Biochar organic fertilizers from natural resources as substitute for mineral fertilizers

Abstract

Biochars are new, carbon-rich materials that could sequester carbon in soils improve soil properties and agronomic performance, inspired by investigations of Terra Preta in Amazonia. However, recent studies showed contrasting performance of biochar. In most studies, only pure biochar was used in tropical environments. Actually, there is little knowledge on the performance of biochar in combination with fertilizers under temperate climate. Therefore, we conducted an experiment under field conditions on a sandy Cambisol near Gorleben in Northern Germany. Ten different treatments were established in 72-m 2 plots and fivefold field replicates. Treatments included mineral fertilizer, biogas digestate, microbially inoculated biogas digestate and compost either alone or in combination with 1 to 40 Mg ha −1 of biochar. Soil samples were taken after fertilizer application and maize harvest. Our results show that the biochar addition of 1 Mg ha −1 to mineral fertilizer increased maize yield by 20 %, and biochar addition to biogas digestate increased maize yield by 30 % in comparison to the corresponding fertilizers without biochar. The addition of 10 Mg ha −1 biochar to compost increased maize yield by 26 % compared to pure compost. The addition of 40 Mg ha −1 biochar to biogas digestate increased maize yield by 42 % but reduced maize yield by 50 % when biogas digestate was fermented together with biochar. Biochar-fertilizer combinations increased K, Mg and Zn and reduced Na, Cu, Ni and Cd uptake into maize. Overall, our findings demonstrate that biochar-fertilizer combinations have a better performance than pure fertilizers, in terms of yield and plant nutrition. Therefore, an immediate substitution of mineral fertilizers is possible to close regional nutrient cycles.

The Effects of Gliricidia-Derived Biochar on Sequential Maize and Bean Farming

“…On the other hand, similar results were observed in temperate climates where high doses of biochar (50 t/ha) did not lead to significant increase in maize productivity over long term [64]. Other research shows [26,65] that the effect of biochar on crop productivity is a function of a range of factors such as the type of biochar and the amount of biochar added to the soil, where biochar is being applied and how much additional nutrient is added. For instance, it is shown [26] that low-dosage cow-urine-biochar application to root zone in a fertile silt loam soil in Nepal resulted in a more than 300% increase in pumpkin yield as compared to treatment with urine only.…”

Biochar for Soil Improvement: Evaluation of Biochar from Gasification and Slow Pyrolysis

“…Because biochar is not always applied purely but also mixed with manures, minerals fertilizers and compost [18][19][20][21], another wealth of data becomes available from trails that, however, also contribute to the complexity to explain the observed effects.…”

Evaluacion del uso de residuos organicos para la produccion de biochar y su aplicacion como enmienda organica

“…En estos estudios, se ha evidenciado la importancia del biochar para mejorar la calidad del suelo y, por tanto, la productividad (Glaser et al, 2014); a la vez que constituye una practica agrícola sostenible en términos ambientales al minimizar las emisiones asociadas al calentamiento global del sector agrícola (Case et al, 2012;Nelissen et al, 2014) y al representar una opción para la gestión de residuos (Shen et al, 2013). …”

“…La mejora del pH del suelo es uno de los efectos mas observados en las investigaciones sobre el uso de biochar como enmienda organica (Glaser et al, 2014;Oleszczuk et al, 2014), lo cual indica que este material carbonoso sería un sustituto adecuado de la cal en la agricultura.…”

“…De cualquier modo, la concentración de Cd en los tejidos vegetales estuvo por debajo del límite de detección, debido a que la biodisponibilidad de metales disminuye cuando se usa biochar como enmienda organica en relación con el uso directo del residuo original Glaser et al, 2014). Por lo tanto, las concentraciones de este elemento en los biochars no parecen constituir un riesgo de contaminación ni para el suelo ni para las plantas.…”