Akintoye, H. A., Lucas, E. O. and Kling, J. G. 1997. Effect of density of planting and time of
nitrogen application on maize varieties in different ecological zones of West Africa. Commum.
Soil. Sci. Plant Anal. 28: 1163-1175.
Andrade, F. H., Uhart, S. A. and Frugone, M. I. 1993. Intercepted radiation at flowering and
kernel number in maize: shade vcrsus plant density effects. Crop Sci. 33: 482-485.
Anon. 1993. Test codes and procedures for farm machinary technical series. RNAM. 12: 279.
Ashrafizadeh, R., Afarinesh, A. 2003. Evaluation soil compaction effect and tillage way on maize
yield and physical characteristics of soil. Proceeding of Conference on Cereal Tillage Tasks.
(in Farsi)
Ayvani, A. 1997. Evaluation of performance moldboard and disk plows at three soil type and
three moisture level. M.Sc. Thesis. Shiraz university. Shiraz. Iran. (in Farsi)
Gill, W. and Mcrry, W. F. 1960. Relation of size of cut to tillage tool efficiency. Agr. Eng. 41:
372-374.
Hendrick, A. 1988. CRC Hand book in Agriculture. Vol. 1. Boca Raton, CRC. Press.
Kepner, R. A. and Barger, E. L. 1978. Principles of Farm Machinary. Chapter 5. The AVI
Publishing Company.
Luttrel, D. H., Bockho, C. W. and Lovely, W. G. 1964. The effect of tillage operation on soil
physical condition. ASAE. Paper. 64-103.
Najafinejad, H. and Rostami, M. A. 2003. The effect of different tillage methods on yield and
yield components of corn and physical characteristics of soil. Proceeding of Conference on Cereal
Tillage Tasks. (in Farsi)
Nasr, H. and Selles, F. 1995. Seeding emergence as influenced by aggrigate size, bulk density and
penetration resistance of the seedbed. Soil and Till. Res. 34: 61-76.
Poneleit. G. M., Egli, D. B. and Reicosky, D. A. 1980. Variation and associations of kernel growth
characteristics in maize populations. Crop Sci. 20: 766-770.
Robinson, D. L. and Murply, L. S. 1972. Influence of nitrogen, phosphorous and plant population
on yield and quality of forage corn. Agron. J. 64: 349-351.
Sadeghi, H., Bahrani, M. J. 2001. Effect of plant density and nitrogen rate on yield and yield
components of corn. Iranian J. Crop Sci. 3(2): 1-11. (in Farsi)
Sayedi, A. 1999. Effect of plant density and distribution methods of nitrogen on corn yield. M.Sc.
Thesis. Shiraz University. Shiraz. Iran. (in Farsi)
Solhjou, A., Loghavi, M. L., Ahmadi, H. and Roozbeh, M. 2001. The effects of moisture content
and plowing depth on soil pulverization and reduction of secondary tillage. J. Agric. Eng. Res.
2(6): 1-12. (in Farsi)
Tahan, Y., Hassan, H. M. and Hammadi, I. A. 1992. Effect of plowing depths using different plow
type on some physical properties of soil. AM A. 23(4): 21-24.
Ulger, A. C., Ibrikci, H. and Gűzel, N. 1997. Influence of nitrogen rates and row spacing on corn
yield, protein content, and other plant parameters. J. Plant Nutr. 20: 1697-1709.
Zareeian, S. 1985. The effect of soil moisture on moldboard draft and degree of soil pulverization.
Iranian J. Agric. Sci. 16: 4-11.