Nutrient management by winter oilseed rape (WOSR) during the seed filling period (SFP) is crucial for seed density (SD), which subsequently determines seed yield (Y). This hypothesis was evaluated based on data from field experiments (2008-2010), with six treatments with sequentially added nutrients (0, NP, NPK, NPKMgS1(1/3 total MgS rate—spring applied), NPKMgS2 (total MgS rate autumn applied); NPKMgS3 (2/3-autumn, 1/3-spring). Nutrients accumulated in seeds were revealed as the most reliable WOSR trait, determining SD and Y. Yield was defined by the amounts of K and Mg in seeds. The amount nutrient remobilized from vegetative WOSR tissues was sufficient to cover the crop requirements during SFP for N, P, and Zn, but not for Ca, K, Mn, and Cu. The post-flowering K uptake resulted in PD, and SD increase, which subsequently resulted in a concomitant net uptake of Ca and Mg. The excessive accumulation of Ca, as well as Cu, and Mn in seeds due to a shortage of Mg, subsequently resulted in both SD and Y depression. The efficient exploitation of WOSR yielding potential as defined by SD, is possible, provided during the SFP reveals a net K and Mg uptake.

The scale and extent of the impact of farming on the natural environment are so wide-ranging that in many places on our planet, and especially in Europe, an ever growing pressure is being exerted on limiting or eliminating negative effects of this impact. Actions in this sphere adopted a concept of so-called sustainable farming, which combines production objectives with the requirements of environmental protection thanks to the application of integrated plant proPol. J. Environ. Stud. Vol. 24, No. 1 (2015), [285][286][287][288][289][290][291][292][293][294] Original Research Microbiological AbstractTraditional ploughing cultivation can contribute to soil erosion as well as to other symptoms of soil degradation, leading to a decline in its biological and production potentials. An alternative to conventional tillage is offered by simplified cultivation systems consisting of shallower and less intensive interference into the soil physical structure or even complete abandonment of cultivation treatment. The aim of the performed investigations was to ascertain the impact of a long-term application of simplifications in soil tillage on select soil chemical and microbiological properties under sugar beet cultivation employing two watering combinations: natural distribution of precipitation and sprinkling. Conventional ploughing tillage was treated as reference. The research hypothesis assumed that the application of simplifications in the pre-sowing soil cultivation of sugar beets contributes to the increase in soil organic carbon content and soil fertility. Its microbiological activity and sprinkling also can modify this effect.Experiments were carried out for a period of four years in conditions of long-term application of three tillage systems (conventional tillage, simplified cultivation, and direct sowing). Select soil chemical (pH, C org. , total N) and microbiological (total bacterial counts, numbers of oligotrophs, copiotrophs, actinomycetes and fungi, plus activity of dehydrogenases and acid phosphatase) parameters were analyzed.The microbiological indices analyzed in this study nearly always spoke in favour of simplifications in soil tillage or complete abandonment of cultivation treatments. In successive years of experiments, almost all the analyzed parameters assumed the lowest values in conditions of ploughing cultivation and the highest ones in direct sowing. Sprinkling and fertilization modified this rule, whereas the level and directions of this impact varied and depended on weather conditions.

This study presents the results of 3-year field trials, whose purpose was to assess the dynamics of dry matter accumulation by maize depending on the placement depth of a two-component (NP) mineral fertilizer in the soil layer, type of nitrogen fertilizer and date of its application. Weather conditions, mainly thermal in the early growing season, had a significant effect on maize responses to placement depth of phosphorus starting dose in the soil profile. In the initial stage of maize development, the temperature determined plant growth to a significantly higher extent than the sum of rainfall. The dry matter yield of ears and whole plants showed a clear reaction to starter phosphorus fertilization, but the effect of the depth of fertilizer placement varied over the years, indicating a depth of 5 cm and 10 cm as advisable and recommended for agricultural practice. The PFPFN (partial factor productivity of fertilizer nitrogen) and PFPFP (partial factor productivity of fertilizer phosphorus) indices confirmed the significant effect of fertilizer (NP) placement in the soil profile, indicating row fertilizer application (regardless of the depth) as recommended to improve the efficiency of maize fertilization. The SPAD (soil plant analysis development) leaf greenness index turned out to be a sensitive indicator of maize response to fertilizer (NP) placement depth in the soil profile.

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Failure to adjust the fertilization system to quantitative needs, and especially to the dynamics of mineral demand, causes plant metabolism disorders, low mineral utilization by the plant, and an increased risk of environmental pollution. Additionally, unbalanced mineral fertilization may reduce the assimilation surface actively involved in photosynthesis, which determines the yield potential of individual varieties. The aim of the strict field experiment was to determine the responses of two types of maize varieties (Zea mays L.) to treatments with different nutrient management systems, as expressed by the growth analysis of active organs during photosynthesis, SPAD (soil and plant analysis development) leaf greenness index, green mass yield, and unit nitrogen productivity from PFPFN mineral fertilization (partial factor productivity fertilizer nitrogen). It was demonstrated that the total area of leaf blades of a single plant and the LAI (leaf area index) value were significantly higher in the “stay-green” hybrid compared to the traditional variety. The analysis of leaf morphological structure of the “stay-green” hybrid, based on SLA (specific leaf area), indicated a highly effective utilization of nitrogen, leading to faster leaf production with a larger assimilation area, which formed the basis for effective absorption of solar radiation. The selection of “stay-green” varieties for silage cultivation guarantees high green mass yields. The risk of lower maize biomass intended for ensilage can only be reduced by applying balanced mineral fertilization of all nutrients. The omission of phosphorus (P) and potassium (K) in the mineral fertilization dose, regardless of the variety tested, was a factor reducing the yield of maize biomass intended for ensilage and a lower partial factor productivity of nitrogen fertilizer compared to the treatment optimally balanced with respect to the nitrogen dose.