The elemental composition of grains of winer wheat for pre-treatment of manganese sulphate

Abstract

The research has been aimed at definition of bioavailable forms of selected trace elements (Mn, Cu, Zn, Co) in agricultural soils.The analyzed soils were generally characterized by acid or very acid pH. Manganese impact on plant growth and a content of the elements in grain have been studied during pre-sowing treatment of winter wheat seeds with solutions of manganese sulphate. The field research was undertaken during 2012-2014. Experimental scheme consisted of the following variants: 1–5 – pre-sowing treatment of winter wheat seeds Artemida by solutions of MnSO4 • 5H2O with corresponding percentage of concentrations: 1.0; 0.5; 0.1; 0.01; 0,001. Processing has been performed a day before sowing. Variant 6 – control, without processing. The soil was sod-brown, hydrolytic acidity – 3,47, exchange acidity – 4,82. Germination of the seeds has been preliminary determined in laboratory conditions. The growth rate, increase of dry weight, has been determined in the tillering stage (3–1 leaves). ICP spectrometry method has been applied to study the elemental compositions of the grain and soil using emission spectrometer ISP-MS Agilent 7700x. Soil samples extracted with ammonium acetate buffer, pH 4.8 in soil-solution correlation 1:5. Samples of the grain have been chosen selectively from the plots of each variant in the stage of full grain maturity. The average sample from each repetition has been prepared for the analysis. The samples were milled and ashed in nitric acid using microwave system of sample preparation – Milestone Start D. Fluka Multielement standard solution 5 for ICP has been used for calibration standards. Biological absorption coefficients (Cba) have been identified for establishing of quantitative parameters of transition of micronutrients from the soil into the wheat plants. Cb.a. have been determined by the correlation between the concentration of the element in wheat and its concentration in soil. Comparison has been conducted between two samples: Cba in the variant of optimal 0,01 % concentration of manganese sulphate in pre-sowing treatment of winter wheat seeds and Cb.a in control variant where the natural influence – high availability of mobile forms of microelements in soil under research - has been taken into consideration. The research on determination of bioavailable forms of trace elements in the sod-brown soils has demonstrated very high provision of mobile forms of manganese and copper as well as high provision of zinc and cobalt. It has been explained by the genesis of these soils since soil forming rocks of volcanic origin are saturated with polymetals and mobility and bioavailability depend on the acid reaction of soil solution. Based on manganese research results there was defined a clear dependence of the plant growth on the concentration of manganese sulphate in pre-sowing treatment of wheat seeds. The usage of 0, 01–0,001 % manganese sulphate solutions is optimal for winter wheat growth. Treatment with these concentrations stimulates the growth of the plants in comparison to the control variant. Higher concentrations, 0,1–1,0 %, can result with deceleration of growth processes. It has been found out that the content of manganese in wheat depends on the concentration of the element used in pre-sowing treatment of seeds. The general conformity to natural laws of this dependence is due to the fact that as the concentration of manganese in pre-sowing treatment of seeds has decreased, its concentration in seeds has increased, but it has been less than in seeds of the control variant. We should mention that the concentration of manganese in wheat seeds of the control variant has a little exceeded the maximum allowable concentration. There was assumed that in the case of pre-sowing treatment of the seeds with solutions of manganese sulphate of 0,01 and 0,001 % concentrations the manganese can act as a microelement without negative influence on formation of harvest and the content of valuable manganese microelement in grain. During the pre-sowing treatment of the seeds the manganese reveals its antagonism in respect to accumulation of copper and not affecting the content of zinc and cobalt in the grain. Manganese, zinc, and copper can be accumulated in the grain of winter wheat, Cba> 1.The reason is high need of crops, including winter wheat, in these microelements.