Main Contacts for Initiative 

Bruno Basso, Michigan State University, USA
L.T Wilson, Texas A&M University, USA

Coordination 

AgMIP Soils and Crop Rotations Initiative will be led by Dr. Bruno Basso and Iurii Shcherbak (Michigan State University) in collaboration with Keith Paustian (Colorado State University), Peter R. Grace (Queensland University of Technology), and Claas Nendel (Zalf).

Rationale

Crop models have been extensively tested for yields, but their validation for soil water balance, and carbon and nitrogen cycling in agricultural systems has been limited. In this effort we will compare the results of different models in simulating soil variables that carry over from one crop to the next. The models will be executed in a sequential mode using different management strategies and crop rotation.

Objective

The objective of this initiative is to assess crop models’ uncertainties in simulating soil carbon, nitrogen and soil water balance dynamics in a maize-fallow and wheat-fallow crop rotation under different management strategies. A secondary objective is also to compare yields simulated using the prior method of constant reinitialized soil parameters used in the wheat and maize pilot studies with the new 30-year simulations accounting for carry-over effects of soil water, carbon and nitrogen obtained by running the model in the sequential mode.

Procedure

The AgMIP soil and crop rotation initiative is targeted to models that can simulate maize and wheat yield and at the same time have soil carbon and nutrient components along with management strategies impact on yield and fluxes. The sites selected for the AgMIP Soil and Crop rotation initiative are the same used for the wheat pilot study (Australia, Netherlands, Argentina and India) and maize pilot studies (USA, France, Brazil, and Tanzania). The soil, climate, management and cultivars are the same used for the wheat and maize pilot studies. The new management treatments compared in this new initiative include soil tillage and residues management (conventional tillage and residues incorporated vs. no tillage and residues retained on the soil surface). Should data input not be available, the instructions and input files will be sent again. Modelers will submit results via a template provided to the participants of this initiative. In this first phase of the AgMIP soil initiative we will only run the models in a sequential mode for 30 continuous years (30 years historical and 30 years future climate projections) using the similar protocols to the ones used in the wheat and maize pilot study.