2Deepak Chaudhuri.performance evaluation of various types of furrow openers on seed drills-a review [J].agric.Engng Res., 2001, 79(02):125- 126.
3Siemens J C, Weber J A.Thornburn.Mechanices of soil as influenced by tillage tools [J].1965, 8(01):1-7.
4Kalk W D, Herzoo R, Lange D, Bernard C.Drill coulters for soil with incorporated crop residues [J].Agricuhural Engineering Abstracts, 1993, 18(06): 226.
5Abernathy G H; Porter5eld J G. Effect of planter openers shape on furrow characteristics [J].Transactions of ASAE, 1969, 12(01): 16-19.
6Gebresenbet G, Johnson H. Performance of seed drill coulters in relation to speed, depth and rake angles[J].Journal of Agricultural Engineering Research, 1992, 52(02): 121-145.
7Baker C J. Experiments relating to techniques for directdrilling of seeds into untilled dead turf[J]. Journal of Agricultural Engineering Research, 1976, 21(02):133-134.
8Ozmeri A.Seed distribution performance of furrow openers used on drill machines [J].AMA, 1986, 17(02): 32-34.
9Woodruff N P, Fenster C R, Harris W W;, Lundquist Marvin. Stubble mulch tillage and planting in crop residue in the great plains [J]. Transactions of ASAE, 1966, 9(06):849-853.
10Wilkins D E, Muilenburg G A, Allamaras R R, Johnson C E.Grain drill opener effects on wheat emergence[J].Transactions of ASAE, 1983, 26(03): 651-655.
