Influence of Grazing and Mulch on Forage Growth

Abstract

IT IS well known that the degree of forage removal affects individual plants, plant succession, forage production, and modifies microclimate and soil. Some investigators have pointed to the necessity of leaving a portion of the plant ungrazed to preclude undue interference with physiological processes. Others have felt that the dead plant or mulch remaining at the end of the grazing season is of even greater importance than conservative grazing in its effect on soil structure, organic content, soil temperature, moisture, and erosion, and thus upon the growing plants (2, 5, 10, 11). While mulch has long been recognized as an important element in range health, specific studies regarding its role have been undertaken rather recently (7, 8). Beutner and Anderson have shown that striking increases in forage production result from rather heavy mulches on semi-desert soils (1). Larson and Whitman have indicated a close relationship between litter accumulation and degree of forage removal (9). To investigate some of these relationships and, particularly, the effects of protection and organic mulch on forage production, plot studies were begun in 1941. The study area is located on the North Fork of Little Thompson River, nine miles east of the Town of Estes Park, Colorado, on the Roosevelt National Forest. At the outset, the study was intended to measure the relative rates of recovery of an overgrazed range under protection and under moderate grazing. As the study progressed, certain aspects of spring and summer forage growth became evident, and the apparent effect of mulch accumulation led to the addition of a mulch study.