Project Overview
Commodities
- Agronomic: wheat
Practices
- Crop Production: cover crops, fallow, nutrient cycling, nutrient management, water management
- Education and Training: on-farm/ranch research, participatory research
- Natural Resources/Environment: biodiversity, soil stabilization
- Production Systems: dryland farming
- Soil Management: nutrient mineralization, organic matter, soil analysis, soil chemistry, soil microbiology, soil physics, soil quality/health
- Sustainable Communities: local and regional food systems
Proposal abstract:
In low rainfall areas of the northern Great Plains cover cropping is appropriately aimed at
greening the summer fallow period, which is an economically risky practice. Over time, soils
may improve sufficiently so that the increased crop return outweighs the cost of cover crops. The
proposed study was begun in 2012 (SARE Project SW11-099) at two on-farm sites in Montana
to compare different plant functional groups’ effects on soil properties. Eleven treatments are
included in this replicated plot-scale study, including paired plant species representing four plant
functional groups (brassicas, fibrous rooted, nitrogen fixing, and tap rooted crops) in various
combinations and sole pea and chemical fallow as controls. The experimental design provides a
unique opportunity to test each functional group, whereby 1) each group appears separately as
four functional group treatments (‘presence’), 2) they appear together in a complete mixture, and
3) the complete mixture minus each functional group (‘absence’). Due to the semi-arid climate,
more time is required to see soil differences. We seek supporting funding to complete the final
soil sampling in spring 2019, after four cycles of cover crops, in association with my M.Sc.
thesis. This should have allowed enough time to elapse for a battery of biological, chemical, and
physical soil assessments to be differentiated by functional group and what that does to the
subsequent wheat quality. This research will fundamentally discover the role of functional
groups within cover crop mixtures, and allow for more strategic design of cover crop seed mixes
for targeted soil improvement. By making this research widely available, producers will be
provided valuable information regarding methods of sustainable soil management. If soil benefits
from long-term cover cropping can be proven to offset the short term economic loss, then this
more sustainable management technique can be more easily adopted into our agricultural
systems.
Project objectives from proposal:
Soil and Agronomic Objectives
1. To investigate how biomass production compares among the ten cover crop treatments
included in this study.
2. To measure how plant functional groups affect biological, chemical, and physical soil
properties, and subsequent wheat yields and protein, differently.
Educational Implications
3. To increase local producer knowledge of the value, or lack there-of, for cover crop
mixtures compared with less diverse cover crops for biomass production, soil water and
nitrogen use, and change in biological, chemical, and physical soil properties.
• Pre- and post-presentation mini-surveys will be used to measure changes in local
producer knowledge at a 2018 field day to be held at either the Amsterdam or
Conrad project site.
4. To provide producers with information regarding the potential benefits of alternative
cover crops through scientific publications, extension publications, popular press articles,
social media, public presentations, and research summaries and factsheets.
• The number of viewers at each presentation will be tracked to assess the impact of
presentations on producers and others present. The number of people who “like”,
“follow” or “view” the information provided on social media will also be tracked.
The results of this research will provide fundamental knowledge on the ability of different plant
functional groups to change soil properties distinctly. This base knowledge will be helpful in
optimizing strategies for deploying cover crop mixtures over time and to serve specific functions
to the soil.