ESTABLISHING, GROWING AND CULTIVATING LUCERNE CROP
Lucerne was one of the first forage crops to be domesticated. It is used as multi-purpose forage, able to be used for both grazing and conservation (hay, silage, meal and forage dehydration). It can be sown as a pure stand or in mixtures with both temperate and tropical grasses. The seed can also be used for human consumption as sprouts.
There are numerous benefits of growing lucerne and if done well, it significantly reduces the need to supplement dairy rations with the costly commercial concentrates. Lucerne is not the only legume that can be incorporated in the pasture profile. There are many legume species commonly used as pasture or fodder but when compared, lucerne comes out with gleaming attributes. It has very high protein content (15 – 25%), highly digestible (60 – 75%) and has high levels of energy (ME 8 – 11MJ/kg DM). It comprises about 50% of all protein supplements in livestock feeds. It can be pelleted and stored in bags
It is usually considered the ‘King of Fodders’ because it grows throughout the year if soil moisture is available. Protein and calcium levels are high, relative to other fodders, but metabolizable energy (ME) and phosphorus levels are low. ME and phosphorus levels are good in young growth but drop rapidly as the foliage matures. Intake of digestible nutrients by livestock is higher than for most other forages. Level of fibrous tissue is low and this allows rapid passage through the rumen. Lucerne foliage is highly digestible.
CHOOSING THE RIGHT CULTIVAR
The choice of cultivar is determined by the climate and soil type. Consult an expert in your region to find a suitable cultivar for your requirements. Whichever cultivar you choose, plant only certified seed. This might be expensive, but it is the only way to ensure a profitable yield.
Inoculate the seed with rhizobium bacteria before planting, carefully following the directions on the packaging to ensure that the correct amount is used.
Select a site 12 months in advance of sowing and soil test for pH and nutrient levels.
Lucerne has limited tolerance to soil acidity. Soils that have a Ph of 4.8-5.2 are at the lowest range suitable for the best growth and persistence of the lucerne and rhizobia. Ideally, these pH levels need to be corrected with the use of agricultural lime.
Lucerne is best established on:
- upper and mid slope sites
- well drained duplex soils
- areas which are at risk to groundwater rise
- coloured sands, loamy sands or finer textured soils.
APPLICATION OF MANURE
Application of manure helps in the recycle of soil nutrients. The replenished soil nutrients secure fast growth and an increase in high quality fodder production. It is recommended that, manure should be applied on land used for growing forage trees during rainy season, If applied in dry period it should be well watered to improve its utilisation by the plants.
SITE PREPARATION AND WEED CONTROL
Sowing should not start until good weed control is achieved. This is because seedling lucerne is a poor competitor against weeds, effective herbicide options are limited and the seedling develops slowly and may take up to eight weeks before herbicides can be safely used.
Thorough weed control prior to sowing is essential in the establishment year. The importance of weed control increases as growing season length shortens. Spring and summer weeds must be controlled before sowing as they are difficult to control in seedling lucerne and will compete for water during the critical first summer.
Lucerne is best established after a crop that has reduced weed burden. If sown after pasture, weed reduction by grazing and winter pasture topping (hay freezing) with glyphosate
- Rainfall: >325mm.
- Drought tolerance: very high.
- Frost tolerance: moderate to high.
- Soil type: grows well on a wide range of well drained soils including deep loams, deep yellow and brown sands, loamy sands over clay or gravel, deep sandy duplex soils and uniform clays. It is not suited to deep pale sands and shallow soils.
- Soil fertility requirements: moderate to high.
- Soil pH (CaCl2): 4.8 to 8.0 in the top 30 centimeters (cm) — note optimum pH >5.5.
- Aluminum tolerance: low.
- Waterlogging tolerance: low.
- Salt tolerance: moderately low (if not waterlogged).
- Nutritive value: digestibility of 65-72% whole plant, 75-80% leaves and 45-70cm stems. Metabolisable energy of 8-11 MJ/kg DM and crude protein (12-24%).
Incorporating lucerne in a dairy ration will have huge benefits that include;
High quality feed: According to its stage of growth, the protein content in lucerne ranges from 15-22 per cent. Grasses usually contain way less than 12 per cent crude protein yet dairy animals require between 16-20 per cent.
It is also rich in vitamins and minerals, and if cut at the early flowering stage, it supplies a good blend of energy and fibre. The roots are known to penetrate to a depth of 3m, thus enabling the plant to draw moisture and minerals from a considerable depth.
Cheap protein: An average-sized bale of lucerne currently costs about Sh450, which translates to around Sh23 a kilo. On the other hand, a kilo of good quality dairy meal may cost up to Sh48.
Assuming that a cow is provided with good quality grass and lucerne, the amount of supplementary dairy meal will definitely be reduced in a dairy cow’s ration.
Flexibility of use: Apart from being utilised in wilted form upon harvesting, lucerne can easily be conserved in either hay or silage form and, therefore, be well-stored during seasons of plenty.
Lucerne should never be fed fresh as it will cause bloat to your dairy animals.
Soil fertility improvement: Lucerne is a legume that is able to fix atmospheric nitrogen into the soil, thus, improving soil fertility in the long run.
The breakdown of the plant’s deep roots also contributes to the fertility of the soil by increasing the humus content while at the same time assisting in soil drainage.
Bumper harvest all-yearlong: On average, lucerne can be harvested twice or thrice in a rainy season. When established in areas with regular rainfall or under constant irrigation, the crop will give a very high dry matter yield with over six harvests annually.
Each harvest can yield between 1.5 to 3 tonnes depending on region, prevailing weather, stage of growth at harvest and crop maintenance standards.
Long lasting:Being a perennial species, this crop should last for many years once established. It does not need re-establishment every other year.
Impressive adaptation to tropical conditions: Lucerne is a tolerant deep-rooting crop, which can survive even at times of low rainfall albeit with diminished herbage mass production.
Therefore, irrigation is required during periods of suppressed rainfall if this crop is to produce all-year round.
Seedling disease: Damping off
Leaf and stem diseases: alfalfa mosaic virus, lucerne yellows, bacterial leaf and stem spot, witches broom, common leaf spot, Stemphylium leaf spot, Leptosphaerulina leaf spot or pepper spot, rust, downy mildew, Cercospora leaf spot, Phoma black stem, powdery mild.
Root and crown diseases: Phytophthora root rot, Colletotrichum crown rot, Rhizoctonia canker (most significant,) violet root rot, Acrocalymma crown and root rot, Stagonospora crown and root rot (sometimes called common root rot), Fusarium wilt, bacterial wilt, Sclerotium blight and Sclerotinia rot