Analysis of young Miscanthus × giganteus yield variability: a survey of farmers’ fields in east central France

Claire Lesur‐Dumoulin,Chantal Loyce,Mathieu Bazot,Marie‐Hélène Jeuffroy,Mathieu Lorin

doi:10.1111/gcbb.12247

Abstract

AbstractMiscanthus × giganteus is often regarded as one of the most promising crops to produce bioenergy because it is renowned for its high biomass yields, combined with low input requirements. However, its productivity has been mainly studied in experimental conditions. Our study aimed at characterizing and explaining young M. giganteus yield variability on a farmers’ field network located in the supply area of a cooperative society in east central France. It included the first three growth years of the crop. We defined and calculated a set of indicators of limiting factors that could be involved in yield variations and used the mixed‐model method to identify those explaining most of the yield variation. Commercial yields averaged 8.1 and 12.8 t DM ha−1 for the second and third growth year, respectively. However, these mean results concealed a high variability, ranging from 3 to 19 t DM ha−1. Commercial yields, measured on whole fields, were on average 20% lower than plot yields, measured on a small area (two plots of 25 m2). Yields were found to be much more related to shoot density than to shoot mass, and particularly to the shoot density established at the end of the planting year. We highlighted that planting success was decisive and was built during the whole plantation year. Fields with the lowest yields also had the highest weed cover, which was influenced by the distance between the field and the farmhouse, the preceding crop and the soil type. Our findings show that growing young M. giganteus on farmers’ fields involves limiting factors different from those commonly reported in the literature for experimental conditions and they could be useful to assess the economic and environmental impacts of growing M. giganteus on farmers’ fields. They could also stimulate the discussion about growing bioenergy crops on marginal lands.

Highlights

Miscanthus 9 giganteus is a C4 perennial rhizomatous grass originating from east Asia, which has been studied as an energy crop since the mid-1980s, mostly in the European Union (Lewandowski et al, 2003) and more recently in the United States (Heaton et al, 2008)
Plot yield was highly variable in the network of farmers’ fields: it ranged from 2.6 t DM haÀ1 to 22.4 t DM haÀ1. plot yield (pYIELD) depended more strongly on shoot density (SH_DENS) (P < 0.001 and partial r2 = 0.61) than on shoot mass (SH_MASS) (P < 0.001 and partial r2 = 0.31) (Table 3)
Yield was related to shoot height (P < 0.001 and partial r2 = 0.24), but was not related to shoot diameter. pYIELD increased with shoot density up to about 390 000 shoots mÀ2 (Fig. 2)

Summary

Introduction

Miscanthus 9 giganteus (hereafter called M. giganteus) is a C4 perennial rhizomatous grass originating from east Asia, which has been studied as an energy crop since the mid-1980s, mostly in the European Union (Lewandowski et al, 2003) and more recently in the United States (Heaton et al, 2008). M. giganteus rhizomes are planted in spring. As crop production during the first growth year is not sufficient to make harvest profitable, the crop is crushed to establish a mulch on the soil surface. From the second year on, the crop is harvested annually. Despite biomass losses during winter, M. giganteus is usually harvested at the ANALYSISOFM.

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Results

Conclusion