Can soil amendment with or without fertiliser benefit the soil and upland rice?

Abstract

Crop production is being threatened by poor soil quality and nutrient loss. An avenue to enhance soil quality for sustainable crop production is to explore the appropriate soil amendment with or without chemical fertiliser. A pot experiment was used to investigate the effects of biochar at 5tha^-1(BC5), sawdust at 5tha^-1(SD5), biochar at 5tha^-1with fertiliser (BC5-F), sawdust at 5tha^-1with fertiliser (SD5-F),  biochar at 50t ha^-1(BC50), sawdust at 50tha^-1 (SD50), biochar at 50tha^-1with fertiliser (BC50-F), sawdust at 50tha^-1 with fertiliser (SD50-F) and control on soil quality, growth, and yield of upland rice.  BC50-F or BC50 increased the soil pH, but SD5-F reduced the soil pH.   Also, SD50-F or SD50 enhanced soil organic carbon and total nitrogen. The BC50, BC5-F and SD5-F treatments enhanced available P in Akim Oda  soil (Ferric Acrisol). In the Winneba soils (Haplic  Lixisol), all treatments enhanced available P except SD5.  Furthermore, all treatments with fertiliser enhanced rice tiller numbers and plant height in Akim Oda, except BC50, which decreased height. Compared to the Winneba soil, BC5-F and SD5-F enhanced rice tiller numbers. However, plant height was maintained for all treatments except for BC50-F.  Similarly, straw yield in the Akim Oda and Winneba soils was improved by all treatments except BC50-F in Winneba soil. Grain yield in the Akim Oda soil was enhanced in BC50-F, SD50-F and SD5-F, but only in SD50-F for Winneba soil. Biochar or sawdust with inorganic fertiliser could enhance soil properties and crop yield, depending on the soil type.