Enhancing energy potential of sweet sorghum by biomass ash compost in the context of climate change and agroecosystem

Abstract

Recycling renewable energy waste, nutrient-rich biomass ash, via composting for biofuel crop fertilization is feasible for integrating waste and crop production to close the nutrient loop and mitigate greenhouse gaseous emissions. The primary purpose of the present study was to investigate the nutrient-rich compost on energy crop production, energy yield, and carbon input to the soil via the root under two different agroclimatic conditions. Compost treatments exhibited superior biomass growth in both sweet sorghum cultivars landrace and Gulseker in both regions. The effect was more potent in the temperate region (Sakarya) due to evenly precipitation during the entire plant growth period. On the other hand, biomass ash compost treatments induced higher Brix values in a region with high solar energy and hot and dry (Bitlis). However, the maximum juice yield (2387 L ha−1) and juice ethanol yield (1583 L ha−1) were obtained from the Sakarya region with cultivar Gulseker due to its high cane yield (68.76 t ha−1). The energy yield of sweet sorghum bagasse ranged from 92 to 282 GJ ha−1, and the maximum value was obtained from compost treatment in Sakarya regions. Compost also promoted an increase in the carbon content of root tissue, and sweet sorghum can bind around 1250 kg ha−1 recalcitrant forms of carbon to the soil via root tissue. Overall results indicate beneficial effects of compost on plant growth, biomass fuel, and root carbon storage in the soil, which could help waste management and agriculture together towards biofuel production with a more circular economy.