Abstract
It is known that plant height is a suitable parameter for estimating crop biomass. The aim of this study was to confirm the validity of spatial plant height data, which is derived from terrestrial laser scanning (TLS), as a non-destructive estimator for biomass of paddy rice on the field scale. Beyond that, the spatial and temporal transferability of established biomass regression models were investigated to prove the robustness of the method and evaluate the suitability of linear and exponential functions. In each growing season of two years, three campaigns were carried out on a field experiment and on a farmer’s conventionally managed field. Crop surface models (CSMs) were generated from the TLS-derived point clouds for calculating plant height with a very high spatial resolution of 1 cm. High coefficients of determination between CSM-derived and manually measured plant heights (R2: 0.72 to 0.91) confirm the applicability of the approach. Yearly averaged differences between the measurements were ~7% and ~9%. Biomass regression models were established from the field experiment data sets, based on strong coefficients of determination between plant height and dry biomass (R2: 0.66 to 0.86 and 0.65 to 0.84 for linear and exponential models, respectively). The spatial and temporal transferability of the models to the farmer’s conventionally managed fields is supported by strong coefficients of determination between estimated and measured values (R2: 0.60 to 0.90 and 0.56 to 0.85 for linear and exponential models, respectively). Hence, the suitability of TLS-derived spatial plant height as a non-destructive estimator for biomass of paddy rice on the field scale was verified and the transferability demonstrated.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 538-560 |
| Number of pages | 23 |
| Journal | Agriculture (Switzerland) |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2015 |
| Externally published | Yes |
Bibliographical note
Funding Information:On each site, three TLS campaigns were carried out in June and July of the respective year to capture the key vegetative stages of the rice plants. During this pre-anthesis period, differences in plant development occur mainly due to the increase of tillers and plant height. This period is important for fertilizer management decisions. In both years, the campaigns on the field experiment and the farmer’s field were carried out on two consecutive days to reach a best possible comparison regarding the plant development. For quantifying the phenological stages of plants and steps in plant development the BBCH-scale was used [46,47]. The abbreviation BBCH is derived from the funding organizations: Biologische Bundesanstalt (German Federal Biological Research Centre for Agriculture and Forestry), Bundessortenamt (German Federal Office of Plant Varieties), and Chemical industry. The campaign dates and BBCH-values for all sites are given in Table 1.
Funding Information:
The accomplished field work was affiliated to the activities of the International Center for Agro-Informatics and Sustainable Development (ICASD). Founded in 2009 by the Department of Plant Nutrition of the China Agricultural University in Beijing and the Institute of Geography at the University of Cologne in Germany, ICASD is an open, international, and multidisciplinary cooperative research center (www.ICASD.org). We would like to thank all colleagues and student assistants for their great effort during the field work (Juliane Bendig, Simon Bennertz, Jonas Brands, Erik Boger, Martin Gnyp, Anne Henneken, and Maximilian Willkomm). Further we extend our thanks to Five Star Electronic Technologies (Beijing, China), the Qixing Research and Development Centre and the Jiansanjiang Agricultural Research Station (both located in Heilongjiang Province, China) for good cooperation as well as RIEGL GmbH (Horn, Austria) for continuous support. This work was financially supported by the International Bureau of the German Federal Ministry of Education and Research (BMBF, project number 01DO12013) and the German Research Foundation (DFG, project number BA 2062/8-1).
Funding Information:
We would like to thank all colleagues and student assistants for their great effort during the field work (Juliane Bendig, Simon Bennertz, Jonas Brands, Erik Boger, Martin Gnyp, Anne Henneken, and Maximilian Willkomm). Further we extend our thanks to Five Star Electronic Technologies (Beijing, China), the Qixing Research and Development Centre and the Jiansanjiang Agricultural Research Station (both located in Heilongjiang Province, China) for good cooperation as well as RIEGL GmbH (Horn, Austria) for continuous support. This work was financially supported by the International Bureau of the German Federal Ministry of Education and Research (BMBF, project number 01DO12013) and the German Research Foundation (DFG, project number BA 2062/8-1).
Funding Information:
Nora Tilly with advice from Dirk Hoffmeister was responsible for the TLS measurements. The field experiment at the Keyansuo experimental station was carried out by Qiang Cao supervised by Yuxin Miao, who is scientific coordinator of the ICASD project, together with Victoria Lenz-Wiedemann. Nora Tilly carried out the post-processing and wrote this article, greatly supported by Dirk Hoffmeister and Victoria Lenz-Wiedemann. Georg Bareth directed the research and supervised the whole acquiring, analyzing, and writing process.
Publisher Copyright:
© 2015 by the authors; licensee MDPI, Basel, Switzerland.
Keywords
- Biomass
- Field level
- Plant height
- Precision agriculture
- Rice
- Terrestrial laser scanning