Additional moisture in the form of irrigation water is available in only a few areas of the province. For the majority of livestock operations, therefore, it is important to make full use of the precipitation they receive. This is particularly critical for coping with dry years. The moisture entering the forage system comes mainly in the form of rain and snow. Not all the incoming moisture actually enters the system and becomes available to plants.
Some moisture is lost by evaporation from the soil surface and intercepting plant materials.
Some moisture is 'lost' through runoff. A portion of the moisture reaches the groundwater system. The magnitude of the above 'losses' depends to a large extent on soil and landscape characteristics, in addition to the kind and intensity of precipitation and weather conditions. However, management can have a substantial influence on the magnitude of such moisture losses. Certain management practices can help minimize the losses and maximize the amount of moisture remaining in the root zone to be utilized for plant growth.