Fagopyrum esculenum
• Family: Polygonaceae
• Overview:
Buckwheat was brought from Asia in the early 15th century because there was a chronic shortage of cereals in Central Europe at that time. The advantage of this crop is that it can grow in infertile sandy and swampy soils.
Buckwheat flour can be used for baking bread, fine and durable confectionery, as well as for pancakes and pasta. As it does not contain gluten, it can also be used in patients with celiac disease.In addition to being used as a cereal, buckwheat can also be used as a weed control plant, a catch crop, a fodder plant or for sowing meadows for bee grazing.
Suitability for green manure:
Buckwheat germinates even in the driest conditions and sprouts quickly. Based on the rapid coverage of the soil, it offers other crops effective protection against germination. Therefore, buckwheat is an excellent ingredient in reclamation mixtures for landscaping. It has a fine root system in the upper humus layer of the soil. Even in mild frosts it freezes. It is not recommended to sow buckwheat as a reclamation crop in pure crops.
Botanical characteristics:
Buckwheat is an annual spring plant with a height of 50-60 cm. On the initially green stem, which later turns reddish, are the typical heart-shaped leaves with a pointed tip and short stalks. From the leaf axil grow globular inflorescences, which are pink, whitish-yellow or yellowish-green in color.Depending on the time of sowing, the plant blooms from June to September and as a result of this long period of flowering buckwheat is suitable for sowing meadows for bee grazing.
The fruit is like a pointed box with three edges in black, dark brown or silver-gray color. The weight of a thousand grains of ordinary buckwheat is 19 - 27 grams, and that of Tatar buckwheat is 15 to 20 grams. Buckwheat reacts very sensitively to adverse weather during flowering and therefore fruit formation is very uncertain.
Selection of a field for cultivation:
Buckwheat is sensitive to cold and during its short growth time (6 to 9 weeks) requires heat in moderate humidity. But it also tolerates harsher climates. Very fertile soils cause vigorous plant growth, but less fruit formation and strong lodging.
Buckwheat prefers light, warm and moderately acidic soils without compaction. It is tolerant of drought, but in extreme drought it reacts with reduced yields. Prefers low pH values, values in the weak acid range are suitable.
Buckwheat is not pretentious to its predecessor. In any case, it must leave the soil free of weeds and low in residual nitrogen. Therefore, green fallow land and legumes are not suitable. Suitable precursors are cereals, potatoes and maize. Buckwheat itself is considered a good precursor (technological soil preparation, weed control, a plant - an enemy of nematodes). Its own tolerance is assessed as relatively high. It is most often found in crop rotation after trench crops, rye and after itself.
• Other:
At first glance, the production of buckwheat grain seems very interesting, but the grain yield is lower compared to cereals, and the difficulties with processing (problems with peeling!) are still unresolved.Before sowing, along with the processing, it should be clarified whether the placement and the price are regulated by a contract.
Buckwheat can be sown as a cereal, as a catch fodder crop or as part of green manure. Its suitability for sowing as a catch crop is a consequence of its very rapid initial development with intensive covering of the earth's surface until the first autumn frost and weed control. To the other components in different mixtures buckwheat offers effective protection against germination.
  Usage of the grains Green manure(in mixtures), second crop
Germinating seeds/m2 around 300 around 300
Thousand kernel weight, g 18 - 35 18 - 35
Sowing rate for clean crops kg/ha 50 - 90 50 - 90
Row width in cm 10 - 15 10 - 15
Depth of sowing in cm 2 - 3 2 -3
Sowing time 5.04. - 5.06. 1.07. - 10.08.

Buckwheat is heat-loving and sensitive to cold; the sowing date should be based on these features. The usual sowing dates are in May, under favorable conditions buckwheat is sown from mid-April.
Caution: temperatures below 5oC can lead to delayed germination and losses. Late frosts can even lead to total destruction.
The sowing bed must be well settled and have a shallow loose sowing horizon without seals.
Five to eight days after sowing, the first sprouted leaves are already visible. Crops need almost no care. Due to the relatively short veg. period of culture (twelve weeks) are suitable and places with higher altitudes. It is possible to sow buckwheat as a second crop after early release crops such as winter barley.
The rate of nitrogen extraction is about 30 - 50 kg / ha, phosphorus - 30 kg / ha, potassium (without chlorides) - 50 kg / ha. Excessive fertilization slows down ripening and increases the moisture content at the time of harvest. Nitrogen fertilization before sowing should not exceed 40 kg / ha N.
Varieties with a large mass per thousand grains and with a certain tolerance to late sowing are preferable. Varieties that have been selected for summer use as a catch crop are less suitable for grain production as a main crop.
Diseases, pests and weeds:
To date, no plant protection products have been registered in Austria. However, buckwheat is quite insensitive. So far no problem enemies and diseases are known.Its competitiveness against weeds is very high; mechanical care with harrow and rake is applicable to a limited extent, as the plant is susceptible to mechanical damage. Therefore, the soil must be repeatedly treated before sowing to remove all weeds and self-seeding. Areas with perennial weeds are not suitable.
Harvesting and yield:
Buckwheat is characterized by a long phase of flowering and late and uneven ripening. Due to the loose connection of the seeds, the losses in the period before and during the harvest can be large. Grain yield varies on average between 500 and 1500 kg / ha.
Harvesting takes place when a large part of the grains change color and they harden. It is not always easy to determine the time for harvesting, because the plant has both flowers and almost ripe grains.
With the onset of the first early frosts, significant grain rot occurs. If the crop is harvested with a combine, then threshing should be more gentle than with cereals. The threshing should be set at 600 rpm. and the distances between the drum rails must be greater.
Sometimes buckwheat is harvested separately - cut on slopes (when the first grains have already begun to crumble). After a week it can usually be threshed.
After harvesting, the grain must be dried immediately and cleaned. Humidity higher than 25% can completely damage it. Additional drying up to about 14% is required (for production of seeds for sowing at 40o C, for consumption at 50o C).