Managing the productivity of flax by optimizing nutrition

In the Tver region, on sod-podzolic light loamy soil, the productivity management of fiber flax varieties (Zaryanka and Diplomat) with different maturation periods was studied by optimizing their mineral nutrition. To calculate the dose of mineral nutrition, 3 methods were used: balanced modified by Kayumov, balanced to compensate for the removal, and by the ratio of elements in the fertilizer. Accordingly, the doses were N0P0K0 (control), N30P0K50, N30P22K80, and N30P60K150. It was found that despite various weather conditions, the use of fertilizers from the initial phases of flax plant growth allowed plants to accumulate a large biomass: in arid conditions, on average, for varieties by 58% more, in optimal water supply conditions – by 45%. The absorption of nutrients by flax plants increased with an increase in the dose of the introduced elements. With an equal dose of nitrogen in the fertilizer, its amount was greater both in the roots and stems of flax, with increasing doses of phosphorus and potassium in the fertilizer. The content of nitrogen, phosphorus and potassium in the flax roots of the late-maturing Diplomat variety was higher than that of the early-maturing Zaryanka. When optimizing nutrition by applying fertilizers in doses of N30P22K80 and N30P60K150, the proportion of stems in the structure of flax plants increased and amounted to 45 and 46% in the Zaryanka variety, 44 and 49% in the Diplomat variety, respectively to dosage. Without fertilizers, the share of the stem was 38%, and the share of roots and leaves was the highest – 22 and 42%. The production process in this case was less rational. The late-maturing Diplomat variety, on average, for 3 years, when applying all doses of fertilizers, had a yield of flax straw by 3.1–3.9 c/ha more than the early-maturing Zaryanka variety. In the early-maturing variety Zaryanka, a higher dose of fertilizers N30P60K150 reduced the quality indicators: the number of the long fiber and the percentage number of the entire fiber, especially during the dry growing season.