Sowing
Method Pack before sowing to make the depth uniform and promote the seed coming into contact with the soil. This method is not advisable for heavy soil. In these conditions, the high moisture content of soil generally found in spring may cause difficulties during sowing. In soil with a surface crust, use a cultipacker instead of a smooth packer. Sow in rows 12 - 15 cm apart. Sowing depth is particularly important: in optimal conditions (well prepared soil, adequate moisture content), place the seed at a depth of 1 cm; when the surface layer is too dry, sow down to a maximum of 2 cm. The sowing rate should not exceed 4 - 5 Km/h. Time The best sowing conditions are in March. Early sowing increases the risk of late frosts, while delayed sowing may lead to water and heat stress, because of insufficient development of the root system. Sowing should be early in loose soil, which heats up more quickly, and later in heavier, colder soils. On hills, sowing should be later and may be delayed until the first half of April. Density For optimal plant density (300 - 400 plants/m2), seed quantities of between 30 and 40 kg/ha should be used in the year of establishment, using 30 kg/ha in better soil preparation, moisture and temperature conditions.
Fertilising
Two specific characteristics of alfalfa need to be considered: it is nitrogen-fixing and perennial. Nitrogen-fixing: alfalfa is a nitrogen-fixing plant. Due to symbiosis with Sinorhizobium meliloti, alfalfa can directly obtain nitrogen from the atmosphere for its own requirements. This means that alfalfa can be considered as self-sufficient as concerns nitrogen nutrition. The use of other elements, in particular phosphorous and potassium, may be more important. Perennial crop: Alfalfa is a perennial crop, which can produce for 4 - 5 years in the best management conditions. Today, as crop technologies are not focussed on this plant, its economic life is declining and alfalfa now rarely lasts longer than the third year. As it is a perennial crop, fertilising covers two aspects: - fertilising in the year of establishment; - fertilising in subsequent years.
FERTILISING during establishment
NITROGEN Despite high use rates, alfalfa does not require the administration of nitrogen and in fact this affects its duration. Phosphorous and potassium. Fertilisation is based on replenishing the used elements, plus administering amounts to enrich the soil, with ground fertilisation (fertilizers are buried during ploughing or additional work to prepare the soil, for example harrowing), and annual crop fertilising.
FERTILISATION in years after establishment
Phosphorous and Potassium If soil has a low content, alfalfa benefits from surface administration at the end of winter. Amounts to distribute must take into account annual use, calculated based on production and the amount used during establishment. Nitrogen Once planted, alfalfa does not require nitrogen, and this would thin the turf leading to the gradual disappearance of alfalfa and increase of weeds, reducing the economic duration of the meadow.