Submitted to: Management Intensive Grazing Symposium Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/24/1995
Publication Date: N/A
Technical Abstract: Intensive animal grazing, under certain conditions, can cause increased soil compaction and damage to soil structure. Infiltration tests on a long-term beef grazing study near Ardmore, OK, showed increasing compaction (and decreasing infiltration) with increasing stocking rates. Three infiltration studies were conducted at the Iowa State Beef Nutrition Farm near Ames, IA. In the first study, beef cows grazed corn stalks for 56 days from November 1990 to January 1991. Treatments were 1.2 (Low), 2.3 (Medium), and 4.7 (High) cow-months per hectare and two rotational stocking systems. Infiltration measurements were made on trampled and untrampled (caged) areas of each treatment and no statistical treatment effects were found. The soil was frozen throughout the grazing period and no soil compaction occurred. In the second study, sixteen plots in a grass pasture were pre-wet to four water contents: 1) 0.16 (no additional water); 2) 0.27; 3) 0.34; and 4) 0.40 g/g. Beef cows and calves were herded in six passes over the plots. Rainfall infiltrometer measurements showed decreasing total infiltration with increasing soil water content. Infiltration measurements made a month later showed little residual effect from the treatments. In the third study, pastures with short-term differences in stocking rates did not show differences in infiltration. However, high traffic areas within the pastures did show great reductions in infiltration due to soil compaction. Areas near the water tanks and paths leading to the water tanks were compacted and showed reductions in infiltration rates which were related to the distances from the watering tanks.