Project Number: 3655-21630-003-00
Project Type: Appropriated

Start Date: Nov 27, 2003
End Date: Nov 02, 2007

Objective:
1) Assess the impact of forage polyphenols on carbon (C) sequestration, nitrogen (N) cycling, protein use, and profitability of dairy farms and develop systems to make use of polyphenol-containing forages. 2) Determine relationships among pasture canopy structure, physio-chemical properties of forage, and ruminant animal intake in grazed grass and grass-legume swards to improve the performance and profitability of grazing-based dairy farms. 3) Reduce nutrient losses and adverse environmental impacts by dairy farms through the development of improved and integrated feeding and manure management practices. 4) Analyze socio-economic and environmental aspects of dairy forage systems. Two SY's are added to this project, as they are principal investigators on related CRADA (425 Log 31562).

Approach:
Obj 1: Conduct field, laboratory & modeling studies to: 1) determine how condensed tannins affect soil C sequestration by forages; 2) improve polyphenol-containing red clover production systems; 3) assess polyphenol impacts on N cycling in forage-corn rotations; 4) assess environmental & harvest management effects on poyphenol-protein interactions in forages; 5) identify optimal forage polyphenol levels & feeding strategies to improve protein use & milk production by cattle; 6) evaluate N use & losses from manure as influenced by dietary polyphenols; & 7) integrate data to optimize management of polyphenol-containing forages on dairy farms. Obj 2: 1) characterize defoliation patterns in rotationally grazed pastures; 2) assess canopy structure of forage grasses; 3) determine forage quality & physical characteristics of grass morphological components; & 4) assess forage plant stature & growth habit influences on canopy structure & species balance in mixtures. Obj 3: Conduct field, lab & modeling studies to: 1) assess dairy diet effects on manure nutrient excretion & cycling in soils; 2) determine livestock-corralling effects on N loss from urine & feces; 3) evaluate bedding material's effects on manure N cycling; 4) evaluate ammonia & nitrate losses from dairy slurry incorporated by various methods; 5) predict crop uptake of manure N; 6) determine if grass leys enhance forage production, manure management, & grain yields of farms; & 7) compare impact of cropping systems & pasture on long-term soil fertility. Obj 4: Utilize surveys, field studies, & modeling to: 1) characterize current practices & identify opportunities, obstacles, & innovative solutions to manage agricultural nutrients on dairy farms; 2) compare yields, profitability, & environmental impact of cash grain & dairy farming systems; 3) evaluate tools to identify nutrient BMPs & develop comprehensive nutrient management plans for dairy farms; & 4) identify sustainable farming practices that reduce production, environmental, & economic risks of dairy forage systems.