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Integrated Cropping Systems
Reza Keshavarz Afshar (PhD)

Research and Extensions Agronomist

Phone: (970) 858-3629 ext. 203


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The Western Colorado Research Center at Fruita serves the agricultural interests of 14 counties in northwest and west-central Colorado. Research on integrated cropping systems is conducted across western Colorado from Hayden, Craig, Meeker, Rifle, Grand Junction, Fruita, Delta, Olathe, and Montrose. This area comprises nearly 20 million acres, representing nearly 30% of the total land area of the state. In total, this region of the state contains a large amount of land used for agriculture and the market value of the agricultural products in this region exceeds $260 million annually.

The Western Colorado region poses opportunities, challenges, constraints, and limitations to agriculture and agricultural research. High water alkalinity, variable soils, limited precipitation, seasonal water availability, and cold injury are some of the challenges. In some areas of the region, producers are mainly limited to wheat and forages.  Also, producers in western Colorado are isolated from many of the major markets for their crops.

To support western Colorado agriculture, we conduct research on sustainable and viable cropping systems, resource-efficient cropping system, conservation agriculture, best management practices, and new and alternative crops for the region. A broad research approach has been taken in order to address as many needs and create as many opportunities as possible.

Agronomic research findings conducted in the western Colorado region are communicated to broad audiences including scientific and agricultural groups and organizations, governmental and non-governmental agencies, private industry, service organizations, and policymakers by using a diversity of technical and popular media in written, oral, and electronic forms.

Developing viable and sustainable cropping systems for western Colorado through adoption of conservation practices, diversification, and intensification (USDA-NIFA Hatch Project Accession No. 1015937).

Conventional grain production systems in Colorado relies on energy-intensive practices including aggressive tillage and excessive use of chemicals (fertilizers and pesticides). This approach poses threats to long-term sustainability, yield stability, and ecosystem security by decreasing soil health and productivity, increasing environmental footprints, degrading natural resources, and consequently negatively impacting human health. Conservation practices such as reduced tillage, cover cropping, and crop diversity could potentially address these issues. The ultimate goal of this project is to improve system productivity, soil health, and economic returns of cropping system in western Colorado while reducing its environmental footprint through adoption of conservation practices. Multi-year replicated field trials will be conducted at WCRC in Fruita investigating how soil tillage, residue management, cover cropping, and crop diversification impact crop yield and productivity, farm economy, and soil health.

Residue management and soil tillage impact on crop yield, economic return, and soil health of continuous corn cropping system under furrow irrigation

Corn is an important component of agricultural systems in Colorado. Conventional tillage such as moldboard plowing is still extensively used by growers in western Colorado. Conservation tillage, the practice of keeping the soil surface covered by crop residues to at least 30%, offers the potential to sequester carbon, enhance soil organic matter, and reduce erosion. One major obstacle of no-till implementation in this area is heavy residue that creates difficulties for surface irrigation. Stover removal facilitates implementation of no-till. The objective of this study is to determine the effect of corn stover management (removal and grazing) and tillage (conventional tillage vs. no-till) on corn yield, economic return, and soil health (chemical, physical, and biological properties) in a 4-year period.

Potential of biochar and manure to mitigate soil carbon depletion when corn stover is removed

Continuous and heavy removal of residue from the field severely affects soil nutrient cycling and depletes soil organic carbon pools. Thus the sustainability of this system is questionable in long term. The objective of this study is to determine how corn stover removal affects crop yield and soil health and whether co-application of biochar and manure can mitigate soil carbon depletion when corn stover is removed.

Multipurpose cover crops for western Colorado

Well-managed cover crops offer numerous benefits to the agricultural system. Despite their multitude of benefits, cover cropping is still underutilized in western CO. The aim of this project is to integrate research and outreach activities to develop low-cost appropriate cover cropping strategies for western CO. Current projects include studying potential of dual-purpose cool-season (fall-planted grain cereals, brassicas, and legumes) and warm-season (millet, cowpea, teff) cover crops. We also are currently evaluating best management practices including species selection and mixture, planting time, fertilization, termination time and method to maximize ecosystem and economic benefits of cover cropping in this environment.

Potential of frost-seeding clover into winter wheat for late-season forage production

Our preliminary investigation indicated great potential for clover frost-seeding in this environment for late-season supplemental forage production. The study includes frost-seeding of various clover species and seeding method (broadcasting vs. drilling) into winter wheat stand in late February. We are investigating how clover frost-seeding impact wheat growth and yield and whether this system is economically feasible for growers in this region.

Cereal-pea intercropping study

Demand for high-quality hay during early spring in western Colorado is high. Intercropping of cereals with legumes is a practice to increase forage quality. In this project we evaluate how intercropping with field pea affect yield and quality of spring barley, oat, and triticale forage. Investigating the most suitable warm season crop (short season corn hybrids, forage sorghum, pearl millet, teff, and cowpea) for double cropping in this system is another component of this project. The overall goal of this project is to find out alternative feasible crops to diversify crop rotation in this region.

In-season nitrogen management in irrigated winter wheat

Successful wheat production requires an appropriate plan for N management. Optimum N rate for wheat, however, varies greatly from site-to-site and from year-to-year due to variation in soil and growing conditions. Most growers apply a similar flat rate of N every year which can result in either over- or under-fertilization. Precision agricultural practices have shown promise to improve nitrogen use efficiency and provide economic and agronomic benefits to the growers. The ultimate goal of this project is to improve nitrogen use efficiency (NUE) in wheat production in western Colorado and improve grower knowledge of efficient N management in wheat to provide agronomic, economic, and environmental benefits.

Variety performance trials in western Slope

We regularly perform variety performance trials across the western slope (on-station and on-farmers fields) to help farmers selecting suitable varieties to grow. This include wheat, corn (grain and silage), alfalfa, and pinto bean (see extension page).

New and alternative crops for western slope

Crop diversity is an important component of sustainable cropping systems. Our focus is on new and alternative crops that requires less irrigation water compared to conventionally grown crops in this region. We are currently investigating production potential of cool-season grain legumes (winter and spring pea, lentil, chickpea, faba bean), alternative forage crops (sorghum, millet, teff, hybrid rye, etc.), and industrial hemp in this region.

Peer-reviewed journal articles (Last three years)

Google Scholar


Weidhuner, A., Keshavarz Afshar, R., Luo, Y., Battaglia, M., Sadeghpour, A., 2019. Particle Size Affects Nitrogen and Carbon Estimate of a Wheat Cover Crop. Agronomy Journal.

Keshavarz Afshar, R., Nilahyane, A., Chen, C., He, H., Stevens, W.B., Iversen, W. 2019. Impact of conservation tillage and nitrogen on sugarbeet yield and quality. Soil and Tillage Research. 191, 216-223


Keshavarz Afshar, R., Chen, C., Eckhoff, J., Flynn, C. 2018. Impact of a living mulch cover crop on sugarbeet establishment, root yield and sucrose purity. Field Crops Research, 223:150-154.

Obour, A. K., Chen, C., Sintim, H. Y., McVay, K., Lamb, P., Obeng, E., Mohammed, Y., Keshavarz Afshar, R. Zheljazkov, V. D., 2018. Camelina sativa as a fallow replacement crop in wheat-based crop production systems in the US Great Plains. Industrial Crops and Products, 111, 22-29.


Huang, Q., Keshavarz Afshar, R., Tao, A., Chen, C. 2017. Efficacy of starter N fertilizer and rhizobia inoculant in dry pea (Pisum sativum Linn.) production in a semi-arid temperate environment. Soil Science and Plant Nutrition. DOI: 10.1080/00380768.2017.1315834

Golzardi, F., Baghdadi, A., Keshavarz Afshar, R., 2017. Alternate furrow irrigation affects yield and water use efficiency of maize under deficit irrigation. Crop and Pasture Science.

Mohammed, Y., Lamb, P., Chen, C., Keshavarz Afshar, R. 2017. Agronomic evaluation of camelina (Camelina sativa L. Crantz) cultivars for biodiesel feedstock. BioEnergy Research. DOI 10.1007/s12155-017-9840-9

Tao, A., Huang, L., Wu, G., Keshavarz Afshar, R., Qi, J., Xu, J., Fang, P Lin, L., Zhang, L., Lin, P. 2017. High-density genetic map construction and QTLs identification for plant height in white jute (Corchorus capsularis L.) using specific locus amplified fragment (SLAF) sequencing. BMC Genomics. 18:355. DOI 10.1186/s12864-017-3712-8

Tao, A., Keshavarz Afshar, R., Huang, Q., Espeo, M., Mohammed, Y., Chen, C., Environmental, agronomic, and genetic factors influencing dry pea yield, starch, and protein prediction. Agronomy Journal. DOI: 10.2134/agronj2016.07.0401

Keshavarz Afshar, R., Lin, L., Mohammed, Y., Chen, C. 2017. Agronomic effects of urease and nitrification inhibitors on ammonia volatilization and nitrogen utilization in a dryland farming system: Field and laboratory investigation. Journal of Cleaner Production. DOI: 10.1016/j.jclepro.2017.01.105

Chaichi, M.R., Keshavarz Afshar, R., Lu, B., Rostamza, M. 2017. Growth and nutrient uptake of tomato in response to application of saline water, biological fertilizer and surfactant. Journal of Plant Nutrition. 40: 457–466.


Huang, Q., Keshavarz Afshar, R., Chen, C. 2016. Response of lentil to nitrogen fertilizer and rhizobia inoculation. Communications in Soil Science and Plant Analysis. 47: 2458-2464. DOI: 10.1080/00103624.2016.1254786.

Keshavarz Afshar, R., Mohammed, Y., Chen, C. 2016. Enhanced efficiency nitrogen fertilizer effect on camelina production under conventional and conservation tillage practices. Industrial Crops and Products. 94: 783–789.

Mohammed, Y., Keshavarz Afshar, R., Chen, C. 2016. Nutrient requirement of camelina for biodiesel feedstock in central Montana. Agronomy Journal. DOI: 10.2134/agronj2016.03.0163.

Hajighasemi, S., Keshavarz Afshar, R., Chaichi, M.R. 2016. Nitrogen fertilizer and seeding rate influence on dual-purpose barley. Agronomy Journal, 108:1486–1494. DOI: 10.2134/agronj2015.0447.

Chaichi, M.R., Keshavarz Afshar, R., Saberi, M., Rostamza, M. 2016. Alleviation of salinity and drought stress in corn production using a non-ionic surfactant. Journal of Animal and Plant Sciences. 26:1042-1047.

Keshavarz Afshar, R., Hashemi, M., DaCosta, M., Spargo, J., Sadeghpour, A. 2016. Biochar application and drought stress effects on physiological characteristics of Silybum marianum. Communications in Soil Science and Plant Analysis, 47: 743–752. DOI: 10.1080/00103624.2016.1146752.


Jahanzad, E., Sadeghpour, A., Hashemi, M., Keshavarz Afshar, R., Hosseini, M. B., Barker, A.V. 2015. Silage fermentation profile, chemical composition and economic evaluation of millet and soya bean grown in monocultures and as intercrops. Grass and Forage Science, DOI: 10.1111/gfs.12216.

Keshavarz Afshar, R., Mohammed, Y., Chen, C. 2015. Energy balance and greenhouse gas emissions of dryland camelina as influenced by tillage and nitrogen. Energy, 91: 1057–1063. DOI: 10.1016/

Keshavarz Afshar, R., Chen, C. 2015. Intensification of a dryland cropping system for bio-feedstock production: Energy analysis of camelina. BioEnergy Research, 8: 1877-1884. DOI: 10.1007/s12155-015-9644-8.

Dai, I., Keshavarz Afshar, R., Chen, C., Miller, P., Kephart, K., McVay, K., Lamb, P., Miller, J., Bohannon, B., Knox, M. 2015. Multi environmental evaluation of dry pea and lentil cultivars in Montana using AMMI model. Crop Science, 56: 520-529. DOI: 10.2135/cropsci2015.01.0032.

Dadrasan, M., Chaichi, M.R., Porbabaee, A.A., Yazdani, D., Keshavarz Afshar, R. 2015. Deficit irrigation and biological fertilizer influence on yield and trigonelline production of fenugreek. Industrial Crops and Products, 77: 156–162. DOI:10.1016/j.indcrop.2015.08.040.

Jahanzad, E., Sadeghpour, A., Hoseini, M.B., Barker, A.V., Hashemi, M., Keshavarz Afshar, R. 2015. Competition, nitrogen use efficiency, and productivity of millet-soybean intercropping in semiarid conditions. Crop Science, 55: 2842-2851. DOI: 10.2135/cropsci2015.02.0130.

Chen, C., Bekkerman, A., Keshavarz Afshar, R. Neill, M. 2015. Intensification of a dryland cropping system for bio-feedstock production: Evaluation of agronomic and economic benefits of Camelina sativa. Industrial Crops and Products, 71: 114–121. DOI: 10.1016/j.indcrop.2015.02.065.

Keshavarz Afshar, R., Chaichi, M.R., Ansari Jovini, M., Jahanzad, E., Hashemi, M. 2015. Accumulation of phenolic compounds in milk thistle seeds under drought stress. Planta, 242: 539-543. DOI 10.1007/s00425-015-2265-9.

Keshavarz Afshar, R., Chaichi, M.R., Alipour, A., Dashtaki, M., Hashemi, M. 2015. Potential of milk thistle for biomass production in a semiarid environment. Crop Science, 55: 1295-1301. DOI: 10.2135/cropsci2014.10.0678.

Keshavarz Afshar, R., Chaichi, M.R., Rezaei, K., Asareh, M.H., Hashemi, M. 2015. Irrigation regime and soil organic fertilizers influence on oil content and fatty acid composition of milk thistle seeds. Agronomy Journal, 107: 187-194. DOI: 10.2134/agronj14.0368.

Keshavarz Afshar, R., Ansari Jovini, M., Chaichi, M.R., Hashemi, M. 2014. Grain sorghum response to Arbuscular mycorrhiza and phosphorus fertilizer under deficit irrigation. Agronomy Journal, 106: 1212-1218. DOI: 10.2134/agronj13.0589.

A wide library of publications from the Western Colorado Research Center can be found at the CSU Agricultural Experiment Station Online Library or the Colorado Digital Collections Agricultural and Natural Resources Archive

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