Influence of mineral fertiliser and foliar dressing rates on buckwheat yield

A significant problem in the cultivation of buckwheat is its low yield, therefore, it is relevant to improve the elements of the technology for growing this crop. The purpose of the study was to establish optimal norms and terms for applying mineral fertilisers and foliar dressing with chelated microfertilisers in the forest-steppe conditions of Western Ukraine, in a zone of sufficient moisture to obtain stable and high yields of buckwheat grain. For this purpose, a two-factor experiment was conducted on the experimental fields of the Lviv National Agrarian University on dark grey podzolized light loamy soil, which included fertiliser rates: N20P20K20, P20K20+N20 (foliar dressing), N40P40K40, P40K40+N40 (foliar dressing), N60P60K60, P60K60+N60 (foliar dressing) and foliar dressing: control (without foliar dressing), Vuksal Boron 2.0 l/ha, Intermag Legumes 2.0 l/ha. Research methods: field studies – to determine the interaction of the object of research with weather factors and elements of the fertiliser system; calculation and weight – setting parameters of crop structure indicators and determining buckwheat yield; methods of mathematical statistics – dispersion, correlation, regressive and graphical display of findings. An increase in fertiliser rates from N20P20K20 to N60P60K60 provided an increase in all indicators of the buckwheat crop structure. Without foliar dressing, they reached the following values: the number of first-order branches – 1.56 pcs./plant, the number of inflorescences and flowers – 10.68 and 1,011 pcs, respectively, the number of full-size and undeveloped grains (pcs./plant) – 41.23 and 11.37, the weight of full-size grains – 1.15 g and the weight of 1,000 grains – 28.00 g. The introduction of nitrogen fertilisers in foliar dressing (at the beginning of flowering) has significant advantages over the introduction of nitrogen for pre-sowing cultivation. One of the proofs of this assumption is the increase in the number of grains, their weight, and the weight of 1,000 grains, respectively, from 35.43 pcs., 0.97 g, and 27.37 g (variant with N40P40K40) up to 37.27 pcs., 1.03 g, 27.80 g (variant with P40K40+N40). This trend is typical for all experiment designs. A positive effect of foliar dressing with microfertilisers on the elements of the crop structure was observed. The use of Vuksal Boron 2 l/ha was more effective. The maximum weight of full-size grains was in the variant P60K60+N60 (foliar dressing) + Vuksal Boron 2 l/ha – 1.21 g, while the use of Intermag Legumes 2 l/ha on a similar background of mineral fertilisers provided this indicator at the level of 1.17 g. Studies have established the positive effect of nitrogen application by foliar dressing during the beginning of flowering on the yield level, and buckwheat yield also increased with an increase in the rate of mineral fertiliser application from N20P20K20 to N60P60K60 and under the influence of foliar dressing with microfertilisers. The maximum yield indicator on average for three years of research is obtained in variant P60K60+N60 (foliar dressing) + Vuksal Boron 2.0 l/ha – 2.64 t/ha