Effect of biochar treatment on soil pH and cucumber fruit: A demonstration of the importance of biochar amendment on the tropical soils of Nigeria

This study hypothesized that biochar produced from different feedstock contains varied nutrient compositions and may ameliorate acidic soil and improve yield parameters of cucumber ( Cucumis sativus ) via an interrelated structure. We aimed to evaluate biochar nutrient composition from different feedstock and inspect the interrelationship between soil pH and yield parameters of cucumber using structural equation modeling (SEM). Eleven treatments consisting of the sole application of biochar (B) from different feedstocks at the rate of 20 t ha−1 and their combinations with poultry manure (i.e., 10 t ha−1 biochar +10 t ha−1 poultry manure) were used. The highest pH value of 5.89 was obtained in fields amended with 20 t ha−1 plantain peel biochar (PPB). We used SEM to find that soil pH produced a negative but significant relationship with fruit weight and length. Combining biochar with poultry manure is recommended for sustainable cucumber production in the tropical region of Nigeria or elsewhere.