The application of organic and mineral fertilizers on grasslands has been performed since hundreds of years. The most prominent example of organic fertilizer application, which has been applied in many regions for centuries, is paddock manuring (Hejcman et al. 2002). The principle of paddock manuring consists of the transport of nutrients by livestock on pasture.
Livestock that grazes on pasture during day time is kept in small mobile fenced enclosures during the night. Most of the nutrients taken up elsewhere on pastures are excreted as feces and urine during the night within this enclosure. After a certain time, about one week in most cases, the enclosure is moved forward to areas to be fertilized. In the past, those fertilized areas were most frequently used for hay making in subsequent years to benefit from the fertilizer effect on biomass production and forage quality. To restrict oligotrophic vegetation dominated by Nardus stricta, a tussock grass of low forage quality and biomass production, sheep paddock manuring has been utilized in Carpathian Mountains in Romania, Ukraine, Slovakia and in the Czech Republic (Fig. 1).
Transportation and application of nutrients by humans has been documented in many regions in Europe since centuries. For example, in the Giant Mts. (Krkonoše, Riesengebirge) located in the borderland between the Czech Republic and Poland, hay was transported from sub-alpine grasslands down the valleys across a distance of 10 – 15 km during the 17th to 20th century (Fig. 2). This hay was used as feed to cows and to goats kept in cow houses in the valleys. The organic fertilizer nutrients originating from that hay were applied to grassland or arable land in close vicinity of the farm houses. As a consequence, biomass production of grasslands at lower altitudes was promoted, whereas nutrient depletion occurred on grasslands in the sub-alpine vegetation zone (Hejcman et al. 2006).
Figure 1. Paddock manuring has been used in the Carpathian Mts. for centuries. Sheep are kept over night in small mobile enclosure that is moved across the grassland plot in intervals of about one week. (Slovakia 2006, photo Michal Hejcman).
Figure 2. Transport of hay from sub-alpine grasslands in the Giant Mts. at the end of 19th century. Men carried up to 80 kg and women up to 50 kg of hay across the distance of 10 – 15 km with super-elevation of almost 1000 m (the Czech Republic, photo archive KRNAP).
The same principle of fertilizer application on the one side and nutrient depletion on the other was described by Bakker (1989) in The Netherlands. In the Iron Age (800 – 0 BC), sandy soils of Drenthian region were so poor in nutrients that after a time of fallow and pasture soil fertility was insufficient to grow crops whereas loamy soils elsewhere in Europe maintained more fertile.
It is well documented that replenishment of nutrients has been practiced by applying organic material to arable fields, such as woodland litter, sods and waste from the settlement and cattle dung when the stubble was grazed. It is important from the vegetation science point of view that the maintenance of arable soil fertility was thus promoting the enlargement of oligotrophic heathland and grassland in less fertile agricultural regions.
In Europe, slurry application on grassland looks back to a long-term tradition. Slurry, a liquid organic fertilizer composed of urine and livestock feces, was produced in mountaineous regions where bedding straw or other organic material was rare. In the Alps, slurry production and application systems have already been used in the middle age. In the Giant Mts., slurry has been applied on grassland since the 16th century. The system of fertilizer application was introduced by German colonists from the Alps. Slurry pit was placed in front of farm house in sloping terrain and slurry was scraped away from the barn manually or washed up by running water. The grassland located below the pit was called Grass Garden and consisted of a system of small ditches connected to the slurry pit through a central channel. In spring time, running water from a water course was used to dilute slurry and so uniformly applied on Grass Garden as an organic fertilizer. Because of high biomass production and forage quality in the Grass Garden and its close vicinity to farm houses, this area was exclusively used for hay production.
Figure 3. Although sub-alpine vegetation zone of the Giant Mts. is no longer utilized for agricultural production, remains of farm houses with slurry pits are still well conserved. Slurry pit on the photograph was used until 1938. (Czech Republic 2004, photo Michal Hejcman).
Apart from organic fertilizer, the use of mineral and chemical-synthetic fertilizers has long-term tradition as well. Romans, for example, used lime, limestone or marl. Probably the oldest well known and largely used organo-mineral fertilizer was wood ash. The content of organic compounds in this fertilizer is dependent on intensity and temperature of combustion process. If combustion is intensive enough, wood ash contains almost entirely alkaline mineral fertilizer rich in K, Ca, Mg, P, Si and many trace elements such as Zn, Co, Fe (Campbell 1990). The content of individual nutrients and ratios among them are dependent on original chemical composition of wood and are thus specific of species combusted.
Further, the volume of ash obtained from an equivalent amount of wood is dependent on combustion temperature. In an experiment conducted by Etiégni and Campbell (1991), ash yield decreased by approximately 45% when combustion temperature increased from 538 to 1093°C. The metal content tended to increase with temperature, although K, Na and Zn decreased.
Wood ash has been frequently mixed with slurry or manure before application on grassland or arable land in the 19th century. Such treatment increased ash fertilizer value because of N enrichment (Semelová et al. 2008). In many tropical regions, small scale slush and burning agriculture still takes advantage of high fertilizer value of wood ash (Menzies &
Gillman 2003). In industrialized countries, wood ash is a fertilizer with a certain future perspective, e.g. when produced by combustion of renewable organic material. In addition to fertilizer application, wood ash has also been used as a binding agent, a glazing base for ceramics, an additive to cement production and an alkaline material for the neutralization of wastes. In former times, wood ash was highly valued and was repurchased and sold in many regions of Central Europe in 18th and 19th century.
It is common knowledge, that mineral fertilizers were used long before the principles of plant mineral nutrition were discovered by Sprengel in 1826 and 1828 and popularized by Liebig in 1840 and 1855 (van der Ploeg et al., 1999). According to the Humus Theory, the addition of mineral compounds such as salts of P, Ca, K and other elements increased availability of organic compounds in the soil. When taken up by plants, these elements increased biomass production of agricultural crops. The rejection of the Humus Theory finally resulted in industrial production of mineral and chemical-synthetic fertilizers across the world. The first superphosphate was manufactured by Lawes in his factory in Deptford in England in 1842 (Leigh 2004). In the Austrian Monarchy for example, superphosphate has been industrially produced since 1856 in Ústí nad Labem (currently in the Czech Republic, Vaněk et al. 2007).