Integrated Management Practices for Establishing Upland Switchgrass Varieties

Pawan Kumar,Masoud Hashemi,Hadi Safari-Katesari,Amir Sadeghpour,Emad Jahanzad,Stephen J Herbert,Martin Battaglia,Omid Reza Zandvakili

doi:10.3390/agronomy11071400

Abstract

Establishment of switchgrass (Panicum virgatum L.) is challenging, and failure in establishment may expose growers to considerable economic risk. The objectives of this research were to (i) evaluate whether management practices are variety-specific for the establishment of switchgrass and (ii) assess the effectiveness of cover crops as preceding crops on ‘Shawnee’ switchgrass establishment. Therefore, two studies were conducted at the University of Massachusetts Agricultural Experiment Station in Deerfield, MA, USA, in the 2011–2012 and 2012–2013 growing seasons. In Experiment 1, cover crop treatments (fallow, oat (Avena sativa L.) and rye (Secale cereale L.)) were the main plots, the two seeding methods (no-till drill and a cultipacker seeder (Brillion)) were the sub-plots, and the two varieties (‘Cave-in-Rock’ (CIR) and Shawnee)) were the sub-sub-plots. The second study was conducted using Shawnee switchgrass and involved the three cover crop treatments used in Experiment 1 using a cultipacker seeder with seed firming prior to planting but not afterwards (consistent in both experiments). The results indicated that a combination of oat and no-till resulted in higher tiller density (493%), lower weed biomass (77%), increased switchgrass biomass (SGB) (283%) and SGB to weed biomass (WB) ratio. Compared with Shawnee, CIR planted into a winter-killed oat residue had higher tiller density (93%), lower weed biomass (18%), higher switchgrass yield (128%) and thus a greater SGB:WB ratio (507%). Trends of switchgrass response to management practices, however, were similar between the two varieties, indicating that seed quality rather than management practices could influence switchgrass’s response to management practices. In Experiment 2, Shawnee tiller density was suppressed by rye as the preceding crop, possibly due to late termination of rye. Shawnee switchgrass yields were below 1000 kg ha−1 under all management practices; thus, harvesting should happen in the year following establishment. Future research should focus on comparing no-till drilling with cultipacker seeder with rolling not only before but after seeding to increase seed–soil contact.

Highlights

Switchgrass (Panicum virgatum L.) is a warm-season (C4) perennial grass with a fibrous root system
Research has shown that the effect of seeding method on switchgrass establishment could be soil type-dependent; in sandy soils in Massachusetts, no-till was effective in conserving soil moisture by not disturbing the soil, and herbicide termination resulted in more consistent switchgrass establishment
Previous reports have all agreed that integrating winter cereals into the establishment year of switchgrass could benefit the production system by reducing soil erosion, increasing switchgrass establishment, offering opportunities for no-till, and offsetting the establishment cost by harvesting the winter cereal crop

Summary

Introduction

Switchgrass (Panicum virgatum L.) is a warm-season (C4) perennial grass with a fibrous root system. Fast-growing cereals, including oat and rye, are widely used as cover crops due to their demonstrated weed-suppressing potential in different crops [13,15,16,17,18] These cereal cover crops often establish well and produce high biomass, and suppress weeds prior to planting the main crops [19,20,21,22,23]. A study by Keyser et al reported that wheat was the only cover crop that positively influenced switchgrass establishment [29] These authors did not report yield data in the establishment year but indicated no yield penalty in the succeeding years. The literature lacks information on whether management practices for establishing switchgrass are variety-specific

Objectives

Methods

Results

Discussion

Conclusion