@article {Sullivan147, author = {D. M. Sullivan and C. G. Cogger and A. I. Bary and S. C. Fransen}, title = {Timing of dairy manure applications to perennial grass on well drained and poorly drained soils}, volume = {55}, number = {2}, pages = {147--152}, year = {2000}, publisher = {Soil and Water Conservation Society}, abstract = {Timing of manure applications is a critical part of dairy farm plans because it affects water quality, crop production, and manure handling costs. We conducted a two year field study to provide information to farm planners on manure application timing for intensive grass production in the Pacific Northwest. We applied dairy manure slurry [340 kg total N ha-1yr-{\textquoteright}; (300 lb N ac-1 yr-1)I to orchardgrass on well drained and poorly drained soils in western Washington, comparing early (February and May), mid-season (May through summer), and late (summer through fall, timing sequences for manure application. We also compared manure N rates ranging from 170 to 670 kg ba-l yf-1 (150 to 600 lb at-1 yr-1) for the mid-season application only. Forage yield, N uptake, apparent N recovery, and late-season soil nitrate-N were measured Cumulative apparent N recovery for manure N averaged 31 \% and ranged from 24 to 38\% over all treatments. The early and late manure sequences on the well drained soil had greater spring-harvest and cumulative yields than for the mid-season sequence. Timing effects were smaller and not statistically significant on the poorly drained soil. The effect of a manure application on grass production was greatest in the first harvest following application, and declined in subsequent harvests. Residual soil nitrate was less than 5 mg N kg-1 soil for all manure timing sequences applied at the 340 kg total N ha-1 yf1 (300 lb N at-1 yr-1) rate.}, issn = {0022-4561}, URL = {https://www.jswconline.org/content/55/2/147}, eprint = {https://www.jswconline.org/content/55/2/147.full.pdf}, journal = {Journal of Soil and Water Conservation} }