EFFECT OF DIFFERENT TILLAGE SYSTEMS ON THE MACRONUTRIENT CONTENT AND UPTAKE IN SUGAR BEETS

The study, carried out in 2012-2013, intended to determine effects of different cultivation systems on the uptake and content of macronutrients (nitrogen, phosphorus, potassium, magnesium, calcium and sodium) in sugar beets at the technological maturity stage. A conventional tillage system (SO) was compared to simplified technologies of soil cultivation. The following conservation tillage systems were analyzed: (2) tillage to a depth of 35 cm and sowing into stubble mulch (MS35); (3) shallow tillage to a depth of 15 cm and sowing into stubble mulch (MS 15); (4) tillage to a depth of 15 cm and sowing into white mustard mulch; (5) strip-till on stubble mulch to a depth of 25 cm and instantaneous beet seed sowing (STS); (6) strip-till to a depth of 25 cm on white mustard mulch and instantaneous beet seed sowing (STG). Mineral nutrient concentrations in beets varied depending on the cultivation system applied and the plant organ analyzed. The experimental factor significantly differentiated the content of P, K, Ca, Mg and Na in both beet leaves and roots, having no effect on the nitrogen content. When compared to the conventional tillage system, a decreasing trend for phosphorus and calcium in beet leaves and a significant increase of sodium both in beet leaves and roots was observed in the simplified cultivation systems. Cultivation simplifications provided some equivocal evidence implicating differences in the nutrient content between the study years. The analysis of correlations between root yields and the total accumulation of nutrients indicated significant relationships for N, P, K, Ca, Mg only in the conventional tillage system and in the treatment with 35 cm deep tillage (soil ripping) along with sowing into stubble mulch (MS35). In the other treatments, strong relationships were observed only for individual nutrients.