Spatial and Temporal Variability of Corn Growth and Grain Yield

Effects of factors influencing spatial and temporal variability of crop yields are usually expressed in crop growth patterns. Consequently, monitoring crop growth can form the basis for managing site-specific farming (SSF). This experiment was conducted to determine whether crop growth patterns forecast grain yields. Effects of irrigation rates (50 and 80% evapotranspiration, ET), elevation, soil texture, soil NO 3 -N, arthropods, and diseases on corn (Zea mays L.) growth and grain yield were evaluated at Halfway, TX, in 1998 and 1999. Data on plant height, leaf area index, leaf dry matter, stem dry matter, and ear dry matter were collected from geo-referenced locations (DGPS). These data were used to derive total dry matter, crop growth rate, and net assimilation rate (NAR). Grain yields at DGPS locations were classified into four distinct clusters. In 1998, a dry season, clusters were strongly influenced by elevation and soil texture. Grain yields were higher at high elevations where water use was high and soil texture was heavy compared with low elevations. Grain yields at low elevations also were reduced by common smut [Ustilago zeae (Beckm.) Unger] that preferred dry conditions. In 1999, a relatively wet season, clusters included areas with different elevation and soil texture combinations. Measured parameters forecast grain yields better in 1998 than in 1999. Differences in NAR were evident before the 12-leaf stage, making NAR a potentially useful measurement for early in-season management decisions. Biomass measurements, for which differences were observed after the 12-leaf stage, also may be used to formulate decisions for both in-season and the following season's management.

[1]  F. J. Pierce,et al.  The state of site specific management for agriculture. , 1997 .

[2]  Philip J. Bauer,et al.  Spatial Corn Yield During Drought in the SE Coastal Plain , 1995 .

[3]  William J. Ripple,et al.  Spectral reflectance relationships to leaf water stress , 1986 .

[4]  R. W. Whitney,et al.  Use of Spectral Radiance for Correcting In-season Fertilizer Nitrogen Deficiencies in Winter Wheat , 1996 .

[5]  Philip J. Bauer,et al.  Site‐Specific Analysis of a Droughted Corn Crop: I. Growth and Grain Yield , 2000 .

[6]  W. W. McFee,et al.  The Nature and Properties of Soils, 8th Edition , 1975 .

[7]  W. M. Lyle,et al.  Low Energy Precision Application (LEPA) Irrigation System , 1981 .

[8]  M. S. Moran,et al.  Opportunities and limitations for image-based remote sensing in precision crop management , 1997 .

[9]  J. Schepers,et al.  Analysis of Aerial Photography for Nitrogen Stress within Corn Fields , 1996 .

[10]  R. Lambert,et al.  The Use of Physiological Traits for Corn Improvement , 1988 .

[11]  P. Sellers.  Canopy reflectance, photosynthesis, and transpiration. II. the role of biophysics in the linearity of their interdependence , 1987 .

[12]  H.W.J. van Kasteren,et al.  Standard relations to estimate ground cover and LAI of agricultural crops from reflectance measurements , 1992 .

[13]  S. Idso,et al.  Canopy temperature as a crop water stress indicator , 1981 .

[14]  W. Pan,et al.  Winter Wheat Yield and Grain Protein across Varied Landscape Positions , 1994 .

[15]  F. J. Pierce,et al.  Modeling Crop Yield for Site-Specific Management , 1997 .

[16]  D. Mulla,et al.  Key processes and properties for site-specific soil and crop management. , 1997 .

[17]  Gary E. Varvel,et al.  Light Reflectance Compared with Other Nitrogen Stress Measurements in Corn Leaves , 1994 .

[18]  J. V. Baglio,et al.  Nonpoint source pollution impacts of alternative agricultural management practices in Illinois: A simulation study , 1993 .

[19]  D. W. Hall.  Effects of Nutrient Management on Nitrate Levels in Ground Water Near Ephrata, Pennsylvania , 1992 .

[20]  K. Bronson,et al.  Spatial and Temporal Variability of Corn Grain Yield: Site-Specific Relationships of Biotic and Abiotic Factors , 2000, Precision Agriculture.

[21]  W. Baethgen,et al.  Optimizing Soil and Fertilizer Nitrogen Use by Intensively Managed Winter Wheat. I. Crop Nitrogen Uptake , 1989 .

[22]  H. Nilsson.  Remote sensing and image analysis in plant pathology. , 1995, Annual review of phytopathology.

[23]  D. White.  Compendium of corn diseases , 1999 .

[24]  Walter E. Riedell,et al.  Leaf Reflectance Spectra of Cereal Aphid-Damaged Wheat , 1999 .

[25]  C. R. Ward,et al.  Influences of Irrigation Practices on Spider Mite Densities on Field Corn , 1979 .

[26]  Kenneth J. Boote,et al.  Physiology and Determination of Crop Yield , 1994 .

[27]  J. R. Thomas,et al.  Estimating Nitrogen Content of Sweet Pepper Leaves by Reflectance Measurements1 , 1972 .

[28]  J. Hanway.  How a corn plant develops , 1966 .

[29]  J. F. Power,et al.  Growth Analysis Based on Degree Days , 1984 .

[30]  Forrest W. Nutter,et al.  Low-Cost,Portable Multispectral Radiometer For Assessment Of Onset And Severity Of Foliar Disease Of Barley , 1983, Optics & Photonics.

[31]  Charles L. Walthall,et al.  Photosynthesis and stomatal conductance related to reflectance on the canopy scale , 1993 .

[32]  A. Kravchenko,et al.  Correlation of Corn and Soybean Grain Yield with Topography and Soil Properties , 2000 .

[33]  E. C. Doll,et al.  Topographic Effects on Spring Wheat Yields and Water Use , 1991 .

[34]  Christopher B. Field,et al.  Reflectance indices associated with physiological changes in nitrogen- and water-limited sunflower leaves☆ , 1994 .

[35]  J. Peñuelas,et al.  The reflectance at the 950–970 nm region as an indicator of plant water status , 1993 .