Precision agriculture on grassland: Applications, perspectives and constraints

Precision agriculture (PA) is an innovative, integrated and internationally standardized approach aiming to increase the efficiency of resource use and to reduce the uncertainty of decisions required to control variation on farms. Worldwide, investments in research and technology on PA have considerably increased during the past decades. Advances in agricultural research, combined with application of PA on grasslands, could provide major economic and environmental benefits. However, most of the available technology is currently being applied on arable land but not on grassland although the latter contributes substantially to agricultural land use as well as to capital and income. The authors hypothesise that heterogeneity of grassland among and within fields is a major constraint to PA application and that understanding such heterogeneity would enable to implement PA where competitive and cost efficient. In this paper, current developments and future perspectives of digital image processing, remote sensing, yield measurement, and site-specific management on grassland are discussed. At fine scales, on-board sensors can provide information on sward properties that application techniques could respond to. At larger scales, remotely sensed information can provide digital maps of type and status of vegetation that allow a precise management, although the mix of spatial coverage and spatial resolution is not yet ideal. The site-specific management on arable land, however, has not yet proven its applicability in different environments. On grassland, some of these technologies are either already implemented as prototypes into research projects or under development with a short-term perspective to be introduced into practice. Grassland scientists can significantly contribute to the current development and, in return, benefit from latest sensor technology and so enable rapid data acquisition and improvement of experimentation and knowledge. Also existing computer simulation models can contribute to make PA on grassland a success. Animal husbandry is strongly linked to grassland utilization and can also benefit from present PA technology through animal production and health control and animal guidance with appropriate electronic stimuli. Considerable interdisciplinary research is required to link existing knowledge on PA technology with grassland science and with animal science. This could mainly be accomplished by the interpretation of signal-object interaction that is needed to set up suitable configurations on grassland.