caa a22 4500 445864648 CHVBK 20180317145454.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s11119-010-9209-y doi (NATIONALLICENCE)springer-10.1007/s11119-010-9209-y Replicability of nitrogen recommendations from ramped calibration strips in winter wheat [Elektronische Daten] [David Roberts, B. Brorsen, Randal Taylor, John Solie, William Raun] Ramped calibration strips have been suggested as a way for grain producers to determine nitrogen needs more accurately. The strips use incrementally increasing levels of nitrogen and enable producers to conduct an experiment in each field to determine nitrogen needs. This study determines whether predictions from the program Ramp Analyzer 1.2 are replicable in Oklahoma hard red winter wheat (Triticum aestivum). Predictions are derived from 36 individual strips from on-farm experiments—two pairs of adjacent strips at each of nine winter wheat fields in Canadian County, OK. The two pairs of strips within each field were between 120 and 155m apart. Each strip was analyzed three times during the 2006-2007 growing season. Nitrogen recommendations from Ramp Analyzer 1.2 are not correlated even for strips that were placed side by side, and recommendations from strips in the same field show no more homogeneity than randomly selected strips throughout the county. The results indicate that ramped calibration strips are unlikely to produce accurate nitrogen requirement predictions at any spatial scale, whether at the county level or for subsections of a single field. In contrast, a procedure that uses only measures from the plot with no nitrogen and the plot with the highest level of nitrogen applied does show replicability. Thus, improvements in the ramped calibration strip technology are needed if it is to become viable. Springer Science+Business Media, LLC, 2010 Fertilizer nationallicence Nitrogen nationallicence Precision agriculture nationallicence Ramped calibration strip nationallicence Winter wheat nationallicence Roberts David Department of Agribusiness & Applied Economics, North Dakota State University, NDSU Dept. 7160, P.O. Box 6050, 58108-6050, Fargo, ND, USA aut Brorsen B. Department of Agricultural Economics, Oklahoma State University, 414 Agricultural Hall, 74078, Stillwater, OK, USA aut Taylor Randal Department of Biosystems and Agricultural Engineering, Oklahoma State University, 111 Agricultural Hall, 74078, Stillwater, OK, USA aut Solie John Department of Biosystems and Agricultural Engineering, Oklahoma State University, 111 Agricultural Hall, 74078, Stillwater, OK, USA aut Raun William Department of Plant and Soil Sciences, Oklahoma State University, 044N. Agricultural Hall, 74078, Stillwater, OK, USA aut Precision Agriculture Springer US; http://www.springer-ny.com 12/5(2011-10-01), 653-665 1385-2256 12:5<653 2011 12 11119 https://doi.org/10.1007/s11119-010-9209-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11119-010-9209-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Roberts David Department of Agribusiness & Applied Economics, North Dakota State University, NDSU Dept. 7160, P.O. Box 6050, 58108-6050, Fargo, ND, USA aut NATIONALLICENCE 700 1- Brorsen B. Department of Agricultural Economics, Oklahoma State University, 414 Agricultural Hall, 74078, Stillwater, OK, USA aut NATIONALLICENCE 700 1- Taylor Randal Department of Biosystems and Agricultural Engineering, Oklahoma State University, 111 Agricultural Hall, 74078, Stillwater, OK, USA aut NATIONALLICENCE 700 1- Solie John Department of Biosystems and Agricultural Engineering, Oklahoma State University, 111 Agricultural Hall, 74078, Stillwater, OK, USA aut NATIONALLICENCE 700 1- Raun William Department of Plant and Soil Sciences, Oklahoma State University, 044N. Agricultural Hall, 74078, Stillwater, OK, USA aut NATIONALLICENCE 773 0- Precision Agriculture Springer US; http://www.springer-ny.com 12/5(2011-10-01), 653-665 1385-2256 12:5<653 2011 12 11119 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer