Abstract

Conservation agriculture with use of crop rotations and residue management provides many benefits to the soil and environment, which vary depending on climatic and soil conditions, crops between of the rotation, and the amount of incorporated residue. The present study evaluated the effect of two medium-term of canola (Brassica napus L.)-wheat (Triticum aestivum L.) and bean (Phaseolus vulgaris L.)-wheat rotations with four residue incorporation rates of preceding crop (0, 50, 100, and 200%) on wheat grain yield and nutrient concentrations; Nitrogen (N), Phosphorous (P), Potassium (K), Calcium (Ca), Magnesium (Mg) and Sulfur (S) at the end of the fourth season in a volcanic soil in south-central Chile. Grain yield varied between 5.77 and 5.96 Mg ha(-1) and was not affected by the preceding crop. The residue incorporation rates had no effect on the evaluated parameters. The preceding crop affected grain K and Mg concentration, which increased after bean. The Ca concentration in the residue was positively affected by the canola crop. Total macronutrient extraction in the wheat crop was 444.1 kg ha(-1). The ranking of total macronutrient extraction in the wheat crop was N > K > P > Ca > S > Mg with means of 198-221, 26.1-30.6, 133-163, 20.8-27.1, 13.4-16.5, and 14.9-16.5 kg ha(-1), respectively.