EFFECTS OF BIOCHAR APPLICATION AND NITROGEN FERTILIZER REDUCTION ON NUTRIENT UPTAKE AND YIELD OF RICE IN COLD REGIONS

The study aimed to evaluate the effects of biochar application and nitrogen (N) fertilization on rice yield and its components to provide insights into sustainable nutrient management strategies.The experiment assessed three biochar application rates (0 tha, 15 tha, 40 tha) and four nitrogen levels (0 kgha, 95 kgha, 180 kgha, 225 kgha).Data were collected on plant height, spike number, grain number per spike, seed setting rate, thousand-grain weight, and yield.Results showed that biochar significantly improved rice productivity.The highest yield (8464.18 kgha) was achieved under moderate nitrogen application (180 kgha) with 15 tha biochar.Biochar-treated plots exhibited superior performance in spike number and grain number per spike compared to untreated controls, while excessive nitrogen (225 kgha) provided no significant yield benefits and reduced seed setting rates.Biochar also mitigated nitrogen losses and environmental risks, promoting sustainable production.These findings demonstrate the combined benefits of biochar and moderate nitrogen levels in enhancing rice yield and reducing environmental impacts.The study concludes that biochar is an effective amendment for improving nutrient uptake and achieving sustainable rice production.Future research should explore biochar's longterm effects on soil health and its interactions with other nutrients to further optimize agricultural practices.