UVM Theses and Dissertations
Format:
Print
Author:
Bakelaar, Joshua
Dept./Program:
Plant and Soil Science
Year:
2012
Degree:
MS
Abstract:
Small-scale dairy farming is economically challenging, however, innovations in management intensive grazing (MIG) have allowed many small farms to become profitable. MIG relies on synergy between farm managers, livestock, and soil ecosystem processes such as decomposition and nutrient cycling to maintain and improve pasture condition and forage quality while reducing farm expenses and labor. Season extension may further allow farms to reduce feed and energy costs. Concepts from MIG were incorporated into three season extension practices: bedded pack, out-wintering, and stockpiling. Bedded pack, out-wintering, and stockpiling practices were monitored during 2009-2010 in 18 permanent pastures on nine Vermont cow dairy fanns using a paired design (treatment/control). Composite soil and forage samples were collected May/June and Octber/November for soil physical, chemical, and biological analysis (nematode community structure) and forage chemical analysis. With a few exceptions, soil and forage quality were similar among treatments (p> 0.10).
Season extension management increased the nematode plant-parasite index suggesting increased plant primary productivity and yield. Soil biological effects were mainly bacterial driven, decreasing the proportion of omnivores and increasing the proportion of predators. The proportion of nematode predators decreased under bedded pack and out-wintering treatments (p = 0.0011); Compared to control sites, soil pH was higher in bedded pack and lower in out-wintering treatments (p =0.0654). Relative feed value of forage increased under stockpiling and out-wintering (p = 0.0254). Forage degradable protein decreased in bedded pack and stockpiling treatments (p =0.0551). Forage calcium decreased under out-wintering (p =0.0877) while chloride(p = 0.0726) and acid detergent insoluble crude protein (p=0.0277) increased. Forage lignin had an increasing trend inbedded pack and out-wintering had a decreasing trend.
Bedded pack, out-wintering, and stockpiling season extension practices maintain and, depending on initial condition, favor bacterial decomposition, increase available resources and plant productivity, and improve soil food web structure. Negative impacts to soil quality, including physical structure, were not detected. Overall, impacts to forage quality were minor but may indicate a negative trend in quality under bedded pack compost amendment. Farm participants gained valuable experience and technical assistance during this study that improved their season extension practices and their experiences were shared with other local farms during field days throughout the study.
Season extension management increased the nematode plant-parasite index suggesting increased plant primary productivity and yield. Soil biological effects were mainly bacterial driven, decreasing the proportion of omnivores and increasing the proportion of predators. The proportion of nematode predators decreased under bedded pack and out-wintering treatments (p = 0.0011); Compared to control sites, soil pH was higher in bedded pack and lower in out-wintering treatments (p =0.0654). Relative feed value of forage increased under stockpiling and out-wintering (p = 0.0254). Forage degradable protein decreased in bedded pack and stockpiling treatments (p =0.0551). Forage calcium decreased under out-wintering (p =0.0877) while chloride(p = 0.0726) and acid detergent insoluble crude protein (p=0.0277) increased. Forage lignin had an increasing trend inbedded pack and out-wintering had a decreasing trend.
Bedded pack, out-wintering, and stockpiling season extension practices maintain and, depending on initial condition, favor bacterial decomposition, increase available resources and plant productivity, and improve soil food web structure. Negative impacts to soil quality, including physical structure, were not detected. Overall, impacts to forage quality were minor but may indicate a negative trend in quality under bedded pack compost amendment. Farm participants gained valuable experience and technical assistance during this study that improved their season extension practices and their experiences were shared with other local farms during field days throughout the study.