Da bismo vanjski prostor što ljepše i ekonomičnije uredili, potrebno je dobro poznavati tlo i biljku, ali i sve one čimbenike koji na njih utječu.
Oblikovanje prostora, bilo da se radi o okućnici ili bilo kojem drugom segmentu krajolika: voćnjaku, vinogradu, povrtnjaku, cvjetnjaku ili travnjaku, a to znači hortikulturi u njezinom punom značenju, zahtijeva pomno planiranje i pripremu. Jedan od vrlo važnih čimbenika u pripremi tla je dobro poznavanje reakcije tla (pH). Reakcija tla značajno utječe na primanje svih hraniva, a varira ovisno o potrebama kultura od kiselog do alkalnog.
Cilj ovog rada je detaljno obraditi potrebe pojedinih ukrasnih vrsta za reakcijom tla, koristeći rezultate terenskih istraživanja i uspoređujući ih s navodima u literaturi.
U tu svrhu korištene su kemijske analize (reakcija tla u 1M KCl) koje je proveo Zavod za ishranu bilja, Agronomskog fakulteta Sveučilišta u Zagrebu, uz vizualno praćenje u okolišu.
Prema dobivenim rezultatima istraživanja 47% od ukupno 131 očitanog uzorka spada u neutralna tla (D). U alkalna tla (E) spada 37%, u slabo kisela (C) spada 11%, u kisela tla (B) 5 %, a u kategoriju jako kiselih tala (A) ušao je samo jedan uzorak.
Stoga rezultati naših istraživanja ukazuju da često puta navodi u literaturi za pojedine ukrasne vrste nisu apsolutno primjenjivi u datim okolnostima, odnosno da su primjenjivi uz manje ili veće korekcije.
Općenito se za krajobrazno uređenje individualnih i javnih površina preporuča slabo kisela do neutralna reakcija tla (5,5,-7,2 – CD), jer većina ukrasnog bilja uspješno raste u tom rasponu. Za vrste koje više vole ekstremnu pH reakciju tla, potrebno je provesti korekciju primjenom adekvatnih gnojiva ili supstrata.
Tako se Erica sp. i Rhododendron sp. preporučuju za jako kisela i kisela tla (pH 4,0-5,5 – AB) dok za slabo kisela tla (5,5-6,5 – C) predlažemo Abies sp., Cupressus sp., Juniperus sp., Pinus sp., te trave. Za kiselo tlo (4,5-5,5 – B) predlažemo Hydrangeu (plavu), Ilex sp., te Picea sp. Za slabo kiselo i neutralno tlo (5,5-7,2 – CD) Chrysanthemum sp., Magnolia sp., Quercus sp., Rosa sp. i Hedera sp. Neutralna reakcija (6,5-7,2 – D) optimalna je za rodove Chamaecyparis i Prunus. Za tla neutralne i alkalne reakcije (6,5-7,2 – DE) predlažemo nešto veći broj vrsta iz rodova Acer, Araucaria, Buxus, Crataegus, Forsythia, Hydrangea (roza i bijela), Lavandula, Thuja, te Vinca. Širok raspon reakcije tla (5,5-7,5 – CDE) podnose vrste iz roda Carpinus, Cedrus, Corylus, Cotinus, Cotoneaster i Taxus.Economy and aesthetic quality of landscaping require a good knowledge of soil and plant, but also of all the factors that affect them.
Landscaping, wether a private holding or any other segment of the landscape: orchard, vineyard, vegetable garden, flower garden or lawn, which means horticulture in the full sense of the word, requires careful planning and preparation. One of the very important factors in soil preparation is a good understanding of soil reaction (pH). Soil reaction has a strong influence on all nutrients uptake and varies, dependending on crop requirements, from acid to alkaline.
The aim of this paper is to deal in detail with the soil reaction requirements of particular ornamental species, using the results of field research and comparing them with the literature reports.
For this purpose, use was made of the chemical analyses (soil reaction in 1M KCl) made in the Department of Plant Nutrition, Faculty of Agriculture, University of Zagreb, along with visual monitoring in the landscape.
According to the research results, 47% of the 131 analyzed samples are neutral soils (D), 37% alkaline soils (E), 11% weakly acid soils (C), 5% acid soils (B), while only one sample belongs to the category of very acid soils (A).
Hence our results show that literature reports for particular ornamental species are often not absolutely applicable in the given conditions, or that their application requires certain corrections.
Weakly acid to neutral soil reaction (5,5-7,2 – CD) is generally recommended for landscape planning of individual and public areas, because most ornamental plants grow well within this range. For species that prefer extreme pH reaction of the soil, corrections should be made by applying adequate fertilizers or substrates.
Thus, Erica sp. and Rhododendron sp. are recommended for very acid and acid soils (pH 4,0-5,5 – AB) while we suggest Abies sp., Cupressus sp., Juniperus sp., Pinus sp., and grasses for weakly acid soils (5,5-6,5 – C). Hydrangea (blue), Ilex sp., and Picea sp. are recommended for acid soils (4,5-5,5 – B). Chrysanthemum sp., Magnolia sp., Quercus sp., Rosa sp. and Hedera sp. are recommended for weakly acid and neutral soils (5,5-7,2 – CD). Neutral reaction (6,5-7,2 – D) is optimal for genera Chamaecyparis and Prunus. A larger number of species from the genera Acer, Araucaria, Buxus, Crataegus, Forsythia, Hydrangea (pink and white), Lavandula, Thuja, and Vinca are recommended for soils of neutral and alkaline reaction (6,5-7,2 – DE). Species of the genera Carpinus, Cedrus, Corylus, Cotinus, Cotoneaster and Taxus tolerate a wide range of soil reaction (5,5-7,5 – CDE)
