Summary:

Results of studies have shown that yield increased achieved as effect of supplemental irrigation of spring or winter cereals are similar. Yield increases resulting from irrigation depend mostly on the kind of soil, particularly its mois-ture conditions. In the definite vegetation season and in the actual soil conditions the effects of irrigation of cereals varried, and they correlate significantly with the rainfall at growth stage when the requirement of moisture is critical. The problems of irrigation of cereals in Poland should be considered in two aspects: 1. Irrigation of cereals grown on medium and light soils should be consid-ered as interventional, so as to prevent yield decreases caused by drought, and to assure stable crops in the Polish transitory climate condition. That measure can lead to average yield increases: absolute of 0,50–1,00 t.ha^-1, relative of 10–30% and unitary of 5–10 kg.ha^-1.mm^-1. This might not encourage farmers to include cereals in their crop rotation on fields equipped with irrigation systems but cere-als should take a part in an equipped with irrigation systems fields meant for other plants. Irrigated should be the bread varieties of wheat and then malt bar-ley. 2. Irrigation of cereal plants grown on very light soils and light soils of permeable subsoil can be considered a basic yield-creating factor. Cereal pro-duction on such soils is pointless (an average yield equals 1,50 t.ha^-1) whereas an average absolute productive effects of irrigation exceed 2,50 t.ha^-1, unitory out-ranks 20 kg.ha-1.mm-1. Therefore it might be considered to be a production re-serve of Polish agriculture, should the need for agricultural production increase arise.