Effect of Biochar on Yield, Yield Components, and Macronutrients of Rice (Oryza sativa L.)

Biochar has recently caught researchers’ attention due to its potential of improving soil fertility and immobilizing pollutants and its emergence as a proper method of increasing crop yields. An experiment was conducted on the effect of chemical, ecological, and organic (biochar and compost) nutritional systems on yield and yield components of rice as a split-plot field experiment based on a randomized complete block design with three replications in two sites in Lahijan in 2018-2019. The experimental factors included nutrition at three levels (ecological, chemical, and control) as the main plot and the organic matter at four levels (urban waste compost, biochar, Azolla, and control) as the sub-plot. The combined application of chemical and organic fertilizers produced the highest grain yield, reflecting the positive effect of their combination on grain yield and yield components of rice cv. ‘Hashemi’. The results showed that the highest grain yield of 3699 kg ha-1 was related to the treatment of chemical fertilizer and biochar and the lowest (2209 kg ha-1 , i.e., a 40% decline) to the control (no chemical or biological fertilizer application). The highest number of fertile tillers and panicles per plant was obtained from the application of chemical fertilizer and biochar, the highest number of filled grains per panicle (116 grains) was observed in the application of chemical fertilizer and biochar at the university farm, and the lowest (84 grains) from the control (unfertilized treatment) at the Kateshal farm. The nutrient uptake was significantly higher in the chemical and biochar treatment than in the other treatments. Organic systems had varying impacts on rice yield and reduced the application of chemical fertilizers. Biochar contributed to increasing the growth, yield, and nutrient uptake of rice plants.