The Latest Cultivation Techniques and Methods Tutorial for Alfalfa
Alfalfa is widely cultivated as forage and pasture grass across Eurasia and around the world. Its stems and leaves are tender and delicious. Whether fed green, ensiled, made into hay, processed into grass meal, or used in compound feed or mixed feed, it is the favorite of all kinds of livestock and poultry, and it is also the preferred green feed for the pig and poultry industries. Let us take a look at the cultivation techniques for alfalfa below!
Alfalfa Planting Time
1. Sowing period: The sowing period of alfalfa is generally divided into spring sowing, summer sowing, and autumn sowing. The determination of the sowing period mainly depends on temperature, moisture, the degree of weed damage, the purpose of use, existing conditions, and so on. Among these many factors, moisture is the decisive condition. In places with irrigation conditions, spring sowing, summer sowing, and autumn sowing are all possible.
2. Northern regions: In the northern regions of our country, spring is dry with little rain and high evaporation. Sowing in this season is not conducive to seedling emergence and seedling retention, and during spring sowing, weeds can easily harm alfalfa seedlings. Summer, however, has more rainfall, and at this time the temperature rises, with rain and heat in the same season, which is very favorable for seed germination and seedling growth. That is to say, from mid-June to the end of July is the best sowing period for alfalfa in northern regions.
3. Cold regions: In cold regions, in order to ensure that alfalfa can safely overwinter in the year of sowing, the sowing time generally must not be later than 40 days before the first frost.
4. Saline-alkali land: When planting alfalfa in saline-alkali land without irrigation conditions, even more attention must be paid to mastering the sowing time. The distribution pattern of salt in the soil of saline-alkali land changes with the seasons. Generally in spring, the salt in the soil is mostly distributed in the upper shallow soil layer, while in autumn it moves to the deeper soil. If spring sowing is followed by rain and then exposure to the scorching sun, a hard crust is very easily formed on the soil surface, making it difficult for alfalfa to emerge. Therefore, the best time to sow alfalfa on saline-alkali land is late summer and early autumn. At this time the rainy season has just passed, the salt in the soil has been leached down, and the soil moisture content is also relatively sufficient, which is very favorable for seedling emergence, and the seedling retention rate is also relatively high.
Alfalfa Cultivation Techniques
1. Sowing: In most regions, drilling is the main method, with a row spacing of 30 cm, which is conducive to ventilation, light penetration, and field management. The sowing rate is generally about 1 kg per mu; seed-production fields should use a little less, and saline-alkali land may appropriately use a little more. If the sowing rate is too large, the seedlings will be thin and weak. Sowing depth is the key to affecting the quality of seedling emergence. Generally, sowing too deep is a problem; the best depth is 0.5-1 cm.
2. Weeding: Clearing weeds is one of the main contents of alfalfa field management. One is during the seedling stage, and the other is after summer harvest. Because in these two periods alfalfa has weaker growth vigor and is more seriously harmed by weeds, especially after summer harvest, when water and heat occur together and weeds grow quickly. No matter what method is adopted, it must be done promptly and according to standard. Herbicides must be chosen carefully to avoid causing livestock poisoning.
3. Drainage and irrigation: Alfalfa consumes a large amount of water; every 1 kg of dry matter produced requires 800 liters of water. Watering is needed before winter, after green-up, and during drought. In coastal and low-lying areas, attention must be paid to drainage during the rainy season; alfalfa will die if submerged for 24 hours.
4. Disease prevention: During the growth period of alfalfa, once pests and diseases occur, they must be controlled promptly, otherwise yield and quality will be affected. Generally, fenitrothion, dimethoate, fenvalerate, and others are sprayed to control pests. If rust, brown spot, or downy mildew occurs, fungicides such as carbendazim and thiophanate are used for control.
5. Harvesting: Generally, harvesting begins at the early flowering stage, that is, when 1/10 of the flowers have bloomed, and at the latest it must not exceed the full flowering stage. Number of harvests and stubble height: Alfalfa is a perennial plant with strong regrowth ability and can be harvested 3-4 times per year. The last harvest should not be too late, otherwise it will affect nutrient accumulation and be unfavorable for safe overwintering. Generally, a growth period of 40-50 days should be left after harvest. The suitable stubble height is 5 cm.
The Cultivation Value of Alfalfa
1. High grass yield: The grass yield of alfalfa varies greatly depending on the number of years of growth and natural conditions. The fresh grass yield per mu 2-5 years after sowing is generally 2000-4000 kg, and the hay yield is 500-800 kg. In areas with better water and heat conditions, the hay yield per mu can reach 733-800 kg. In arid and low-temperature areas, the hay yield per mu is 400-730 kg. In irrigated areas of desert oases, the hay yield per mu is 800-1000 kg.
2. Long years of use: Alfalfa can live as long as 30 years, and the period of field cultivation and use can be as long as about 7-10 years. However, after entering the high-yield period, its yield declines as age increases.
3. Strong regrowth ability: Alfalfa has very strong regrowth ability and can quickly recover its vitality after mowing. Generally, it can be mowed 2-4 times per year, and in some cases 5-6 times.
4. Strong palatability: The stems and leaves of alfalfa are tender and delicious. Whether fed green, ensiled, made into hay, processed into grass meal, or used in compound feed or mixed feed, it is the favorite of all kinds of livestock and poultry, and it is also the preferred green feed for the pig and poultry industries.
5. Rich nutrition: The stems and leaves of alfalfa contain abundant protein, minerals, multiple vitamins, and carotene, especially with higher content in the leaves. When alfalfa is fresh and tender, the leaves account for about 50% of the weight of the whole plant, the crude protein content in the leaves is 1-1.5 times higher than that in the stems, and the crude fiber content is less than half that of the stems. On the same area of land, the digestible total nutrients of alfalfa are 2 times those of gramineous forage grass, the digestible protein is 2.5 times, and the minerals are 6 times.
6. Fertilizing the field and increasing yield: The well-developed root system of alfalfa can provide a large amount of organic matter to the soil, and can absorb calcium from deep soil layers, decompose phosphates, leave them in the plow layer, and through decomposition form organic colloids, which can cause the soil to form stable aggregates and improve soil physical and chemical properties. Root nodules can fix nitrogen from the atmosphere and increase soil fertility. In alfalfa grassland 2-4 years old, the fresh root weight per mu can reach 1335-2670 kg, and the root stubble per mu contains about 15 kg of nitrogen, 2.3 kg of total phosphorus, and 6 kg of total potassium. Each mu can fix 18 kg of nitrogen from the air each year, equivalent to 55 kg of ammonium nitrate. Alfalfa stubble land can allow the following crop to remain stable and high-yielding for three years without fertilization. The yield increase range is usually 30%-50%, and in high cases can reach more than 1 time. As the farming proverb says: “One mu of alfalfa is three mu of field, and after three consecutive years of planting it still has strength.”
7. Soil and water conservation: Alfalfa has luxuriant branches and leaves and a high degree of ground cover. Forty days after green-up of second-year alfalfa, the coverage can reach 95%. It is also a perennial deep-rooted type, and its role in improving soil physical and chemical properties, increasing water permeability, blocking runoff, preventing erosion, maintaining slope surfaces, and reducing soil and water loss is very significant. According to measurements: on sloping land, compared with planting alfalfa, planting ordinary crops loses 16 times more water and 9 times more soil per mu each year.
8. Honey-source plant: Alfalfa is a strictly cross-pollinated plant, often relying on external mechanical force and insects collecting nectar to spring open the tightly closed keel petals for pollination. The flowering period lasts 40-60 days. Placing bees in the field during the flowering period can greatly increase honey production and also increase alfalfa seed yield.