Physiological behaviour and nutritional status of coffee (Coffea arabica L. var. Castillo) trees in response to biochar application

Abstract

Applying coffee pulp biochar (BC) can be a complementary practice to the application of chemical fertilizers (CF) of crops; however, little evidence of its combined effects on coffee cultivation has been reported. A field trial was carried out during two evaluation years (2019 and 2020) to analyse the effect of the application of different BC doses (0, 4, 8 and 16 t/ha) in combination with four levels of fertilization (0, 33, 66 and 100% of the nutritional requirements) on physiological responses of 3-year-old coffee (Coffea arabica L. var. Castillo) trees. The results indicated that trees with 0 t/ha BC and 0% CF showed the lowest values in all the physiological variables studied (gs = 269.9 and 126.8 mmol/m2/s; Chl = 61.7 and 54.7 At-leaf readings; yield = 0.21 and 0.22 kg of dry parchment coffee (DPC)/tree for 2019 and 2020, respectively). Coffee trees treated with 8 t/ha BC and CF levels of 100% registered the highest results in gs (424.9 and 366.9 mmol/m2/s), Chl (71.1 and 69.8 At-leaf readings), yield (0.41 and 0.57 kg of DPC/tree) in 2019 and 2020, respectively. In conclusion, the application of BC from coffee pulp, especially at a dose of 8 t/ha, generates a positive effect on yield, gs, leaf nutrient concentration and Chl of coffee trees. The use of BC can be an alternative to complement the mineral nutrition of commercial coffee crops to help reduce the application of CF.

Assessing the Potential of Biochar as a Viable Alternative to Synthetic Fertilizers in Sub-Saharan Africa Smallholder Farming: A Review

“…The beneficial effects of combining biochar with other fertilizer sources on plant growth and yield have also been observed in coffee (Coffea arabica L. var. Castillo) [116], potato (Solanum tuberosum L.) [117], tomato [109], and wheat [118]. Nevertheless, further research is needed to determine how biochar can decrease chemical fertilizer use input while maintaining the fruit yield and quality in other agronomic and horticultural crops [102].…”

Physiological response of ‘Castillo el Tambo’ coffee plants to biochar and chemical fertilization applications

“…The BC doses were the equivalent to 0, 4, 8, and 16 t ha -1 (BC0 = 0 g plant -1 ; BC4 = 3 g plant -1 ; BC8 = 6 g plant -1 , and BC16 = 12 g plant -1 ). The doses were selected based on the agronomic responses in a field experiment (Sanchez-Reinoso et al, 2022). The BC used was manufactured from coffee pulp under medium pyrolysis at 500 °C and showed the following characteristics: pH 9.42; electrical conductivity 19.4 dS m -1 ; organic C (OC): 46.4%; ashes 20.8%; N: 2.81%; P: 1.11%; Ca: 0.97%; K: 4.37%; Mg: 0.43%; Cu: 53.5 mg kg -1 ; Fe: 2795 mg kg -1 ; Zn: 110 mg kg -1 ; B: 99.3 mg kg -1 ; CEC: 103 meq 100 g -1 ; OC/N: 16.5.…”

“…It is also the second most commercialized product worldwide after oil. In Colombia, coffee is one of the main crops with a production of about 13 890 000 60-kg bags of green coffee in 853 700 ha and 11 218 000 bags exported in 2020 (Federación Nacional de Cafeteros de Colombia, 2022;Sanchez-Reinoso, 2022).…”

“…However, several organic components have been developed to reduce the excessive use of chemical fertilizers, with BC being a potential alternative that improves both, soil quality parameters and crop productivity (Alam et al, 2020). Nevertheless, the positive effect of the use of BC on plant physiology remains limited, especially in tropical or subtropical crops such as coffee (Sanchez-Reinoso et al, 2022).…”