The study looked at how soil respiration changes throughout the day in soil with soybean plants at different growth stages. They measured the amount of CO2 released from the soil and found that it peaked between 12:00 and 16:00 when soybeans were growing. The rate of soil respiration was highest during the pod and grain-filling stages. The temperature and watering of the soil also affected how much CO2 was released. The roots of the soybean plants played a big role in soil respiration, especially during the grain-filling stage. Overall, the growth stage of the soybeans, temperature, and watering all influenced how much CO2 was released from the soil.