Increasing Crop Diversity Mitigates Weather Variations and Improves Yield Stability

Abstract

Cropping sequence diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Yield advantages of more diverse crop rotations and their synergistic effects with reduced tillage are well documented, but few studies have quantified the impact of these management practices on yields and their stability when soil moisture is limiting or in excess. Using yield and weather data obtained from a 31-year long term rotation and tillage trial in Ontario, we tested whether crop rotation diversity is associated with greater yield stability when abnormal weather conditions occur. We used parametric and non-parametric approaches to quantify the impact of rotation diversity (monocrop, 2-crops, 3-crops without or with one or two legume cover crops) and tillage (conventional or reduced tillage) on yield probabilities and the benefits of crop diversity under different soil moisture and temperature scenarios. Although the magnitude of rotation benefits varied with crops, weather patterns and tillage, yield stability significantly increased when corn and soybean were integrated into more diverse rotations. Introducing small grains into short corn-soybean rotation was enough to provide substantial benefits on long-term soybean yields and their stability while the effects on corn were mostly associated with the temporal niche provided by small grains for underseeded red clover or alfalfa. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure. In hot and dry years, diversification of corn-soybean rotations and reduced tillage increased yield by 7% and 22% for corn and soybean respectively. Given the additional advantages associated with cropping system diversification, such a strategy provides a more comprehensive approach to lowering yield variability and improving the resilience of cropping systems to multiple environmental stresses. This could help to sustain future yield levels in challenging production environments.

Limited Irrigation of Corn‐Based No‐Till Crop Rotations in West Central Great Plains

“…In rainfed agriculture, lower water productivity for CC was reported compared with other rotations (Copeland et al, 1993;Varvel, 1994;Pikul et al, 2012). Studies available on crop rotations in limited and full irrigation conditions show a similar result to the present paper, that is, less or similar impact of rotation compared with continuous cropping in yield and resource use (Schneekloth et al, 1991;Gaudin et al, 2015). Holling (1973) defined a resilient system as a system that retains its productivity following a perturbation (drought, disease, pest…).…”

“…Holling (1973) defined a resilient system as a system that retains its productivity following a perturbation (drought, disease, pest…). Crop diversity was, therefore, suggested as a big contributor to increasing a cropping systems resilience (Lin, 2011;Gaudin et al, 2015). Water limitation is among the main factors that challenge a systems resilience.…”

Yield Stability in Winter Wheat Production: A Survey on German Farmers’ and Advisors’ Views

“…Furthermore, crop rotations with a higher share of cereals show a negative impact on yield stability of winter wheat, especially for wheat monocultures. In contrast, diverse crop rotations with favorable preceding crops (e.g., legumes) affect the yield stability of the main crop winter wheat positively [15][16][17][18][19]. Beyond that, cultivar choice is an effective tool in farming practice, which is used to support yield stable wheat production [3,12,20].…”

System-level approach needed to evaluate the transition to more sustainable agriculture

“…In fact, our results suggest that further investment in research into diversification techniques has the potential to improve productivity of sustainable agricultural methods to equal conventional yields. Encouragingly, the few long-term studies that have been conducted have demonstrated that diversification techniques enhance yields while enhancing ecosystem services, profitability and stability [18,23,[32][33][34][35].…”