HERBAGE YIELDS AND WATER-USE EFFICIENCY ON A LOAMY SITE AS AFFECTED BY TILLAGE, MULCH, AND SEEDING TREATMENTS

The effects of surface treatments alone and with seedling of an introduced bluestem (Bothriochloa ischaemum) on herbage yields and water-use efficiency on a loamy range site in poor condition were studied. The study was in a 560-mm average annual precipitation area in the Southern Great Plains. Prior to treatment, buffalograss (Buchloe dactyloides) and silver bluestem (Bothriochloa saccharoides) produced the bulk of the herbage on the site. Disking or furrowing the native range produced no measurable change in herbage yields or in the water-use efficiency as compared to no treatment (control) over the 5-yr study period. Furrowing plus sand fill in the furrows or a rock mulch resulted in greater (P < 0.05) herbage yields than from the control. Most of the increased yield was by silver bluestem, a species that is ranked low in palatability. Establishment of the introduced bluestem ''Plains'' increased herbage yield 2- to 4-fold and significantly increased water-use efficiency.