Manusha I. Influence of length of the meadow period in fodder crop rotation on perennial grasses productivity in the conditions of drained organogenic soils in Polissja.

Object of reserarches - drained organogenic soils, fodder crop rotation. Objective of researches -basing of duration of meadow period in fodder crop rotation and researching it's influence of soil fertility and grasses productivity perennial. Methods of investigations - in general use. Theoretical results and novelty - hte regularity's are found out about influence of meadow period in crop rotation on soil fertility and energetic and economical parameters of grass growing. Practical results and novelty - hte recommendations are worked out of the duration of meadow period in crop rotation and high effective agronomic measures in perennial grass growing. Object and degree of extension - the crop rotations are mastered by collective agriculture enterprise "Zorja" in Rivne region on the acreage 128 ha and seed production farm "Lypova dolina" in Sumy region on the acreage 164 ha. Effectiveness of mastering - increase of dry matter 25-32 hkg/ha and gain 124 grivnas per hectare/ Region of using - agricultural .