Land use is central to addressing sustainability issues, including biodiversity conservation, climate change, food security, poverty alleviation, and sustainable energy. In this paper, we synthesize knowledge accumulated in land system science, the integrated study of terrestrial social-ecological systems, into 10 hard truths that have strong, general, empirical support. These facts help to explain the challenges of achieving sustainability in land use and thus also point toward solutions. The 10 facts are as follows: 1) Meanings and values of land are socially constructed and contested; 2) land systems exhibit complex behaviors with abrupt, hard-to-predict changes; 3) irreversible changes and path dependence are common features of land systems; 4) some land uses have a small footprint but very large impacts; 5) drivers and impacts of land-use change are globally interconnected and spill over to distant locations; 6) humanity lives on a used planet where all land provides benefits to societies; 7) land-use change usually entails trade-offs between different benefits—"win–wins" are thus rare; 8) land tenure and land-use claims are often unclear, overlapping, and contested; 9) the benefits and burdens from land are unequally distributed; and 10) land users have multiple, sometimes conflicting, ideas of what social and environmental justice entails. The facts have implications for governance, but do not provide fixed answers. Instead they constitute a set of core principles which can guide scientists, policy makers, and practitioners toward meeting sustainability challenges in land use.

This paper examines the potential of airborne videography as a remote sensing tool in a project aimed to develop a rapid and cost-effective system for assessing and monitoring the conditions of crops, pastures and native forest areas in the agricultural region of Western Australia. This implies a close examination of current techniques for low cost/high resolution data capture, and the requirements for image-based precision farming. The research approach comprises reviewing stress indicators that can be used as early signs of changes in the conditions of crops and pasture, and the identification of value-added products, such as vegetation indices, that can be used by farmers and land planners interested to know where field variations occur. Four vegetation indices, Namely Plant Pigment Ratio (PPR), Photosynthetic Vigour Ratio (PVR), the Normalized Difference Vegetation Index (NDVI) and the green NDVI (NDVIg) are tested. Experimental results related to the identification and mapping of crop density variations, crop types, and variations in crop conditions due to the presence of weeds and dead standing vegetation are discussed. Statistical analysis ( T -test and multiple comparisons procedure using the Fisher LSD test, at @ =0.05) suggest the PVR as the best index to detect relative variations (e.g. high, medium, low) in crop density, followed by the NDVI. Results also show the indices ability to separate canola from lupins and wheat. Additionally, the PPR appears to detect the presence of weeds ( Arctotheca calendula ) in pasture and cereal crops, while NDVIg and NDVI can only identify weeds in pasture. The NDVI and NDVIg appear as the more sensitive indices to detect the presence of dead standing vegetation (stubble) in pasture. The status of high-resolution satellite imagery, as compared to airborne videography, for crop management applications, and main findings in regard to the potential of video-based vegetation indices to support precision farming, are presented as well.