2014 New AES Research Projects – 728

COL00728 – Improving Cropping System Resilience through Diversification and Soil Conservation

Sponsoring Institution: National Institute of Food and Agriculture

Project Director:

Meagan Schipanski
Assistant Director
(970) 491-1320
meagan.schipanski@colostate.edu
Department of Soil and Crop Sciences

Non-Technical Summary

The overarching goal of this project is to improve the resilience of our agricultural systems. The main rationale is that current management systems in the Western Great Plains are vulnerable to soil degradation, the proliferation of herbicide resistant weeds, and more frequent droughts due to climate change. In addition, there is a growing demand for forage crops and interest and policy support for the integration of cover crops into dryland crop rotations. Through field-based and modeling experiments, this research will analyze how different management practices, particularly crop rotations, affect multiple ecosystem services. Through the integration of research from small plot to landscape scales, this research will expand the management toolbox for growers to improve long-term agricultural sustainability and resilience.

Goals / Objectives

  1. Develop cropping systems adapted to the Semi-Arid Western Plains that are productive, resilient in the face of climatic variability, and environmentally sustainable through:
    1. Quantifying the influence of different cropping systems on multiple ecosystem services.
    2. Apply cropping systems models to evaluate cropping system resilience in the face of future climate scenarios.
  2. Improve our understanding of plant-soil-microbe interactions that influence carbon and nitrogen cycling and water use in cropping systems by:
    1. Quantifying crop and crop rotation effects on soil carbon and nitrogen cycling and water use from rhizosphere to field scales.
    2. Applying long-term field data to improve carbon and nitrogen cycling and water use modules within existing cropping system models.

Methods:

This research will utilize long-term cropping systems experiments and datasets, on-farm research sites, research station sites, and modeling approaches. The long-term Dryland Agroecosystem Project (DAP) sites will be used to understand the impacts of crop rotation legacies on ecosystem services. In addition, new rotations will be initiated at DAP while maintaining the central base rotations, to maintain the relevance of those research sites to current grower interests in integrating forage and cover crops into dryland rotations. On-farm research will be established to evaluate the impacts of alternative rotations on profitability and soil quality through collaborations with innovative producers in the region.

This research will also utilize the long-term datasets from DAP and other long-term research sites for modeling efforts and to analyze relationships between crop rotations, soil C pools, climate variability, crop yields, and water use efficiency. In particular, soil C modules within RZWQM and Daycent and other cropping system models will be compared to identify the most robust approach to modeling soil C dynamics for future climate scenarios. This work will be carried out in collaboration with the USDA Agricultural Systems Research Unit. The interactions between crop growth, microbial activity, and soil C and N cycling will be quantified through collaborations with other USDA and CSU scientists. In particular, we will evaluate the impacts of deficit irrigation treatments on corn root production, root activity, and total soil respiration and nitrous oxide production. Stable isotopic methods will also be employed to track plant and soil C and N dynamics in plot-scale and greenhouse studies.

Products:

Products associated with this research will include conducting, analyzing, and publishing results from experiments; mentoring graduate and undergraduate students; organizing field days at research sites; and development and maintenance of a professional web page to communicate results.

Expected Outcomes:

By identifying the potential benefits and trade-offs of different crops and crop rotations, this research will provide additional management options for growers, thereby increasing the adoption of more resilient cropping systems. Expanding the number of crops and cover crops integrated within dryland rotations using an adaptive management approach has the potential to substantially improve multiple ecosystem services. Specifically, diversification of cropping systems has the potential to: 1) increase soil C; 2) reduce wind erosion; 3) improve cumulative water use efficiency; 4) reduce the risk of developing herbicide resistant weeds; 5) reduce N fertilizer requirements; and 6) improve cropping system productivity. Through collaborations with multi-disciplinary teams of researchers, this work will build on a 29-year legacy at long-term research sites that have had dramatic effects on the farming landscape, contributing to the conversion of 200,000 acres from wheat-fallow to more intensified crop rotations since 1985. Through the comprehensive integration of long-term and on-farm sites and modeling scenarios, this work will influence grower adoption of more diversified rotations if proven to be resilient. In developing successful management systems adapted to one of the more climatically vulnerable cropping systems in the U.S., this work will indicate the potential for rotational diversity to contribute to ecosystem service provisioning and climate change adaptation with applicability to other regions projected to experience more frequent droughts. By integrating field experiments with modeling estimates, this research will link rhizosphere C and N cycling and water use dynamics to their relative importance in agroecosystem and broader biogeochemical cycles.

Keywords: cropping systems, climate change, biodiversity, soil organic matter, stable isotopes, rhizosphere

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