Hakan Çelik

Effect of Foliar-Applied Humic Acid to Dry Weight and Mineral Nutrient Uptake of Maize under Calcareous Soil Conditions

Greenhouse research was conducted to determine the effects of foliar application of humic acid on dry matter and some nutrient element uptake of maize grown under calcareous soil conditions. Agricultural lime was used to obtain five calcium carbonate (CaCO3) doses (0, 5, 10 20, and 40%) and three foliar application doses of humic acid (0, 0.1, and 0.2%) sprayed at 20 and 35 days after emergence. Although the dry weight and mineral element uptake of maize were affected negatively, especially at 20 and 40% of lime levels, foliar application of humic acid had a statistically significant positive effect on dry weight and copper (Cu), zinc (Zn), and manganese (Mn) uptakes (P < 0.01) of maize plants. The greatest dry weight and Cu and sodium (Na) uptakes were obtained from the 0.01% humic acid treatment. The interaction of lime and humic acid was also statistically significant on dry weight, nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), Cu, Zn, and Mn uptake (P < 0.01).

Comparison of Various Chemical Extraction Methods used for Determination of the Available Iron Amounts of Calcareous Soils

This study was conducted to compare the most appropriate method for the evaluation of available iron (Fe) status of calcareous soils by using nine different chemical extraction methods. Leaf and soil samples were collected from nine peach (Prunus persica L.) orchards, each of which included green, slightly chlorotic, and severely chlorotic peach trees. According to the chlorosis degrees of the leaves, total and active Fe contents and some soil properties were determined. Relationships between these parameters and Fe amounts obtained from the methods were correlated. Among the methods tested, method 3 (M3) [0.05 N hydrochloric acid (HCl) + 0.025 N sulfuric acid (H2SO4)] and method 8 (M8) 0.05 M ethylenediaminetetraacetic acid (EDTA) (pH 7.0) were the most suitable methods to indicate the available Fe status of the soils.

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

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).

Evaluation of Analytical Methods for Boron Determination in Maize Shoots

ABSTRACT For the comparison of the digestion and spectroscopic determination methods used to measure boron (B) concentrations in maize shoots, increasing doses of boron (0, 2.5, 5, and 10 mg kg−1 B) were applied to soil and maize plants (Zea mays L.) cultivar “Euralis Es Armandi” (FAO 640). The plants were grown under greenhouse conditions. Dried and ground maize shoots were digested according to two digestion procedures of microwave and dry ashing. Boron concentrations were determined using spectrophotometer and inductively coupled plasma-optical emission spectrometry (ICP-OES). The concentrations of boron influenced statistically (p < 0.01) due to the B applications and analysis methods. Spectrophotometric measurement of B amounts of the samples prepared with microwave digestion method was found irrelevant with other indicated methods. However, the ICP-OES measurements were found compatible with the dry ashing also with microwave digestion and suggested as a suitable method to determine boron contents of the maize shoots.