Catch crop cultivation with the aim of incorporation should be a constant element of improving soil fertility. The most frequently recommended type of green manures for vegetables is stubble catch crops. It is not always possible to sow plants at the optimum date, that is in the second half of July. The aim of the study was to determine the yield of fresh and dry matter of stubble catch crops and macroelement accumulation in them depending on the sowing date. The experiment was carried out in central-east Poland. In years 2004-2006, the yield of fresh and dry matter and macroelement contents were estimated in the following catch crops: phacelia (Phacelia tanacetifolia Benth.), amaranth (Amaranthus cruentus L.), sunflower (Helianthus L.), seradella (Ornithopus sativus), and faba bean (Vicia faba L. ssp. minor). The seeds were sown on three dates: July 21^st, August 4^th, and August 18^th. In the third decade of October, plant samples were collected in order to estimate the yield of fresh and dry matter, as well as macroelements in the catch crops. The amount of biomass and macroelement content depended on the length of catch crop growth season. The highest organic matter yield and macroelement contents were characteristic for the catch crops sown on July 21^st, and the lowest ones for the catch crops sown on August 18^th. Due to high fresh and dry matter yields, sunflower was the best species to be sown on July 21^st, sunflower and phacelia on August 4^th, and phacelia on August 18^th. Faba bean accumulated the highest amounts of nitrogen and phosphorus in the dry matter. Sunflower accumulated the highest total mass of macroelements (N + P + K + Ca + Mg) in the dry matter yield. The smallest percentage decrease in dry the matter yield and amount of macroelements as a result of delaying the catch crop planting date was found for seradella.

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