Core Ideas: Increased P availability increases leaf P and Mg in wheat, oat, and rye. The grass tetany ratio is improved with greater P availability in these species. Unlike cereal rye and oat, wheat increases shoot growth with high P levels.

Winter annual species grown for forage are prone to mineral imbalances that could result in animal nutritional disorders, such as grass tetany. Adequate soil P has been found to be critical for the growth and adequate nutrient content of Mg, Ca, and K in other forages for grazing animals. This study examined the effect of P availability on growth and leaf nutrients in annual cereal grains commonly grown for winter forage. Winter wheat (Triticum aestivum L.), oat (Avena sativa L.), and cereal rye (Secale cereal L.) were grown hydroponically in greenhouse conditions in complete nutrient solutions with P treatments of 0, 200, 400, and 800 µmol L−1 P. After 32 d, plants were harvested and analyzed for P, Mg, Ca, and K content. Shoot growth of all three species increased from 0 to 200 µmol L−1 P; however, only wheat shoots increased incrementally with the other P treatment concentrations. Leaf P also responded incrementally to increased P treatments in all three species. Wheat and cereal rye exhibited increases in leaf Mg and improved grass tetany ratio from 200 to 400 µmol L−1 P, whereas oat showed these improvements from 0 to 200 µmol L−1 P treatments. This study suggests increased P availability could improve the grass tetany ratio, with or without increased shoot growth, in winter annual forage production on low P soils.


Environmental Plant Science and Natural Resources

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© 2019 American Society of Agronomy and Crop Science Society of America. This is an open access article distributed under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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Agrosystems, Geosciences & Environment