REFERENCES
- Solie , J. B. , Raun , W. R. and Stone , M. L. 1999 . Submeter Spatial Variability of Selected Soil and Bermudagrass Production Variables . Soil Sci. Soc. Am. J. , 63 : 1724 – 1733 .
- Fiez , T. E. , Pan , W. L. and Miller , B. C. 1995 . Nitrogen Use Efficiency of Winter Wheat Among Landscape Positions . Soil Sci. Soc. Am. J. , 59 : 1666 – 1671 .
- Filella , I. , Serrano , L. , Serra , J. and Penuelas , J. 1995 . Evaluating Wheat Nitrogen Status with Canopy Reflectance Indices and Discriminant Analysis . Crop Sci. , 35 : 1400 – 1405 .
- Raun , W. R. , Solie , J. B. , Johnson , G. V. , Stone , M. L. , Lukina , E. V. , Thomason , W. E. and Schepers , J. S. 2001 . In-season Prediction of Potential Grain Yield in Winter Wheat Using Canopy Reflectance . Agron. J. , 93 : 131 – 138 .
- Sowers , K. E. , Miller , B. C. and Pan , W. L. 1994 . Optimizing Yield and Grain Protein in Soft White Winter Wheat with Split Nitrogen Applications . Agron. J. , 86 : 1020 – 1025 .
- Halvorson , A. D. , Reule , C. A. and Follett , R. F. 1999 . Nitrogen Fertilization Effects on Soil Carbon and Nitrogen in a Dryland Cropping System . Soil Sci. Soc. Am. J. , 63 : 912 – 917 .
- Tilman , D. 1999 . Global Environmental Impacts of Agricultural Expansion: The Need for Sustainable and Efficient Practices . Proc. Nat. Acad. Sci. U.S. Am. , 96 ( 11 ) : 5995 – 6000 .
- Sembiring , H. , Lees , H. L. , Raun , W. R. , Johnson , G. V. , Solie , J. B. , Stone , M. L. , DeLeon , M. J. , Lukina , E. V. , Cossey , D. A. , LaRuffa , J. M. , Woolfolk , C. W. , Phillips , S. B. and Thomason , W. E. 2000 . Effect of Growth Stage and Variety on Spectral Radiance in Winter Wheat . J. Plant Nutr. , 23 : 141 – 149 .
- Large , E. C. 1954 . Growth Stages in Cereals: Illustration of the Feekes Scale . Plant Path. , 3 : 128 – 129 .
- Schepers , J. S. , Francis , D. D. and Thompson , M. T. 1989 . Simultaneous Determination of Total C, Total N and 15N on Soil and Plant Material . Commun. Soil Sci. Plant Anal. , 20 : 949 – 959 .
- Thomason , W. E. , Raun , W. R. and Johnson , G. V. 2000 . Winter Wheat Fertilizer Nitrogen Use Efficiency in Grain and Forage Production Systems . J. Plant Nutr. , 23 : 1505 – 1516 .
- Wuest , S. B. and Cassman , K. G. 1992 . Fertilizer-nitrogen Use Efficiency of Irrigated Wheat. I. Uptake Efficiency of Preplant Versus Late-season Application . Agron. J. , 84 : 682 – 688 .
- Raun , W. R. and Johnson , G. V. 1999 . Improving Nitrogen Use Efficiency for Cereal Production . Agron. J. , 91 : 357 – 363 .