Site observation data of farmland sites in the middle and lower reaches of Yangtze River, China

<p>The meteorological data from the cropland site used to drive the model mainly includes&nbsp;downwelling longwave and shortwave radiation, precipitation, surface pressure, relative humidity, temperature, and wind speed.&nbsp; The file of&nbsp;meteorological forcing data is named &quot;site_airforcing&quot;</p> <p>Plants were collected at key growth stages of rice and winter wheat. The carbon and nitrogen content of each plant part was measured using an elemental analyzer (Flash Smart, Thermo Fisher, Germany).&nbsp;The file of&nbsp;plant carbon and nitrogen content data during the growing season is named &quot;plant_CN&quot;</p>