Alfalfa

Technical Regulations for High-yield Cultivation of Alfalfa

High-yield and high-quality alfalfa lays the foundation for the benefit of raising dairy cows and other livestock. The lush, dense plants are the key to high yield of alfalfa, which requires correct sowing methods, seedbeds and environmental conditions that are conducive to seed germination. The key factors that determine whether high-density and lush plants can be obtained are: suitable soil pH and fertility, well-prepared seed beds, adjusting the rotation sequence to avoid the influence of pesticide residues in the previous crop, selecting good varieties, timely sowing, and precise adjustment of the sowing amount and the seeding mechanism. Sowing deep, can control the damage of weeds and pests.

Preparation before planting

1. Plot selection

It has the potential to develop a deep root system, and is most suitable for planting in deep soil plots, so that the root system can obtain water and nutrients from a wide range of soil. In the case of soil without a restricted layer, the root system of Baizhu can penetrate 4-5 meters underground, so it has a strong ability to withstand early dryness. Plots with shallow hard layers, rock layers or high groundwater levels will restrict root growth and are not suitable for planting. The planting site requires that there is no restriction layer that restricts the growth of the root system below the ground surface 0.9-1 meters. In early dry areas, it is difficult to ensure sufficient water for good growth or survival of plants if the soil depth is less than 0.9 meters. The requirements for soil texture are relatively broad, and medium-textured soils such as soil, silt sand and sandy soil are the best; light soils such as coarse sand are prone to dry early, unless they have irrigation conditions, they are not suitable for planting; clays are of the same weight. Quality soil is often too high in water content, which is not conducive to the healthy growth of roots. The stones on the surface of the soil can be cleaned out or fed into the ground with stones during the first planting. The ground surface of the planting area must be relatively flat and well-drained. Only first on the soil with good drainage ability can obtain the highest yield and lasting utilization. Planting in poorly drained fields has poor persistence, because the pathogens that cause root rot are wet; the density of the soil in the country is very high, which will cause the first plants to die continuously. The root system is more sensitive to anoxic environment, and the soil will die after reaching the highest field water holding capacity or being submerged for a certain period of time. Generally, a 1-meter-deep drainage ditch is dug every 80 meters to ensure that the accumulated water is discharged in time. The drainage capacity of the soil under the topsoil, gray and variegated soils have poor drainage, and brown or red soils have good drainage.

2. Improve the soil with stone and fertilizer

Lime and fertility adjustment: Determining the amount of fertilization based on the results of soil testing is an important part of planting high-yield and long-lasting land. The fertilization plan should be made based on soil pH, soil fertility and planting history. Plowed land

Blocks need to take soil samples from the cultivated layer to represent the condition of the seed bed. Soil acidity is an important factor limiting high yields because it affects the absorption of nutrients. Lime can adjust the acidity of the soil and provide calcium or magnesium. The proper pH value (6.5-7.0) can not only enhance the absorption of nutrient elements, promote the growth of beneficial microorganisms, but also reduce the harm of harmful elements such as aluminum and manganese. It is best to apply lime and plow 6-12 months before planting to make it act on the cultivated layer.

Apply enough farmyard manure as base fertilizer before sowing, 1.5 tons/mu; if farmyard manure is insufficient, apply 20kg/mu, or use special fertilizer 45-55/mu.

Before sowing, apply sufficient farmyard manure as base fertilizer, 15 tons/mu; if farmyard manure is insufficient, apply a certain amount of compound fertilizer, 15-20kg/mu, or use special fertilizer 45-55kg/mu.

pH value 4.5-5.0, 150kg lime per mu; pH value 5.0-5.5, 120kg lime per mu; pH 5.5-6.0, 80kg lime per mu; pH 6.0-6.5, 50kg lime per mu; planting Before applying manure or chemical fertilizers can improve soil fertility. Phosphorus content has the greatest impact on seedlings. In low-phosphorus soils, phosphate fertilizer can promote the rapid growth of roots and the successful establishment of seedlings. The demand for pressed fertilizer for seedlings is relatively low, but the pressed fertilizer is very important for the high yield and regeneration of the well-established land. Should try to avoid direct contact between seeds and fertilizers, so as not to affect seed germination.

When soil N content is low (less than 15ppm) or soil organic matter content is less than 1.5%, nitrogen fertilizer can be applied during planting to increase yield. When the soil nitrogen content is higher than 15 ppm and the soil environment is suitable for root nodule gas fixation (soil pH 6.2-7.5 and soil nitrogen-fixing bacteria are rich), using nitrogen fertilizer as a base fertilizer will not only increase yield, but also inhibit the growth of rhizobia, Affect nitrogen fixation.

3. Weed control

Seedling weed control plan should be formulated and implemented before planting. When formulating prevention and control measures, the residual effects of herbicides used in previous crops should be taken into consideration. If the previous crop is corn, the triazine herbicide residues are often encountered during planting. If lime is applied before planting, the harm of the residual herbicides will be aggravated.

Controlling weeds is a key part of spring planting. With the competition of a large number of weeds and the dry and hot environment, it is difficult to establish successfully without weed control measures. There are relatively few alfalfa weeds in autumn. In traditional tillage and sowing, pre-emergence herbicides should be used to control weed competition before planting. If there are still weeds after the emergence of Hundred Centipede, post-emergence herbicides need to be applied.

In Henan, you can choose to plant a hundred seeds in autumn (before September 10), and seal the land once after leveling; if weeds are severe in the seedling stage, you can choose Cludojing herbicide for weeding.

4. Alfalfa self-toxicity

In areas where the soil is suitable for growing alfalfa and is well managed, alfalfa can be used for 5 years, and sometimes even 7 to 10 years can maintain a certain yield. It is best not to plant alfalfa immediately after the old alfalfa is harvested, because alfalfa will produce harmful chemicals and harm the new seedlings. If the alfalfa is planted continuously or the interval is too short, the survival rate of newly planted alfalfa is low. Even if the plants that survive and grow, although they seem to be no problem on the surface, the later production will continue to decrease. Because alfalfa is self-toxic, it is difficult to increase the density of alfalfa through supplementary sowing. Existing plants will inhibit the emergence and growth of seedlings within a radius of 20 cm around it. Block seedlings will be suppressed. Studies have shown that one year of alfalfa rotation interval on the same plot is sufficient.

5. Variety selection

The selection of alfalfa varieties is very important because it will affect the yield of the alfalfa throughout the production cycle. In a specific area, many alfalfa varieties may behave similarly, and it is difficult to make a clear choice. Which variety to choose depends on your own situation and the conditions of different plots. The price of seeds is often the main consideration when choosing a variety. However, the long-term use of cheaper old varieties is more expensive than the improved new varieties with higher prices. The improved characteristics of new varieties will bring higher value returns to enterprises. If the planting cost is allocated to each production year, the use life is the primary factor considered in the selection of varieties.

It is very important to choose high-quality seeds. Seeds with high purity and superior quality should be selected as much as possible. Many new varieties perform better than low-priced old varieties in terms of yield, disease resistance, and insect resistance, and have higher economic benefits for planting. It is necessary to choose alfalfa varieties according to the planting location and purpose. Some varieties are suitable for producing hay, some are suitable for grazing, and some are used for both cutting.

Alfalfa is divided into fall dormancy levels. Varieties with fall dormancy levels 1-3 have good overwintering performance and are suitable for planting in northern regions. Varieties with fall dormancy levels 8-9 are not dormant in winter and are only suitable for planting in southern regions with warm winters.

Disease resistance is also an important reference indicator when selecting alfalfa varieties. Varieties resistant to root rot (such as Phytophthora root rot) can be planted in poorly drained or occasionally flooded plots, because these plots are often better than well-drained plots. The disease of the plot is more serious.

2. Seeding guidance

1. Sowing in time

The two most suitable time for planting alfalfa are spring and autumn, but there are big differences in different regions. The best planting time depends on the specific local conditions. Spring sowing is generally used in cold climate areas, but if sowing too early, the cold and wet soil will cause problems such as low germination rate, dead seedlings caused by fungal diseases, and weak seedlings. On the other hand, planting too late in spring is prone to failure of establishment due to high temperature, dryness, and weed competition.

It is better to sown in late summer in warmer climates, and alfalfa seedlings can grow in a cooler environment. The advantage of planting in late summer and early autumn is that there is less competition for weeds, which reduces the workload of the busy farming period in spring, the soil is drier and harder to compact, and the incidence of fusarium wilt is reduced. At the end of summer and early autumn, two points should be paid attention to. One needs enough water, and the other is to ensure that there is enough accumulated temperature before the frost. Therefore, the final sowing time is 6 weeks before the lethal frost. This means that most of the northern regions need to complete planting before August, while in some areas of the south and southwest, planting can be done in November.

2. Seeding depth

The cotyledons of alfalfa seeds are small, and the energy for germination is very small, so the appropriate seeding depth is very important. Generally, the seeding depth is 1.5-2.0cm and the row spacing is 15-20cm. A compact seed bed helps the seeding depth to be moderate and the seeds fully contact the corner empty soil, which is the key to successful seeding. The seeds should be covered with enough soil to provide the water needed for germination, but not too deep so that the seedlings will not emerge from the soil.

3. Seed-soil contact

Alfalfa seeds must absorb at least water equivalent to their own weight to start germination, and water generally enters the seeds from the surrounding soil. The full contact of the seed with the soil can ensure that the seed quickly obtains water. Due to soil conditions (too much or too much soil

If the seeds and soil cannot be closely connected to the corners due to looseness, the germination time of the seeds is often longer and the germination is not neat. Lead pressure after sowing can enhance the gap between the seed and the soil.

4. Seeding amount

It is normal that less than one-third of the sown seeds can emerge, and half of the seedlings are generally left after a year. It is about 1.5 kg/mu in most areas of my country, but the sowing amount of coated seeds can be increased to 2.0 kg/mu.

Three, sowing method

According to different soil cultivation methods, sowing can be roughly divided into land preparation sowing and no-tillage sowing.

1. Soil preparation for sowing

The land needs to be plowed before planting. The purpose of plowing the soil is to loosen the soil, remove vegetation residues, and purge the seeds of ground weeds.

Underground, mix the soil with lime or fertilizer, and prepare a flat surface for future harvest. Plowing helps lime and fertilizer act on the rhizosphere soil of alfalfa, helps alfalfa emerge as soon as possible, and helps pre-emergence herbicides to reduce weed damage. The prepared seedbed should be flat enough to facilitate the field operations of harvesters and other machinery multiple times a year. After raking the ground for the last time, you can press the ground with a ballast or a circle to ensure that the ground is firm and flat. Adults walking on the seedbed can judge whether the hardness of the seedbed is appropriate. The seedbed is compact enough, and the footprint of an adult is about 2.5 cm deep. If the seed bed is too soft, it will cause the seeding to be too deep, the seed bed is too tight or the soil particles are too large, it is difficult for the seeds to fully contact with the soil, which is not conducive to seed germination.

2. Ditching to suppress sowing

The ditching and suppressing planter has two sets of corrugated rollers, and the seeding box is between them. The first set of rollers makes small wavy trenches, and then the seed box discharges the seeds. After the second roller rolls, the soil covers the seeds and compacts the soil around the seeds. This kind of planter is easy to control the planting depth and make the soil and the seeds fully contact. For many years, this planter has been mainly used for planting alfalfa on plowed land.

1. The principle of base selection

1. Choose a land with high terrain, flat land, good drainage, deep and fertile soil, which is good for high-quality and high-yield grass.

2. The grassroots organization team is united, the masses have a strong sense of science and technology, and there are villages that are urgently required to develop mechanization.

3. Suitable for mechanized operation and convenient transportation. Inappropriate

Choose soils that are firm, sticky, heavy, excessively humid, and have high groundwater levels and poor drainage. The salt content should be less than 0.3%.

2. Preparation before broadcasting

1. Site preparation

Mainly to clean the ground (weeding, stubble removal), pine nut, fertilizer, and evenly mixed, and level the ground. The suitable moisture content is about 20%. If the soil moisture content is not good, it should be watered once and then the soil should be prepared. At the same time, deep application of base fertilizer is necessary. It is not advisable to apply more compressed fertilizer in the year of planting. It can be used as base fertilizer in combination with soil preparation. The amount of fertilizer applied is 225kg/hm2. When planting in weedy soil, first eliminate the weeds, then deep plowing, and then combine with the flat ground spraying trifluralin to treat the weeds, while spraying and mixing the soil to a depth of 5cm, and then sowing after 7 days. The main procedures of land preparation are: heavy harrowing to eliminate stubble, fertilization → deep plowing and turning → light harrowing and diagonal rake leveling → suppression

2. Seed variety selection and treatment

Choose good varieties with resistance to premature and high yield, such as American alfalfa, the sweet clover content should not exceed 2%, the clarity should be more than 95%, and the germination rate should be more than 90%.

Three, sowing

1. Selection of sowing time

Alfalfa can be sown in spring, summer and autumn. Beijing spring is dry and less rainy. It is suitable for sowing in late summer and early autumn. At this time, the seedlings are good, the cost is low and easy to manage, and the autumn sowing should be early. If irrigation conditions are available, sowing can also be done in spring when the ground temperature is stable above 5°C, but weeds must be prevented. Seedlings are broadcast quickly in summer, and attention should be paid to the prevention and control of weeds and pests.

2. Seeding method

In order to facilitate weeding, fertilization, and irrigation, drill seeding is generally used, using 2BJ F-9 type precision seeder or modified grain seeder, and at the same time as seeding, 30kg per hectare can be applied as seed fertilizer.

(1) Line spacing: 15-20cm.

(2) Sowing: 1.5-2.0kg per mu.

(3) Sowing depth: 0.5-2cm, clay soil should be slightly shallower, sandy soil can be slightly deeper.

(4) It should be suppressed in time after broadcasting.

Four, field management

1. Weed control:

Alfalfa should be cultivated and weeded in time during the growth period. The seedlings grow slowly in the first year and are vulnerable to weeds. Special attention should be paid to weeding during this period.

2. Irrigation and drainage:

When the weather is dry, water in time. Generally, water when it is green and after each harvest. However, too much water or too much sediment in the seedling period is not good for seedlings. Alfalfa is not tolerant to flooding, and there must be water in the soil in time. Drain.

3. Pest control:

Insect pests mainly include aphids, ants, parasitic dodder and so on. Generally, pesticide control and early harvesting are used to prevent and control insect pests, but the fundamental control is to choose pest-resistant varieties.