IMPACT OF GRAZING STRATEGIES ON SOIL COMPACTION

Authors: Daniel, John; Phillips, William

Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 7/9/2000
Publication Date: 7/9/2000
Citation: N/A

Interpretive Summary: Livestock grazing on pastures can cause compaction of a ground surface, which can result in a decrease in soil structure by increasing soil bulk density and reducing surface water infiltration. Ultimately, this leads to lost crop and forage yields and potentially, increased erosion of agricultural lands. This study examined soil compaction associated with the grazing of a summer legume versus no summer grazing following a typica fall, winter and spring livestock grazing of winter wheat. Compaction of the soil was determined by resistance to penetration methods. Results show that changes in soil surface compaction occurred with livestock grazing compared to ungrazed sites. However, while it was found that compaction occurred, additional grazing of the summer legumes did not increase surface compaction as compared to fallow paddocks. This suggests that while changes in soil compaction as determined by penetration methods are impacted by livestock grazing, the effects do not appear to be cumulative.

Technical Abstract: Four 1.6 ha paddocks were used in the study of livestock-induced compaction with two winter wheat production system strategies. Both systems utilized the normal strategy of grazing in the fall, winter and spring. However, during the summer, one strategy included summer grazing while the second did not. Two enclosures in each paddock were not grazed at any time and were used as control sites. Compaction of the soil was determined by resistance to penetration methods. Results show that changes in the cone index for the soil surface increased with both strategies compared to the control sites. However, the additional summer grazing of the legumes did not impact the penetration measurements as compared to ungrazed summer paddocks. This suggests that changes in soil compaction as determined by resistance to penetration were impacted by grazing, but the effects do not appear to be cumulative.