Long-term influence of biochar on native organic carbon mineralisation in a low-carbon clayey soil

Abstract

Biochar can influence native soil organic carbon (SOC) mineralisation through “priming effects”. However, the long-term direction, persistence and extent of SOC priming by biochar remain uncertain. Using natural 13C abundance and under controlled laboratory conditions, we show that biochar-stimulated SOC mineralisation (“positive priming”) caused a loss of 4 to 44 mg C g−1 SOC over 2.3 years in a clayey, unplanted soil (0.42% OC). Positive priming was greater for manure-based or 400°C biochars, cf. plant-based or 550°C biochars, but was trivial relative to recalcitrant C in biochar. From 2.3 to 5.0 years, the amount of positively-primed soil CO2-C in the biochar treatments decreased by 4 to 7 mg C g−1 SOC. We conclude that biochar stimulates native SOC mineralisation in the low-C clayey soil but that this effect decreases with time, possibly due to depletion of labile SOC from initial positive priming, and/or stabilisation of SOC caused by biochar-induced organo-mineral interactions.

Effects of Biochar Application on CO2 Emissions from a Cultivated Soil under Semiarid Climate Conditions in Northwest China

“…Some studies have shown that biochar addition could stimulate the mineralization of soil organic carbon (SOC) [11,12] and correspondingly increase emissions of CO 2 . However, conversely, the suppression of SOC mineralization was also reported [13,14], thereby causing a decrease in CO 2 emissions. The interactions of biochar and soil properties contribute to the different processes of SOC mineralization [11].…”

Effect of biochar on soil CO2 production

“…Generally, more CO 2 is produced in fertilized soils than in non-fertilized soils (Reicosky and Lindstrom, 1995;Pascual, et al, 1998). Biochar is considered as soil additive, which contributes to an increase of carbon sequestration (Singh and Cowie, 2014;Han et al, 2016), through decrease of CO 2 production. Overall, the average amount of released CO 2 over the reference period was significantly affected by the application of different rates of biochar (Table 1).…”

Kontribusi Kompos Jerami-Biochar Dalam Peningkatan P-Tersedia, Jumlah Populasi BPF dan Hasil Padi Sawah

“…Dalam kondisi ketersediaan hara anorganik yang berlimpah namun ketiadaan bahan organik, mikroba memperlihatkan ketidakmampuan untuk melaksanakan aktivitas metabolismenya sehingga jumlah populasi menurun. Hal ini sejalan dengan hasil penelitian Zhan dan Sun [26], yang menunjukkan terjadinya penurunan populasi bakteri di dalam tanah pada kondisi ketersediaan hara yang tinggi. Singh [27] menjelaskan bahwa keberadaan nutrisi hara anorganik menyebabkan kebutuhan tanaman menjadi segera tercukupi, sehingga bakteri tidak mendapatkan substrat yang dibutuhkan oleh sistem metabolismenya pada saat terlibat dalam proses mineralisasi unsur hara.…”