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Report deals with the possibilities of the fertilisation use in forestry in the Czech (Middle European) conditions. Fertilisation, forest nutrition management and nutrient cycling are an object of intense study periodically, in correlation with acute disturbances of these topics in the forestry. At present, there is several cases, where the fertilisation use is topical: 

  1. fertiliser application in extreme immission conditions in high elevations, aiming more rapid plantation growth, canopy and forest environment establishing and functioning forest stands formation,
  2. application in areas of low pollutants concentration but high acid deposition, leading to nutrient (bases) leaching and losses,
  3. application at reintroducing site more demanding species, such as beech, fir etc. on sites degraded by long-term spruce (pine) monocultures cultivation,
  4. application on technogenically degraded sites, and (5) commercial fertilisation. These possibilities are discussed and examples of our results confirming our conclusions are demonstrated.


KEY WORDS: Fertilisation of forests, nutrition, amelioration, forest plantations



Object of the presented study is the possibilities consideration of fertilisation in the forestry of the Czech Republic. Problems of fertilisation, nutrition management of forest tree species, and nutrients cycling are periodically in the focus of interest of forest managers, usually in periods of heavy nutrition disturbances and forest decline. In recent days, we can observe one of recession of interest, paid to the forest nutrition and to the fertilisers and amelioration materials application in forests, after a stage of more intense activities initiated in the period of heavy acid deposition and soil acidification. This situation is a results of the general contemporaneous conditions in the Czech economy on one side, as well as of the absence of skilled and professional demand for research results in the forestry administration sphere on the other one.


Despite of this unfavourable policy, potential for fertilisation use in the forestry is considerable and it can be separated in 5 main application types: (1) fertilisation in extreme immission areas on clearings, where it should to initialise more rapid plantation growth and functioning stands formation, (2) fertilisation in areas with lower direct immission load (low air concentration of pollutants), but relatively high acid deposition. Nutrient (bases, magnesium) deficiency originates very often here, being very rapidly eliminated by fertilisation, (3) fertilisation at reintroducing more site demanding species, especially on locations degraded by long-time conifer monocultures cultivation, (4) fertilisation on technogenically degraded sites and (5) fertilisation for commercial purposes, i.e. for timber growth stimulation.


Because the research results are very sparse and originated in greater extent several decades ago, it is topical to restart research activities concerning the forest nutrition management in Czech forestry, especially in cases with expected vital role of fertiliser use. It can be included also the liming research program from the last decade. This research is important from the economical point of view (functions of the forest), as well as from the ecological one (nutrient cycling, ecological stability and resistance).



Only partial research programs are disposable at present. From these, a restricted amount of results can be taken to document forest nutrition management potential and its benefits for the forestry. From the five items mentioned above, we can demonstrate only examples of item (1), i.e. fertilisation in extreme immission sites and (3), i.e. fertilisation at reintroduction of site demanding species. Besides this, we are able to document also the importance of appropriate fertilisation in the forest nurseries.


Research plots and their characteristics are presented in the following table 1. In the first case, the basic rock powder (amphibolite - A) and SILVAMIX FORTE pellets are tested on an extreme site on immission clearcut in the Jizerske hory Mts., further 2 experiments test the effect of fertilisation at reintroducing site demanding species on degraded sites. The last case documents the fertilisation effect in the forest nursery, ameliorating the Silver fir (i.e. a site and nutrition demanding tree species) seedlings.


Table 1: Presentation of research plots for the fertilisation effects study

Research plot (1)Jizerka (3)Babin 2 (3)Babin 3 Zelena bouda
Stand 257 B7 330 C 330 C12 nursery
Altitude (m) 960 580 580 cca 250
Forest type 8K2 5K8 5K8 -
Soil type podzol kambisol kambisol sandy soil
Species spruce beech fir fir
Plantation establishment 1994  1994 A,L
1993 S-t,p
1990-91 1997
Experiment establishment 1994  1994 A,L
1997 S-t,p
1997  1997 
Variants C, A, S-t S-t
Note clearcut underplanting underplanting  


Particular variants were as follows:


Plot Jizerka: plots 10 x 10 m, spacing 2 x 1 m (50 pcs of spruce). C - control plots, A - application of 2 kg of amphibolite and mixing with the earth just before plantation (1994), S-t - four 10 g pellets of SILVAMIX® FORTE (1997) in a distance 30 cm from the stem and 10 - 15 cm deep. Number of replications - 3.


Plot Babin 2: plot with 5 rows by 14 plants in spacing 1 x 1 m. 1 kg of finely ground dolomitic limestone (25.5% Ca, 11.25% Mg) or 2 kg of fine amfibolite (Choltice locality) spread on the surface in a 0.5 m circle around plantings (1994). S-t - SILVAMIX FORTE pellets (see above) variant (1997). Number of replications 2.


Plot Babin 3: 6 rows by 10 plantings at 3 replications established 1997. Variants: 4 pellets of SILVAMIX® FORTE or 40 g of SILVAMIX® MG powder in 50 cm circle around particular trees.

In the forest nursery Zelena Bouda was established an experiment in the Silver Fir parcelle in spring 1997. Application of a complex, rapidly soluble fertiliser CERERIT (NPK) and SILVAMIX® MG powder took place on the soil surface. The fertilisers amount was equivalent as for nitrogen (100 kg/ha). In the case of SILVAMIX® MG it represented: 144 kg P2O5, 67 kg K2O and 189 kg MgO per 1 ha, in the case of  CERERIT 82 kg P2O5, 127 kg K2O and 2 kg MgO per 1 ha. Nutrients content of particular SILVAMIX® variants is documented in the following table 2.


Table 2:  Nutrient content of particular SILVAMIX® fertilisers

Fertiliser N
nutrient sum
SILVAMIX® MG 9.0 13.0 6.0 17.0 45.0
SILVAMIX® FORTE 17.5 17.5 10.5 9.0 54.5



Results are disposable being obtained till the growing season 1998. They are short-time, but allow the first insight in the fertilisation effect potential and the consideration of its effectiveness. At first, table 3 documents the fertilisation effect on the locality Jizerka. There are not big differences in the plantation mortality, only it seems, that this phenomenon is the slightest on the amphibolite variant. Favourable effect of this material on the spruce growth appeared in 1996, i.e. 2 years after the basic rock powder application. SILVAMIX® fertiliser affected the plantation growth and development much faster, first signs of accelerated growth were visible in the first year after fertilisation, statistically significant differences in plantations growth are registered just in the second year. Differences in heights of young spruces reached 7 cm for both fertiliser variants.


Table: 3  Plantations development on the plot Jizerka

Variant n92
C 135
44.0 a
51.1 a
A 138
47.0 b
55.8 b
S 134

Note: the same letters indicate statistically homogenous groups


Acceleration of plantation growth plays an important role in these unfavourable conditions. Plants have to escape the ground vegetation, causing relatively high mortality. Also the replenishment of deficient nutrients plays vital role for fast spruce growth, as well as for differentiation in heights of particular trees. Fertilisation should be so very important on extreme sites in immission areas, despite playing less role that e.g. ecological shelter of preparatory tree species. Application of the chemical amelioration in these conditions, minimising the mortality and increasing vitality as well as stability of plantations can be recommended. Besides powders of basic rocks (limestone, dolomitic limestone, amphibolite etc.), slowly soluble fertilisers can be used. Favourable effects can be reached by the classic soluble mineral fertilisers too, but this approach needs the skilled fertilisation professionals.


Next table 4 documents the fertilisation effects on the plot Babin 2, where the beech plantation in the shelter position was fertilised. Effects of the amelioration with powder of basic rocks are visible since the second year after experiment establishing, the differences in plantations growth among variants are increasing in time, as well as the year increment is increasing in every season. The increment acceleration is the greatest for amphibolite, despite its surface application, being considered not effective. The SILVAMIX® effect (in the pelleted form) is visible since the first year. The subplots with the powdered type suffer from the shade of neighbouring trees, also nutrient content of this type is less (especially as for nitrogen). This could also contribute to lower effectiveness of this form.


Table 4: Effect of the fertilisation on the plot Babin 2

Variant H93
C 24.4 27.2 36.4 54.6 72.8 a 121.5 a
L 24.3 28.0 39.7 64.5 89.4 b 138.0 b
A 24.9 28.7 43.5 70.6 98.3 b 147.8 b
S-t         84.6 ab 135.4 b
S-p         74.3 a 121.2 a

Note: the same letters indicate statistically homogenous groups


Further table 5 presents the results obtained after fertilisation with different forms of the SILVAMIX® in the Silver fir plantation, established 5 - 6 years before amendments application. In undisturbed conditions on a poor site, the fertilisation effect appears in the first growing season, differences in height reaching 25 cm and in year increment almost 20 cm in the second year.


Table 5:  Effect of particular SILVAMIX® types on the Silver fir plantation growth

Variant H96
H 97
C 59.3 78.7 a 107.0 a 19.4 a 27.4 a
S-t 66.1 90.8 b 129.8 b 24.8 b 38.3 b
S-p 63.6 88.0 ab 133.8 b 24.3 b 46.6 b


Fertilisers affected very favourably the growth of more site demanding species of trees, planted on locations, considered to be degraded by generations of spruce monocultures. In these impoverished conditions is the fertilisation a good tool for increase of plantations growth, as well as for increase of their stability and vitality. Complex forms of amendments, balanced as for nutrients content, seem to be more appropriate. In forests, there are more convenient the slowly soluble types, allowing a long lasting effect with lower danger of luxury nutrition offer and nutrients losses.


Last example documents the effect of fertilisers in the forest nursery in the case of a fir bed. After fertilisation in the spring of 1997, first results were determined in autumn of the same year. Both types of fertiliser, the rapidly soluble (Cererit) as well as the slowly soluble form (SILVAMIX) had the comparable effect, statistically significant. In the second growing season were all total heights statistically significantly different, but the year increment of the Cererit variant  ceased almost on the level of the control plot, indicating the probable end of effect of this fertiliser type.


Table 6:  Effect of particular fertilisers on the height growth of silver fir in the forest  nursery

Variant  H97
C 9.4 a 16.0 a 5.2 a
CER 12.4  b 17.9 b 5.5 a
S-p 12.3  b 19.0 c 6.2 b


Also in other cases, e.g. on mechanically degraded sites, in areas with high acid deposition and nutrition disturbances and disbalances and in the case of production fertilisation, good results can be expected as well. In some cases, e.g. on location with humus layer removal and in plantations with nutrition disbalances and deficiencies (Jizerske hory Mts., Bohemian Forest) we established large experiments this year. One season results are promising, but not instructive enough to be presented here.


A special case is the fertilisation to increase productivity of forest stands. These activities were often also in our country since 50ies till 70ies, being stopped more recently. Numerous experiments reveal production increase reaching 1 - 3 m3 per year/ha for a period at least 5 - 15 years. This could bring considerable financial benefit in many stands. Good policy for this fertilisation application needs a complex approach and good ecological as well as economical analyse.



Considerable potential of the fertilisation to increase productivity, stability and vitality of forest trees plantations was documented in many cases, in different site and ecological conditions. First of all, fertilisation with appropriate kinds of materials can increase the growth and vitality, as well as to reduce mortality of plantations in immission areas. It can be recommended as a part of forest restoration technologies. The form of fertilisers is less important, convenient are the powders of basic rocks, slowly soluble fertilisers, as well as more rapidly soluble forms. The more is the fertiliser soluble and the nutrient loss greater, the more is needed a skilled approach and state analyses before each treatment. On the contrary, the danger of fertilisation fail is less using matter with more durable effects. Favourable effects of fertilisation were documented also treating plantations of more site demanding tree species, reintroduced on locations degraded by long term cultivation of conifer monocultures and in forest nurseries, where are vital for soil fertility restoration. The potential of fertilisation use in forestry is great and in this time there is a big lack for relevant information, how to use it with maximum benefit for forest owner as well as for the benefit of the whole society.



List of more important references, describing more detailingly the experiments

  • Podrazsky, V.: Vapneni lesu. In: Racionalni pouziti prumyslovych hnojiv. Vapneni a hnojeni horcikem. 28.11.1996. Praha, CZU Praha 1996, s. 43 - 47.
  • Podrazsky, V.: Vliv stanovistnich podminek, ekologickeho krytu a aplikace moucek bazickych hornin na vyvoj kultur buku. Zpravy lesnickeho vyzkumu, 42, 1997, c. 2, s. 9 - 11.
  • Podrazsky, V. - Balcar, C.: Liming of spruce plantation on the top locality of the Jizerske Mts. Scientia Agriculturae Bohemica, 27, 1996, c. 4, s. 271 - 282.
  • Podrazsky, V. - Remes, J. - Kratochvil, J.: Vysledky zkusebni aplikace hnojiv rady SILVAMIX. /Zaverecna zprava/. Praha, LF CZU v Praze 1998. 18 s.
  • Acknowledgements: We wish to express our gratitude to the firm ECOLAB, Znojmo, producer of the SILVAMIX? fertilisers, for financial support of this research.

Address of the author: Ass.prof. Ing. Vilem Podrazsky, CSc.
Department of  Silviculture, Faculty of Forestry, Czech University of Agriculture, Prague
Kamycka 129, 165 21 Praha 6 - Suchdol, Czech republic, Tel: +420 2 24383403,
E-mail: podrazsky@lf.czu.cz