Impact of climate change stressors—temperature, CO2, and UV-B—on early growth and development of different cover crop species

Authors: Kharel, Tulsi; REDDY, RAJA - Mississippi State University; SEHGAL, AKANKSHA - Mississippi State University; KODADINNE, NISARGA - Mississippi State University; BHEEMANAHALLI, RAJU - Mississippi State University; Bhandari, Ammar; Reddy, Krishna; GAO, WEI - Colorado State University

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2024
Publication Date: 1/21/2025
Citation: Kharel, T.P., Reddy, R.K., Sehgal, A., Kodadinne, N., Bheemanahalli, R., Bhandari, A.B., Reddy, K.N., Gao, W. 2025. Climate change effect on early growth and development of different cover crop species. Agrosystems, Geosciences & Environment. https://doi.org/10.1002/agg2.70037.
DOI: https://doi.org/10.1002/agg2.70037

Interpretive Summary: Cover crop (CC) biomass is helpful for weed and pest control, soil erosion control, nutrient re-cycling, and overall soil health and crop productivity improvement. These benefits may vary based on cover crop species and their growth and development response to the different environmental conditions. Scientists from the USDA-ARS Crop Production Systems Research Unit, Stoneville, MS, Mississippi State University, and Colorado State University conducted a study with 5 cover crop species and their response to future climate projection scenario using controlled-environmental chambers, soil-plant-atmosphere research (SPAR) system. The study looked at how different CC species (cereal rye, triticale, winter wheat, crimson clover, and mustard) respond to climate change. They tested these plants in a controlled environment with different levels of carbon dioxide (CO2), ultraviolet-B (UV-B) radiation, and temperatures. High CO2 levels helped all five CC species grow better. High UV-B radiation had a negative impact on their growth. The best conditions for the plants were high CO2 and increased fall temperatures, which mimic conditions in the US Midsouth. Mustard was the most affected, growing much better with high CO2 and high temperatures, but much worse with high UV-B radiation. Rye and triticale were the least affected by the climate stressors. The results help in selecting and developing CC species that can adapt to climate change.

Technical Abstract: Different cover crop (CC) species may respond differently to the projected climate change scenarios. A study was carried out in a controlled environmental chamber to evaluate early season growth and development of five CC species: cereal rye (Secale cereale L.), triticale (x Triticosecale Wittmack), winter wheat (Triticum aestivum L.), crimson clover (Trifolium incarnatum L.), and mustard (Brassica juncea). Treatments consisted of two levels of carbon dioxide (CO2) (420 and 720 ppm), ultraviolet-B (UV-B) radiation (0 and 10 kJ m-2 day-1), and temperatures (29/21°C and 19/11°C day/night), and their combinations. Root, shoot, and physiological parameters were recorded, and a combined stress response index (CSRI) was derived. Results indicated that higher CO2 (+CO2) had a net positive effect on all five CC species, with CSRI values ranging from 1.0 to 5.1. Conversely, higher UV-B radiation (+UV) had a net negative impact, with CSRI values ranging from -2.9 to -7.6. The most favorable environment for all CC species was the combination of increased fall temperature and elevated CO2 (+T+ CO2). The negative impact of +UV was mitigated in an elevated CO2 and a high temperature environment, mimicking fall temperatures in the US Midsouth. Among the CC species, mustard was the most responsive, with a 151% increase in root and shoot combined dry weight under the +T+ CO2 treatment and an 86% decrease under the +UV treatment. Rye and triticale were the least impacted by the imposed climatic stressors. These results are of particular interest to the agricultural and environmental science community as they offer insights into developing and selecting CC species with adaptable and desirable morphological characteristics in anticipation of a changing climate.