The influence of N and Mg fertilizers and CaCO3 on the absorption of Mg by oats

Abstract

The effects of applying CaCO₃, MgSO₄, 7H₂O, (NH₄)₂SO₄ and Ca(NO₃)₂ to the soil on the drymatter yield and Mg absorption of oats at the 4-5-leaf stage were studied in a factorial pot experiment with a Mg-deficient acid sandj soil.Yield of dry matter was increased by all treatments, particularly CaCO₃.Applying CaCO₃, MgSO₄, 7H₂O and Ca(NO₃)₃ generally increased % Mg and total Mg uptake of oats. Applying (NH₄)₂SO₄, which reduced the % Mg in oats growing in the unlimed soil, generally increased % Mg where CaCO₃ was also added. The rate of nitrification of NH4, which was slow in the acid soil, was greatly increased by applying CaCO₃.