Medium-Term Crop Rotations with Different Residue Incorporation Rates: Effect on Durum Wheat Production and Plant Nutrient Concentration and Extraction

This study aims to evaluate the medium-term effect of two biannual rotations and four residue rate incorporation on durum wheat production and its nutritional composition and nutrient extraction. The effects of two biannual rotations of canola (Brassica napus L.) durum wheat (Triticum turgidum L.) and bean (Phaseolus vulgaris L.)-durum wheat and four incorporation rates (0%, 50%, 100%, and 200%) of residues of each preceding crop were evaluated after four seasons on durum wheat production and on its nutritional composition and nutrient extraction, in a volcanic soil in south-central Chile. Results indicated that the highest grain yield and residue production of durum wheat was obtained after bean (7.40 and 7.92 Mg ha−1, respectively). In the grain were obtained lower N and P concentrations after bean, and higher K, Ca, and Mg concentrations in the residue. The extraction of most durum wheat grain and residue nutrients was higher after bean. Nutrient distribution in the durum wheat plant concentrated in the grain was 79.9 to 80.7% N, 91.3 to 92.1% P, 27.1 to 27.4% K, 16.8 to 18.8% Ca, 68.3 to 70.4% Mg, and 56.3 to 57.4% S. In the residue, nutrient distribution was 19.3 to 20.4% N, 7.9 to 8.7% P, 72.6 to 72.9% K, 81.2 to 83.2%, Ca, 29.6 to 31.7% Mg, and 42.6 to 43.7% S. The highest grain and residue production of durum wheat was obtained after bean crop and also the extraction of most nutrients.