Lucerne is a potential alternative to red clover in areas where the soil is closer to neutral and well drained. In the right conditions lucerne can very productive and drought tolerant. However, establishment failures limit the geographic area in which it is typically sown. This project tests possible solutions to prevent poor lucerne establishment.
The project is funded by Lantmännens Forskningsstiftelse. Field experiments are being established in a field where lucerne has previously been cultivated (Skåne), and three regions where lucerne establishment lucerne is often problematic, in fields where lucerne has not been recently cultivated (Halland, Jönköping, Väster-Götaland). The first experiments were established in 2019 and harvested in 2020, and new experiments were established in 2020. The 13 treatments are combinations of micronutrients and inoculation products and processes. Plants are assessed in the establishment year and during the first production year for leaf colour, yield, height, plant density, and protein concentration.
One of the major reasons to include legumes, such as clover and lucerne, in forage mixes is that they “fix nitrogen”. This means that through a symbiotic process with Rhizobia bacteria from the soil, legumes obtain nitrogen gas from the air and convert it into nitrogenous compounds. These compounds contribute to the fertility of the soil as the plant or parts of the plant dies and decomposes.
In order for nitrogen fixation to occur, the right bacteria have to be available in the soil. Different types of legumes have different strains of Rhizobia. For example, red and white clover are infected by the same strains of Rhizobia; however, these will not work for lucerne, which needs a different type. Therefore, to grow lucerne in a place where it has not been grown before, it is necessary to provide the right bacteria. The process of treating the seed with the Rhizobia is called inoculation, and there are different products and processes available.
Legumes can be more sensitive to nutrient deficiencies than other plants. Nutrients are not only necessary for the plant, but also for the legume-Rhizobia symbiosis. In addition to macronutrients such as phosphorus, sulphur and potassium, micronutrients such as molybdenum, cobalt, and boron are also important.
An aerial view of the experiment at Rådde station in 2019. The image is an orthomosaic, composed of numerous images captured with a drone at 30-m altitude. Different plots appear different shades of green. Photo: David Parsons
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