Use of near infrared reflectance spectroscopy to predict nitrogen uptake by winter wheat within fields with high variability in organic matter

Abstract

. (2005) Use of near infrared reflectance spectroscopy to predict nitrogen uptake by winter wheat within fields with high variability in organic matter. Plant and Soil. Volume: 269, pp 251-258. http://dx.doi.org/10.1007/s11104-004-0556-1.Access to the published version may require journal subscription. Published with permission from: Springer.Standard set statement from the publisher: "An author may self-archive an author-created version of his/her article on his/her own website and or in his/her institutional repository. He/she may also deposit this version on his/her funder's or funder's designated repository at the funder's request or as a result of a legal obligation, provided it is not made publicly available until 12 months after official publication. He/ she may not use the publisher's PDF version, which is posted on www.springerlink.com, for the purpose of self-archiving or deposit. Furthermore, the author may only post his/her version provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at www.springerlink.com".Prior versions of the article published on non-commercial preprint servers like arXiv.org can remain on these servers and/or can be updated with the author's accepted version. The final published version (in PDF or HTML/XML format) cannot be used for this purpose. Acknowledgement needs to be given to the final publication and a link should be inserted to the published article on Springer's website, accompanied by the text "The final publication is available at www.springerlink.com". AbstractIn this study, the ability to predict N-uptake in winter wheat crops using NIR-spectroscopy on soil samples was evaluated. Soil samples were taken in unfertilized plots in one winter wheat field during three years (1997)(1998)(1999) and in another winter wheat field nearby in one year (2000). Soil samples were analyzed for organic C content and their NIR-spectra. N-uptake was measured as total N-content in aboveground plant materials at harvest. Models calibrated to predict N-uptake were internally cross validated and validated across years and across fields. Cross-validated calibrations predicted N-uptake with an average error of 12.1 to 15.4 kg N ha -1 . The standard deviation divided by this error (RPD) ranged between 1.9 and 2.5. In comparison, the corresponding calibrations based on organic C alone had an error from 11.7 to 28.2 kg N ha -1 and RPDs from 1.3 to 2.5. In three of four annual calibrations within a field, the NIR-based calibrations worked better than the organic C based calibrations. The prediction of N-uptake across years, but within a field, worked slightly better with an organic C based calibration than with a NIR based one, RPD = 1.9 and 1.7 respectively. Across fields, the corresponding difference was large in favour of the NIR-calibration, RPD = 2.5 for the NIR-calibration and 1.5 for the organic C calibration. ...

Visible and Near Infrared Spectroscopy in Soil Science

“…Notably, the range in N uptake in the Californian field was considerably smaller than that reported in other studies. In addition, the range of total soil C (9-16 g kg -1 ) was generally small compared to those reported by Börjesson et al (1999), Stenberg et al (2005) and Wetterlind et al (2008a). Wetterlind et al (2008a) failed to predict N uptake of winter wheat at one field with large variations in N uptake but only small variations in SOM content (corresponding to 12-32 g kg -1 C in the top 30 cm) suggesting that vis-NIR predictions of N uptake could be limited to fields with quite large variations in SOM content.…”

“…Vis-NIR spectroscopy has been used to predict N uptake in greenhouse pot experiments with promising results, cross-validated R 2 of about 0.8 (Russell et al, 2002;Wagner et al, 2001). In the field, comparable results (R 2 = 0.7-0.8 and RMSE = 6-21 kg N ha -1 ) have been found for N uptake in cereal and rice crops within single or nearby fields (Börjesson et al, 1999;Dunn et al, 2000;Stenberg et al, 2005;Wetterlind et al, 2008a), thus indicating the feasibility of calibrations over smaller areas with similar soil and weather conditions. However, one out of two rice experiments in south-eastern Australia only resulted in R 2 of 0.5 (Dunn et al, 2000).…”

“…Wetterlind et al (2008a) failed to predict N uptake of winter wheat at one field with large variations in N uptake but only small variations in SOM content (corresponding to 12-32 g kg -1 C in the top 30 cm) suggesting that vis-NIR predictions of N uptake could be limited to fields with quite large variations in SOM content. Similarly to the studies on other biological characteristics, vis-NIR predictions could explain more of the variation in N uptake compared with organic C (Börjesson et al, 1999;Stenberg et al, 2005). Results from the study by Wetterlind et al (2008a) indicated that the additional predictive capacity of vis-NIR was related to soil texture.…”

“…Results from the study by Wetterlind et al (2008a) indicated that the additional predictive capacity of vis-NIR was related to soil texture. Stenberg et al (2005) predicted N uptake in one field with a calibration model created from a nearby field with R 2 of 0.6 and RPD 2.5, but building reliable prediction models for N uptake over larger areas has so far proven to be more difficult (Fox et al, 1993;Russell et al, 2002;Wetterlind et al, 2008a). However, 50 out of the 95 sites studied by Fox et al (1993) had received farmyard manure and 25 had a legume crop in the previous year.…”

Replicability of nitrogen recommendations from ramped calibration strips in winter wheat

“…They also found that spatial disaggregation of soil data did not significantly improve model fit. Although the variation of mineral N availability has also been welldocumented within individual fields (Blackmer et al 1996;Scharf et al 2005;Stenberg et al 2005), and even at resolutions of less than one m 2 in Oklahoma (Solie et al 1999), several studies have determined that it is not always profitable to address small-scale spatial variation (Batte2000; Biermacher et al 2009;Boyer et al 2010). Thus, a producer might need only one RCS per five fields (if they are close together, similar in soil type, and planted on the same date), rather than five or more strips for the same set of fields, as currently recommended ).…”