Effect of Carbon Content in Wheat Straw Biochar on N2O and CO2 Emissions and Pakchoi Productivity Under Different Soil Moisture Conditions

Abstract

Agricultural soils are a primary source of greenhouse gas (GHG) emissions. Biochar is commonly used as a soil amendment to prevent climate change by reducing GHG production, increasing soil carbon storage, improving soil moisture retention, and enhancing crop productivity. However, the impact of biochar’s carbon content under subsurface drip irrigation (SDI) has not been well studied. Here, we investigated the effect of different carbon (C) contents in wheat biochar under different SDI depths on soil nitrous oxide (N2O), carbon dioxide (CO2), soil moisture distribution, and Pakchoi productivity. A pot experiment was conducted using three SDI depths, emitters buried at 0.05, 0.10, and 0.15 m below the soil’s surface, and three levels of C content named zero biochar (CK), 50% C (low (L)), and 95% C (high (H)) in greenhouse cultivation. The findings showed biochar significantly decreased N2O and CO2 emissions. Compared to CK, the L and H treatments decreased N2O by (18.20, 28.14%), (16.65, 17.51%), and 11.05, 18.65%) under SDI5, SDI10, and SDI15, respectively. Similarly, the L and H treatments decreased CO2 by (8.05, 31.46%), (6.96, 28.88%), and (2.97, 7.89%) under SDI5, SDI10, and SDI15, respectively. Compared to CK, L and H increased soil moisture content. All plant growth parameters and yield traits were enhanced under SDI5. In summary, biochar addition significantly decreased soil N2O and CO2 emissions compared to CK, and increased growth performance and yield, and maintained soil moisture content. The H treatment significantly reduced N2O and CO2 emissions, increased plant growth and yield, and maintained soil moisture content compared to the L treatment. Soil moisture was reduced vertically and horizontally with increased radial distance from the emitter.

Biochar use in agriculture as a nature-based solution: factors influencing N>small<>sub<2>/small<>/sub<O emissions in tropical soils

“…The most significant reduction was seen in soils amended with sugarcane straw biochar, where N2O emissions were 50% lower than in NF (Figure 12 B). This finding corroborates with studies that have observed suppression of N2O emissions caused by straw-based biochars (Abbruzzini et al, 2019;Hamad et al, 2023;Zhang et al, 2022). Conversely to previous studies that reported no reductions in soil N2O emissions in response to woody biochar application (Lan et al, 2019;Ramlow et al, 2019), we observed that both wood-based biochars reduced N2O emissions.…”

Optimization of a Lower Irrigation Limit for Lettuce Based on Comprehensive Evaluation: A Field Experiment

“…Irrigation is the leading water resource consumer and a key factor affecting soil greenhouse gas emissions [ 1 ]. Irrigation can change the conditions of soil moisture, temperature, oxygen, and microorganisms, thus influencing the production and release of greenhouse gases such as carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) [ 2 , 3 ].…”

Soil Gaseous Carbon Emissions from Lettuce Fields as Influenced by Different Irrigation Lower Limits and Methods

“…Climate change is a serious global issue due to increasing environmental pollution and the fast expansion of agricultural lands. Gaseous carbon emissions are released continuously into the atmosphere [1]. The carbon cycle in agroecosystems is the most fundamental ecological process and has a crucial impact on greenhouse gas emissions such as CO 2 and CH 4 [2].…”

“…The carbon cycle in agroecosystems is the most fundamental ecological process and has a crucial impact on greenhouse gas emissions such as CO 2 and CH 4 [2]. At the 75th United Nations General Congress [1], China proposed that its carbon dioxide emissions would reach a peak by 2030 and it would achieve carbon neutrality by 2060. Therefore, it is urgent to increase crop production by paying more attention to reducing greenhouse gas emissions and increasing their sequestration.…”

“…Thus, the present study hypothesizes that drip irrigation, as a water-saving method, affects gaseous carbon emissions mainly by influencing the soil's environment and properties. Hence, three different drip irrigation methods were designed in a lettuce field to (1) quantitatively investigate the different irrigation effects on soil gaseous carbon emission, (2) evaluate the relationship between gaseous carbon emission and soil properties under different irrigation schemes, (3) and find out the optimal irrigation method that should be employed as an effective irrigation scheme for reduced greenhouse gas emissions. Moreover, furrow irrigation, a traditional irrigation practice locally, was used for comparison to help understand the impact of changing irrigation methods on gaseous carbon emissions.…”