Effect of liming on the magnesium status of some mineral soils and on the fate of fertilizer magnesium

Abstract

Nine mineral soils were incubated in laboratory without lime (Ca0) or limed (Ca1) with calcium carbonate (lab.reag.), and without magnesium fertilizer (Mg0) or fertilized with MgSO4*7H20 (Mg1 = 4 mg/100 g soil Mg). The incubation covered a period of seven weeks in aerobic conditions at constant 20 °C temperature. The relative increase in the effective cation exchange capacity (ECEC) caused by liming seemed to be in coarse mineral soils greater than in clay soils. The differences in pH (CaCl2) values between soil types was not so evident. In seven soils of the nine, liming decreased the 0,01 M CaCl2 extractable magnesium content more than in 1 M KCI or in 1 M neutral ammonium acetate extractable magnesium contents. The limed soils contained ammonium acetate extractable magnesium 2—24 % less than the unlimed soils. The decrease in magnesium content was greatest in acid muddy silt (Littorina soil) and in acid silty clay. Without lime the I M KCI extractable (Al+H) contents of these soils were 6,6 and 2,2 me/100 g soil and pH (CaCl2) 3,9 and 4,5, respectively. In finesand soils liming seemed to increase the magnesium content although not significantly. In limed soils 17—73 %of the fertilizer magnesium was extractable in 0,01 M CaCl2, 67—100 % extractable in 1 M KCI and 57—100 % extractable in 1 M neutral ammonium acetate. The equivalent ratio of exchangeable (1 M ammonium acetate, pH 7) calcium to magnesium in the soils may give pointers to the choice of liming agents, especially in the liming of low cation exchange capacity soils.

Effect of liming on the value of magnesium sulphate and two dolomitic limestones as magnesium sources for ryegrass

“…In this pot experiment the dolomitic limestones seemed to have a smaller effect on the effective CEC than the same amount of calcitic limestone. It has also been reported that the effective CEC of soil is not affected by either magnesium sulphate (GROVE et al 1981, JOKINEN 1981 or magnesium carbonate (GROVE et al 1981) (HUNSAKER andPRATT 1970, McBRIDE 1978) or other reactions due to the high aluminium content of the soil (KINNIBURG et al 1976, CHAN et al 1979, GROVE et al 1981 …”

“…If the pH of soil containing only small amounts of plant available magnesium is raised by the application of calcitic limestone, the need for the addition of magnesium becomes even greater because some of the soil magnesium is converted in a form not extractable in neutral ammonium acetate (McLEAN 1956, ADAMS and HENDERSON 1962, KAILA 1974, GROVE et al 1981, JOKINEN 1981. Similarly, some of the readily-soluble magnesium applied to the soil is converted into the not extractable form OUO andUZU 1977, JOKINEN 1981 (KAILA 1971) The growing season 1979 was extremely wet.…”

Effect of liming and N fertilization on growth, macronutrient content and uptake by mixed stands of three clovers and timothy

“…In the second growing season with N addition and K shortage, timothy seemed to be stronger than clover in the competition on K, and therefore the K content of clover remained lower than without N. The earlier results of field studies also imply the existence of competition on K between clover and timothy (Raininko 1968, Jokinen 1969).…”

“…The possible reason for the decreased growth may be e.g. the high Ca concentration in the soil (Munns and Fox 1976), the inbalance in Ca/Mg (Jokinen 1981 a), the incapacity to take up non-exchangeable cations (unlike ryegrass) and decrease in nodule number, nodule weight and N fixation (Edwards et al 1981, Ssali 1981. Edwards et al (1981) obtained the highest yield increases of cowpea with 2.5 t/ha lime at pH 4.3; higher lime amounts decreased the yield.…”

İç Anadolu Bölgesi tarım topraklarının bazı verimlilik parametrelerinin belirlenerek haritalanması

“…Bunun nedeni bölgedeki sıcak ve kurak iklim koşullarının yanında, bölgedeki düşük yağış nedeniyle, yıkanmanın olmamasıdır. Ayrıca, bitki besin elementlerinin dengesi bakımından ideal bir tarım toprağında Ca/Mg= 6, Ca/K= 12, Mg/K= 2 olması beklenmektedir (Jokinen 1981). Bölge topraklarının Ca/Mg oranlarının %11.6'sı, Ca/K oranlarının %14.3'ü ve Mg/K oranlarının %37'si bu oranlara uymaktadır.…”