The Queen of Feed Crops

In EkoNiva, alfalfa is an essential component of a high-yield cow diet. This year, the farmers have planned a further increase of the acreage planted with this crop.







 

Willie Drews, PhD in Agronomy

Alfalfa, which is one of the oldest and one of the best feed crops with a high yield potential, is often referred to as the ‘Queen of Feed Crops’.

Alfalfa has been granted this title not only because it boosts the fodder protein content, but also because it improves the health of the animals. In diets with high corn-silage content, alfalfa hay ensures better fodder digestion and stimulates rumination due to the high content of crude fibre, which normally must constitute at least 18% of an animal's diet. Numerous research results show that feeding alfalfa hay leads to higher fodder intake and increases an animal's productivity. In addition, being rich in vitamins, carotene and micro-elements - alfalfa improves an animal's diet.

Owing to its well-developed root system, which penetrates the soil to the depth of over 4 meters, and to the accumulation of nitrogen by the root nodule bacteria, alfalfa is a perfect first crop.

Which factors concerning alfalfa cultivation need special attention?

Because of a high level of weed infestation, we recommend to plant alfalfa in summer without a cover crop. At the beginning of summer the fields should be weeded with the help of a glyphosate herbicide treatment and zero tillage, and alfalfa should be seeded between the15th and 30th of June.

The recommended seeding amount for pure alfalfa crops is 15-18 kg/hectare.

The optimum stand density is:

350–400 plants/m2 in the seeding year;
200–220 plants/m2 after the first wintering;
120–150 plants/m2 after the second wintering;
80–120 plants/m2 after the third wintering.

What mistakes are to be avoided in the process of alfalfa crop tending and use?

The first mowing must not be attempted before the blooming period. This phase is characterized by the maximum growth rate of the alfalfa root system (up to 5 cm. daily). All subsequent mowings must be done when the lower 2-3 leaves turn yellow, generally during the bud-forming phase, but not later than the beginning of the blooming period. Normally, alfalfa crops need 3-4 mowings per year. To ensure good wintering, it is necessary to observe a 7-week interval between the last two mowings. In this way, the plants will store enough food to last them through the winter. It is necessary to avoid close cutting of the plants, especially directly before wintering. Reproduction buds, which are normally found at the height of 10 cm. from the ground, must not be damaged during the mowing.

Is it better to cultivate alfalfa together with grasses or strictly by itself?

The recommended mixtures of alfalfa (70%) with fescue grass (25%) and timothy grass (5%) have a number of advantages:

The three-component mixtures of grasses with different periods of regrowth ensure stable yield throughout the whole vegetation period.

The grass components contribute to the production of quality silage (due to a better sugar-protein ratios) However, alfalfa mixtures have a number of shortcomings:

In many cases, the difference in the biological development of alfalfa and grasses impedes the selection of the optimum tending technique and harvest.

Because of its high competitive ability, alfalfa forces out the grass components and their share reduces, especially during dry conditions.

Considering the above, the selection of alfalfa-grass mixtures should be carried out individually in each particular case depending on such factors as climatic and soil conditions, intensity of land-use, etc.

Quite a few mistakes are made when preparing alfalfa hay. Alfalfa has a high protein-sugar ratio, which makes silaging somewhat slow and complicated.

40% of the dry matter is the only way to ensure the optimal fermentation in the haylage bunker. Because of the uneven moisture emission rates of the stalk and the leaves, it is necessary to use a moderate harvesting regime in order to reduce the losses of the leaf material. Haylage bunkers should be filled in even layers, each not more than 30 cm thick, to provide continuous and thorough compacting of the green material. The whole haylage preparing chain, from cutting alfalfa with harvesting machines to compacting hay with the help of heavy-duty tractors must be coordinated with regards to the final output. It is important to protect the bunker from mud, dust and debris, all of which impair fermentation. Alfalfa silaging can be improved by adding molasses or lactic acid bacteria preservatives. Compliance with the above recommendations for harvesting and haylaging will provide high quality alfalfa hay, which makes an ideal fodder for high-yielding cattle.

Figure 1: Summer-planted alfalfa needs weed-free, well-levelled and properly prepared soil. Figure 2: Only the first alfalfa regrowth needs mowing during the blooming period when the root depth growth rate reaches 5 cm a day. In subsequent mowings the cutting time is determined by the yellowing of the two bottom leaves. Figure 3: Alfalfa under-seedings planted together with wheat suffer due to the fierce competition for soil moisture and will grow to their full extent only in autumn.