Influence of compound NPK fertilizer against sulfate ammonium background on yield and quality of linseed flax seeds

In the Central natural-economic zone of the Altai Region, leached chernozems with low to increased nitrogen content, high phosphorus content and low to high exchangeable potassium content predominate in arable land. The weather conditions during the study period were characterized by sharp temperature fluctuations and precipitation. Common (linseed) flax has increased requirements for mineral nutrition, especially in the critical phases of development – “herringbone” stage and fast growth stage. It is at these stages, when the maximum consumption of nutrients, primarily nitrogen, is observed. To optimize the nitrogen regime at the initial stages of development, it is advised to apply starting rates of nitrogen fertilizers in the form of ammonium sulfate and compound NPK fertilizer (diammophoska) which provide plants with available forms of nitrogen and promote normal passage through the critical stages of growth and development without negative consequences for crop formation. Growing common flax variety Severniy in the Central natural and economic zone of the Altai Region according to the conventional technology of crop growing with the application of mineral fertilizers in rates of N42S48, N55P26K26S48 and N57P39K36S48 increases the linseed yield from 1.44 t ha in the control to 1.56-1.78 t ha, or by 8.5-14.6%. These fertilizers contribute to greater accumulation of protein and oil in linseeds: 17.7-20.7% and 49.4-50.1% compared to 20.0% and 48.0% in the control, respectively. On three-year average, protein yield amounted to 0.0311-0.0357 t ha compared to 0.0290 t ha in the control. The average oil yield varied from 0.0806 to 0.0943 t ha compared to 0.0737 t ha in the control. The content levels of crude ash and crude fiber did not exceed the accepted nutritional standards.