Seedbed Preparation of Rhizoma Peanut Living Mulch for Cereal Production.

Low-input agriculture is growing in popularity and relies on enhancing sustainability within a cropping system. Decreased herbicide use characteristic of these systems mandates innovative weed suppression methods such as living mulch. Rhizoma peanut (Arachis glabrata Benth.; RP) has weed suppressing and nutrient adding potential, but has not been tested in cereal production without supplemental fertilizer or herbicide. This study measured the effects of seedbed preparation methods of RP living mulch on weed suppression, grain yield, and herbage biomass yield in pearl millet (Pennisetum glaucum (L.) R. Br.) and grain sorghum (Sorghum bicolor (L.) Moench.). Seedbeds were tilled, mowed, and no-tilled within an established RP field in Stephenville, TX, USA on 25 April (T1) and 17 June (T2) 2013. Weed mass was greatest (P<0.05) by at least 35% under tillage across all cereal treatments at T1. There was no difference (P>0.05) in weed mass across treatments at T2. Mowing lead to RP reemergence during the 2013 cereal production season that was approximately 200% greater (P<0.05) than tilling at both times. Tilling, however, fostered the greatest (P<0.05) RP reemergence the following spring in 2014. Tilled plots yielded the greatest (P<0.05) grain and biomass of both cereal species at T2. These sorghum and millet grain yields were, however, 36-48% and 75-90% less (P<0.05), respectively, than comparable conventional systems. Cereal biomass yields were similar with 51% less (P<0.05) sorghum and 81% less (P<0.05) millet biomass produced in this system vis-à-vis a fertilized trial in Stephenville, TX, USA.  This study indicated low cereal crop grain and biomass yields requiring further research of RP as a living mulch. Future research can add insight on how long RP should be rested between intercropping, how to improve weed suppression, and the residual effect this system has on soil health.