Establishing a high producing lucerne stand
Date: 28 October 2014
Profitable lucerne production is based on a rapidly-growing, dense stand which is the result of careful selection of well-drained paddocks, ideal soil nutrient levels, a proven variety and the use of good crop establishment practices.
Lucerne requires well-drained soils for maximum production. Waterlogged soils create ideal conditions for fungal root diseases which may kill seedlings, reduce yields and kill established plants. Poor soil drainage reduces oxygen movement to the roots, reducing stand performance.
Good lucerne weed control is critical for good stand establishment and subsequent yield and persistence. If possible, perennial weeds should be completely controlled prior to planting as they can re-establish quickly and are difficult and expensive to remove from seedling crops. In cases where perennial weed pressure is severe, consider cropping for 12 months prior to lucerne establishment.
High soil fertility promotes early growth and increases stand tolerance to insect and disease pressure. A 150 mm soil sample should be collected in the autumn preceding spring planting. Test for standard nutrients as well as sulphate-sulphur and micronutrients, particularly copper, molybdenum and boron. Once you have the soil test results contact your local Pioneer Representative, merchant or fertiliser company representative for a fertiliser recommendation. If possible, a proportion of the base fertiliser and lime should be applied several months in advance to allow micronutrients to become plant-available and to raise the pH close to the desired level.
The optimum soil pH for lucerne is above 6.3. If soil pH is below this, lucerne production may be reduced. It takes 6 months from the time of application until the maximum pH drop of lime is achieved.
There are a number of important factors to consider when choosing a lucerne seed variety. These include high yield potential, disease resistance and forage quality. Healthy plants that persist for longer deliver higher profitability, however a number of factors other than variety influence persistence. These include weed and pest levels and management, soil fertility and climatic conditions.
Sow when soil temperature is above 8°C in the spring or 14°C in the autumn. Soil moisture level is important as lucerne germinates only after the seed has absorbed about 125% of its weight as water.
Lucerne is a small seed with a limited supply of stored energy to support the developing seedling therefore correct planting depth is very important. Plant lucerne no deeper than 25 mm with the optimum depth being 6-12 mm on clay and loam soils and 12-25 mm on sands.
The recommended sowing rate for lucerne ranges from 12-18 kg/ha. Planting rate will vary depending on the condition of the seedbed, method of planting and planting date. The aim is to establish 60-90 plants per square metre in low rainfall areas and 110-130 plants per square metre in high rainfall or irrigated areas. Lucerne is a self-thinning crop and it is more desirable to over rather than under populate. High initial densities do not detrimentally affect long-term yields or persistence.
Once inoculated, lucerne can convert atmospheric N to plant-available nitrogen. All seed should be inoculated with Group A Rhizobium bacteria prior to planting. There are two options - seed can either be freshly inoculated or growers can plant coated seed.
Pioneer® brand products' Nitragin® Plus seed treatment contains:
• Superior strains of Rhizobium resulting in high levels of nitrogen fixation
• Apron XL® fungicide which is effective against seedling fungal diseases
• Lime for localised pH correction around the seed.
It is a light (9%) seed coating delivering more pure seed for every kilogram of coated seed planted.
Nitragin® Plus is a registered trademark of EMD Crop BioScience and/or its affiliates
Apron XL® is a registered trademark of Syngenta