RESIDUE MANAGEMENT AND SEED PRODUCTION IN
DRYLAND KENTUCKY BLUEGRASS

W.J. Johnston¹, G.A. Murray², H.R. Hinman³, K.E. Saxton⁴,
J.B. Swensen² and C.T. Golob¹

¹Crops and Soil Sciences, Washington State University, Pullman, WA 99164-6420; ²Plant, Soil & Entomological Sci., 375 Line St., Univ. of Idaho, Moscow
³Agricultural Economics, Washington State University, Pullman, WA 99164-6210; ⁴Biological Systems Engineering, USDA-ARS, Washington State University, Pullman

Regulations banning burning of post-harvest residue from Kentucky bluegrass (Poa pratensis L.) seed fields in Washington State, USA, and health concerns from smoke requires development of alternative residue removal methods. The agronomic response of dryland bluegrass to mechanical residue alternatives was compared to open-field burning. Seed yield with several residue removal alternatives compared favourably to seed yield with burning of consecutive crops (crop years 2 and 3), but all were less than burning in crop year 4. Panicle density was not affected by residue left on the surface and was only correlated with seed yield in the fourth harvest. Compared to burning, all mechanical treatments essentially created more dust, had increased weeds, and increased soil erosion in the spring. In two of the three harvests, burning, in general, was more economical that the mechanical residue removal treatments.