Effects of biochar use on drought and salinity stresses for cowpea production

Abstract Climate change is unavoidable and compromises future food availability. The aim of this research is to identify the physiological behaviour of vigna unguiculata . It is a common plant in Africa with drought’s resilience. An experiment was conducted at the University of Life Science “King Michael I”, Romania in 2023. Four treatments included C (Control soil without stresses), B (soil with 5% of biochar without stresses), D (soil with 5% of biochar with drought stress) and S (soil with 5% of biochar with salinity stress) were compared under total randomized experimental design. The biochar used during experiment come from rice husk. The drought-stress starts with 90% of plant watering and finished to 22% of plant watering and the salinity stress starts at 250 mM and finished at 450 mM. Evaluation are focussing on leaf area, chlorophyll content and stomatal conductance. The results show that water stress does not affect leaf area until 22% of plant watering. Also at this stage, stomatal conductance shows significant difference of 22.51±0.95 mmol/m 2 s 1 compared to control 59.96±0.37 mmol/m 2 s 1 . Under salinity stress at 450 mM of concentration, the leaf area are 111.40 ± 6.77 cm 2 compared to control 174.88 ± 3.91 cm 2 . The treatment with biochar improves positively leaf area 266.56 ± 7.34 cm 2 the leaf area is correlate of the fresh biomass weight result. Total chlorophyll is not affected by the various stresses. These results contribute for having better knowledge that vigna unguiculata can offer response to climate change and also how biochar can preserve crop production under stresses.