Effects of varying nitrogen fertilization on crop yield and grain quality of emmer grown in a typical Mediterranean environment in central Italy
2011
Marino, S. | Tognetti, R. | Alvino, A.
Experiments were carried out to study the effects of N fertilizer rates and timing of application on the yield and grain quality of a rainfed emmer crop (Triticum dicoccum Shübler) under Mediterranean conditions. The following parameters were analyzed: hulled and net grain yield, hulled index, spikesm⁻², spikelets per spike, kernelsm⁻², thousand-kernel weight, biomass, plant height, lodging, grain protein and ash content. In the first experiment, different N rates (30, 60 and 90kgNha⁻¹ plus a control not fertilized) were split at three phenological stages (seeding 20%, tillering 40% and stem elongation 40%). In the second experiment, three N doses (30, 60 and 90kgNha⁻¹) were applied to three crop stages (seeding, tillering and stem elongation). In the third experiment, the rate of 90kgNha⁻¹ was distributed in different amounts (90-0-0, 0-90-0, 0-0-90, 45-45-0, 45-0-45, 0-45-45, 30-30-30) at the three mentioned crop stages. Increasing N rates resulted in higher hulled and net grain yield, as well as protein content. Fertilization (from 60 to 90kgNha⁻¹) applied to tillering maximized hulled and net grain yield. Fertilization (90kgNha⁻¹) applied to stem elongation gave the highest grain protein content (%) while splitting application (30kgNha⁻¹ each) at three phenological stages maximized protein yield per hectare. Application of half or one-third of 90kgNha⁻¹ to stem elongation improved grain protein content in comparison with applications at sowing, or at both sowing and tillering. The main factor determining higher yields with increasing N rates in this emmer crop was the number of kernelsm⁻². None of the yield components accounted for differences in grain yield when timing and splitting application were varied.
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