Cattle Grazing Affects Peanut Root Characteristics in a Bahiagrass-Based Crop Rotation System

The critical aspect of production agriculture in the southeastern US with increasing associated costs is to improve economic and agronomic sustainability. A four yr sod-based rotation system consisting of two yr of bahiagrass (Paspalum notatum Flueggé) (grazed or non-grazed) followed by a yr of peanut (Arachis hypogaea L.) and a yr of cotton (Gossypium hirsutum L.), each with winter cover crop (grazed or non-grazed) was established in Marianna, FL. The effect of grazing on root parameters (length, volume, surface area, and diameter) of peanut was observed using a mini-rhizotron. There were differences in several root parameters between grazed and non-grazed plots including: peanut root length (307 mm in grazed vs 167 mm in non-grazed), volume (50 mm3 in grazed vs. 23 mm3 in non-grazed), surface area (399 mm2 in grazed vs. 197 mm2 in non-grazed), and diameter (2.4 mm in grazed vs. 1.7 mm in non-grazed). Roots at the 45-60 cm and 60-75 cm depths had significantly greater length in the grazed than the non-grazed plots. Likewise, surface area was significantly greater in the grazed plots at the 30-45 cm, 45-60 cm and 60-75 cm depths. Grazed plots at the 40-65 cm depths showed significant increase in root diameter. No significant difference in peanut yield was observed for the grazed or non-grazed treatments. A more developed root system associated with cattle grazing in the sod-based rotation system may enable peanuts to be more resilient in adverse environmental conditions such as drought stress, enhance nutrient cycling without affecting yield, thereby improving long-term sustainability.