Location: Soil, Water & Air Resources Research
Title: Fragipan soil changes with growth of annual ryegrass and festulolium with surface applied amendmentsAuthor
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MURDOCK, LLOYD - University Of Kentucky |
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KARATHANASIS, ANASTASIOS - University Of Kentucky |
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CALL, DOTTIE - University Of Kentucky |
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Dinnes, Dana |
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Chatterjee, Amitava |
Submitted to: Open Journal of Soil Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/23/2024 Publication Date: 12/26/2024 Citation: Murdock, L., Karathanasis, A.D., Call, D., Dinnes, D.L., Chatterjee, A. 2024. Fragipan soil changes with growth of annual ryegrass and festulolium with surface applied amendments. Open Journal of Soil Science. 14(12):765-777. https://doi.org/10.4236/ojss.2024.1412037. DOI: https://doi.org/10.4236/ojss.2024.1412037 Interpretive Summary: Fragipans are compacted subsurface soil layers that restrict root penetration and water movement. This greenhouse experiment was conducted to compare the effect of two grasses (annual ryegrass and festulolium) with and without addition of other chemicals, on the degradation of the fragipan layer. Results showed that two plantings of annual ryegrass separated by a soybean planting changed the physical structure in the surface layer of the fragipan. Other chemicals, such as sodium nitrate placed on the surface of the fragipan in combination with growing annual ryegrass, may have further promoted fragipan degradation, due to the capability of sodium to disperse soil. These results will be useful to understand the effect of ryegrass or festulolium and other chemicals on the degradation of the fragipan layer. The findings could be of interest to growers and scientists managing soils with restrictive soil layers. Technical Abstract: A greenhouse experiment was conducted involving complete/intact 100 cm cores of a fragipan soil. The cores were maintained in moist conditions throughout the experiment as annual ryegrass (Lolium multiflorum) or festulolium (Lolium spp and Fescue spp hybrid) were grown with and without additional surface applied amendments, including NaF, NaNO3, NaCL, and KCl. The results suggest a significant effect of annual ryegrass and festulolium on fragipan horizon degradation after 24 months. Annual ryegrass and festulolium were found to effectively change the structure of the fragipan horizon when planted on the soil surface and roots grew through the upper soil profile and penetrated into the fragipan. The fragipan structural change (degradation) appeared to increase with each planting sequence, particularly with soybean crop rotations. Sodium nitrate added to the soil surface with the growth of annual ryegrass resulted in a significant synergistic effect for degrading the fragipan horizon. The other amendments were not as effective in causing additional fragipan degradation. |