Of all the crops, this is the most demanding of the soil moisture. For comparison, to create a unit of dry matter, buckwheat uses water twice as much as wheat and three times more than millet. The need for moisture is maximum at the very beginning of growth and during the flowering phase.
Thus, the maximum yield can be expected if there is enough rainfall during flowering and especially when the ovary is formed. Generative period (flowering and ripening) is a critical moment for moisture deficiency. It was at this time that plants should absorb 50-60% of all moisture in their lives.
Air temperature - no more than 25 degrees. If during 3 days air temperature wil be over + 30 ° and the humidity of the air is less than 40%, then all ovaryes on the plant will die. Thus, for the cultivation of buckwheat is better to choose the field, next to which there is a forest or forest belt, which can mitigate fluctuations of the microclimate.
Buckwheat shows the best results at pH 5-6. If the value is lower than the specified one, it is necessary to make liming of the soil, good results are obtained by using dolomite flour, which additionally enriches the soil with magnesium.
The root system is not as well developed as that of other representatives of grain crops, but it has more thin roots and root hairs that live longer than those of the grain crops ones and are distinguished by high activity. The total mass of roots per unit area of sowing in buckwheat is 3 times less than in wheat, barley - in 1.6. At the same time, the absorption capacity is higher than that of wheat by 2.7 times, and that of barley by 5.5 times. This helps buckwheat to use even poorly soluble forms of phosphates and potassium in the soil.
Buckwheat straw contains 2-3 times more potassium, phosphorus and calcium than straw of any other cereal. Mineral consumption increases during certain periods. Before the flowering period, 60% of total nitrogen and potassium, 40% of phosphorus are usually absorbed.
Like other grains, buckwheat needs some mandatory starter fertilizer of phosphorus (20 kg/ha) before sowing, as this mineral is necessary for growth and root formation. Its deficiency also causes the death of part of the inflorescences.
Due to the peculiarities of the root system, buckwheat responds well to the aftereffects of fertilizers that have been introduced under the crop of its predecessor.
Manure is not recommended for direct use for buckwheat - only for its predecessor. If the application of manure is still produced and the weather is humid, the vegetative period is significantly lengthened and the ripening of the grain is postponed.
It is necessary to carefully fertilize buckwheat with nitrogen, since its excess provokes active growth of green mass to the detriment of the development of grain and prolongs the growing season.
The recommended application dose for middle and late ripening varieties is no more than 60 kg / ha on previously untreated fields, after tilled crops 30-40 kg / ha. For early ripening buckwheat, the dose is increased by 20-30 kg / ha. Good results are shown by the use of ammonium sulfate.
Nitrogen fertilizers enhance the effect of phosphate on leached chernozem and even more on podzolic soils. The effect of phosphate fertilizers is especially noticeable on black soil. If the content of mobile phosphates in the soil is more than 100 mg / kg, it makes no sense to add them additionally, only as starting materials at the time of sowing.
The application of potassium-containing fertilizers may not have a visible effect, since the buckwheat root system perfectly assimilates this mineral on all types of soil. Some positive effect can be noted on the soils of light particle size distribution. In addition, it should be remembered that buckwheat is a typical chlorophobe, that is, chlorine-containing fertilizers can be used only in the fall, so that during the winter all the chlorine would washed out from the growth zone of the root system of this crop. Potassium fertilizers that do not contain chlorine can be applied in spring.
Signs of lack of potassium: first, the edges of the lower leaves turn yellow, then turn red and die. The growth rate in general slows down, the grain size decreases.
Buckwheat grain contains twice as rich in copper as in all other cereals. An interesting feature of buckwheat is its ability to translate poorly soluble metal compounds in the soil into readily available. This is more pronounced at neutral and alkaline pH values, slightly worse at acidic. The content of readily available forms of zinc increases fourfold, zinc and copper doubled. This should be taken into account as a positive factor when choosing crops for crop rotation.
In addition to these substances, one should not forget about boron - with its deficiency, die-off of buds, flowers and even ovaries is noted.
As one of the options for plant nutrition with minerals, seed treatment can be considered. The main rule is to use no more than two minerals for one treatment.