1- Abdel Monem M. A. S., Harmsen K., Lindsay W.L. and Vlek P.G. 1987. Fat of nitrogen - tagged urea applied to wheat in the arid Mediterranean region. p. 103-110. In A. Matar et al. (ed.). Soil Test Calibration in West Asia and North Africa. Proc. of the Second Regional Workshop Ankara, Turkey, 1-6 Sept. 1987. ICARDA, Aleppo, Syria.
2- Abdel Monem M., Azzoui A., El Gharous M., Ryan J. and Soltanpour P.N.1990. Response of dryland wheat to nitrogen and phosphorus in some Moroccan soils. p. 52-65. In J. Ryan et al. (ed.) Proc. Third Regional Soil Test Calibration Workshop. Amman, Jordan.3-9 Sept. 1988. ICARDA, Aleppo, Syria.
3- Ali Ehyaei M. and Behbahani Zadeh A.A. 1993. Study of soil chemical analysis. Technical Soil and water Research Institute, 893. (in Persian).
4- Ayadi S., Karmous C., Hammami Z., Trifa Y. and Rezgui S. 2014. Variation of durum wheat yield and nitrogen use efficiency under Mediterranean rainfed environment. International Journal of Agriculture and Crop Sciences, 7(10): 693-699.
5- Aziz F.C., Mohammad B.I. and Salih H.M. 1990. Nitrogen forms in calcareous soils and their correlation to nitrogen indices of wheat. p. 175-187. In J. Ryan et al. (ed.). Proc. Third Regional Soil Test Calibration Workshop. 3-9 Sept. 1988. Amman, Jordan. ICARDA, Aleppo, Syria.
6- Bell M.J., Wayne S., Denis E. and Charlie W. 2013. Soil nitrogen - crop response calibration relationships and criteria for winter cereal crops grown in Australia. Crop and Pasture Science, 64(5):442-460.
7- Benbi D.K., Singh R., Singh G., Sandhu K.S. and Saggar S. 1993 .Response of dryland wheat to fertilizer nitrogen in relation to stored water, rainfall and residual farm yard manure. Fertilizer Research, 36:63-70.
8- Calvino P. and Sadras V. 2002. On-farm assessment of constraints to wheat yield in the south-eastern Pampas. Field Crops Research, 74:1–11.
9- Davis J.G. and Westfall D.G. 2005. Fertilizing Winter Wheat. Colorado State University, U.S. Department of Agriculture and Colorado counties cooperating. NO. 0.544.
10- Deng X.P. 2014. Enhancing drought resistance of plants using wheat as a test crop. p 215-231. In A. Tsunekawa et al. (eds.), Restoration and Development of the Degraded Loess Plateau, China. Springer Verlag, Japan.
11- Di K. C. and Cameron H.J. 2004. Effects of temperature and application rate of a nitrification inhibitor, dicyandiamide (DCD), on nitrification rate and microbial biomass in a grazed pasture soil. Soil Research, 42(8):927–932.
12- El Gharous M. 1997. Nitrogen challenges in dryland agriculture. p. 47-56. In J. Ryan (ed.). Accomplishments and future challenges in dryland soil fertility research in the Mediterranean area. ICARDA, Aleppo, Syria.
13- Farooq M., Wahid A., Kobayashi N., Fujita D. and Basra S.M.A. 2009. Plant drought stress: effects, mechanisms and management (Review article). Agronomy for Sustainable Development, 29:185–212.
14- Fatima M., Bedhiaf M. and Rhomari Y. 1992. Fertilization of cereals: Soil-nitrogen test calibration in Morocco,s Gharb Area. p. 212-224. In J. Ryan et al. (ed.). Fertilizer use efficiency under rain-fed agriculture in West Asia and North Africa. ICARDA, Aleppo, Syria.
15- Feiziasl V. 2007. Evaluate the effects of different nitrogen forms on quantitative and qualitative characteristics of dryland wheat (Final Report). Dryland Agricultural Research Institute. Publication No. 317. (in Persian with English abstract).
16- Feiziasl V. 2011. Study on the effects of nitrogen different amounts and timing application on nitrogen requirement, nitrogen use efficiency and the quantity and quality of wheat grain yield. (Final Report). Dryland Agricultural Research Institute. Publication No. 39694. (in Persian with English abstract).
17- Feiziasl V., Jafarzadeh J., Pala M. and Mosavi S.B. 2009. Determination of micronutrient critical Levels by plant response column order procedure for dryland wheat (T. aestivum L.) in Northwest of Iran.
International Journal of Soil Science, 4(1):14-19.
18- Feiziasl V., Kasraei R., Moghaddam M. and Valizadeh G. 2004. Investigation on uptake limitation and nutrient deficiency diagnosis at applied phosphorus and zinc fertilizers by different methods in Sardari wheat, Journal of Agricultural Sciences and Natural Resources 11: 23-33. (in Persian with English abstract).
19- Follett R.H., Follett R.F. and Halvorson A.D. 1992. Use of a chlorophyll meter to evaluate the nitrogen status of dryland winter wheat. Communications in Soil Science and Plant Analysis, 23(7-8):687-697.
20- Fowler D.B. and Brydon J. 1989. No-till winter wheat production on the Canadian prairies: Placement of urea and ammonium nitrate fertilizers. Agronomy Journal, 81:518-524.
21- Fowler D.B., Brydon J. and Buker R.J. 1989. Nitrogen fertilization of no-till winter wheat and rye. II. Influence on grain protein. Agronomy Journal, 81:72-77.
22- Garabet S. 1995. Fertilizer-use efficiency and nitrogen dynamics in rainfed and irrigated wheat under a Mediterranean type climate. PhD. Thesis. Soil Sci. Dept., Univ. Reading, Reading, Uk.
23- Gharbi A., Haddad A. and Ettouns L. 1992. Nitrogen and phosphorus in rain –fed regions of Tunisia: wheat responses and soil impacts. p. 172-182. In J. Ryan et al. (ed.). Fertilizer use efficiency under rain-fed agricultural in West Asia and North Africa. Proceedings of the Fourth Regional Workshop 5-10 May 1991. Agadir, Morocco. ICARDA, Aleppo, Syria.
24- Hazelton P. and Murphy B. 2007. Interpreting soil test results; what do all the numbers mean? CSIRO Publishing.
25- Huffman J.R. 1989. Effects of enhanced ammonium availability for corn. Journal of Agricultural Education, 18:93-97.
26- Johnston A.M. and Fowler D.B. 1991. No-till winter wheat production: response to spring applied nitrogen fertilizer form and placement. Agronomy Journal, 83:722-728.
27- Koenig R.T., Cogger C.G. and Bary A.I. 2011. Dryland Winter Wheat Yield, Grain Protein, and Soil Nitrogen Responses to Fertilizer and Biosolids Applications. Applied and Environmental Soil Science, 2011: 1- 9.
28- Legendre P., and Legendre L. 2003. Numerical ecology. Third english edition. Elsevier, Amsterdam.
29- Limon-Ortega A. 2009. Wheat grain yield response to N application evaluated through canopy reflectance. Cereal Research Communications, 37(4):595-601.
30- Lobell D.B., Ortiz-Monasterio J.I., Asner G.P., Naylor R.L. and Falcon W.P. 2005. Combining field surveys, remote sensing, and regression trees to understand yield variations in an irrigated wheat landscape. Agronomy Journal, 97:241–49.
31- Lobell D.B., Cassam K.G. and Field C.B. 2009. Crop Yield Gaps: Their Importance, Magnitudes, and Causes. Annual Review of Environment and Resource, 34:1-26.
32- Malakouti M.J. and Gheibi M.N. 1997. Determination of critical levels of macronutrients in the soils of Iran for field crops and orchards. High Concoil for Appropriate Use of Pesticides and Chemical Fertilizers, Ministry of Agriculture. (in Persian).
33- Matar A.E., Jabbour E. and El Hajj K. 1987. Prediction of barley response to fertilizers by means of soil nitrogen and phosphorus tests. p. 12-22. In A. E. Matar et al. (ed.). Soil test calibration in West Asia and North Africa. Proc. 2nd Regional Workshop, Ankara, Turkey, 1-6 Sept. 1987. ICARDA, Aleppo, Syria.
34- Mosseddaq F., Bedhiaf M. and Rhomari Y. 1992. Fertilization of cereals: Soil nitrogen test calibration in Morocco's Gharb area. p. 212-224. In J. Ryan et al. (ed.). Fertilizer use efficiency under rain-fed agriculture in West Asia and North Africa. Proc. Fourth Regional Workshop. Agadir, Morocoo, 5-10 May, 1992. ICARDA, Aleppo, Syria.
35- Mousavi Shalmani M.A. 2008. Use of 15N isotope in soil fertility and plant nutrition. Nuclear Science and Technology Research Institute. (in Persian).
36- Mulvaney R.L. 1994. Nitrification of different nitrogen fertilizers. In: Illinois Fertilizer Conference Proceedings, January 24-26. Department of Crop Sciences, University of Illinois Extension.
37- Orphanos P. L. and Metochis C.1990. Nitrogen responses to barley grain and barley forage grown continually or after fallow. p. 125-137. In J. Ryan et al. (ed.). Proc. Third Regional Soil Test Calibration Workshop. Amman, Jordan, 3-9 Sept.1998. ICARDA, Aleppo, Syria.
38- Pala M. and Matar A. 1987. Soil test calibration with N and P for wheat under dryland condition in Syria. p. 55-66. In: A. Matar et al. (ed.). Soil Test Calibration in West Asia and North Africa. Proc. Second Regional Soil Test Calibration Worshop, 1-6 Sept. Turkey. ICARDA, Aleppo, Syria.
39- Pala M., Oweis T., Benli B., De Pauw E., El Mourid M., Karrou M., Jamal M. and Zencirci N. 2011. Assessment of wheat yield gap in the Mediterranean: case studies from Morocco, Syria and Turkey. International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria.
40- Pilbeam C.J. 1996. Effect of climate on the recovery in crop and soil of 15N-labelled fertilizer applied to wheat. Fertilizer Research, 45:209–215.
41- Puttanna K., Nanje Gowda N.M. and Prakasa Rao E.V.S. 1999. Effect of concentration, temperature, moisture, liming and organic matter on the efﬁcacy of the nitriﬁcation inhibitors benzotriazole, o-nitrophenol, m-nitroaniline and dicyandiamide. Nutrient Cycling in Agroecosystems, 54: 251–257.
42- Raun W.R. and Johnson G.V. 1999. Improving nitrogen use efficiency for cereal production. Agronomy Journal, 91: 357-363.
43- Raun W.R., Solie J.B., Johnson G.V., Stone M.L., Mullen R.W., Freeman K.W., Thomason W.E. and Lukina E.V. 2002. Improving nitrogen use efficiency in cereal grain production with optical sensing and variable rate application. Agronomy Journal, 94:815-820.
44- Rice W.A., Akhtar M.E., Rohul Amin Y. and Campbell J.A. 1990. Wheat response to nitrogen and phosphorus fertilizers in rainfed areas of Pakistan. p. 66-75. In J. Ryan et al. (ed.).Soil Test Calibration in West Asia and North Africa. Proc. of the ThirdRegional Workshop Amman, Jordan, 3-9.Spt.1988. ICARDA, Aleppo, Syria.
45- Salazar Sosa, E., Lindemann W.C., Cardenas E.M. and Christensen N.B. 1998. Nitrogen mineralization and distribution through the root zone in two tillage systems under field conditions. Terra Latinoamericana, 16(2): 163-172.
46- Salsac L., Chaillou S., Morot-Gaudry J.F., LesaintC. and Jolivoe E. 1987. Nitrate and ammonium nutrition in plants. Plant Physiology and Biochemistry, 25:805-812.
47- Singh Y. and Beauchamp E.G. 1989. Nitrogen transformations near urea in soil: effects of nitrification inhibition, nitrifier activity and liming. Fertilizer Research, 18:201-212.
48- Soltanpour P.N., El Gharous M., Azzaoui A. and Abdelmonen M. 1987. Nitrogen and phosphorus soil-test calibration studies in the Chaouia Region of Morocco. p. 67-81. In A. Matar et al. (eds.). Soil Test Calibration in West Asia and North Africa. Proc. Second Regional Soil Test Calibration Worshop, 1-6 Sept. Turkey. ICARDA, Aleppo, Syria.
49- Soltanpour P.N., El Gharaous M., Zzaoui A. and Abdelmonem M. 1989. Soil-test based N recommendation model for dryland wheat. Communications in Soil Science and Plant Analysis, 20:1053-1068.
50- Soon Y.K., Clayton G.W. and Rice W.A. 2001. Tillage and previous crop effects on dynamics of nitrogen in a wheat–soil system. Agronomy Journal, 93:842–849.
51- Subhani A., Tariq M., Sulaman Jafar M., Latif R., Khan M., Sajid Iqbal M. and Shahid Iqbal M. 2012. Role of Soil Moisture in Fertilizer Use Efficiency for Rainfed Areas-A Review. Journal of Biology, Agriculture and Healthcare, 2(11):1-10.
52- Svoboda P. and Haberle J. 2006. The effect of nitrogen fertilization on root distribution of winter wheat. Plant, Soil and Environment, 5(7): 308–313.
53- Torabi B. and Soltanei A. 2013. Soltani assessment of nitrogen fertilizing of wheat farms in Gorgan region. Electronic Journal of Crop Production, 6(4):19-32. (in Persian with English abstract).
54- Van Harwaarden A.F., Farquhar G.D., Angus J.F. and. Richards R.A 2006. Physiological responses of six spring wheat varieties to nitrogen fertilizer (project report). Proceeding of the Australian Agronomy Conference, Australian Society of Agronomy.
55- Wall D.P. 2009. Soil Tests for Winter Wheat Nitrogen Management in the Southeastern USA. Ph.D. Dissertations & Theses. North Carolina State University. Copyright ProQuest, UMI Dissertations Publishing.
56- Wang, X. and Below F.E. 1992. Root growth, nitrogen uptake, and tillering of wheat induced by mixed-nitrogen source. Crop Science, 32:997-1002.
57- Weeks C., Robertson M.J., Oliver Y. and Fairbanks M. 2007. Managing seasonal risk is an important part of farm management but is highly complex and therefore needs a ‘horses for courses’ approach. WA Agribusiness Crop Updates 2007, 14–15 February 2007, Perth, Australia.
58- White R.G. and Kirkegaard J.A. 2010. The distribution and abundance of wheat roots in a dense, structured subsoil – implications for water uptake. Plant, Cell and Environment, 33:133–148.
59- Yazdani A., Ghadiri H. and Kazemi S.A. 2012. Interaction effects of weeds, sowing rate and N splitting on dryland wheat (Triticum aestivum L.) yield. Journal of Plant Protection, 26(2):152-16. (in Persian with English abstract).
60- Zadoks, J.C., Chang T.T. and Konzak C.F. 1974. A decimal code for the growth stages of cereals. Weed Research, 14:415-421.