The effect of yararega fertilization on the nitrogen effectiveness and yield of sweet sorghum ( Sorghum bicolor (l.) Moench)

Background. The sorghum (C4) species has a high potential for accumulation of photosynthetic radiation. It is possible to obtain a high biomass yield after meeting the fertilization needs of plants, especially as regards nitrogen.Material and methods. In 2013–2015 at the Experimental Station Pawlowice, which belongs to the Department of Crop Production, a field experiment was conducted that aimed to assess the usefulness of the fertilizer YaraRega to fertilize sweet sorghum. Two methods of using the fertilizer were used: broadcasting application and fertigation, using two rates (40 and 80 kg N per ha), and were compared with the control (without fertilization). The fertilizer in the foliar form was applied in two solutions: 0.20 and 0.40%, respectively, for rates of 40 and 80 kg N per ha. The study estimated the effect of fertilization on the productivity of fresh and dry matter and the effectiveness of these treatments.Results. The statistically significant increase in the fresh matter yield obtained under the influence of nitrogen rates was about 25% (after fertilization with 40 kg N per ha) and 32% (after the application of 80 kg N per ha). Taking into account also the dry matter yield, only fertilization with 40 kg N per ha caused a significant increase in the yield compared with the control. Fertilization with a rate of 40 kg N per ha caused an increase in the fresh matter yield of about 300 and 334 kg per 1 kg of nitrogen used after of broadcasting and fertigation application methods respectively. Agronomic efficiency expressed in dry matter yield amounted to 75 and 76 kg per 1 kg of nitrogen used.Conclusion. YaraRega is recommended to be applied to sorghum with the fertigation method. No toxic effect on sorghum plants was observed after an application of the 0.4% solution.