Assessing Various Seedbed Preparations On Switchgrass Establishment and Production.

Establishment is the most challenging stage of switchgrass (Panicum virgatum L.) production. Increasing seed-soil contact might not only increase the uniformity of seed placement but also increase the germination rate of switchgrass. Our objective was to assess the influence of various seedbed conditions on switchgrass stand establishment. A randomized block design with nine seedbed preparation treatments and four replications was conducted at the University of Massachusetts Agricultural Experiment Station in Deerfield in 2012. In this study, a roller and a cultipacker - which is more common among growers - were used to increase the seed-soil contact. The treatments were no-till planting, disking-planting (DP), disking-cultipacker-planting (DCP), disking-cultipacker-planting-cultipacker (DCPC), disking-cultipacker-planting-cultipacker (2 times) (DCPC2), disking-rolling-planting (DRP), disking-rolling- planting-rolling (DRPR), disking- rolling-planting-rolling (2 times) (DRPR2),disking-rolling-planting-rolling (3 times) (DRPR3). Soil resistance was measured the day after the soil compaction at 10 and 20 cm depth. Number of seedlings were counted a month after the planting. No seedling was observed in the no-till planting. Before the harvest, number of established plants, number of tillers per plant, tiller density, and switchgrass biomass was measured. Soil resistance was lowest in DP and increased with increasing the number of rolling or cultipacking. A quadratic relationship was found between soil resistance and tiller density as well as dry matter yield (DMY). Since soil resistance was slight (up to 1.2 MPa), increasing the soil resistance resulted in higher tiller density as well as DMY. The highest biomass production in the establishment year was recorded from DCPC2 with 1137 kg ha^-1.