Climate Change, Agricultural Inputs, Cropping Diversity, and Environmental Covariates in Multivariate Analysis of Future Wheat, Barley, and Canola Yield in Canadian Prairies, a Case Study
Citation
This manuscript was submitted in May 2016 and approved by the acting associate director Susan Tosh. The publication was accepted for publication in February 2017. The citation will be provided, once the publication is posted on the Canadian Journal of Soil Science web page. The publication date is a place holder
Plain language summary
Canada’s grain and oilseed production in the Canadian Prairies will be influenced by climate change in the coming decades. The impact of agricultural inputs and crop diversity typically practiced in the region has not been assessed relative to changes in future precipitation and temperature. Such an assessment is important in order to identify key yield defining factors as climate change continues to affect agriculture in Canadian Prairies. This study assessed wheat, canola, and barley yield simulated with the Environmental Policy Integrated Climate model under historical weather and future climate scenarios in the context of agricultural inputs and cropping diversity at Scott, Saskatchewan, Canada. Agricultural inputs were organic, minimum, and conventional tillage. Cropping diversities were wheat-fallow, diversified annual grains, and diversified annual perennials. We found that precipitation in May, June, and July and temperature in April, May, June, August and September were the most important yield defining factors on the future yield. Future growing season maximum and minimum temperatures increased by 1.06 and 2.03°C, respectively, and 11% in future precipitation, compared to historical weather. We also found that tillage affected wheat yield, but not barley or canola. Wheat yield was highest in minimum, and lowest in organic system. This study showed the relative importance of precipitation and temperature as important factors in analyses of climate change impacts on future yield in the context of typical farming practices in the Canadian Prairies.
Abstract
Grain and oilseed production in the Canadian Prairies are affected by precipitation and temperature but the relative impact of crop inputs, tillage, and diversity on yield have not been assessed with respect to climate change predicted in global-regional models. This study assessed wheat, canola, and barley yield simulated with the Environmental Policy Integrated Climate (EPIC) model for historical weather (1971-2000) and future climate scenarios (2041-2070) in the context of management of agricultural inputs including tillage, and cropping diversity at Scott, Saskatchewan, Canada. Yield, simulated with EPIC for future climate scenarios, was explored with recursive partitioning in multivariate analyses of agricultural inputs, cropping diversity, future growing season precipitation (GSP) and growing degree days (GDD). A combination of reduced tillage and inputs significantly increased wheat yield, but not barley or canola. Wheat yield was highest with reduced tillage and inputs, but was lowest under organic management. Input and diversity accounted for about one third of the variation in future wheat yield and about 10 % for barley. Most of the variability in yield was correlated with GSP in May, June, and July and GDD in April, May, June, August and September. Growing season maximum and minimum temperatures increased by 1.06 and 2.03°C respectively, due to climate change, and 11% in future GSP. Both GSP and GDD are key covariates for crop yield in analyses of climate change as assessed by recursive partitioning. This study shows the impact of input management on yield, in particular with respect to tillage, in the context of increases in maximum temperature due to climate change.