Ecological land use in the undulating landscape of Lithuania and Baltic sea environment

The research data presented in this paper were obtained in the undulating landscape of the Zemaiciai upland (Western Lithuania), where loamy sand and clay loam (Eutric, Dystric and Gleyc Albeluvisols) prevail. The thickness of the lost soil layer differed owing to the common effects of water, wind and tillage erosion, and varied from 0.12 to 1.07 m according to the slope gradient and degree of soil erosion. The fertility of soil measured by productivity of spring barley on slopes of 2-5degrees, 5-10degrees and 10-14degrees decreased by 21.7-22.1%, 38.9-39.7% and 62.4% respectively. The soil was slightly, moderately and severely eroded on the above-mentioned slopes. The mean water erosion rate under the field crop rotation varied from 9.9 t ha(-1) yr(-1) to 32.2 t ha-1 yr(-1) on the slope of 10-14degrees being 23.4 t ha(-1) yr(-1) on the slope of 5degrees-10degrees according to average results of 18 years investigations. The mean annual erosion rates decreased by 74.7-79.5% under erosion-preventive grass-grain crop rotations compared with field crop rotation, and they decreased by 22.7-24.2% under the grain-grass crop rotation. The resourceful selection of optimum erosion-preventive phytocenoses (sod-forming perennial grasses or erosionpreventive crop rotations) assists the control of erosion, purification of water and the ecological stability of the landscape. All investigated land management systems were ecologically sound and environment friendly, according to crop quality records.