Biochar application to low fertility soils: A review of current status, and future prospects

Soil carbon increased by twice the amount of biochar carbon applied after 6 years: Field evidence of negative priming

“…A few field studies reported that biochar application at 10 and 20 Mg/ha to soils used for switchgrass production can increase soil C concentrations (Allaire et al, 2015;Backer et al, 2016), reduce soil bulk density (Aller et al, 2017), and increase water infiltration and retention (Sandhu & Kumar, 2017). Therefore, biochar applications could be effective for increasing soil productivity and enhancing the sustainability of dedicated bioenergy production systems in degraded or otherwise low-quality agricultural soils (El-Naggar et al, 2019).…”

Addition of Biochar to a Sandy Desert Soil: Effect on Crop Growth, Water Retention and Selected Properties

“…Only the BC300 treatment showed a consistent positive impact on pH, OM, and CEC. Pyrolysis temperature of date palm residue along with aging are key factors in determining the potential benefit of BC derived from date palm residues added to sandy desert soil.crop yield is largely dependent on BC production temperature and the feedstock (FS) [5][6][7]. In a recent review, it was reported that the fertilizing value of BC and its nutrient availability, especially N and P, decrease with increasing pyrolysis temperature [5].…”

“…Some studies found BC to be the most effective when it is applied with mineral fertilizers [8,14,[17][18][19]. Therefore, positive impact of BC on soil fertility and crop yield is not always certain, and it highly depends on FS, BC production temperature, and most importantly soil type [3,[5][6][7]20].BC benefits to soil also include improvement of soil physical properties. For instance, soil bulk density (BD) and porosity was found to be improved after BC application [20][21][22][23][24][25][26].…”

“…BC was also reported to increase the soil ability to retain water, and this is mostly attributed to the high total porosity (TP) of BC, retaining water in small pores and thereby increasing water holding capacity and infiltration [5,20,21]. However, enhancement of soil physical properties following BC application is more evident in infertile and course-textured soils [7,23].Key soil chemical properties, such as pH, OM content, and CEC are also influenced by BC addition, affecting soil fertility and productivity [3,7,[27][28][29]. In most cases, BC is alkaline, and therefore its effect on increasing acidic soil pH was demonstrated in several studies whereas its impact on alkaline soil pH is expected to be minimal [5][6][7].…”

“…In most cases, BC is alkaline, and therefore its effect on increasing acidic soil pH was demonstrated in several studies whereas its impact on alkaline soil pH is expected to be minimal [5][6][7]. Reviewed studies reported increases in CEC and organic matter in soil treated with BC; however, the magnitude of this effect varies according to the BC production condition, application rate, and soil type [3][4][5][6][7].BC use is most frequently reported to be effective in tropical zones where soils are acidic and nutrient leaching potential is high [30]. Under these soils conditions, BC can have liming and nutrient availability effects, as BC was found to increase pH values of acidic soils and thereby improve nutrient bioavailability and use efficiency [7,31].…”