Flax is a valuable technical culture. Flax fiber is superior in strength to cotton, wool and jute. Flax fabric is distinguished by high strength, durability and resistance to decay.
The vegetative period of flax is 70-80 days. The root system is poorly developed and not very actively extracts nutrients from the soil. To grow it is important that:
For the formation of 1 ton of straw from a hectare of soil, flax will take:
Flax finds the most favorable conditions for its growth on sod-podzolic light loamy and sandy soil at pH 5.5-6.0. With a soil acidity of more than 6 units, calcium chlorosis is often happens. At pH values of 5.7-5.8, potash fertilizers can be used, which reduce the effect of excess calcium. It is not recommended to use liming in fields where seeding of long-flax is planned in the future crop rotation.
In the process of growth, there are several critical periods of nutritional deficiency:
A sufficient amount of phosphorus and potassium increases resistance to lodging and fungal infections, and also accelerates the ripening of flax. Before the budding phase begins, flax absorbs 50% of the total nitrogen and phosphorus, 70% of potassium. For the first 10 days of the beginning of the rapid growth, half of this nutritients will be used.
With a lack of nitrogen flax will:
As a result, there will be less yield of both straws and seeds.
An excess of nitrogen is also harmful to the flax crop, since it causes excessive growth of the leaves, as a result - shading of the stems and their rapid elongation. Plants become more vulnerable to lodging and the defeat of various infections. Ripening is delayed, fiber output decreases, its quality decreases. Thus, it is important to accurately maintain the dose ratio of nitrogen, phosphorus, and potassium when nitrogen fertilizers are applied.
The most active absorption of phosphorus is noted in the phase of «herringbone» and budding. The initial stage of growth is from the moment of emergence of shoots to the appearance of 5-6 leaf pairs. Like many cereals, the lack of available phosphorus compounds at the initial stage of growth is critical for general development, and in the case of flax - for the formation of elementary fibers in the stems.
Accordingly, a correctly selected dose of phosphate fertilizers accelerates the ripening of the crop and increases the amount of both straw and seed.
The lack of potassium at the initial stage of growth negatively affects the overall yield. Signs of potassium deficiency:
With a properly selected dose of potassium, flax leaves live longer, fiber quality is higher. Plants are more resistant to lodging.
As a rule, manure as a fertilizer for feeding flax is not used, because it enhances the growth of weeds. In addition, it is technologically impossible to apply such fertilizer evenly over the entire area, which will cause uneven maturation and create problems during harvesting.
The manure can be applied under the precursor culture (most often potatoes) at a dose of 30-50 t/ha. Directly before sowing flax, you can make dry bird droppings at a dose of 6-8 c/ha. On soils of light grain size distribution, a good increase in yield is provided by the use of green fertilizer. For example, use lupine, which should be plowed into the ground in the gray-gray bean phase. Also, cabbage cultures (white mustard, radish) can be used as a flax precursor crop, if before this field was under grain.
The example ratio of minerals doses:
When used in this proportion, we can expect an increase in yield from 3 to 8 c/ha. It is not recommended to exceed them, because during drought this will cause a slowdown in growth, and if there is an excess of moisture, the lodging risk increases.
The maximum dose of nitrogen that can be applied after non-legume precursors is 40 kg/ha. After pulses, tilled and perennial herbs, the dose should be 20-25 kg/ha.
On soils with a sufficient nitrogen content, a ratio of 1 : 3 : 4 (nitrogen : phosphorus : potassium) is recommended. With a low nitrogen content in the soil, the ratio can be shifted to a ratio of 1 : 2 : 2.
Phosphorus and potash fertilizers are usually applied for ground soil treatment, nitrogen - during pre-sowing cultivation. On the soils of light particle size can be applied full fertilizer during pre-sowing cultivation. For flax, choose potash fertilizers without chlorine.
Directly during sowing 10-15 kg/ha of phosphate fertilizers are applied. If nitrogen has not been added before planting, the nitrogen fertilizers should be used into the «herringbone» phase.
The first in importance for flax should be noted boron and zinc. After liming the soil, they turn into poorly soluble compounds, and the plant is affected by calcium chlorosis, which reduces the yield.
Foliar application can be used to feed the flax with microelements. Usually, microelements are used together with herbicides application in the «herringbone» phase.
Another option of feeding with microelements is the presowing treatment of seeds with a mixture (kg/t):
If the soil pH is more than 5.5 units, then it is necessary to use top dressing with boric fertilizers at a dose of 0.5 kg/ha of active substance.
From the moment of emergence of shoots and up to the «herringbone» phase (at a height of 5-6 cm), it is advisable to feed the crops of long-flax with boron (100-200 g/ha) and zinc (200-300 g/ha). It can combined with treatment against flax flea. Extra root treatment with these minerals is obligatory at pH 5.7-5.9, it allows to protect plants from excessive calcium intake and prevent the development of calcium chlorosis.
If the pH is 6.0-6.2, then potash fertilizers are applied in a dose of 150-180 kg/g, which should protect against the influence of calcium in the soil and reduce its entry into plants. Usually, potassium is divided into two equal parts and introduced by foliar method - the first part in the «herringbone» phase, and the second in a week.