Overfertilization. In 2002, the average rate of nitrogen (N) fertilizer application for rice production in China was 180 kg/ha, about 75% higher than the world average. Only 20–30% of this N is taken up by the rice plant, with a large proportion lost to the environment. In some cases, overapplication of N fertilizer may actually decrease grain yield by increasing the plant’s susceptibility to lodging (falling over) and damage from pests and diseases.