Which of the following is not an effect of bush burning on the soil?

The option that is not an effect of bush burning on the soil is "maintaining high levels of soil nutrients reserves." Bush burning is a traditional practice of burning grasses and bushes in farmland, which has both negative and positive effects on the soil. The burning of vegetation can destroy the structure of the soil and expose it to erosion, making it more susceptible to water runoff. Also, the heat from the fire can sterilize the soil against some beneficial soil microorganisms. On the positive side, bush burning can increase the rate of nitrogen mineralization in the soil, making nutrients more available to plants. However, it does not maintain high levels of soil nutrient reserves because the ash produced by bush burning usually contains a limited amount of nutrients, which are quickly leached out by rainfall.