Biochar and other indigenious additives for improving soil fertility in Ghana’s savanna

Das Erfordernis, Ernährungssicherheit zu gewährleisten und negative Klimawandelfolgen zu mindern, verdeutlicht den Wert eines innovativen Bodenfruchtbarkeitsmanagements. Viele Böden Ghanas, besonders der Savannenzonen, besitzen eine geringe Fruchtbarkeit, was eine optimale Pflanzenproduktivität stark beeinträchtigt. Steigende Kosten und unregelmäßige Verfügbarkeit von anorganischen Düngern machen es notwendig, lokal verfügbare und nachhaltige Strategien zur Bodenfruchtbarkeitsverbesserung zu finden. Diese Arbeit untersuchte den Einsatz von Biokohle und lokalen Ressourcen wie Herdasche, Kompost und Abwasser in Laborinkubations-, Gewächshaustopf- und experimentellen Feldversuchen, um Bodenfruchtbarkeit und Pflanzenproduktivität zu steigern. Die Zugaben erhöhten den Gehalt bodenorganischer Substanz und verbesserten Nährstoffverfügbarkeit und mikrobielle Aktivität, wodurch der Boden fruchtbarer und resilienter wurde. Die verbesserte Bodenfruchtbarkeit korrelierte mit höheren Ernteerträgen

Short-term effect of biochar on microbial biomass, respiration and enzymatic activities in wastewater irrigated soils in urban agroecosystems of the West African savannah

Irrigated urban agriculture (UA) supports the economy and health of urban inhabitants in low-income countries. This system is often characterized by high nutrient inputs and mostly utilizes wastewater for irrigation. Biochar has been proposed to increase crop yields and improve soil properties. In this study, we assessed the transient effect of rice husk biochar (20 t $ha^{−1}$) and/or fertilizer (NPK: 15-15-15) on microbial respiration, microbial biomass carbon and enzyme activities of irrigated (wastewater and tap water) soil from an UA field experiment in the Guinea savannah zones of Ghana. Our results showed an increase by up to 123% in soil organic carbon (SOC) after a year of biochar application, while hot water extractable carbon (HWEC) was increased by only 11 to 26% and microbial biomass carbon (MBC) by 34%. Basal respiration was significantly increased in mineral fertilized soil by up to 46% but decreased by 12–45% under wastewater irrigation. Overall, the metabolic quotient ($\it q$$CO_{2}$) indicated less stress for the microbial community and increased carbon use efficiency with biochar application and wastewater irrigation. Total enzymes activity was increased under wastewater irrigation and biochar treated soils exhibit a more diverse composition of C-cycling enzymes and a higher activity of aminopeptidases. Biochar and wastewater showed positive effects on biological soil properties and contributed to soil fertility. Our results suggest beneficial effects of biochar on non-biochar SOC stocks in the long term