Sweet sorghum responses to different water input and to compost fertilization in controlled environment under high temperature regime

The climate change can strongly affect the agricultural activity especially in relationship to the reduction of available water supply for the crops. On the other hand the agriculture can mitigate the global warming increasing the soil organic carbon stock and producing biomass for biofuels. In this context drought-tolerant energy crops can represent a way to combine the mitigation and adaptation measures. The aim of this study was to determine the vegeto-productive response of sweet sorghum (Sorghum bicolor (L.) Moench) under different watering regimes and to the compost fertilization. The experiment was carried out in a controlled environment condition under high-temperature regime. Two fertilization treatments, without (WO) and with compost (WC) incorporation, and three irrigation treatments, corresponding to a water supply respectively of 50% (LI), 75% (MI) and 100% (HI) of the field capacity, were applied. The dry weight of the total epigel biomass (TDB), the water use efficiency (WUE) and the phenological development were monitored. The irrigation treatments did not influence the WUE but significantly affected the plants TDB showing a positive relationship between the biomass growth and the water supply. The presence of compost did not significantly influence the plants TDB and WUE. The high-temperature regime compromised the phenological development and decreased the crop WUE.