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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #363770

Research Project: Conservation Systems to Improve Production Efficiency, Reduce Risk, and Promote Sustainability

Location: Soil Dynamics Research

Title: Response of arbuscular mycorrhizal fungi to cover crop mixtures in a cotton-soybean rotation

item YANG, ANNA - Auburn University
item UCAR, GOKHAN - Auburn University
item Balkcom, Kipling
item FENG, YUCHENG - Auburn University

Submitted to: Southern Cover Crop Conference
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with roots of most row crops, improving plant absorption of nutrients and water. Cover cropping keeps living roots in the soil between periods of normal crop production and maintains the viability of fungal propagules. In this study, we examined the effects of cover crop mixtures on AMF colonization of cotton roots and AMF spore density in a cotton (Gossypium hirsutum L.) and soybean (Glycine max) rotation under conservation tillage. Winter cover crop treatments included fallow, cereal rye (Secale cereale L.), cereal rye + crimson clover (Trifolium incarnatum L.), cereal rye + radish (Raphanus sativus L.), crimson clover + radish, and a mixture of all three cover crops. Mycorrhizal colonization rates and spore densities were determined in 2018 after cover crop treatments had been in place for three years. AMF infection rates of cotton roots at the four-leaf stage were significantly different among treatments, ranging from 24.2% for the fallow treatment to 52.8% for the cereal rye + crimson clover treatment. AMF spores present in soil samples collected after cotton harvest were counted and identified. Although significant treatment effects were not observed, the spore density was highest numerically in the cereal rye treatment at the 0–15 cm depth and the clover + radish treatment at the 15–30 cm depth. Dominant AMF species identified were Acaulospora scrobiculata, Rhizophagus sinuosa and Entrophospora-like sp. A positive correlation between AMF colonization rate and spore density at the 0–15 cm depth was found only in the fallow treatment. Our results showed that cover crops were beneficial to AMF colonization of the subsequent cotton crop and the use of radish, a non-host to AMF, in the cover crop mixture did not have a negative impact.