The impact of cover crops and foliar application of micronutrients on accumulation of macronutrients in potato tubers at technological maturity stage

Abstract

The aim of the study was to assess the effect of mineral fertilization (NPK) in combination with manure and stubble crops (white mustard, pea, phace-lia) and foliar application of micronutrients on the content and accumulation of macro-elements (N, P, K, Mg and Ca) in potato tubers at the of stage technological maturity. The tested plant was a potato cultivar ‘Bila’. The experiment was carried out in 2010–2012, at the Wierzchucinek Research Station of the Bydgoszcz University of Technology and Life Sciences. The experimental factors were (I) fertilizer variants (n=5): the control (NPK), NPK + manure (FYM + NPK), NPK + white mustard (NPK + WM), NPK + pea (NPK + P), NPK + blue phacelia (NPK + PH), and (II) foliar fertilization with micronutrients (n=2): no fertilization with microelements (M0) and applications of fertilizer (M1). Micronutrients were applied twice a vegetation season in the form of a chelated fertilizer. The content and accumulation of nutrients in potato tubers at the stage of technological maturity were analyzed. It was found that the applied mineral NPK fertilization (the control), when in combination manure treatment and the three intercrops, significantly differentiated the content of all the studied nutrients in potato tubers. The highest concentration of nitrogen and calcium in tubers was found in the control plants, while highest concentrations of P, K and Mg were observed in tubers grown after manure application. Significantly higher nitrogen content (exclusive of 2011) as well as that of phosphorus were observed in the treatments with no foliar fertilization. In the case of magnesium and calcium, the relationship was reversed (exclusive of Ca content recorded in 2010). The experimental factors significantly differentiated the uptake values of all the nutrients analyzed and, irrespective of the study year, the largest accumulation of nutrients in potato tubers was found in the experimental variant with manure and micronutrient fertilizer application. The highest uptake of nutrients was recorded in tubers grown after pea intercrop as compared with other two intercrops tested. The correlation analysis as regards tuber yields, dry mass and starch as well as the total accumulation of nutrients, showed that regardless of the experimental variant analyzed, there was a highly significant correlation between yield/starch content and uptake of all the macronutrients under the study. Accordingly, intercropping may be an alternative to manure in potato fertilization as it does not require large expenditure, and constitutes the source of macronutrients and organic matter, as well as improves soil structure and prevents its degradation.