Biochar co‐compost improves nitrogen retention and reduces carbon emissions in a winter wheat cropping system

Abstract

Organic amendments, such as compost and biochar, mitigate the environmental burdens associated with wasting organic resources and close nutrient loops by capturing, transforming, and resupplying nutrients to soils. While compost or biochar application to soil can enhance an agroecosystem's capacity to store carbon and produce food, there have been few field studies investigating the agroecological impacts of amending soil with biochar co-compost, produced through the composting of nitrogen-rich organic material, such as manure, with carbon-rich biochar. Here, we examine the impact of biochar co-compost on soil properties and processes by conducting a field study in which we compare the environmental and agronomic impacts associated with the amendment of either dairy manure co-composted with biochar, dairy manure compost, or biochar to soils in a winter wheat cropping system. Organic amendments were applied at equivalent C rates (8 Mg C ha −1 ). We found that all three treatments significantly increased soil water holding capacity and total plant biomass relative to the noamendment control. Soils amended with biochar or biochar co-compost resulted in significantly less greenhouse gas emissions than the compost or control soils. Biochar co-compost also resulted in a significant reduction in nutrient leaching relative to the application of biochar alone or compost alone. Our results suggest that biochar co-composting could optimize organic resource recycling for climate change mitigation and agricultural productivity while minimizing nutrient losses from agroecosystems.

The effects of different biochar‐dairy manure co‐composts on soil moisture and nutrients retention, greenhouse gas emissions, and tomato productivity: Observations from a soil column experiment

“…Organic beefsteak tomato ( Solanum lycopersicum ) was chosen as the crop for the column study. The rationale for selecting this crop is because it followed the wheat–tomato crop rotation at the field site (Gao et al., 2023). In addition, tomato holds a major role in the California vegetable industry, with the majority of acreage harvested in the Central Valley (USDA‐NASS, 2020).…”

“…An extensive literature review conducted by Agegnehu et al (2017) highlights the greater potential of biochar co-compost to positively impact soil ecosystem services, as compared to biochar or compost alone. Similarly, a more recent meta-analysis conducted by Wang et al (2019) also reveals a substantial gain in yield (39.7%) for cereal crops grown with biochar co-compost, though much remains unknown about how agroecosystems respond to biochar co-compost application (Gao et al, 2023). Furthermore, balancing ecological stewardship and high levels of crop production remains a difficult task to resolve (Tully & Ryals, 2017).…”

Microbial community and network differently reshaped by crushed straw or biochar incorporation and associated with nitrogen fertilizer level

“…One of the positive effects of straw returning was the capture and reuse of nutrients that would have otherwise been lost during the straw removal from the agroecosystem, reducing the requirement of chemical fertilizers (Gao et al, 2023). Furthermore, straw returning can retain soil nutrients for a longer term compared with the use of chemical fertilizers alone (Siedt et al, 2021).…”

“…bacteria and fungi, biochar, chemical nitrogen fertilizer, diversity and function, network and modular pattern, straw return modes practices impacted a diverse set of soil microbial properties (Nie et al, 2018;Wang et al, 2019). Previous reports have suggested that a combination of straw and chemical fertilizers is considered the most beneficial treatment for soil bacteria communities and functions (e.g., increases in the richness of bacteria and fungi or the rate of N 2 fixation in soil); however, the effect is not always positive, which depends on straw characteristics, soil properties, and experiment conditions (Chen, Li, et al, 2022;Gao et al, 2023;Yang, Muhammad, et al, 2022). Notably, the turnover rate, stress tolerance, and nutritional requirements of bacteria markedly differ from fungi.…”

An appraisal of the utility of biochar in a rotation involving tobacco–rice in southern China

“…As a cost-effective and environmentally friendly soil amendment, biochar plays a huge role in improving soil nutrients conditions (Lian et al, 2020), enhancing crop growth and yield (Hale et al, 2020), and altering the composition of soil microbial. More importantly, an increasing number of research results confirm that biochar plays an undeniable role in reducing carbon emissions in agricultural production (Gao et al, 2023;Sun et al, 2021). Since Rondon et al (2005) first reported the decrease in N 2 O emissions followed by modifying the biochar soil amendment in a greenhouse test, employing biochar as a greenhouse gas emission control strategy for agricultural soils has become more appealing.…”