Determination of the quality of forecast moisture content of cereals at harvesting time using forecast weather elements

摘要

The moisture content of wheat and barley is forecast during the harvesting period. Each hour theforecast model uses standard weather elements of air temperature, dew-point temperature, windspeed, amount of precipitation, global radiation and cloud cover. Over a period of four years, 1989-1992 inclusive, a five-day weather forecast is made every day for one month during the harvestingperiod. The forecasts were compared with those made using realized weather elements in this period.Forecasting the moisture content of wheat and barley up to three days ahead gives a better predictionof moisture content than with a longer forecasting period. Mean deviation in forecasting the moisturecontent of wheat and barley is at most 1.1 and 1.2% w.b. On average, barley has a greater deviationin the forecast moisture content than wheat. High moisture contents of the grains (about 25% w.b.)can be caused by low air temperature, low global radiation, high dew-point temperature, high windspeed, and precipitation. The low moisture content of cereals (10-30% w.b.) compared with cutgrass destined for ensiling (50-85% w.b.) denotes that dew point temperature and wind speed arealso important.