A study looked at how adding rice straw back to the field along with nitrogen fertilizer affects rice growth and soil health in cold regions. They found that using a specific combination of rice straw, ammonium bicarbonate, and calcium carbonate led to the highest rice yield, increasing it by up to 10.6%. This method also improved the rice plants' resistance to diseases and lodging. Adding more crop residue increased the number of grains per plant but decreased the weight of each grain. Overall, adding ammonium bicarbonate positively correlated with higher rice yields.