Use of dominance analysis in selecting the best cropping technique based on long term agronomic experiments

Yield averages and variability from three long-term agronomic experiments (LTAEs) have been used in a preference scheme for cropping system options by means of a dominance approach. Preference maps are obtained and include both parametric and stochastic dominance based on yield level and risk for wheat and maize crops grown in the Mediterranean area. Dominance method could add to classic ANOVA the direction of the effect of a treatment and a comparative approach. It allowed comparing technical options and practices on the basis of treatments explored in 3 still running LTAEs: rotation, tillage, mineral fertilisation level and organic amendment

Use of dominance analysis in selecting the best cropping technique based on long term agronomic experiments

Yield averages and variability from three long-term agronomic experiments (LTAEs) have been used in a preference scheme for cropping system options by means of a dominance approach. Preference maps are obtained and include both parametric and stochastic dominance based on yield level and risk for wheat and maize crops grown in the Mediterranean area. Dominance method could add to classic ANOVA the direction of the effect of a treatment and a comparative approach. It allowed comparing technical options and practices on the basis of treatments explored in 3 still running LTAEs: rotation, tillage, mineral fertilisation level and organic amendment

Rotation and Fertilization Effects on Soil Quality and Yields in a Long Term Field Experiment

Understanding the complex relationships among soil quality, crop productivity, and management practices would help to develop more sustainable agricultural production systems. In this study, we investigated the combined effects of crop rotations and fertilization treatments on soil quality and crop yield in a long term (about 50 years) field experiment. Crop rotations included continuous corn (Zea mays L.), a 2 year corn-wheat (Triticum aestivum L.) rotation, and a 9 year corn-wheat-corn-wheat-corn-wheat-alfalfa-alfalfa-alfalfa (Medicago sativa L.) rotation. Fertilization treatments included control, mineral fertilization with urea and triple superphosphate, and amendment with cattle manure. Crop rotations and fertilization treatments were combined in a factorial experimental design with two replications for each rotation and six replications for each fertilization treatment. The continuous corn and the corn-wheat rotations had negative effects on the main soil quality indicators considered (carbon (C) and nitrogen (N) pools, microbial biomass and activity). On the contrary, the 9 year rotation had positive effects on soil organic carbon (+24%) and total nitrogen (+23%) but resulted in impoverished available P (5%). Positive effects on soil microbial biomass (+37% of microbial biomass C and +23% of microbial biomass N) and activity (+19%) were also observed. Soil amendment with manure built up soil organic carbon (+13%), increased nutrient content (+31% of extractable C and +19% of extractable N), including that of available P (+47%), and stimulated microbial growth (+34%) and activity (+8%). As compared to manure, mineral fertilization increased the soil nutrient content to a lesser extent. This study showed that the combined use of rotations, including legume forage crops, and soil amendment with manure may help preserve soil quality and crop productivity in the long term