Impact of the seeding and nitrogen fertilizer rates of spring wheat that is used as a cover crop on the yielding ability of tetraploid red clover stand established at different seeding rates
Estonian Crop Research Institute, Aamisepa 1, EE 48 309 Jõgeva, Estonia
In the years 2013–2014, a field trial was conducted at the Estonian Crop Research Institute in order to investigate a possibility of using spring wheat as a cover crop in the establishment of red clover seed field. In the trial the cover crop had four different seeding and fertilization rates. Two tetraploid red clover cultivars, ‘Varte’ (early) and ‘Ilte’ (late), were seeded at rates 2, 4, 6 and 8 kg PLS per hectare in four replications. In the year of sowing the height and density of generative tillers of spring wheat, the grain yield and its quality, the number of red clover plants per m², and the seed yield of red clover and its quality in the 1st year of harvest were determined. Economic feasibility was calculated based on the prices valid at the time of trial conduction. The trial confirmed that while establishing a red clover seed field, it is possible to replace the earlier recommended six-rowed early barley cultivars with early spring wheat cultivars. It is expedient to reduce the seeding rate and nitrogen fertilizer rate of cover crop by one third. The optimum seeding rate of tetraploid red clover cultivars was 4–6 kg PLS ha-1.