caa a22 4500 445864249 CHVBK 20180317145453.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s11119-010-9163-8 doi (NATIONALLICENCE)springer-10.1007/s11119-010-9163-8 Use of soil nitrogen parameters and texture for spatially-variable nitrogen fertilization [Elektronische Daten] [H. Shahandeh, A. Wright, F. Hons] Recent studies have demonstrated the potential importance of using soil texture to modify fertilizer N recommendations. The objective of this study was to determine (i) if surface clay content can be used as an auxiliary variable for estimating spatial variability of soil NO3-N, and (ii) if this information is useful for variable rate N fertilization of non-irrigated corn [Zea mays (L.)] in south central Texas, USA across years. A 64ha corn field with variable soil type and N fertility level was used for this study during 2004-2007. Plant and surface and sub-surface soil samples were collected at different grid points and analyzed for yield, soil N parameters and texture. A uniform rate (UR) of 120kgNha−1 in 2004 and variable rates (VAR) of 0, 60, 120, and 180kgNha−1 in 2005 through 2007 were applied to different sites in the field. Distinct yield variation was observed over this time period. Yield and soil surface clay content and soil N parameters were strongly spatially structured. Corn grain yield was positively related to residual NO3-N with depth and either negatively or positively related to clay content depending on precipitation. Residual NO3-N to 0.60 and 0.90m depths was more related to corn yield than from shallower depths. The relationship of clay content with soil NO3-N was weak and not temporally stable. Yield response to N rate also varied temporally. Supply of available N with depth, soil texture and growing season precipitation determined proper N management for this field. Springer Science+Business Media, LLC, 2010 Spatial soil N variability nationallicence Residual NO3-N nationallicence Soil texture nationallicence Variable and uniform N rates nationallicence Corn grain yield nationallicence Shahandeh H. Department of Soil and Crop Science, Texas A&M University, 77843-2474, College Station, TX, USA aut Wright A. Everglades Research and Education Center, University of Florida, 32 00E. Pal Beach Road, 33430-4702, Belle Glade, FL, USA aut Hons F. Department of Soil and Crop Science, Texas A&M University, 77843-2474, College Station, TX, USA aut Precision Agriculture Springer US; http://www.springer-ny.com 12/1(2011-02-01), 146-163 1385-2256 12:1<146 2011 12 11119 https://doi.org/10.1007/s11119-010-9163-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11119-010-9163-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Shahandeh H. Department of Soil and Crop Science, Texas A&M University, 77843-2474, College Station, TX, USA aut NATIONALLICENCE 700 1- Wright A. Everglades Research and Education Center, University of Florida, 32 00E. Pal Beach Road, 33430-4702, Belle Glade, FL, USA aut NATIONALLICENCE 700 1- Hons F. Department of Soil and Crop Science, Texas A&M University, 77843-2474, College Station, TX, USA aut NATIONALLICENCE 773 0- Precision Agriculture Springer US; http://www.springer-ny.com 12/1(2011-02-01), 146-163 1385-2256 12:1<146 2011 12 11119 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer