika poraba mineralnih gnojil in sredstev za varstvo rastlin, primer je iz Tomaja (fotografija Anton Brancelj). Figure 3. Poppy on a wheat field is because of widely spread use of herbicides rare (photography Anton Brancelj). Slika 3: Mak na p{eni~nem polju je zaradi raz{irjene uporabe herbicidov redek gost (fotografija Anton Brancelj). The Pohorje range is comprised of 61% metamorphic rock, 12% plutonic rock, and 11% carbonate gravel, rubble, till, conglomerate, breccia, and tillite. The structure of the Posavsko hribovje and [kofjelo{ko hribovje regions is more diverse. In the Posavsko hribovje region, there is 35% dolomite, 22% siliceous sandstone and conglomerate, 10% claystone, 10% siltstone and 10% limestone. In the [kofjelo{ko hribovje region the proportions are 28% claystone and siltstone, 26% dolomite, 16% siliceous sandstone and conglomerate, and 15% limestone. The study also focused on three karst regions in southeastern Slovenia: Bela krajina, Dobrepolje, and Ribni{ko-Kocevsko podolje (the Ribnica-Kocevje valley system). The rock structure of all three is similar: the prevailing rock is limestone (Bela krajina 66.6%, Dobrepolje 70.9%, and Ribni{ko-Ko~evsko podolje 48%), almost one fifth of the surface is composed of dolomite (Bela krajina 9.6%, Dobrepolje 20.4%, and Ribni{ko-Ko~evsko podolje 16.4%), and the third greatest surface proportion is composed of clay and silt (Bela krajina 19.9%, Dobrepolje 8.3%, and Ribni{ko-Ko~evsko podolje 32.4%). They also have the dominant Dinaric orientation running northwest-southeast and certain hydrographic characteristics in common. Vertical bifurcation is characteristic of the Ribni{ko-Kocevsko podolje region, which lies between the other two regions. Part of its waters flow underground to neighbouring Dobrepolje and the springs of the Krka River, while the other part flows to Bela krajina and the springs of the Kolpa River. Because of the permeability of the karst world and the water-supply importance of some springs, it is particularly important to know what is happening in their hinterland. 4. Characteristics of agricultural land use The basic characteristic of agricultural pollution is its broad impact and as a consequence of the land fragmentation typical of Slovenia also its dispersion. Radinja (1997) established that the extent of agricultural pollution can be equated with the surface area of agricultural land, and particularly of cultivated land. Slovenia ranks among the European countries with the smallest proportions of agricultural (43%) and cultivated land (32%). From the environmental protection perspective, this can be seen as an advantage, since more than half of Slovenia's surface (54%) is covered by forest. In recent decades, the forest areas have been increasing in size, which in the European context is a rather exceptional process. This is a consequence of the typical dispersion of settlement in Slovenia and the method of exploiting the land -stripping the forest cover. (Slovensko kmetijstvo... 1997). From the environmental protection point of view, the overgrowing of former agricultural areas can be considered a positive process since the direct runoff of precipitation water decreases, flood danger decreases, and influences originating from neighbouring cultivated land are relieved (the forest gives shelter to animals), etc. In the last ten years, the surface area of agricultural land in Slovenia has decreased by almost 10%, primarily due to forest overgrowth and urbanization, while in European Union countries it has decreased by 4% (ibid.). The most intensive agricultural production occurs in fields, vineyards, and orchards, so these areas are most subject to agricultural pollution. In European Union countries, cultivated fields account for almost 55% of all agricultural land but for less than one third - 30% - in Slovenia (ibid.). The fields are therefore limited to small areas, and their proportion is smaller in Slovenia than in any country of the European Union except Ireland. There are 0.12 hectares of field per inhabitant in Slovenia, the critical limit for ensuring food self-sufficiency (Gabrovec, Kladnik 1996). Almost two thirds of the agricultural land is occupied by meadows and pastures, which represent an environmentally more favourable land use since they do not demand so much energy and material input to maintain. In European Union countries, mead-owland accounts for only one third of all agricultural land. The most favourable areas for the intensive cultivation of crops in Slovenia are the flatlands and the hilly regions of the Pannonian plain and other smaller consolidated areas at the bottom of basins and plains. More than a quarter of the agricultural land (28%) lies in the flatlands, while some 72% of the agricultural land occurs in regions with poor natural conditions: hilly and mountainous regions (28%), high-mountain regions (21%), karst regions (13%), and other regions (10%) (Erjavec et al. 1994). Among Figure 4: Land structure of polled households by regions in 1996. Karta 4: Zemljiška sestava anketiranih gospodinjstev po pokrajinah leta 1996. LAND USE I fields meadows vineyards orchards pastures I gardens I forests Size of farms in ha Sources: Območja preučevanja: ankete IG, 1996 Vsebina: I. Rejec Brancelj Kartografija: I. Sajko Inštitut za geografijo, Ljubljana 1998 the land categories in the flatlands, fields account for 40% of all land, and forests 20%. The reverse is true in mountainous and karst regions where fields account for about 8% and forest for almost 60% (Gabrovec, Kladnik 1996). Agricultural pollution is greatest in the flatlands and at the bottom of basins; however, these regions comprise only about one tenth of Slovene territory (Perko 1991), while cultivated fields covered 11.6% of the entire surface in 1995 (Statistični letopis 1996). Nevertheless, it is evident at certain places in the flatlands that the pollution has already achieved local dimensions (the pollution of the water source in Skorba) and even regional dimensions, for example, the pollution of the groundwater in Dravsko-Ptujsko polje and Pomurje. Figure 4 shows the land structure of the regions and farms we studied. The proportion of cultivated surface is greatest in flatland regions (63%) and hilly regions (65%) where their proportion on average amounts to about two thirds. The largest proportion of cultivated land is on the farms of Dravsko-Ptujsko polje (79%) and Kr{ko-Breži{ka ravnina (73%), while in the hilly regions, this proportion is greatest in Gori{ka Brda (73%) and Kozjansko gričevje (71%). The proportion of cultivated land is smallest on the farms of the hilly regions: Kamni{kobistri{ka ravnina (50%), Kranjsko-Sor{ko polje (53%), and Haloze (53%). As we can see, cultivated land-the land producing agricultural pollution-occupies more than half of all land in both flatland and hilly regions, and in the Pannonian world even more than three quarters. Field crops cover the greatest part of the cultivated land. On the farms of the mountainous regions, the proportion of cultivated land is much smaller (43%); in certain exceptional cases due to favourable natural conditions, it reaches as much as half, for example, in Pohorje (52%) and Mirnska dolina-Raduljsko hribovje (55%). The situation is similar in the karst regions where cultivated land accounts for about one third of all land. The most outstanding among the karst regions is Bela krajina where this proportion amounts to 55%. Among the cultivated areas, the predominant land use categories are meadows and pastures. As mentioned, agricultural pollution is heaviest in field, vineyard, and orchard areas. However, relative to the proportion of each of them in the land structure, fields are the most important. On flatland farms, fields account for 32% of all land categories, more than half of all cultivated land (in Dravsko-Ptujsko polje, 70% of the cultivated land; in Kr{ko-Breži{ka ravnina, 51%; and in other flatland regions, less than a half). The proportion of fields is relatively high as well in the hilly regions where it accounts on average for one third (in Slovenske Gorice for almost half- 47%). Among the polled farms in the mountainous and karst regions, fields accounted for one third and one half, respectively, of all cultivated land. Among the landscape types studied, the proportion of meadows does not differ as much as the proportion of fields. On average, meadows occupy from one fifth to one quarter of all farm land, and in hilly regions their proportion is only slightly larger than elsewhere. The proportion of meadows is greatest on farms in the mountainous and karst regions where it accounts for one half to two thirds of all cultivated land. In the hilly regions, farms use one half of the land as meadows. Among the flatland regions, the most outstanding are the farms on the Ljubljansko barje moor where meadows account for 61% of all cultivated land. The high proportion of meadows is a consequence of the specific natural conditions in Slovenia where the predominant relief type is the mountainous regions, which covers 46% of all land, and where the proportion of hilly regions (34%) is also quite large (Perko 1991). The large proportion (63%) of grass-covered land, both pastures and meadows, which is typical of Slovene agriculture and is twice larger than the average for European Union countries (Erjavec et al. 1997), can be seen as an advantage from the environmental protection standpoint. As we shall see later, as regards both energy and materials used, these areas are substantially less polluted than cultivated field areas. The average yearly use of mineral fertilizers on the fields of the farms studied amounts to 450 kg/ha, while on meadows it is about half smaller, amounting to 237 kg/ha. Land use is a basis for further environmental assessment of agriculture. However, analyses of land use at the polled farms, as well as comparisons with Slovenia as a whole and with European Union countries, did not show this to be the main reason for agricultural pollution. The proportion of fields in the land use structure is-with the exception of flatlands and hilly landscapes-small, and it is on fields that production is most intensive. Also small is the proportion of permanent plantations that like fields require intensive production. On the other hand, two thirds of the agricultural land is occupied by meadow areas where fertilizing is necessary to achieve a suitable level of production. From the environmental protection point of view, the features of land use-with the exception of flatland and karst regions-can not be characterized as problematic. 5. Agriculture in the light of environmental pollution The intensiveness of agriculture or agricultural production determines the effects on the landscape. Intensiveness is reflected in yield per hectare, which is the result of various activities and processes during production. In addition to using high quality seeds, what matters particularly is appropriately supplying the plants with nutrients and the protection of plants from pests and disease. Quality seeds are ensured by the state through legislation and are available to farmers. In the private sector, however, the appropriate supply of plants with nutrients and plant protection are left to individuals. The methods of handling these substances in the landscape depend on the expertise and awareness of these individuals. The science of agronomy and, particularly in local conditions, the agricultural counselling service have contributed much to improving the expertise and awareness of farmers. We were interested in the extent and level of the use of nutrients (both organic and mineral) and plant protection agents as well as in the practices followed by farmers in using these agents. 5.1. Use of manure and liquid manure In fertilizing cultivated surfaces, farmers usually combine the use of manure and mineral fertilizers, and 87% of all the farmers polled use this combination of fertilizers. The proportion of farmers fertilizing exclusively with mineral fertilizers is small, only 4%, and this fertilizing method is more frequently used in Gori{ka Brda, Kr{ko-Breži{ka ravnina, and Kozjansko gričevje. Manure is used exclusively by 9% of the farmers polled, and this fertilizing method is important especially in Posavsko hribovje, Ribni{ko-Kočevsko podolje, and [kofjelo{ko hribovje. We have already mentioned that livestock breeding plays an important role in the orientation of farm production in Slovenia. There are almost no farms not breeding livestock, and they all must cope with the problem of managing manure and liquid manure. For the agricultural pollution of the environment, two things are especially important: how much manure and liquid manure is there relative to the amount of cultivated land on which they are spread and how they are used. At the farms studied, we questioned farmers about the quantities of manure and liquid manure used. We also calculated the quantities of manure based on the number of livestock on the farms, and the quantities differed by a quarter. The farmers reported quantities of manure and liquid manure larger by one quarter than those implied by the number of livestock. This difference may be a result of the calculation method based on »livestock units« that does not consider the manure and the liquid manure specifically or an error on the part of the farmers. In order to provide a young crop with nutrients effectively, the farmers must know the quantity and the content of the nutrients in both natural and mineral fertilizers so they can decide how to use them appropriately. The average annual use of manure and liquid manure on the farms studied amounts to 9 m3 of manure and 6m3 of liquid manure per hectare of cultivated land (Fig. 5 and 6). The highest use of organic fertilizers occurs in the flatlands where average use amounts to 12 m3 of manure and 11m3 of liquid manure per hectare. However, there are great differences in the use of manure between individual flatland regions, primarily due to the farming orientation in these regions. The greatest use was found in Kranjsko-Sor{ko polje (25 m3/ha), while in Dravsko-Ptujsko polje, Kr{ko-Breži{ka ravnina, and Ljubljansko barje, use var- ied between 7 m3/ha and 10 m3/ha. The use of manure was smallest in Kamni{kobistri{ka ravnina, where it amounted to 6 m3/ha. In the karst regions, use is smaller by a quarter, amounting to 9 m3/ha of manure and 8 m3/ha of liquid manure. Due to a pronounced orientation toward livestock breeding, the greatest use occurs in Ribni{ko-Kočevsko podolje, where it amounts to 11 m3/ha of manure and 12 m3/ha of liquid manure. Due to the large number of livestock, the use of manure is also large in Dobrepolje (11 m3/ha). In contrast, the use of manure and liquid manure in Bela krajina is smaller by half (4 m3/ha and 7 m3/ha, respectively). In the hilly and mountainous regions, the use of manure and liquid manure is similar. Manure use amounts to 7 m3/ha in the hilly regions and 8 m3/ha in the mountainous regions, while liquid manure use is 3 m3/ha in the mountainous regions and 5 m3/ha in the hilly regions. Distinguished by a use twice as high as the average, [kofielo{ko hribovje stands out among the mountainous regions, and Dravinjske gorice among the hilly regions. On the other hand, Gori{ka Brda uses 3 m3/ha, only half as much as the average; this is the smallest manure use among all the studied regions. The reason lies in the farming orientation and in the small number of livestock. As evident from the graphs, the mountainous regions have the smallest use of liquid manure of all the regions, primarily a consequence of its landscape characteristics (the more difficult use of suitable farm machinery) and the livestock-breeding orientation adapted to it (more pastured livestock and a greater orientation toward meat production). Sufficient quantities of manure and liquid manure reduce the need for mineral fertilizers. Because of the polycultural orientation (as well as the mixed-production orientation) of the majority of Slovene farms, the quantity of manure and liquid manure available played a positive environmental protection role. Exceptions are the intensively market-oriented farms and farms where the ratio between the number of livestock and the area cultivated is inappropriate. The quantity of manure alone should therefore not cause environmental protection problems, which are, as we shall see later, primarily the consequence of unsuitably arranged manure pits and the use of manure and liquid manure in water-protection zones. However, the farmers' inadequate knowledge of the dangers of nitrate pollution is a problem. In using nitrogenous fertilizers, it is necessary to consider the nutrients entering the soil with both organic and mineral fertilizers. It is therefore necessary to manage the nutrients appropriately, which requires knowledge of certain characteristics of these nutrients (leaching processes, accumulation), their appropriate use with individual cultures, and the physical geographic characteristics of individual landscapes (soil, water, etc.). The agricultural counselling service plays an important role here and has already organized individual seminars related to these problems. 5.2. Use of mineral fertilizers As we have already mentioned, livestock breeding is an important characteristic of polyculturally-oriented Slovene farms, and we can therefore expect that mineral fertilizers mainly have the function of supplementary fertilizers. For the most part, mineral fertilizers represent a supplement in supplying plants with nutrients. As we have already mentioned, 79-94% of the farmers polled combine the use of organic and mineral fertilizers. The average quantity of mineral fertilizers used on the farms studied amounted to 328 kg/ha of cultivated land. Farms in the flatlands and in the hilly regions lead according to quantities used (Fig. 7). The difference between them is small, as average use in the flatlands amounts to 439 kg/ha and in the hilly regions to 435 kg/ha of cultivated land. Production is intensive both in the flatlands (fodder plants) and in the hilly regions (special cultures), and in spite of the use of organic fertilizers, it is necessary to add larger quantities of mineral fertilizers. The differences within these regions are also significant. The smallest quantities of mineral fertilizers per hectare of cultivated land are used in Haloze (266 kg/ha), Kr{ko-Breži{ka ravnina (272 kg/ha), and Kamni{kobistri{ka ravnina (296 kg). Among the largest users are the farms in Dravsko-Ptujsko polje (671 kg/ha), Gori{ka Brda (577 kg/ha), and Kranjsko-Sor{ko polje (575 kg/ha). In Gori{ka Brda, the high proportion of mineral fertilizers used could be attributed to the lack of organic AREA □ 1 - 4 m3/ha □ 5 - 9 m3/ha □ 10 - 14 m3/ha □ 15 - 19 m3/ha □ 20 m3/ha < Mirnska dolina in Raduljsko hribovje FARMS Krško - Brežiška ravnina 15 1050 Bela krajina 19 10 20 30 km _J m3 manure / ha Sources: Območja preučevanja: ankete IG, 1996 Vsebina: I. Rejec Brancelj Kartografija: I. Sajko Inštitut za geografijo, Ljubljana 1998 15 30 25 20 Pohorje 15 10 5 Dravinjske gorice vsko hribovje srednji del) 12 m—ml H. Mirnska dolina in Raduljsko hribovje a Bela krajina 19 15 Kozjansko gričevje 4 30 km AREA □ < 1 m3/ha □ 1,1 - 2 m3/ha □ 2,1 - 3 m3/ha □ 3,1 - 4 m3/ha □ 4,1 - 5 m3/ha □ 5,1 - 10 m3/ha 10 m3/ha < FARMS 15 10 5 0 J i i i i 2 3 4 5 O < m3 liquid manure / ha Sources: Območja preučevanja: ankete IG, 1996 Vsebina: I. Rejec Brancelj Kartografija: I. Sajko Inštitut za geografijo, Ljubljana 1998 8 40 3 10 20 □o. Pohorje 15 i Dravinjske gorice 6 1 ribovje del) 15-1 rs 10- — 5 0 Mirnska dolina in sRaduljsko hribovjem 12 Do. - Ko~evsko olje Bela krajina 19 D JUL Kozjansko gri~evje 25 20 15 10 5 0 Krško - Brežiška _ ravnina 10 20 30 km AREA ZZ < 100 I I 101 - 200 I I 201 - 400 IZZI 401 - 800 FARMS 15 10 5 0 A 5 O Ol 1 co oo —L o o o o - —1 - —1 - —1 - o < 0 2 4 8 O o o o o o o kg of mineral fertilizers / ha Sources: Območja preučevanja: ankete IG, 1996 Vsebina: I. Rejec Brancelj Kartografija: I. Sajko Inštitut za geografijo, Ljubljana 1998 8 fertilizers, which, however, is not the case with the other two regions where the reason lies primarily in the intensiveness of production. In Dravsko-Ptujsko polje (with the agricultural land-exploitation system based on root crops and grains) and Kranjsko-Sorško polje (with the agricultural land-exploitation system based on root crops and fodder), the use of both organic and mineral fertilizers is high. The intensiveness here is certainly among the highest among the Slovene landscape regions. The quantity of mineral fertilizers used is smaller by half in the karst regions (averaging 219 kg/ha), and smaller by two thirds in the mountainous regions (150 kg/ha). The smallest average quantity of mineral fertilizers used was found on the farms of Ribniško-Kocevsko podolje (75 kg/ha) and the central part of Posavsko hribovje (79 kg/ha). More than half of the mineral fertilizer is used on cultivated fields (55%), one third on meadows (35%), 7% on vineyards, and 3% on orchards. Of course, there are differences between individual regions and landscape types resulting from the individual crop orientations. In the flatlands, the proportion of mineral fertilizers used on fields is 64%, and on meadows 34%. Only 2% of mineral fertilizers are used for other agricultural categories, which are only marginally present here. In the hilly regions, 45% of the mineral fertilizers are used on fields, and 32% on meadows. Here, the most widespread categories are vineyards and orchards, on which an average 19% and 5% of mineral fertilizers are used respectively. Among the studied regions, Goriška Brda stands out with its orientation toward orchards and vineyards, and the proportion of mineral fertilizers used in vineyards is 67% and in orchards 23%. In the mountainous regions, 40% of the mineral fertilizers are used on fields, 54% on meadows, and 6% for other cultures. In the three karst regions, the conditions are quite varied. In Dobrepolje and Ribniško-Kocevsko podolje, the greater proportion of mineral fertilizers is used on meadows, and in Bela Krajina on cultivated fields. The majority of mineral fertilizers are used in the field and meadow categories. Average use amounts to 451 kg/ha for fields and 237 kg/ha for meadows. As expected, the differences between individual landscape region types are significant. The use of mineral fertilizers is greatest on the fields and meadows of the flat-lands where the quantity of mineral fertilizers used on farms was 578 kg/ha for fields and 377 kg/ha for meadows. The use on mountainous region farms was found to be only slightly smaller, averaging 535 kg/ha for fields and 272 kg/ha for meadows. Other farms use much smaller quantities. In the karst regions, farms use 244 kg/ha on average for fields, and in the mountainous regions 187kg/ha. For meadows, the karst farms use 189 kg/ha, and the mountainous region farms 137kg/ha. According to agronomy experts, fertilizing causes no environmental side effects if the nutrients are correctly applied and measured. This demands appropriate decisions about fertilizing cultivated land, which as a rule are based on the expertise of the farmers and on analyses of the soil and the crops. Foreign experience recounts the general problems of improving fertilizing practices and describes as promising the □ personal experience (75%) lastne izkušnje (75 %) occasionally on the basis of analysis (11%) ob~asno z analizami (11 %) regularly on the basis of soil analysis (8%) redno z analizami zemlje (8 %) regularly on the basis of plant analysis (1%) redno z analizami rastlin (1 %) no data (2%) ni podatkov (2 %) not applicable (3%) ni pojava (3 %) Graph 1: Proportions of farmers according to how they decide to fertilize cultivated land, in % (Source: IG questionnaire, 1996) Graf 1: Delež kmetovalcev po načinu odločanja glede gnojenja obdelovalnih zemljišč v % (Vir: Anketa GI, 1996). Danish approach where there is mandatory documentation of plant rotation and requests for fertilizers on all production units (Germon 1989). During the study, we determined that the farmers largely base their fertilizing decisions on personal experience, as 75% of all the farmers polled decide on this basis (Graph 1); 11% of the farmers polled base their fertilizing decisions on occasional soil analyses, and 8% on regular soil analyses. There are no major differences relative to individual landscape region types. 83% of the farmers in the hilly regions, 80% in the karst regions, 73% in the flatland regions, and 69% in the mountainous regions base their fertilizing decisions on personal experience. 17% of the farmers in the flatland regions, 11% in the hilly regions, 9% in the mountainous regions, and 5% in the karst regions fertilize with the help of occasional analyses. Only 7% of the farmers in the flatland regions, 3% in the hilly regions, 11% in the mountainous regions, and 13% in the karst regions rely on regular soil analyses. The proportion of farmers basing their fertilizing decisions on occasional analyses was found to be greatest in Kranjsko-Sorško polje (33%), Goriška Brda (25%), Dravsko-Ptujsko polje (20%), Brkini (18%), and in the central part of Posavsko hribovje (16%). 28% of the farmers in Ribniško-Kočevsko podolje, 24% of the farmers in Škofjeloško hribovje, and 22% of the farmers in the western part of Posavsko hribovje were found to rely on regular analyses. It is surprising that analyses are used more frequently in the regions with a livestock-breeding and mixed farming orientation, and less frequently used in those with a field crop orientation. The survey of the type and quantity of mineral fertilizers used revealed that the farmers use about seven different types of mineral fertilizer on average. For the most part, these are complex fertilizers nitrogen -phosphate - potassium (NPK), urea, and mould. As regards quantities, the prevalent type is the complex fertilizer with equal proportions of nutrients (nitrogen- phosphate- potassium 15: 15:15), which shows that the farmers are afraid that their crops will decrease if they do not fertilize abundantly and that they decide according to the method »a bit of everything can do no harm« that we encountered frequently in our field interviews. We were interested in whether the farmers recorded the quantities used and the types of organic and mineral fertilizers they spread on their cultivated land. The answer, with rare exceptions, was negative. Quite exceptionally, we did find cases of exemplary bookkeeping on farms in individual regions; however, these were usually only records of expenses. This situation with the farmers is also not the most promising in the light of the Regulations on the Input of Dangerous Substances and Plant Nutrients in Soil (Official Gazette RS, No 68/96), which prescribes their management. Along with the exaggerated quantity of fertilizers added, a further reason for environmental pollution by nutrient substances is the timing of their application relative to the requirements of the plants being cultivated. With appropriate management, the nutrients are not leached away and lost. In order to determine the farmers' awareness of the importance of the appropriate quantities and timing for fertilizing, we asked when they executed basic and supplementary fertilizing of the plants they cultivate. The vast majority of farmers (73%) do only the basic fertilizing during sowing or immediately before it. Only 27% of farmers do supplementary fertilizing as well. The poll results show poor fertilizing practices among our farmers. Their awareness of the need for the precise application of fertilizers is not yet high enough. Consequently, the water and soil are certainly polluted on occasion, which is also reflected by data gathered during the regular observation of the quality of waters (Kakovost voda... 1997). 5.3. Nitrogen pollution The inappropriate addition of organic and mineral fertilizers in agriculture is the source of one of our main environmental problems: the disturbed nitrogen balance, a consequence of which is polluted soils and waters, especially of groundwater. Figure 8: Introduction of nitrogen in m3/hectare on cultivated land on the farms studied and in landscape regions in 1996. Karta 8: Vnos dušika v kg Na ha obdelovalnih zemljišč na anketiranih kmetijah in po pokrajinah leta 1996. Dravinjske gorice 6 Posavsko hribovje (osrednji del) 25 20 12 li Bela krajina 19 Kozjansko gričevje Krško - Brežiška^ ravnina AREA I I < 100 ZZ 101 - 200 I I 201 - 400 IZZI 400 < FARMS <2 15- a r 10- o A 2 Ol IV) Ol 1 IV) 4 O) —L o o o - - —1 - —1 - o < 5 0 2 4 o O o o o o 10 20 30 km —I Sources: Območja preučevanja: ankete IG, 1996 Vsebina: I. Rejec Brancelj Kartografija: I. Sajko Inštitut za geografijo, Ljubljana 1998 20 8 Farmers introduce nitrogen into the landscape with animal and mineral fertilizers. The ratio between the two in the majority of regions leans toward animal fertilizers, which means that the farms studied still introduce more nitrogen with stable manure and to a lesser extent liquid manure than with mineral fertilizers. The only exceptions are Gori{ka Brda, where the proportion of nitrogen originating from animal fertilizers is 17%, and Kozjansko gričevje, where the proportion is 48%. In fact, the only landscape type that stands out is the flatlands, where the proportion of nitrogen originating from animal fertilizers is just slightly over one half. It is only here that the ratio is almost 1:1; in other landscape types, the ratio of almost 8: 2 strongly favours nitrogen originating from animal fertilizers. All farms studied introduce two thirds of the nitrogen with animal fertilizers and one third with mineral fertilizers (Graph 2). Matičič and his colleagues (1995) report similar figures for conditions on Slovene farms. However, there are obvious differences between individual regions and landscape types. The average proportion of nitrogen introduced through animal fertilizers according to individual landscape types was as follows. There is only a small difference between the average in the flatlands (55%) and the average in the hilly regions (57%); however, the diversity within the hilly regions is great. The nitrogen input in the mountainous regions (72%) and the karst regions (74%) was half again greater. The inverse ratio of nitrogen input with mineral fertilizers was found to be 45% in the flatlands, 43% in the hilly regions, 28% in the mountainous regions, and 26% in the karst regions. Relative to nitrogen input per hectare of cultivated land, the individual regions were classified into the following classes. Input greater than 400kgN/ha was found only in Dravinjske gorice: 800kgN/ha due to a greater number of poultry breeders. Regions with up to 400kgN/ha include Dravsko-Ptujsko polje, Kranjsko-Sor{ko polje, and Dobrepolje. The majority or nine regions were ranked in the class of between 101 and 200kgN/ha: Pohorje, Haloze, Kozjansko gričevje, Mirnska dolina-Raduljsko hribovje, Kr{ko-Breži{ka ravnina, Bela krajina, Ribni{ko-Kočevsko podolje, Ljubljansko barje, and Kamni{kobistri{ka ravnina. The following regions were classified in the group with inputs up to 100kgN/ha: Slovenske Gorice, Posavsko hribovje, [kofjelo{ko hribovje, Brkini, and Gori{ka Brda. It is characteristic of the latter that relatively large quantities of mineral fertilizers are introduced during agricultural production; however, the prevailing winegrowing orientation in recent years has relied on the knowledge of agricultural experts that the quantity of nitrates and the quantity of grapes produced are inversely proportional to quality ([ikovec 1992). If we look at the density of the nitrogen input per hectare of cultivated land by individual regions and landscape types, we establish the following: the input is greatest in the hilly regions and totals 258 kg N/ha. This can be attributed to the orientation of the agriculture in these areas where the crop farming and livestock breeding are joined by special cultures: fruit orchards and winegrowing. Among the hilly regions studied, Dravinjske gorice stands out strongly, where, as we have mentioned, the survey showed that one fifth of the farms breed hens and chickens. Without Dravinjske gorice, the average would be lower than in the flatland and karst regions, amounting to 121 kg N/ha. The hilly regions are followed by the flat-land regions, where the input amounts to 188 kg N/ha, the karst regions with 179 kg N/ha, and the mountainous regions with 100kgN/ha. The average on the farms studied amounted to 190kgN/ha. As the Regulations on the Input of Dangerous Substances and Plant Nutrients in Soil (1996) prescribe alimit on the annual nitrogen input of 210 kg/ha, we can also consider the inputs on the farms studied in this light. Nitrogen inputs through animal and mineral fertilizers exceed 210 kg of nitrogen per hectare in Dravinjske gorice (806kgN/ha, due to the greater number of poultry breeders), Kranjsko-Sor{ko polje (297kgN/ha), and Dobrepolje (279kgN/ha). Regions quite close to the limit include Dravsko-Ptujsko polje (204kgN/ha), Kozjansko gričevje (194kgN/ha), Ljubljansko barje (176kgN/ha), and Bela krajina (151 kgN/ha). We have already mentioned that one third of the nitrogen comes from mineral fertilizers and two thirds from animal fertilizers. In Slovenia, the deposit of nitrogen from the atmosphere amounts to 20 kg N/ha yearly, and its contribution is small (Matičič et al. 1995). Comparisons of the nitrogen inputs studied with previous research done on larger Slovene regions (ibid.) show that although the more detailed studies do complete the picture, at the same time they draw atten- ■ with mineral fertilizers (34%) ™ iz mineralnih gnojil (34 %) □ with animal fertilizers (66%) iz živinskih gnojil (66 %) Graph 2: Nitrogen input with animal and mineral fertilizers on the polled farms in 1996. Graf 2: Vnos du{ika z živinskimi in mineralnimi gnojili na anketiranih kmetijah leta 1996. tion to the inadequacy of using average values in Slovenia where the landscape is extremely diverse. Matičič and his colleagues (1995) report an average value for all nitrogen of 137kg/ha, 90kgN/ha from animal fertilizers and 47kgN/ha from mineral fertilizers. As we have mentioned, the average total input on the farms studied amounts to 190 kg N/ha. The total input per hectare is greatest in the hilly regions, amounting to 258kg, smaller by a third in the flatlands (188kg) and the karst regions (179kg), and smallest in the mountainous regions (100kg). According to European Union standards, a particular region is vulnerable to the leaching of nitrates when the nitrogen is greater than 100 kg/ha (ibid.). This value is exceeded in more than two thirds of regions studied: all flatland regions; all karst regions; Dravinjske gorice, Kozjansko gričevje, and Haloze among the hilly regions; and Mirnska dolina-Raduljsko hribovje and Pohorje among the mountainous regions. Figure 8 shows the distribution of the individual farms polled by classes according to the input of nitrogen per hectare of cultivated land. Two thirds of the farms in the flatlands and the hilly regions, almost half of the farms in the karst regions, and a third of the farms in the mountainous regions can be classified according to nitrogen inputs in the middle two classes where inputs are between 51 and 100kgN/ha and between 101 and 200 kg N/ha. 15% of the farms in the flatlands, 13% of the farms in the hilly regions, 5% of the farms in the karst regions, and 2% of the farms in the mountainous regions introduce more than 200kgN/ha. The input is smallest, less than 50kgN/ha, on 64% of the farms in the mountainous regions and on 51% of the farms in the karst regions. In the flatlands, the input of nitrogen is lower than 50 kg N/ha on one quarter of all farms, and in the hilly regions on one fifth of the farms. Nowadays, it is almost impossible to imagine agriculture without the use of plant protection agents. 93% of the farmers polled use such agents, and only 7% do not. The differences between individual regions are small; only in the mountainous region did a somewhat smaller use of such agents appear. The average use of plant protection agents on the farms studied was 3.42 kg/ha. The use was greatest in the hilly regions, 9 kg/ha of cultivated land, which is primarily a consequence of the orientation of these regions toward fruit orchards and winegrowing and the larger quantities of fungicides used. In the flat-land regions, the use amounted to 2 kg/ha, and in the karst regions to 1 kg/ha. The use was smallest in the mountainous regions where it amounted to 0.88 kg/ha. Figure 9 shows the quantity of plant protection agents used by regions and their internal structure. The use of these agents is greatest in Goriška Brda where it amounts to 35.2 kg per hectare of cultivated land, a consequence of this region's pronounced orientation toward winegrowing. Up to 6 kg of plant protection agents per hectare, the average use for the farms studied, is used in Krško-Brežiška ravnina (4.8kg/ha) and Kozjansko gričevje (4.4kg/ha). The majority of the regions studied (11) use up to 3kg 5.4. Use of plant protection agents Dravinjske gorice 10 Mirnska dolina in Raduljsko hribovje/- 12