Effect of Biochar on Growth, Photosynthetic Characteristics and Nutrient Distribution in Sugarcane

Abstract

Continuous growing of exhaustive crops like sugarcane and imbalanced use of fertilizers would deplete the soil nutrients, degrade its health and ultimately restrict the crop growth. Biochar due to its unique nature can improve soil health, plant growth and nutrient distribution. The pot experiment was carried out with the biochar which derived from cassava straw additions of 0 t/ha (C0), 10 t/ha (C10) and 20 t/ha (C20), respectively. The biomass, green leaf number, leaf area, shoot/root ratio, photosynthetic characteristics and nitrogen, phosphorus and potassium nutrient contents were measured during sugarcane seedling, elongating and maturity stages to analyze the effect of biochar on sugarcane growth. The results showed that biochar application improved leaf biomass from 7.80 to 50.40%. However, biochar addition did not show a significant increase in sugarcane total biomass except form leaf biomass. Total biomass of sugarcane showed the coherent pattern of 0.20%, − 4.24% and 5.81% for C10 and 1.74%, 11.98% and − 1.83% for C20 at seedling, elongation and maturity stages, respectively. The accumulation of nitrogen, phosphorus and potassium contents in leaves, shoots and roots was significantly increased at seedling, elongation and maturity stage, respectively. Furthermore, maximum total nitrogen content (4.64%) for C10, total phosphorus content (11.47 g kg−1) and total potassium content (76.29 g kg−1) for C20 also were higher than those of control at elongation stage. Biochar application significantly increased net photosynthetic rate and decreased transpiration rate during all the growth stages. These findings not only lead us to know that biochar application has positive effect on sugarcane growth, photosynthetic characteristics and nutrients utilization, but also indicate that field trials for several growing cycles are needed to fully understand the effects of biochar on sugarcane growth.