Rice Residue-Based Biochar Mitigates N2O Emission from Acid Red Soil

Muhammad Aamer,Maria Batool,Adnan Rasheed,Maria Naqve,Muhammad Umair Hassan,Muhammad Shaaban,Zhong Chuan,Athar Mahmood,Muhammad Bilal Chattha,Jinhua Shao,Guoqin Huang,Haiying Tang,Fahd Rasul

doi:10.3390/agronomy11122462

Abstract

Biochar application is considered an effective approach to mitigating nitrous oxide (N2O) emissions from agricultural soils. However, the mechanisms of biochar to mitigate N2O emissions from acidic red soils are still unclear. Therefore, the present study aims to underpin mechanisms associated with rice residue-based biochar in mitigating N2O emissions from acid soils. Soil treated with different rates of biochar control, from 1%, 2%, and 3%, and different soil properties, including soil pH, microbial biomass carbon (MBC), NH4+-N, NO3−-N, genes abundance (nosZ, nirK, AOA, and AOB), and enzymatic activities ((nitrate reductase (NR) and urease (UR)) were studied. The application of 3% biochar increased the soil pH (5.21–6.48), MBC (565–685 mg/kg), NO3−-N contents (24.23–44.5 mg/kg), genes abundance (nosZ, nirK, AOA, and AOB) and UR activity. The highest N2O emission (43.60 μg kg−1) was recorded and compared with the application of 1% (26.3 μg kg−1), 2% (18.33 μg kg−1), and 3% biochar (8.13 μg kg−1). Applying 3% biochar effectively reduced the N2O emission due to increased soil pH, MBC, NO3−-N contents, genes abundance (nosZ, nirK, AOA, and AOB), and weakened NH4+-N and NR activities. Therefore, increasing soil pH, genes abundance, and weakened nitrification following the addition of rice residue-based biochar can effectively reduce the N2O emissions from acidic red soils.

Highlights

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) that has persisted in the atmosphere for over 120 years, accelerating ozone layer depletion [1]
500 mL glass beakers were taken, 100 g incubated soil was added in each beaker, with biochar added according to treatments in each beaker and carefully mixed, and moisture was brought to 60% water-filled pore spaces (WFPS)
The application of 3% biochar significantly increased the soil pH by 13.78% compared to the control (Figure 1)

Summary

Introduction

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) that has persisted in the atmosphere for over 120 years, accelerating ozone layer depletion [1]. Agriculture is a major source of N2O emissions, and it has contributed 60% to global anthropogenic N2O emissions [2]. Excessive use of nitrogenous fertilizer is a major reason for this increase in N2O emissions [3]. The substantial increase in N2O emissions is a major reason for climate change and subsequent global warming. This has increased the concern across the globe to reduce the N2O emissions by using efficient measures to reduce impacts associated with rapid climate change and global warming [6,7]

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Conclusion