Combined Application of Biochar and Lime Increases Maize Yield and Accelerates Carbon Loss from an Acidic Soil

Abstract

Biochar, an ecologically friendly soil amendment, is suggested for large-scale field application for its multiple potential benefits, including carbon sequestration, crop yield improvement, and the abatement of greenhouse gas emissions. However, it is unknown how effective it is in changing soil properties and its associated yield improvement when biochar is co-applied with lime in acidic soil. Here, we examined the effects of two different biochars, i.e., rice husk biochar (RHB) and oil palm empty fruit bunches biochar (EFBB), and lime on nutrient availability, the yield of maize, and soil CO2 emission of acid soil. Biochars were applied at two different rates (10 and 15 t ha−1) in combination with two rates of lime (100% and 75%), while the recommended rate of NPK fertilizers, 100% lime, and without any amendments (control) were also included. Hybrid sweet corn was grown in pots with 20 kg soils for 75 days. Plant performance and soil analyses were performed before and after crop maize cultivation while CO2 emission was recorded. Compared to the control, combined RHB biochars with lime significantly buffered soil pH and increased nutrient availability (e.g., P by 137%), while reducing Al and Fe concentration at harvest. These changes in soil properties significantly increased maize yield (by 77.59%) and nutrient uptake compared to the control. Between the two biochars, RHB was relatively more effective in making these changes than EFBB. However, this treatment contributed to a greater carbon loss as CO2 (209% and 145% higher with RHB and EFBB) from soil than the control. We believe that biochar-mediated buffering of soil pH is responsible for this change. Our results suggest that combined biochar application could bring desirable changes in soil properties and increase crop performance, although these effects can be short-lived.

Combined Application of Rice Husk Biochar and Lime Increases Phosphorus Availability and Maize Yield in an Acidic Soil

“…In the initial stage of our pot study, the emission of CO 2 flux was highest on day 5 from all the amended soil due to the speedy mineralization of soil organic carbon [68]. This result is consistent with the findings of Mosharrof et al [69]. According to Fidel et al [70], the daily emission of CO 2 was changed because of the variation of density of root and biomass of plants, resulting in the labile soil organic carbon variation.…”

Reducing aluminum is the key nutrient management strategy for ameliorating soil acidification and improving root growth in an acidic citrus orchard

“…In summary, it can be preliminarily concluded that Al 3+ stress has become a major threat to root growth in pomelo orchards. In general, crop roots indeed improved, while crop yield also significantly increased after the application of soil amendments, that is, lime and biochar, to neutralize Al 3+ (Demchak & Smith, 2019; Hale et al, 2020; Hin et al, 2020; Li, Cui, et al, 2019; Mosharrof et al, 2021). Conversely, studies also found that short‐term lime application was not sufficient to completely solve soil acidification (Li, Conyers, et al, 2019; Li, Cui, et al, 2019; Li, Li, et al, 2019; Zhang, Yang, Hsu, et al, 2021; Zhang, Yang, Muneer, et al, 2021), which might be the cause of the lack of a significant difference in yield among the different treatments in the first 2 years (2019 and 2020) (Figure 8).…”

Effects of Biochar on the Microenvironment of Saline-Sodic Soil and Maize Growth

“…In particular, SOC was the most critical factor consistently affecting bacterial and fungal community structure. Shortly after the application of carbon-rich biochar, the unstable carbon in the biochar will rapidly act on soil microorganisms and promote their growth and reproduction [28][29][30]. Furthermore, some small molecules in biochar act as potential regulators that alter soil microbial activity and community structure [31].…”