Effects of soil applied humic substances to dry weight and mineral nutrients uptake of maize under calcareous soil conditions

Abstract

A greenhouse research was conducted to determine the effects of soil application of humus on dry matter and some nutrient element uptake of maize grown under calcareous soil conditions. Agricultural lime was used to obtain five CaCO₃ doses (0, 5, 10, 20 and 40%). Three doses of solid humus (0, 1 and 2 g kg⁻¹) were applied to soil one month before planting. Although the dry weight and N, P, K, Ca, Mg, Fe, Cu, Mn, Zn and Na uptake of the plants were affected negatively, especially at 20 and 40% of lime levels, the soil application of humus had statistically significant effect on dry weight, N, Fe, Na (p < 0.05) K, Mg, Cu, Zn and Mn (p < 0.01) except P and Ca uptake of maize plant. The highest mean of dry weight, N, P, Ca, Mg, Fe, Zn and Mn uptake were obtained from 1 g kg⁻¹ humus treatment. In contrast, the highest mean of K, Cu and Na uptake was determined at 2 g kg⁻¹ doses of humus treatment, respectively. The interaction effect between lime and soil humus was also found statistically significant on dry weight, and the uptake of N, P, Ca, Mg, Fe, Cu and Mn (p < 0.01).

Keywords:

• calcareous soil
• humus
• maize
• nutrient elements
• plant growth

Acknowledgement

This work was supported by the Research Fund of The University of Uludag Project Number: 2003/92 and The Scientific and Technical Research Council of Turkey (TOVAG 105 0 345). We also thank Mrs Mine Uzun, from English Language studies, University of Wollongong, Australia for her critical reading of the manuscript.