BIOCHAR AS A POTENTIAL SOIL CONDITIONER IN SALINE PRONE COASTAL AREA OF BANGLADESH

Abstract

Soil salinity restricts normal crop production of coastal areas in Bangladesh, and increases with the desiccation of the soil. Currently, biochar has attracted great attention as a smart soil amendment for mitigating the adverse effects of salinity. In this respect, a field experiment was performed to examine the responses of biochars on soil characters and growth of okra (Abelmoschus esculentus L.) and to identify a suitable biochar amendment for salt-affected soils. The experiment was conducted in a completely randomized block design (CRBD) with five replications. Three types of biochar (produced from rice straw, sawdust and water hyacinth) were applied @ 10 t ha in a silt loam soil along with the control. Results revealed that biochar application to the soil enhanced height of plant, leaf number, largest leaf area, shoot fresh weight, shoot dry weight and yield of okra as well as improving the soil quality e.g., field capacity (FC), cation exchange capacity (CEC), organic carbon (OC), total N, available P, S, K, and Ca. Water hyacinth biochar improved almost all of the growth and yield attributes of okra along with most of the soil properties than that of others. The results suggest that water hyacinth biochar might be recommended as a suitable soil amendment for better crop growth and soil quality. Moreover, water hyacinth biochar had significantly (P<0.001) higher surface area (205.40m2g-1); consequently, higher capacity in salt and water adsorption which might prevent soil desiccation. Side by side, it significantly (P<0.001) increased the soil Ca content which might replace Na+ in the root rhizosphere minimizing the Na+ uptake by plants. Taken together, water hyacinth biochar could also be the best choice of organic amendments to reduce the detrimental effect of salt stress in coastal areas of Bangladesh.