| Abstract | Reakcija tla ili pH vrijednost pripada u najvažnija agrokemijska svojstva nekog tla te predstavlja
najčešću analitičku metodu mjerenja. Pokazatelj je produktivnosti tla i važno je mjerilo procjene fizikalnokemijskog
stanja tla. Istraživanje je provedeno mjerenjem pH reakcije tla u H2O, KCl i CaCl2 otopinama.
Provedena je usporedba standardne ISO metode mjerenja pH reakcije tla u omjeru tla i otopine 1:5 (5ml
tla/25ml otopine) s najčešće primjenjivanim omjerom 1:2,5 (10g tla/25ml otopine). Istraživanje je provedeno
na ukupno 135 uzoraka tla, tj. 15 uzoraka sa svakog od 9 tipova tala (eutrično smeđe, lesivirano, lesivirano
pseudoglejno, pseudoglej, aluvijalno, pseudoglej-glej, ritska crnica, močvarno glejno hipoglejno i močvarno
glejno amfiglejno tlo) s područja Istočne Hrvatske uključujući samo oranične horizonte (0-30 cm). Uzorci tla
(135) osim na pH vrijednosti, analizirani su također na: organska tvar, sadržaj gline te KIK (BaCl2 metoda) pri
čemu je utvrđen utjecaj pojedinog svojstva na pH reakciju tla. Prosječno utvrđene vrijednosti sadržaja humusa
na svim istraživanim tipovima tala su iznosile su od 0,83 do 11,80%, KIK-a (BaCl2) od 4 do 47,50 cmol (+)
kg-1 te gline od 1,83 do 58,86%. Najniža pH vrijednost izmjerena je na pseudoglej-gleju metodom KCl m/v u
iznosu 3,57 dok je najviša vrijednost izmjerena na močvarno glejnom amfiglejnom tlu metodm H2O m/v u
iznosu 8,60. Utvrđene pH vrijednosti metodom v/v (1:5) su iznosile: H2O od 4,88 do 8,60, CaCl2 od 4,09 do
7,76 te KCl od 4,09 do 7,76. dok su tvrđene pH vrijednosti metodom m/v (1:2,5) iznosile: H2O od 4,81 do
8,41, CaCl2 od 4,01 do 7,75 te KCl od 3,57 do 7,65. Razlike u pH vrijednostima u mjerenju metodama v/v
(1:5) i m/v (1:2,5) su prosječno iznosile: H2O metodom 0,13 pH jedinica, CaCl2 metodom 0,02 pH jedinica te
KCl metodom 0,11 pH jedinica. Prosječno utvrđene pH vrijednosti su se kretale redoslijedom: H2O v/v > H2O
m/v > CaCl2 v/v > CaCl2 m/v > KCl v/v > KCl m/v. Koeficijent korelacije između metoda i podmetoda mjerenja
pH reakcije iznosi r=>98, a utjecaj ostalih agrokemijskih i agrofizikalnih svojstava je ovisio o metodi mjerenja
te o samim svojstvima sistematske jedinice tla. Metode mjerenja su međusobno kompatibilne te je idući korak
u statističkoj obradi podataka izrada regresijskih modela te njihova validacija. |
| Abstract (english) | Soil reaction or pH value belongs to the most important agrochemical properties of a soil and is the
most common analytical method of measurement. It is an indicator of soil productivity and is an important
criterion for assessing the physical and chemical condition of the soil. The research was carried out by
measuring the pH reaction of the soil in H2O, KCl and CaCl2 solutions. A comparison was made between the
standard ISO method of measuring soil pH reaction in a soil-solution ratio of 1:5 (5ml of soil/25ml of solution)
with the most commonly used ratio of 1:2.5 (10g of soil/25ml of solution). The research was carried out on a
total of 135 soil samples, i.e. 15 samples from each of 9 types of soil (eutric cambisol, luvisol, luvic pseudogley,
pseudogley, fluvisol, pseudogley-gley, humic gleysols, eugleyic hypogley and eugleyic amphigley) from the
area Eastern Croatia including only arable horizons (0-30 cm). Soil samples (135), in addition to pH values,
were also analyzed for: organic matter, clay content and KIK (BaCl2 method), whereby the influence of
individual properties on soil pH reaction was determined. The average determined values of organic matter
content on all investigated soil types ranged from 0.83 to 11.80%, KIK (BaCl2) from 4 to 47.50 cmol (+) kg-1,
and clay from 1.83 to 58 ,86%. The lowest pH value was measured on the pseudogley-gley using the KCl m/v
method in the amount of 3.57, while the highest value was measured on the eugleyic amphigley soil using the
H2O m/v method in the amount of 8.60. The pH values determined using the v/v (1:5) method were: H2O from
4.88 to 8.60, CaCl2 from 4.09 to 7.76 and KCl from 4.09 to 7.7. while the pH values determined using the m/v
(1:2.5) method were: H2O from 4.81 to 8.41, CaCl2 from 4.01 to 7.75 and KCl from 3.57 to 7.65. Differences
in pH values measured by the v/v (1:5) and m/v (1:2.5) methods averaged: H2O method 0,13 pH units, CaCl2
method 0.02 pH units and KCl method 0.11 pH unit. The average determined pH values are ranged in the
following order: H2O v/v > H2O m/v > CaCl2 v/v > CaCl2 m/v > KCl v/v > KCl m/v. The correlation coefficient
between the methods and submethods of measuring the pH reaction is r=>98, and the influence of other
agrochemical and agrophysical properties depended on the measurement method and on the properties of the
systematic soil unit. The measurement methods are mutually compatible, and the next step in statistical data
processing is the development of regression models and their validation. |
