The response of lignocellulosic perennial grasses to different soil water availability

The Mediterranean climate is a climate change hot spot suffering by increasing drought periods during summer, with low rainfall and high evapotranspiration, which are limiting conditions for plant CO2 assimilation and biomass production, particularly for spring-summer crops. This would be even worst under marginal lands, where climatic, terrain and other limiting factors will further aggravate growing conditions and productivity. The present field experiment investigated the response to irrigation of several lignocellulosic perennial grasses. Plant stem density, stem height, stem weight and leaf area index were evaluated during the growing season with a monthly frequency. Stem density showed the lowest values for A. donax genotypes and the highest for the Miscanthus seed-based hybrids. High stem densities are observed at high irrigation levels. Stem height and weight are inversely correlated to stem density. A. donax genotypes had higher stem height and weight than the other genotypes. Irrigation has a significant positive effect on both measures. Leaf area index varied among genotypes, and irrigation increased this trait.