Grown as a high-quality forage crop around the world, alfalfa provides nitrogen fixation, increased soil organic matter, and many other benefits. As a result of the plant’s ability to produce two or more harvests per year for several years following initial planting, growing alfalfa results in substantial economic gains. However, realizing the full potential of the crop requires proper planting, management, and care throughout the growing period. To find a happy medium between yield and quality, the timing of your alfalfa harvesting is also crucial. Improved efficiency in sowing, fieldwork, and harvesting planning thanks to the advancement in agricultural technology has led to higher yields and greater revenues from farming alfalfa.
Alfalfa (Medicago sativa), or lucerne, is a perennial feed crop yielding the most in its second year. It can grow continuously for 3–4 years in regions with mild winters and 6–9 years in regions with cold winters. It is also cultivated as a short-season plant in crop rotations.
Alfalfa is an important forage crop grown across the world for hay silage and grazing. Proper planting depth is crucial for good emergence and stand establishment of alfalfa. In this article, we will discuss optimal planting depths for alfalfa and key considerations for successful planting.
Optimal Planting Depth
The ideal planting depth for alfalfa seeds ranges from 1⁄4 to 1 inch, depending on soil texture Here are some general guidelines
- Heavy soils (clay, clay loam): 1⁄4 to 1⁄2 inch deep
- Medium soils (silt loam, loam): 1⁄2 to 3⁄4 inch deep
- Light soils (sandy loam, sand): 3⁄4 to 1 inch deep
In heavier soils, planting too deep can lead to poor emergence. In lighter soils, planting too shallow risks drying out. Adjust depth based on soil type for best results.
When planting, check seed depth regularly to ensure proper placement. You should see around 10% of seeds on the surface. If not, adjust planter settings. Using a depth gauge can help achieve optimal depth.
Why Proper Depth Matters
Planting at the right depth is important because
-
It ensures good seed-to-soil contact needed for germination and emergence.
-
It prevents seedling death from shallow planting in light soils or rotting from deep planting in heavy soils.
-
It allows the young root system to easily access moisture and nutrients near the surface.
-
It gives seedlings the best start before facing weather stresses and competition.
Other Key Tips
In addition to depth, consider these tips for successful planting:
-
Prepare seedbed by tilling to depth of 12-15 inches for drainage and removing weeds/rocks.
-
Fertilize according to soil test recommendations to ensure good fertility.
-
Plant recommended varieties suited to local climate and conditions.
-
Use quality seed with fresh inoculant to nodulate roots for nitrogen fixation.
-
Drill seeding for best placement but broadcast if needed. Increase rates 10-15% for broadcasting.
-
Seed oats as nurse crop at 1-2 bu/acre to prevent erosion without competing too much.
-
Control weeds before and after seeding to prevent competition in establishing stand.
-
Irrigate to keep top 2 inches moist for 10-14 days after planting for good germination and emergence.
Planting Dates
Timing planting properly is also key. Ideal planting dates for alfalfa are:
-
Spring – 4-6 weeks before last expected spring frost.
-
Summer – Not recommended due to heat/drought stress on new seedlings.
-
Fall – At least 6 weeks before first expected fall frost for root establishment.
Adjust dates to fit your local climate and weather conditions. Avoid frost periods damaging tender seedlings.
Following the guidelines for depth, soil prep, variety selection, and planting date will set your alfalfa planting up for success. Adapt practices to your specific soil and climate. Monitor and adjust depth settings while seeding. Proper depth along with good fertility, weed control, and moisture will establish thick, uniform alfalfa stands.
Proper Care For Alfalfa
Proper care is essential for ensuring the longevity and productivity of lucerne stands. Nutrient management and pest control are cornerstones of this care. Last but not least, growing healthy stands entails rotating crops at the right time.
Nitrogen (N), which a plant produces on its own, phosphorus (P), and potassium (K) are the three vital nutrients for growing lucerne. Vegetative growth requires N, whereas root growth requires P. Potassium strengthens plant defenses, increasing crop resistance to environmental stresses and diseases.
The standard alfalfa fertilization recommendations are to apply 18–22 lb/acre (20–25 kg/ha) of phosphorus and 170–218 lb/acre (190–245 kg/ha) of potassium fertilizer. For greater confidence in fertilizer distribution across a field, use the Productivity maps provided by EOSDA Crop Monitoring. Dividing the field into zones based on productivity can help you save money on soil testing while getting the most out of your K and P fertilizer applications for alfalfa.
Variable rate P2O5 fertilizer application based on the Productivity map.
Companion Planting Vs. Clear Planting
Growing oats or another companion crops (corn or wheat) with lucerne to control weeds, mitigate soil erosion, and give extra yields. Yet, in most cases, growing alfalfa by itself is more fruitful since companion crops typically reduce the alfalfa’s first-year output as well as its stand density. On erodible soil, lucerne may not even germinate without a companion crop. Therefore, the benefits of companion cropping vs. clear planting are location- and objective-dependent.
Fields analytics tool with access to high-resolution satellite s for remote problem areas identification!
Impact of Seeding Depth on Alfalfa Emergence
FAQ
How deep does alfalfa need to be planted?
How far down do alfalfa roots grow?
What is the best month to plant alfalfa?
What is the best soil for alfalfa?
How deep should alfalfa seed be planted?
First, it’s important to understand the ideal depth for planting alfalfa seed. In dry climates, alfalfa seed should be planted to a depth of 1/4 to 1/2 inch. This ensures that the seed has enough moisture to germinate and grow, while also shielding it from the sun and wind. Next, gardeners should prepare the soil for planting.
How do you plant alfalfa seeds?
Once the alfalfa seeds are lightly incorporated in the soil, you can gently pat down the soil to ensure that the alfalfa seeds are planted at the correct depth. It is important to water the alfalfa seeds after planting. The soil should be kept moist, but not saturated, until the alfalfa seeds have germinated and the seedlings are established.
What soil should alfalfa grow in?
Although alfalfa soil requirements are not too strict, the plant grows best in deep, well-drained, loamy soil. Soil pH for alfalfa should be between 6.5 and 7.0, as this allows for symbiotic nitrogen fixation. By adding lime, you can bring the acidic soil’s pH up to a desirable level.
What should I know before planting alfalfa?
Before you begin the process of planting alfalfa, there are some things you should know. The first is that the success of your crops depends on the soil. The best soil to plant alfalfa in is well-drained soil located on level ground.