Detailed Explanation of Key Techniques for High-Yield Buckwheat Cultivation
Buckwheat is an annual herbaceous plant of the genus Fagopyrum in the Polygonaceae family. It originated in China, has a very long history of cultivation, and there is also rich cultivation experience. The earliest discovered buckwheat specimen was unearthed from Han Tomb No. 4 at Yangjiawan, Xianyang, Shaanxi, dating back more than 2000 years. In addition, specimens from the Former Han and Later Han periods were also unearthed at Maquan in Xianyang, Shaanxi, and Mozuizi in Wuwei, Gansu, respectively. Now let us take a look at high-yield buckwheat cultivation techniques!
Buckwheat Growth Habits
1. Temperature: Buckwheat prefers cool and humid conditions, is not tolerant of high temperatures and dry winds, and is afraid of frost. An accumulated temperature of 1000-1500°C can satisfy its heat requirements. Seeds can germinate in about 4-5 days when the soil temperature is above 16°C. The most suitable temperature for flowering and fruiting is 26-30°C. When the temperature is -1°C, the flowers die; at -2°C, the leaves and even the entire plant die.
2. Sunlight: Buckwheat is a short-day crop. When the day length decreases from 15-16 hours to 12-14 hours, the growth period shortens. Late-maturing varieties are more sensitive than medium- and early-maturing varieties. Each plant can produce more than 2000 flowers, but the seed-setting rate is very low, only about 10%. In addition, the leaves have weak assimilation capacity, and flower and fruit drop is serious.
3. Water: Buckwheat is a crop with relatively high water requirements. During seed germination, it needs to absorb about 50% of its own dry weight in water. During flowering and fruiting, it consumes a large amount of water, and the peak water demand period is during full flowering. Its transpiration coefficient is generally 450-630, and the relative air humidity should not be lower than 30-40%.
4. Soil: Buckwheat has low soil requirements. Its root system is weak, and the seed's ability to push through the soil is poor, so loose soil is required to facilitate seedling emergence and promote root development. Reproductive growth is rapid, and its fertilizer uptake capacity is strong, making it suitable for newly reclaimed land. The required soil acidity is pH 6-7, and strongly alkaline soil is not suitable for planting.
5. Fertilizer: Buckwheat is a crop sensitive to fertilizer. With sufficient fertilization, the stems can produce a large number of branches. Phosphate fertilizer can promote grain formation and increase nectar secretion. Using bees to assist pollination can thereby increase yield. The demand for potassium fertilizer is relatively high, but chlorine-containing potassium salts easily cause leaf spot disease.
Cultivated Varieties of Buckwheat
1. Common buckwheat: Common buckwheat, also called sweet buckwheat, has no mycorrhizae, slender stems that often have ridges, and a pale red color. Its achenes are relatively large, triangular in shape, with smooth surfaces and edges, and good quality. It is the type more widely cultivated in China.
2. Tartary buckwheat: Tartary buckwheat, also called bitter buckwheat, has mycorrhizae, and its stems are often smooth and green. Its achenes are relatively small, triangular, with inconspicuous ridges, sometimes wavy, and rough surfaces. It is more widely cultivated in southwestern China.
3. Winged buckwheat: Winged buckwheat has pale red stems and large leaves, and is mostly self-pollinated. Its achenes have thin ridges that form wing-like structures, and its quality is relatively poor. It is cultivated in small amounts in both northern and southwestern China.
4. Rice buckwheat: Rice buckwheat is distributed in almost all major buckwheat-producing areas of China. Its achenes resemble those of common buckwheat, are plump between the two ridges and appear ready to split, but are smooth without deep concave lines, with blunt ridges and wrinkled skin. It is named for its seed coat, which easily bursts.
Buckwheat Sowing Techniques
1. Crop rotation selection: Buckwheat is not strict about the previous crop and can grow after any crop, but continuous cropping is avoided. To obtain high buckwheat yields, it is best to choose a good previous crop in the rotation. Better previous crops are legumes and potatoes, which are soil-improving crops. Next are corn, wheat, and vegetable field stubble, which are soil-depleting crops.
2. Land preparation: Buckwheat has relatively strong adaptability to soil. As long as the climate is suitable, it can be planted in any soil, including poor land and newly reclaimed land unsuitable for other cereal crops. However, soil rich in organic matter, with good structure, sufficient nutrients, strong water retention, and good aeration can produce high-quality, high-yield buckwheat.
3. Sowing: The topography, soil quality, and cropping systems vary greatly from place to place, so sowing methods also differ. The main methods are drilling, dibbling, and broadcasting. Scientific buckwheat cultivation should advocate drilling. Broadcasting results in uneven seed distribution, uneven emergence, and poor ventilation and light penetration, so yields are not high. Dibbling is too labor-intensive. Drilling provides high sowing quality and is conducive to comprehensively coordinated development, thereby increasing bitter buckwheat yield.
① Drilling: For drilling, beds are made 167-200 cm wide, with a sowing width of 13-17 cm. The advantages are consistent depth, even seed distribution, and uniform emergence. In cases of severe spring drought and poor soil moisture, deep sowing at the proper time ensures full stands, and it is also convenient for intertillage, weeding, and topdressing.
② Dibbling: Dibbling makes it difficult to control the amount of seed, and the number of hills per mu is also difficult to manage, and it is relatively labor-intensive. Beds are made 167-200 cm wide, with row spacing of 27-30 cm and hill spacing of 17-20 cm. Sow 8-10 seeds per hill, and after emergence, retain 5-7 plants.
③ Broadcasting: In some areas, after wheat harvest, the land is first plowed and then seeds are broadcast. Because broadcasting has no distinction of plant or row spacing, density is difficult to control, the field population structure is unreasonable, dense areas form clumps, and sparse areas show no seedlings. Field management is also difficult, and yields are generally low.
Field Management of Buckwheat
1. Seedling stage management: After sowing buckwheat, active measures should be taken to protect seedlings. If drought occurs at sowing, timely compaction and firming of the soil should be carried out to reduce voids, so that the cultivated soil layer is loose on top and firm below, which helps groundwater rise and seed germination and emergence. If rain occurs after sowing or soil moisture content is high, surface crusting may form. Buckwheat cotyledons are large and have poor soil-penetrating ability, so surface crusting will affect emergence. A nail rake can be used to break the crust and loosen the surface.
2. Reasonable close planting: The factors constituting buckwheat yield are mainly the number of plants per mu, the number of grains per plant, and 1000-grain weight, all of which are related to density. Reasonable close planting means fully and effectively using light, water, air, heat, and nutrients, coordinating the contradiction between population and individual, and ensuring healthy individual growth and development under the premise of maximum population development, so that the number of grains per plant and grain weight per unit area are maximized to obtain high yield.
3. Reasonable fertilization: Buckwheat is a crop with relatively high fertilizer demand. To obtain high yield, sufficient fertilizer must be supplied. For arid poor land and high-cold mountain land, increasing fertilizer application, especially nitrogen and phosphate fertilizer, is the foundation for high buckwheat yield. Fertilization should be based mainly on base fertilizer, supplemented by seed fertilizer, and supplemented by topdressing, mainly organic fertilizer, supplemented by inorganic fertilizer. The application rate should be scientifically controlled according to the soil fertility basis, yield target, fertilizer quality, and climatic characteristics of planting.
3. Intertillage and weeding: Intertillage loosens the soil, increases soil permeability, stores water and preserves moisture, raises soil temperature, promotes seedling growth, and also eliminates weed damage. The number and timing of intertillage and weeding depend on the region, soil, seedling condition, and amount of weeds. The first intertillage and weeding is carried out when seedlings are 6-7 cm tall, combined with thinning and spacing of seedlings. The second intertillage is carried out before buckwheat rows close, combined with topdressing and earthing up, with an intertillage depth of 3-5 cm.
4. Irrigation and watering: Buckwheat is a typical dryland crop, but its drought resistance during growth is relatively weak, and it needs the most water during flowering and grain filling. Spring buckwheat in China is mostly planted on dry slopes lacking irrigation conditions, and buckwheat growth depends on natural precipitation. In spring buckwheat areas with irrigation conditions, if drought occurs during flowering and grain filling, water should be supplied to meet buckwheat's water requirements to ensure high yield.
5. Flowering stage management: Common buckwheat is a cross-pollinated crop and also has bisexual flowers. Its seed-setting rate is low, only 10-15%, which is the main factor in low yield. The way to improve the seed-setting rate of common buckwheat is to create pollination conditions. Common buckwheat is an insect-pollinated crop, and insects can increase its pollination and seed-setting rate. Bee-assisted pollination is carried out during the full flowering stage of buckwheat. 2-3 days before buckwheat flowering, place 1-3 bee hives per mu of buckwheat field.