Soil organic matter dynamics, soil fertility and acidification, soil health, and precision farming in dryland cropping systems.
The overarching goal of my research is to develop sustainable soil and crop management strategies with a strong scientific basis, and provide growers and agricultural consultants with relevant information and tools for better land management decisions. I am working to build a database to evaluate climate change effects on wheat yield, biomass production, soil carbon and nitrogen dynamics, and soil pH in Pendleton Long-Term Experiments (some dating back to 1930s) with different cropping systems and residue management. These on-going studies revealed that no-till, reduced tillage and other conservation tillage systems could build SOM levels while maintaining crop yields, compared to traditional fall plowing. However, changes in SOM stocks in response to agronomic practices are slow and show years later when it is too late for adjustments in management. I have identified several SOM pools including permanganate oxidizable C and water extractable organic C as sensitive early indicators of tillage-induced changes in SOM under wheat-pea that will allow growers with early management decisions and quick remedial actions. Agricultural soils in the PNW have been acidifying due to long-term use of ammonium-based fertilizers. I am investigating the effectiveness of alkaline biochar amendment as one countermeasure to increase soil pH, improve soil fertility, increase SOM, and enhance crop productivity. This study provided positive indication on the applicability of biochar amendment to improve soil pH, SOM, and increase wheat-pea yields over chemical-N alone. I am also evaluating the feasibility of including cover crops (spring pea, spring barley, yellow mustard, and their mixture) in a 2-year wheat-fallow based cropping system to build SOM. Preliminary results indicated that wheat-cover cropping system could potentially replace wheat-fallow system without compromising soil water availability and wheat productivity, but with the added benefit of increasing soil N particularly with spring pea. Besides, I am also working to identify field scale spatial patterns in soil and crop parameters employing sensors (EM38, VERIS3100, CropScan, and AgDrone) and grid sampling technique for developing high-resolution soil and crop maps for precision wheat farming.
Rakesh Awale is a post-doctoral researcher of crop and soil sciences at the Columbia Basin Agricultural Research Center, Oregon State University since 2015. He received his doctoral degree from North Dakota State University, where he studied nitrogen transformations in poorly drained soils under tile-drainage at for improving N use efficiency of row crops and reducing N escaping from agroecosystems.
Publications and Presentations:
Awale, R., Emeson, M., Machado, M. 2017. Soil organic carbon pools as early indicators for soil organic matter stock changes under different tillage practices in Inland Pacific Northwest. Frontiers in Ecology and Evolution. 5:96.
Awale, R., Machado, S., Ghimire, R., Bista, P. 2017. Chapter 2: Soil health. Pages 47-97 in G. Yorgey, and C. Kruger, editors. Advances in Dryland Farming in the Inland Pacific Northwest. Washington State University Extension Publication EM108, Pullman, WA.
Awale, R., Bista, P., Machado, S. 2017. Tillage and residue management systems and impacts on soil health in drylands. REACCH Webinar Series: Advances in Dryland Farming in the Inland Pacific Northwest, Dec. 11, 2017 (Webinar).
Machado, S., Awale, R., Pritchett, L., Rhinhart, K. 2017. Alkaline biochar amendment increased soil pH, carbon and wheat-pea yields. ASA, CSSA & SSSA International Annual Meetings, Oct 22-25, 2017, Tampa, FL (Poster).
Machado, S., Pritchett, L., Rhinhart, K., and Awale, R. 2017. Alkaline Biochar Amendment Increased Soil pH, Carbon, and Wheat-Pea Yields. Oregon State University. Technical Report OSU-FDR-2017, p. 39.
Awale, R., Machado, S., Ghimire, R., Bista, P. 2017. Chapter 2: Soil Health. Pages 47-97 in G. Yorgey, and C. Kruger, editors. In: G. Yorgey and C. Kruger, editors. Advances in Dryland Farming in the Inland Pacific Northwest. Washington State University Extension Publication EM108, Pullman, WA.
Yorgey, G., W. Pan, R. Awale, S. Machado, B. Bary. 2017. Chapter 7: Soil amendments. Pages 283-318 in G. Yorgey, and C. Kruger, eds. Advances in Dryland Farming in the Inland Pacific Northwest. Washington State University Extension Publication EM108, Pullman, WA.