Influence of soil texture and crop management on the productivity of miscanthus (Miscanthus × giganteus Greef et Deu.) in the Mediterranean

Abstract

Biomass productivity is the main favorable trait of candidate bioenergy crops. Miscanthus 9 giganteus is a promising species, due to its high-yield potential and positive traits including low nutrient requirements and potential for C sequestration in soils. However, miscanthus productivity appears to be mostly related to water availability in the soil. This is important, particularly in Mediterranean regions where the risk of summer droughts is high. To date, there have been no studies on miscanthus responses under different soil conditions, while only a few have investigated the role of different crop managements, such as irrigation and nitrogen fertilization, in the Mediterranean. Therefore, the effects of contrasting soil textures (i.e. silty-clay-loam vs. sandy-loam) and alternative agricultural intensification regimes (i.e. rainfed vs. irrigated and 0, 50, 100 kg ha À1 nitrogen fertilization), on miscanthus productivity were evaluated at three different harvest times for two consecutive years. Our results confirmed the importance of water availability in determining satisfactory yields in Mediterranean environments, and how soil and site characteristics strongly affect biomass production. We found that the aboveground dry yields varied between 5 Mg ha À1 up to 29 Mg ha À1 . Conversely, nitrogen fertilization played only a minor role on crop productivity, and high fertilization levels were relatively inefficient. Finally, a marked decrease, of up to À40%, in the aboveground yield occurred when the harvest time was delayed from autumn to winter. Overall, our results highlighted the importance of determining crop responses on a siteby-site basis, and that decisions on the optimal harvest time should be driven by the biomass end use and other long-term considerations, such as yield stability and the maintenance of soil fertility.

Ecosystem model parameterization and adaptation for sustainable cellulosic biofuel landscape design

“…Our resulting model explains approximately half of the observed variability in yield and GHG observations in our dataset, and realistically captures climate effects and responses to management intensity. While soil type has been observed to have an effect on bioenergy grass productivity in semi‐arid climates outside the U.S. (Di Virgilio et al ., ; o Di Nasso et al ., ; Roncucci et al ., ), we did not observe a strong texture signal in our domestic switchgrass productivity dataset, consistent with a similar previous large‐scale model parameterization effort (Wullschleger et al ., ). Future modeling work on soil‐climate interactions in the U.S. would greatly benefit from additional field trails like Wilson et al .…”

Miscanthus × giganteus nutrient concentrations and uptakes in autumn and winter harvests as influenced by soil texture, irrigation and nitrogen fertilization in the Mediterranean

“…This study focused on nutrients in miscanthus aboveground biomass, while dry biomass yield data have already been described by Roncucci et al . (). In Experiment 1 dry biomass yields were lower in SL compared to SiC soil (around 21 vs. 7 Mg ha −1 as the 2 year average).…”

“…This study was based on the experimental framework of miscanthus previously described by Roncucci et al . () in the Mediterranean (Pisa, Italy). Here, two main questions were addressed: (i) how soil texture and crop management (i.e.…”

Importance of biophysical effects on climate warming mitigation potential of biofuel crops over the conterminous United States

“…The albedo effects, however, are secondary to the effects of crop type on LE, which is a major component of the water cycle. Both crop productivity and LE are strongly influenced by irrigation, particularly in arid environments (Roncucci et al ., ). Experiments suggest miscanthus has larger transpiration due to the higher stomatal conductance to support its high carbon assimilation rate (Dohleman et al ., ), which is consistent with our results.…”