### Changes of the growing season

#### Indicators:

Length of the growing season (graph) Length of the growing season (map) Length of the dry season | Mean temperature of the growing season (graph) Temperature of growing season (map)

The growing season is defined as the period in a year with adequate temperature and moisture availability for crop growth. The characteristics of the growing season strongly determine the suitability for specific agricultural crops and their productivity. The calculation of the growing seasons follows the definitions of the Food and Agriculture Organization of the United Nations (FAO) and is based on an interpolation towards daily values from monthly climate records. The model calculates for each grid cell the seasonal evolution of the growing season on the basis of temperature, precipitation, evapotranspiration and soil moisture conditions. In boreal regions, the growing season is generally limited by cold periods, while in the tropics the length of the growing season is determined by dry periods. Arid regions are always characterized by prolonged dry periods.

| #### Length of the growing season (graph)
| unit: days/yr (days per year) dimension: region, land-cover type

The length of the growing season is the period in a year with adequate temperature and moisture availability for crop growth. Crops can grow when the daily temperatures exceed 5oC and soil moisture content is above wilting point. In arid regions, the growing period starts after the dry period when precipitation exceeds half the potential evapotranspiration. This implies that water stored in the soil does not need to be replenished completely, because most crops (grown from seed) can utilize the rain falling on the surface.

The length of the growing season can be displayed for regions, land-cover types and latitudinal bands (0-30o: tropics; 30-60o: temperate zones; 60-90o: boreal zones)

| #### Length of the growing season (map)
| unit: days/yr (days per year) dimension: length of the growing period

The length of the growing season is the period in a year with adequate temperatures and moisture availability for crop growth. It is calculated by the terrestrial vegetation model. Crops can grow when the daily temperatures are above 5oC and soil moisture conditions are above wilting point. In arid regions, the growing period starts after the dry period when precipitation is larger than half the potential evapotranspiration. This means that water in the soil does not need to be replenished completely, because most crops (grown from seed) can utilize the rain falling on the surface.

| #### Length of the dry season
| unit: days/yr (days per year) dimension: length of the dry season

The length of the dry season is defined as the period in a year with inadequate moisture availability for crop growth. It is calculated by the terrestrial vegetation model. Crops can grow when soil moisture conditions are above wilting point. In arid regions, the growing period starts again after the dry period when precipitation exceeds half the potential evapotranspiration. This means that water in the soil does not need to be replenished completely, because most crops (grown from seed) can utilize the rain falling on the surface.

Changes in the length of the dry season are especially important in arid regions. Shortening of the dry season indicates improved climatic conditions for agriculture, while any increase depicts a reduction of possibilities for agriculture.

| #### Mean temperature of the growing season (graph)
| unit: oC (degrees Celsius) dimension: region, land-cover type

The mean temperature of the growing season is the average temperature over all days with adequate temperature (larger than 5oC) and moisture availability. The mean temperature of the growing season is an important determinant of crop productivity.

| #### Temperature of growing season (map)
| unit: oC (degrees Celsius) dimension: temperature of the growing season

The mean temperature of the growing season is the average temperature over all days with temperature exceeding 5oC and soil moisture content exceeding the wilting point. The mean temperature of the growing season is an important determinant of crop productivity.