Evaluation of forage resources under poorly drained soils for dairy systems

Alfalfa is crucial for dairy farms, but its potential production and persistence can be hindered by waterlogging, poorly drained soils, and high-water tables. The objectives of this study were (a) to evaluate herbage mas and quality of different forage species on poorly drained soils, and (b) to evaluate root biomass accumulation and their impacts on soil physical properties. The study was conducted in Santa Fe, Argentina, on an Aquic Argiudoll. Four treatments were established in March 2017: Alfalfa (control), Fescue, Annual (Ryegrass and Sorghum rotation regime), and Mixture (a mixture of Brome, Chicory, Red clover, and White clover). Aboveground herbage mass and nutritive quality were analyzed frequently, while roots and soil samples were collected after 2 years for further analysis. Root biomass was significantly higher (p < 0.05) in Annual and Mixture pastures compared to Alfalfa and Fescue. Lower root biomass in Alfalfa was attributed to temporary waterlogging and low plant density. Fescue exhibited reduced root biomass due to higher bulk density and lower soil porosity. Soil bulk density was lowest in Mixture, and no significant differences in soil penetration resistance were found among treatments (p > 0.05). There are alternatives to alfalfa with high production and quality that ensure a good economic return to farmers. The choice of forages for its root biomass accumulation has effects on the physics of the soil that ultimately modify the water dynamics. These findings have implications for sustainable forage management strategies, particularly in areas prone to waterlogging and poorly drained soils.