Preface

Climate change, water scarcity, soil degradation, and greenhouse gas (GHG) emission are the major challenges for food security. The world's population is expected to reach 9 billion by 2050, which will require an increase of more than 50% in agricultural food supply to meet the growing demand. Throughout the world, agricultural crop residue is usually handled as a liability, often because the means to transform it into an asset are lacking. Concerns regarding global warming and food security have led to a surge in interest in the management of crop residues to increase carbon sequestration and grain yield in agriculture. Crop residue burning has become a major environmental problem causing health issues as well as contributing to global warming and the degradation in soil health. India, being an agriculture-dominant country and the second largest agro-based economy with year-round crop cultivation, produces a large amount of agricultural waste. According to the Indian Ministry of New and Renewable Energy, India generates on an average 500 million tons of crop residue per year. In the absence of adequate sustainable management practices, approximately 92 metric tons of crop waste are burned every year in India, causing excessive particulate matter emissions and air pollution. Biochar offers the opportunity to provide a sustainable solution to mitigate these issues.

Soil organic carbon (SOC) content, which plays an important role in soil sustainability, is a key indicator of soil fertility. SOC is the basis of soil fertility. It releases nutrients for plant growth, promotes the structural, biological, and physical health of soil, and is a buffer against harmful substances. The main source of SOC in cropland is crop residue; therefore, crop residue amendment is considered one of the most important management practices in maintaining soil fertility. Efficient use of biomass by converting it to a useful source of soil amendment is one way to improve soil fertility. Agriculture is a major source of GHG emissions globally. Increased use of production inputs, such as mineral fertilizer, has made agriculture more GHG intensive. Rising concentration of the GHG carbon dioxide in the atmosphere is a major anthropogenic cause of climate change. The changing climate impacts society and ecosystems in many harmful ways.

To increase carbon sequestration, farmers can use biochar, which is the pyrolyzed product of the thermal degradation of organic materials in the absence of oxygen and is distinguished from charcoal by its use as a soil amendment. Over the past few years, pyrolyzed organic carbon has received much attention from researchers because of the possible benefits arising from soil quality and crop yields. It is a unique substance that retains exchangeable and plant-available nutrients in the soil, improving crop yields while decreasing environmental pollution by nutrients. Biochar is an effective means to withdraw carbon dioxide from the atmosphere and consequently influence the trend of global climate change. The physical structure of biochar improves soil fertility by decreasing soil tensile strength and bulk density. Biochar also acts as a soil aggregate, which provides a habitat for microorganisms. Additionally, the porosity of biochar improves nutrient and water retention in soils thereby improving agronomic efficiency and increasing yields. It has often been referred to, not only as one of the possible means for enhancing soil fertility, but as black gold for agriculture as well. If the fertility or nutrient status of soil

is increased, it leads to an increase in crop production and plays a significant role in maintaining soil quality and health. It offers not only an attractive solution for reducing air pollution from the open burning of crop residues, but is also a favorable sustainable model for reutilizing agricultural wastes.

This book attempts to gather and discuss the information and technologies developed for biochar production and its application to agriculture. The emphasis in this endeavor is on the use of biochar in agriculture for improving soil health, crop productivity, and GHG mitigation. This book contains chapters that look at outcomes of biochar research being conducted in different parts of India, and the potential benefits of biochar use in improving soil health, crop productivity, and in mitigating climate change through reduction in emission of GHGs and carbon sequestration. Biochar has great potential for improving soil fertility and crop productivity.

We are thankful to the authors who are experts in their respective fields, and who have written a comprehensive and valuable resource for researchers, academicians, and students interested in gaining knowledge of role of biochar in the field of agricultural sustainability.

Last but not the least, we acknowledge wholeheartedly IntechOpen for publishing this book for the benefit of the agricultural fraternity.

> **Vikas Abrol and Peeyush Sharma** Division of Soil Science and Agricultural Chemistry, Sher-e-Kashmir University of Agricultural Sciences and Technology, India

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Section 1

Biochar for Sustainable

Crop Productivity and Soil

Health

### Section 1
