Key points needing attention in alfalfa seed breeding

Many people are not familiar with clover, what it is. In fact, it is a relatively common clover, it is widely planted in our country, mainly used for lawn construction and environmental beautification, or can be used as livestock feed, so its use is still very wide.

What is alfalfa?

Medicago is a generic term for alfalfa plants, commonly known as "clover"(clover can also be called other clover plants). It's a perennial flowering plant. One of the most famous is alfalfa (Medicago sativa), which is used as pasture. It's livestock feed. Alfalfa to "the king of grass" known, not only high yield, but also excellent grass quality, all kinds of livestock are fond of eating. At present, the planting area of alfalfa in China is about 1.33 million hm ^2. With the development of commodity economy, alfalfa industrialization scale has developed rapidly in recent years, and alfalfa planting area is expanding.

The main value of alfalfa

Clover has four special values:

1. When the stem and leaf is about 30 cm in spring, it is a first-class vegetable. It is a typical green food. It sells well every year in the vegetable market everywhere. It becomes popular at the age of the year. It often eats its vegetables and feels comfortable and relaxed.

2. The whole grass is used as medicine. It is cut once in May and June every year, and then cut once every one and a half months or two months. It is dried for later use.

3. At the same time, it is also a good pasture. It is 50 cm to 90 cm high. Cattle, horses, sheep, pigs and chickens like to eat it. It grows fast, does not need feeding, does not get sick, and its fur looks smooth and shiny. After cutting in late autumn, it is dried and is a good fodder grass for winter livestock, with a yield of 1500-2000 kg per mu.

4, alfalfa is also a good green barrier, it has tenacious vitality, is a fine variety of sand prevention and sand-fixing greening mountain areas and poor ridge areas, lush every year, to add an infinite beautiful scenic spot to nature.

The main points needing attention in alfalfa breeding

1. Land selection, soil preparation and sowing with sufficient moisture. Select flat, fertile plots for seed fields. Because alfalfa seeds are small and have poor topsoil ability, it must be carefully prepared before sowing, and enough moisture must be ensured for planting. Sowing methods can be used to drill or broadcast. Sowing depth of 2 cm is appropriate. 2. Apply sufficient basal fertilizer. Alfalfa for perennial, in addition to breeding, a year can also harvest 2 crops. Therefore, there must be an adequate supply of nutrients. Before soil preparation, it is necessary to apply sufficient base fertilizer. Generally, 2000-3000 kg organic fertilizer and 50-100 kg calcium superphosphate shall be applied per mu. Enter flowering period, should be watered in time, and with the water urea 10 kg, boron fertilizer 0.5 kg. Third, control the field density. After 1-2 years of alfalfa growth, the density is very large, the ventilation and light transmission in the middle and lower parts are very poor, which is not conducive to pollination and seed maturity. When alfalfa returns to green in spring, iron harrow can be used for 2-3 times depending on the density, harrowing part of plants and tillers to improve ventilation and light transmission. Generally, it can increase production by more than 30%.

4. Artificial pollination. Alfalfa is a cross-pollinated crop, which needs insect pollination. It can be released at flowering stage to help alfalfa pollinate and improve seed setting rate. 5. Timely harvest. Alfalfa florescence is longer, seed maturity is inconsistent, harvest late makes lower seed fall off, should be harvested in time when the middle and lower pods turn brown. 6. Do a good job in seed treatment. The newly harvested seeds of that year have a dormancy period of 1-2 months, but the seed harvest period is generally in late July, which is also the sowing season. If seeds are urgently needed, they can be frozen at a low temperature below-5~-10℃ for 48 hours, then exposed to sunlight for 12 hours, and finally broken by light vehicle rolling. After the above treatment, the germination rate of grapes can reach 75-80%.

The method of sowing alfalfa

1. Seed treatment. Seeds should be cleaned and dried to make the purity of seeds reach 90%. Pesticides, herbicides, rhizobia and fertilizers can be mixed in proportion before sowing to avoid diseases and insect pests at seedling stage. Seed dressing with rhizobia and other bacterial fertilizers (1 kg rhizobia can be mixed with 10 kg seeds) can increase yield by more than 20%.

2. Sowing time. Seed germination requires two conditions: one is that the ground temperature is 5℃--6℃, and the optimum temperature is within 25℃; the other is that more water is needed. Spring and autumn sowing have the best effect. Saline-alkali plots are not suitable for spring sowing, which is easy to cause dead seedlings.

① Spring sowing. Sowing in spring should be done before Qingming Festival (end of March-early April). At this time, the soil humidity is high, and it is easy to obtain whole seedlings. Late spring drought, seedling difficulties.

2 Summer sowing. Usually in June-July. This period of high temperature, rain more, seedlings grow fast, but weeds are also more, diseases and insect pests occur frequently.

③ Autumn sowing. Usually in late August-early September. After rainy season, soil moisture is good, temperature is suitable, weed growth slows down, and seeding success rate is the highest. No matter what kind of sowing method is used, it should be combined with rain or irrigation, and it is best after rain. After sowing, it should be suppressed to facilitate the germination of seeds.

3. Sowing method. Generally used drill, row spacing 30 cm--40 cm. At present, the popularization of dense ridge and sparse planting technology, row spacing 15 cm-20 cm, not only increases coverage, improves yield, but also facilitates field management.

4. Sowing quantity. Select imported seeds, 0.75 kg--1.0 kg per mu; domestic seeds, 1.0 kg--1.5 kg per mu. The amount of saline-alkali land should be increased appropriately. In arid areas, due to lack of water, sowing should not be too dense. Use a low limit when dry and a high limit when wet.

5. Sowing depth. Alfalfa seeds are very small, sowing depth depends on the type of soil, wet soil shallow sowing, dry soil slightly deeper. Generally 2 cm-3 cm, sandy soil 3 cm-4 cm, clay 2 cm.

6) Repression. If the soil is loose, first suppress it before sowing to facilitate the control of depth; suppress it again after sowing to help preserve moisture.

It can be seen that alfalfa can not only beautify the environment, but also have a great ornamental effect. After drying, it can also be used as a medicinal material. It can also play a certain conditioning role in some diseases of the human body. Therefore, don't underestimate this small clover. In fact, it can release great effects.