by Jan Zastawny*
3. CLIMATE AND AGRO-ECOLOGICAL ZONES 4. RUMINANT AND LIVESTOCK PRODUCTION SYSTEMS 5.1 Types of grasslands 6. OPPORTUNITIES FOR IMPROVEMENT OF PASTURE RESOURCES 6.1 Mixtures to improve
meadows and pastures 7. RESEARCH AND DEVELOPMENT ORGANIZATIONS AND PERSONNEL 8. REFERENCES 10. CONTACTS *deceased The Republic of Poland has 38 500 000 inhabitants (according to the
World Factbook
the estimated population in July 2006 was 38,536,869 with a growth
rate of - 0.05%), an area of over 312 685 km2, a border
length of 3 582 kilometres (including 528 km of coast) and is divided
into 16 administrative provinces. To the north-east and east, it borders
the Russian Federation, Lithuania, Belarus and Ukraine; to the south,
the Czech Republic and Slovakia; to the west, Germany (see Figure
1).
Polish agriculture is in an economic crisis – with a marked decrease in both production and farmers’ incomes and rising unemployment. Agriculture contributes six to seven percent of the Gross National Product but its share in employment is much greater – it employs 1 900 000 people, 14 percent of all registered workers; moreover, there are about 2 000 000 people of pre - and post - productive age and disabled persons. Rural people comprise 38 percent of the population but rural unemployment is 46 percent of the total (i. e. about 2 000 000 people). Agriculture has therefore to cope with unemployment while preparing to be competitive on the market by the time of its entry into the European Union. Increased competitiveness could come from increasing farm size. Polish agriculture is characterized by many small farms: the average family farm is 6.7 ha of arable; 54.0 percent of family farms are under five hectares and 95.7 percent of all farms are under twenty hectares. The public sector share in cropland has fallen to less than 8 percent. Per capita area of arable land is now 0.36 ha. The area under crops has decreased. In 1999, agricultural lands fell
in comparison to 1990 by 285 000 ha (Tables 1 and 2, figure 2) and
sown areas - by 1 657 000 ha. Barren and and unused lands increased
by 163 000 ha. According to the Ministry of Agriculture and Food Production
the area of marginal soils (unprofitable for production) is 3 700 000
–4 700 000 ha; 1 500 000 ha of the poorest soils are designated
for afforestation. Table 1. Land use (in thousand ha)
This means that cropland may decrease to 14 000 000-15 000 000
ha; i.e. 2 000 000-3 000 000 ha below the area
which guarantees sustainable food production for 50 000 000
people, assuming annual meat consumption of 72 kg person.
The reduction in agricultural land should therefore be compensated
by an appropriate increase in productivity, which depends mostly on
agro-chemicals. Sixty percent of the crop increment is estimated to
be from fertilizer, 40 percent is ascribed to mineral fertilizer,
consumption of which increased to 195 kg/ha by 1989. Now farming has
become more extensive, which is shown by 2-3 times lower fertilizer
use (Table 3), a constant decline of crops (Table 4) and pesticide
consumption 7 times lower than in OECD countries (0.59 kg/ha of active
substance in 1999 and 0.52 kg in 1990). A decrease in fertilizer consumption
to 163.9 kg NPK/ha occurred in 1989/1990 and now (1998/1999) it is
87.4 kg NPK/ha and is characterized by an unfavourable N:P:K ratio.
Table 3. Use of mineral fertilizers in kg/hectare on agricultural land
Poland’s oldest uplands and mountains were formed in the Tertiary. Old geological structures (like the Sudetes) were levelled and uplifted several times. Lowland relief was formed in the Pleistocene. The present relief of the north appeared during the last Baltic glaciation. Its remnants are characteristic postglacial forms: hills of front moraines, morainic plains, drumlins, glacial channels (sometimes with lakes), outwash plains and old river valleys. The geologically and morphologically oldest areas are in the south. The highest and largest is part of the Carpathian Mountains, divided in their Polish part into the Podkarpacie, the Beskidy Zachodnie, the Beskidy Srodkowe and the Bieszczady Zachodnie in the outer mountain zone and the Podhale with Pieniny and Tatra Mountains in the inner zone (see Figure 1). The geologically oldest mountains - the Sudetes with the Przedgórze Sudeckie - are in the south-west. North of the mountains is an extensive upland area, which is divided into the Slaska, Woznicko-Wielkunska and Kielecka Uplands, the Holy Cross (Swietokrzyskie) Mountains, the Lubelska Upland and Roztocze. All these uplands slope north and west into the Srodkowopolskie Lowlands: the Poludniowowielkopolska Lowland, Wal Trzebnicki, the Slaska Lowland and the Mazovian Lowland, which turns eastward into the Podlaska Lowland Lakelands (situated north of the lowlands), are divided into the Pomorskie, Wielkopolskie and Mazurskie Lakelands. North of the lakelands a belt of seashore lowlands extends to the Southern Baltic Coast, divided into the Szczecin, Koszalin and Gdansk Coasts. Soils. Lowland and upland soils cover 92 percent of the area, those in the mountains, only 8 percent. Among the former the largest area is covered by a complex of podzolic, brown and grey brown soils (80 percent). Other types, which cover 16.5 percent, are: alluvial soils (4.5 percent), rendzinas (1 percent), black turf soils (2 percent), chernozem (1 percent) and bog soils (8 percent). Light soils are characteristic of lowlands and occupy over half (52.5 percent) of the country. Alluvial soils are typical of lower accumulation terraces of the Vistula valley. Bog soils mostly occur in the coastal zone, on lakelands, in the old Biebrza-Narew river valleys and between the Bug and Wieprz rivers. Black peat soils are found near Inowroclaw, Brzesc Kujawski, Blonie, Sochaczew, Wroclaw and Pyrzyce (see Figure 3). Upland areas are rich in loess of the brown earth and chernozem class and in rendzinas typical of calcareous rocks. Many types, subtypes and classes of soils have been distinguished in detailed divisions depending on the relief differentiation, substrate, moisture, plant cover or evolutionary stage. In the Sudetes and their foothills there is a variety of mountain soils of the podzolic and acidic brown soil types. Less diversified in that aspect are the Carpathians, which are dominated by the lithologically monotonous acidic brown and leached brown soils formed from clastic rocks. These sedimentary rocks of maritime origin are composed of interspaced layers of sandstone, siltstone, clay and marl shale and of conglomerates. On the Carpathian Foothills a long belt ranging from Oswiecim through
Wieliczka, Bochnia, Brzesko, Pilzno, Rzeszów Lancut, Przeworsk to
the vicinity of Przemysl is lined with loess covered by brown and
grey brown soils and, sometimes, also by chernozem.
Grassland soils. Meadow soils are commonest in river valleys, through-flow valleys, old river beds, and various depressions but also on mountain slopes and high-mountain pastures where ground water level or steep slopes favour the development of meadow and pasture vegetation and prevent development for crops. Prevailing water regime creates an environment, which favours multi-species meadow swards. Therefore, these soils require different classification criteria from those applied to croplands. Two types of soils are distinguished on permanent grasslands in Poland: I - soils formed from mineral formations with the following types: brown soils, chernozem, black turf soils, alluvial soils, rendzinas and gley soils created from non-silted and silted formations (called muck-bog soils). II - organic soils (bog soils called also hydrogenic or hydromorphic soils); moss-peat, sedge, rush and alder peat belong to this class. Further subdivisions are based upon organic matter content and its
thickness, on the type of soil established according to its degree
of mineralisation and on the advancement of soil processes. Qualitatively,
six soil classes are distinguished, which form the so-called productive
complexes defined for the management of the permanent grasslands.
For fiscal and planning reasons associated with the land trade, a
quality index and an appropriate calculation coefficient of agricultural
usefulness (expressed in relative numbers - Table 5) has been prescribed
for each soil class. Table 5. Agricultural usefulness of permanent grasslands in Poland in relation to the soil quality classes
* range of a coefficient of agricultural usefulness respective to particular classes of meadow-pasture soils in relation to a given tax district 3. CLIMATE AND AGRO-ECOLOGICAL ZONES Climate: Poland’s climate is temperate, determined by air masses coming from the North Atlantic, from the region of the Azores, from the Arctic Sea, polar continental air from the northern part of Eastern Europe or tropical continental air masses from over south-east Asia. Thus, the climate is characterized by great weather variability, both seasonal and between years. Winters are wet, of the oceanic type, or fair of the continental type. Mean summer air temperatures vary from 16.5o C in the north to 19.0O C in the south and south-west; in winter mean air temperatures vary from 0 to -1O C at the sea-shore and in the west to -5O C in the north-east. Average annual precipitation is 600 mm being lower on lowlands (from 450 - 750 mm) and higher in the mountains (1200-1500 mm). Climatic conditions for plant production are typical for the temperate zone, though marked differences may occur between regions: the growing season is longer and annual temperatures higher in the south and west. Transitory climates are characterized by: - in the west - predominance of oceanic influences, lower temperature amplitudes, early springs and summers, short winters; - in the east - predominance of continental influences, greater amplitudes increasing eastward, long summer, especially in the south, long and cold winter; - in the north - predominance of maritime impacts, cloudiness, amplitudes increasing landward, mild and short summer, winters shorter in the west and longer in the east; - in the south - predominance of the impact from the mountains and uplands, lower temperatures, higher precipitation, variability of climatic conditions in relation to the altitude and exposure. Based on climate properties the following climatic regions are distinguished: (see Figure 4). - Pomorski Region. Prevalence of oceanic influences with the superimposed direct impact of the Baltic Sea. Small temperature ranges. Short, mild winters and summers. High precipitation dependent on aspect. Southward and eastward the effect of the Baltic Sea diminishes, winters tend to be longer, the number of cloudy days increases, precipitation decreases. - Mazurski Region. Direct impact of the Baltic Sea (declining to the south and east) is interspersed with continental influences - weaker in the northern and western parts and stronger in the south and east. Greater temperature ranges tend to increase eastward. Summers are mild and short, winters - long, cold and snowy, especially in the east. - Nadwislanski and Gdanski Region. Intermediate. Direct effect of the Baltic Sea is moderated by an impact of the lakeland hills. Summers are warmer and longer, winters - moderate. Low precipitation depends on the slope exposure. - Slasko-Wielkopolski Region. Predominance of oceanic influences. Temperature ranges below average. Early, long and warm spring and summer, short and mild winter. Precipitation decreasing towards the centre of the country. - Mazowiecko-Podlaski Region. Prevalence of continental influences. Temperature ranges greater than average, especially in the east. Early and rather long summer, longer and colder winter, especially in the east. - Kujawski (with Northern Wielkopolska and Northern Mazovia) Region. Intermediate. A great number of cloudy days, the lowest precipitation in Poland. - Lódzki Region. Intermediate with a mixture of oceanic and continental impacts. - Malopolski Region with the Holy Cross (Swietokrzyskie) Mountains Upland. Oceanic influence pronounced and more marked in the west, continental in the east. Longer summer and winter. High precipitation, highest in the west. - Lubelski Region. Upland. Predominance of continental influences. Long summer, long and cold winter. The greatest number of fair and hot days in Poland. High winter precipitation. A great daily temperature range. - Sandomierski Region. Lowland with predominance of continental influence and that from the neighbouring mountains and uplands. Many fair days, long summer, long growing period, frequent hail showers.
- Sudecki Region. Predominance of oceanic influences. Sub-mountainous in the north-eastern part. Mountainous in the south-western part. Temperature decreases, summer shortens and winter lengthens with increasing altitude. High precipitation in the south. - Karpacki Region. Marked oceanic impact in the western part, in the central and eastern part continental influence prevails. Sub-mountainous in the northern part, mountainous in the western and southern part. Temperatures decrease, summer shortens and winter lengthens (especially in the east) with increasing altitude. High precipitation in the west dependent on the aspect. - Podkarpacki Region. Intermediate, lowland. Predominance of influences from neighbouring mountains and uplands. Long and warm summers. Many cloudy days. Thermal conditions and distribution of precipitation enable cultivation of most temperate zone crops in almost the whole country; they do not favour, however, soybean and maize for grain and limit second crops after harvesting cereals; in the north and east of the country they limit also cultivation of plants with high thermal requirements. A significant water deficit occurs in dry years, so irrigation is needed to obtain relatively high yields. Yields of potatoes, sugar beet, rye, wheat, barley and oats as well as of winter rape, legumes and forages are fairly good. The type of crops is chiefly determined by soil quality, thus there is uneven distribution of plants which require high fertility soils like sugar beet, wheat, barley, lucerne (Medicago sativa) or red clover. A basis for increased productivity is the regulation of the water supply. According to the Institute of Crops, Fertilization and Soil Science, soils with a good water regime occupy 44 percent of the area, excessively wet - about 20 percent and semi dry and dry soils - 36 percent. Development of irrigation-drainage reclamation is thus required. Almost 6 700 000 ha of agricultural land have been reclaimed up to now, but 2 750 000 ha still await reclamation. Irrigation is required on 1 800 000 ha, 1 500 000 ha of which are grasslands (data from the Ministry of Agriculture and Food Production). Regulation of the water regime on grasslands has an ecological aspect and improves the productivity of such habitats. There are many signs of soil deterioration: about 20 percent of Poland is affected by hydraulic and aeolian erosion and over 30 percent of soils are seriously acidified. The amount of humus in soils is falling and the effect of the flood of 1997 can easily be seen - with the loss of fertile top soil and increased acidification of 500 000 hectares. 4. RUMINANT AND LIVESTOCK PRODUCTION SYSTEMS Obviously, livestock are the factor stimulating efficiency of permanent grasslands. The most important are cattle and sheep, which inspire farmers to find and mobilize fodder reserves, found mostly in meadows and pastures. Total reduction of the number of these two groups of animals in the last decade of political transformation (Table 6) does not help the economic efficiency and proper care of permanent grasslands and fodder from arable land. According to the Main Statistical Office (1997), fallow and barren land occupied 1 799 200 ha of agricultural land at the end of 1996, of which 948 400 ha were on private farms. A reduction of grazing animals (Table 6) cannot improve biological and technical progress and other yield-forming factors, for example those associated with the soil and with mineral fertilizers, consumption of which also drastically declined (Table 3). This has resulted in a "backward" agriculture compared to that of most countries of Western Europe. To obtain high yields from meadows and pastures it is necessary to grow high-yielding mixtures and to develop the best ways of green fodder preservation. There is still much to be done in this aspect. Table 6. The number of farm animals (in absolute numbers and per 100 ha of agricultural lands)
* 2005 as % 1985/86; Supply of slaughter stock (cattle, pigs, sheep, horses and poultry)
to the market was 3 628 500 tons in 1999 i.e. 2.4 percent
more then a year before and the total production was 4 360 000 tons
(Table 7). At the end of March 1999 pig stock was 18 900 000 head
but changes in herd structure (a decrease in the number of sows by
3.1 percent and of piglets by 1.6 percent) clearly shows the farmers’
actions to reduce livestock keeping. Table 7. Production of slaughter stock, milk and eggs
Cattle have declined gradually from June 1990 - June 1999 by almost 3 500 000 head (35 percent) and stock density per 100 ha of croplands decreased from 54 to 26.3 individuals. Dairy cows decreased in number by 1 500 000 head (over 30 percent) in the same period and their number per 100 ha decreased from 31 to 19. By 2004 cattle numbers had decreased some 4,771,000 from 1990. Private farms’ contribution to animal production increased from 82.8 percent in 1990 to 93.8 percent in 1999. At the beginning of 1999 cattle totalled 6 555 000 head and by 2004 had decreased to 5, 277,000. A decline of dairy cow numbers continued - from only 0.7 percent in December 1998 to 3.5 percent in June and 5.0 percent in December 1999. Milk production, with fewer cows and an average annual production of 3 465 litres per cow (3 491 litres in 1998), achieved 11 763 000 000 litres, down by 23.5 percent on 1990 (Table 7). In Poland pastures are a separate category of cropland. Their physiographic features associated with the shape, location and specifics of meadow habitats and associations enable their rapid transformation into arable land. Since the type of grassland is strictly related to its habitat, the latter is a basis of grassland typology. For lowland meadows the division was elaborated by Bury-Zalewska and Pronczuk (1954), improved by Pronczuk (1962) and modified by Grzyb (1996). For mountainous regions the typology was elaborated by Kielpinski and Nowak (1954). Physiography of terrain, water-air relations and the type and fertility of soils were adopted as a basis for classification. To make the principles of typology easier to understand, all lowland meadow habitats can be presented in the form of a triangle (Figure 5), the sides of which depict the borders between meadow and other habitats and vertices - habitat systems most extreme in hydration, fertility and air relations in soil. The upper apex of the triangle refers to the driest, poorer and well aerated habitats, lower left - to rich habitats and lower right - to wet and poorly aerated habitats. Considering various habitat features the triangle has been divided into sections representing the division of lowland grasslands into groups and types. The sections, marked with digits and letters in the figure, indicate the respective groups and types of meadows. Groups are encircled by a triple line and types - by a single line. In this system, natural permanent grasslands in Poland are divided into three typological groups: I - flooded meadows: A - proper flooded meadows, B - with flowing water, C - with stagnant water II - dry meadows: A - post-flooded dry meadows, B - moistened meadows, C - proper dry meadows, D - impoverished dry meadows, E - waterlogged dry meadows III - boggy and post-bog meadows: A - flooded, B - partly flooded, C - proper boggy meadows, D - "moorsched" – (meadows not dependent on soil type)
I- Flooded meadows – are mainly in river valleys or on the margins of lakes - on the so-called flood terraces. Water supply is cyclic - flood is followed by water draining to a river or a lake or valley. Therefore, water content in the meadow varies throughout the growing season. Floods result in the formation of alluvial soils. There is a tendency for organic matter accumulation at a distance from open water due to poor soil aeration. Soils dominating here are: alluvial soils, mud-gley soils, peat-gley soils, peat-mud and sometimes peat soils. Flooded meadows are characterized by a high vegetation composed mainly of grasses and sedges. Dominating species from the associations Cynosurion Tx, Arrhenaterion Br. – Bl., Phragmition Koch and Magnocaricion Koch are: Alopecurus pratensis, Arrhenatherum elatius, Poa palustris, Glyceria aquatica, Phalaris arundinacea, Carex acuta. II - Dry meadows - occur on higher ground and are mainly fed by atmospheric precipitation. On slopes and in the depressions of dry valleys, dry meadows use seepage from ground water or that flowing down from higher ground. As the moisture supply of these sites is thus correlated with precipitation and with seasonal ground water movement. Dry meadows develop on various mineral soils Diversified vegetation is found here, generally however, less so and having a greater ability for turf formation than that on flooded meadows. Dominant species of the class Molinio–Arrhenatheretea Koch i Festuco–Brometea Br. – Bl are: Poa pratensis, Festuca rubra, Agrostis vulgaris, Nardus stricta, Alopecurus pratensis, Trifolium repens, Agrostis stolonifera, Deschampsia caespitosa, Juncus refusus, J. conglomeratus, and Carex panicea. III -Boggy and post-bog meadowsBoggy and post-bog meadows are found in sites without an outflow, or in wide river valleys and are fed mainly by ground water. Such conditions favour the growth of sedges and mosses and enhance peat-forming processes. After reclamation boggy meadows transform into the post-bog meadows with typically muck soils. Vegetation on both boggy and post-bog meadows does not form a compact sward in spite of species diversity within particular genera. Organic soils are the substrate for these meadows. Dominating species of the class Molinio – Arrhenatheretea Tx are Festuca rubra, Carex glauca, Poa pratensis, Alopecurus pratensis, Phalaris arundinacea and of the class Schenchzerio – Caricetea fuscae North – Carex nigra, Carex panicea, Calamagrostis sp., Carex acutiformis, Carex rostrata, Carex vesicaria, Carex lasiocarpa, Carex paradoxa. Typology of mountain meadows. Forest is the dominating plant formation in the mountains. Grass associations are mostly of anthropogenic origin resulting from a replacement of forests (after logging) with grasslands. All forms of the mountain landscape are small, close to each other and characterized by great dynamics of processes. The nature of these processes is, however, the same as on lowlands thus flooded, dry, and boggy habitats can be found there. Grasslands are a source of fodder and have also some non-production functions, in all aspects they are environmentally friendly. Their location is usually associated with the physiography. Most Polish grasslands are on soils with high ground water (river valleys, lake margins) or on hilly areas with steep slopes i.e. in habitats unsuitable for other crops. Playing the landscape and protective role in the environment, grasslands are, first of all, a valuable source and the cheapest ruminant fodder, which, especially in summer, may be the only food for cattle. A comparison of the costs of obtaining one oat unit (this unit, the equivalent of one kilogramme of oat grain, was previously widely used in Eastern Europe; 1 barley unit = 0.06 oat units) from various types of fodder shows that pasture is the cheapest fodder. These costs expressed in relative numbers are as follows:
The total area of permanent grassland is over 4 100 000 ha, which comprises 13.2 percent of the country area and 22.3 percent of all agricultural land. The private sector uses 3 600 000 ha of grassland, 87.9 percent of the total. The number of farms with permanent meadows and pastures was 1 871 700 and comprised 61.0 percent of the total. Mean area of the permanent grassland in the private sector was 1.8 ha, that in the public sector 213.0 ha. Permanent meadows covered an area of 2 800 000 ha in 1996 and comprised 66.9 percent of all permanent grassland while the area of permanent pastures was 1400 000 ha, 33.1 percent of all grasslands. Permanent meadows were owned by 1 698 000 farms i.e. 55.4 percent of farms (mean area 1.5 ha/farm) and permanent pastures were possessed by 784 000 farms i.e. 25.6 percent of farms (mean area 1.4 ha/farm). In comparison with the past a marked shift has taken place from grazed to mown area, from pastures to meadows. This means an extensifying of agricultural production in general and on permanent grasslands in particular. As much as 64 percent of nutritional units were obtained from field
fodder crops, which covered 30.1 percent of the total fodder area
in 1996 (main crop only), thus more than from combined meadows and
pastures covering almost 70 percent of the total fodder area (Table
8). This is a result of abandoning production on parts of the permanent
grasslands or of their being abandoned (Table 9).
In practice, there are several ways of using meadows and pastures; they can be exploited by free grazing (extensively), tethering livestock (intensive use but extensive management), rotational grazing without cutting the excess fodder and variable use with single or double cutting on parts every year. Meadows can also be used by cutting once (extremely extensive), twice (semi-intensive) and three or four times (intensive use). Rotational pastures and meadows, especially those intensively used, require regulation of the water regime and intensive fertilization with at least 450-525 kg NPK ha at the proper N:P:K ratio (1:0.25:0.5). No other crops respond better to intensive fertilization than grasslands. At this level of fertilization and the proper N:P:K ratio, we might expect hay increments of 20-25 kg per kg NPK i.e. 12 - 13 tons of hay per ha and the total yield (at a mean yield of 5 tons/ha of hay from an average meadow) of 17-18 tons of herbage per hectare or about 85-95 tons of the raw material for haylage production. From among various ways of grazing the most rational
and useful in farms seems to be limited and paddock grazing wi th
a typical (10-14 paddocks) or a decreased number of quarters (4-8).
In every case this is a rotational grazing. Parameters to calculate
pasture area and animal stock are given in Table 10. At an alternating
(mown-pasture) system, given areas should be enlarged by 50-100 percent.
*) utilization of the pasture is assumed at 80% (20% of unused fodder), which gives the daily consumption of 70 kg green mass per animal The number of paddocks on a sub-divided pasture is estimated from the number of days needed for sward to regrow during autumn (September-October) and from the number of grazing days of one quarter in rotation. At moderate soil-climatic conditions and on good pastures regrowth period lasts:
In the classic quarter way, the period of grazing for one quarter in rotation is 3-4 days, in that of limited number of quarters: 7-10 days. Alternate mown-pasture utilization increases the yield by 5-10 percent and results in more equilibrated botanical composition of the sward. This optimum composition comprises 60-70 percent of grasses (low, medium and high grasses in a similar proportion), 20-30 percent of legumes (mostly Trifolium repens) and herbs as a dietary-palatable component. Herb plants should constitute ca. 10 percent. This type of utilization favours the formation and maintenance of a strong, resilient turf, which determines proper management and enhances the growth of a compact sward yielding 0.4-0.5 t of green fodder per ha per each cm of height of its main mass. This type of meadow and pasture management improves also fodder utilization by animals (unused food is lower even by 10 percent), yielding repeatability and distribution (more uniform supply throughout the season) and fodder quality. 6.OPPORTUNITIES FOR IMPROVEMENT OF PASTURE RESOURCES 6.1. Mixtures to improve meadows and pastures Pasture sward should be dense and have a good and diversified botanical composition. The following species should dominate: Lolium perenne, Poa pratensis, Phleum pratense, Dactylis glomerata, Festuca pratensis, F. rubra, Agrostis alba and Trifolium repens. The contribution of each species depends on the soil type and moisture, on the trophic status of the habitat and on fertilizer used. Trifolium repens is of special importance for rational pasture
management due to its high ability to fix atmospheric nitrogen by
bacteria of the genus Rhizobium. This allows decreased mineral
fertilizer use since grasses use this nitrogen with almost the same
efficiency as that delivered with mineral fertilizers. It is best
to introduce Trifolium in a mixture with grasses when managing
or renewing the grassland. Examples of grass mixtures for meadows
and pastures developed in the Institute for Land Reclamation and Grassland
Farming are presented in Tables 11 and 12. Table 11. Seed mixtures used in management or in renewing lowland pastures, after Grzyb [1988]
1) Surrogate cultivars Table 12. Seed mixtures used in management and in renewing lowland meadows after Grzyb [1988]
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