Biochar combined with nitrogen fertilizer: a practical approach for increasing the biomass digestibility and yield of rice and promoting food and energy security

Abstract

Rice is an important food crop that provides abundant biomass residues for biofuels. The use of nitrogen (N) fertilizer to increase rice biomass and yield in China has become increasingly common; however, the overuse of N fertilizer can create several environmental hazards and contribute to climate change. Biochar is well known for its ability to reduce N fertilizer amendment requirements without compromising rice yield and biomass. No studies to date have examined the effect of biochar on rice straw cellulose, pentose, and total sugar content under pretreatment and enzymatic hydrolysis. We conducted a two-season -early (spring) and late (autumn) -field experiment that involved the application of four levels of biochar (0, 10, 20, and 30 t ha −1 ) and two levels of N (low: 135 kg ha −1 ; high: 180 kg ha −1 ) to evaluate rice biomass digestibility, yield, and soil quality during 2019. Compared with sole N fertilizer (i.e., both treatments with 0 t biochar ha −1 ), biochar application at the rate of 30 t ha −1 combined with 135 kg N ha −1 significantly (P < 0.05) enhanced soil physiochemical properties, including increases in the activity of urease, catalase, and β-glucosidase by 69%, 25%, and 54%, respectively during both seasons (spring and autumn). Similarly soil microbial biomass carbon and nitrogen were increased in 30 t B ha −1 along with both N rates as compared to sole N treatments. Furthermore, hexoses, pentoses, and total sugars released with NaOH pretreatment were increased by 22%, 10%, and 12.93%, respectively, with 30 t biochar ha −1 plus 135 kg N ha −1 compared with the sole N treatments in both seasons. Moreover, under enzymatic hydrolysis, the hexoses, pentoses, and total sugars released were increased by

Impact of Nitrogen, Zinc and Humic Acid Application on Wheat Growth, Morphological Traits, Yield and Yield Components

“…Nitrogen is often the most deficient of all the plant nutrients. Nitrogen is the key element in achieving consistently high yields in cereals (Iqbal et al, 2019;Iqbal et al, 2020, Ali et al, 2020Wu et al, 2021, Ali et al, 2022.…”

Effects of Biochar and Nitrogen Application on Rice Biomass Saccharification, Bioethanol Yield and Cell Wall Polymers Features

“…Several alternative energy production technologies have been created, with crops biomass energy generation receiving particular attention due to its ecologically beneficial nature [ 1 , 2 ]. Rice is the most cultivated crop in Guangxi province of China and a staple food worldwide, resulting annually in more than 800 million metric tons of biomass [ 3 , 4 ]. However, a huge quantity of agricultural biomass is burned in the field and buried in soil in southern China, which is not environmentally friendly since it harms soil fauna and degrades soil quality.…”

“…Moreover, fertilizer management significantly affects rice biomass and its yield [ 5 , 6 , 7 ], and to improve rice yield and biomass, farmers excessively use chemical fertilizer, especially N, which is not eco-friendly [ 8 , 9 ]. To cope with this problem, many studies reported that biochar has the potential to decrease the requirement of N fertilizer without compromising rice yield and biomass [ 3 , 9 , 10 , 11 ].…”

“…Biochar is a carbon-rich, refractory organic substance made by the controlled combustion of organic material (biomass) from agricultural and forestry wastes, animal bones, algae, and animal manures [ 3 , 12 ]. The application of biochar not only improves physiochemical soil properties [ 9 , 13 ] but also reduces greenhouse gas emissions [ 14 , 15 , 16 ].…”

“…The application of biochar not only improves physiochemical soil properties [ 9 , 13 ] but also reduces greenhouse gas emissions [ 14 , 15 , 16 ]. Previously, it was reported that biochar can improve rice biomass digestibility [ 3 ]. However, the impact of biochar in combination with nitrogen fertilizer on rice crop cellulose, hemicelluloses, lignin, hexoses, and bioethanol yield has not yet been reported.…”