Remote Sensing for Site-Specific Crop Management: Evaluating the Potential of Digital Multi-Spectral Imagery for Monitoring Crop Variability and Weeds within Paddocks

This paper analyses the potential and limitations of airborne remote sensing systems for detecting crop growth variability and weed infestation within paddocks at specified capture times. The detection of areas of crop growth variability can help farmers become aware of regions within their paddock where they may be experiencing above and below average yields due to changes in soil or management conditions. For instance, the early detection of weed infestation within cereal crops is crucial for lessening their impact on the final yield. Transect sampling within a canola paddock of a broad acre agricultural property in the South West of Western Australia was conducted synchronous with the capture of 1m spatial resolution DMSI. The four individual bands (blue, green, red and near- infrared) of the DMSI were correlated with LAI and weed density counts collected in the paddock. Statistical analyses show the LAI of canola had strong negative correlations with the blue (-0.93) and red (-0.89) bands and a strong positive correlation was found with the near-infrared band (0.82). The strong correlations between the canola LAI and selected bands of the DMSI indicate that this may be a suitable technique for monitoring canola variability to derive information layers that can be used in creating meaningful "within-field" management units. Likewise, DMSI could be used as a non-invasive tool for in season crop monitoring. The correlation analysis with the weed density (e.g. self sown wheat, ryegrass and clover) attributed to only one negative weak correlation with the red band (-0.38). The less successful detection of weeds is attributed to the minimal weeddensity within the paddock (e.g. mean 34 plants m-2) and indistinct spectral difference from canola at the early time of imagery capture required by farmers for effective variable rate applications of herbicides.LAI, remote sensing, crop density, vegetation indices, weed mapping., Crop Production/Industries,

Assessing chronological changes in remnant native forest at catchment level : a case study on the Toolibin catchment area

The aim of this study were to construct a digital database of the historical patterns of land clearing (amount, spatial distribution); to reconstruct the historical vegetation of the Toolibin catchment, Western Australia, using mallet maps and reports of the period; to produce maps showing the rate of clearing for the periods 1960-70, 1970-80, 1980-96; and to analyse the relationships between soil types, topographic position and land clearing

Synergies between Land Degradation Neutrality goals and existing market-based instruments

© 2019 Since the concept of the Land Degradation Neutrality (LDN) emerged in global policy discourse, a key point of contention has been the development of market-based instruments to promote the LDN agenda. Much of this discussion has focused on the use of LDN-specific offset mechanisms and private-public partnerships. However, there is also an opportunity to capitalise on the synergies that exist between LDN objectives and those of existing market-based instruments that have previously been developed for carbon, biodiversity, bioenergy and in other contexts. LDN objectives could be integrated into such schemes through targeted eligibility rules and certification schemes, supporting methodologies, adaptations to multifunctional indices used in auction-based approaches and the restructuring of mandates, tax breaks and feed-in tariffs for bioenergy and other products

A semi-automated approach for GIS based generation of topographic attributes for landform classification

This paper presents LANDFORM, a customized GIS application for semi-automated classification of landform elements, based on landscape parameters. Using custom commands, topographic attributes like curvature or elevation percentile were derived from a Digital Elevation Model (DEM) and used as thresholds for the classification of Crests, Flats, Depressions and Simple Slopes. With a new method, Simple Slopes were further subdivided in Upper, Mid and Lower Slopes at significant breakpoints along slope profiles. The paper discusses the results of a fuzzy set algorithm that was used to compare the similarity between the map generated by LANDFORM and the visual photo- interpretation conducted by a soil expert over the same area. The classification results can be used in applications related to precision agriculture, land degradation studies, and spatial modelling applications where landform is identified as an influential factor in the processes under study

'This country just hangs tight': Perspectives on managing land degradation and climate change in far west NSW

© 2019 Australian Rangeland Society. Discussions of land degradation often display a disconnect between global and local scales. Although global-scale discussions often focus on measuring and reversing land degradation through metrics and policy measures, local-scale discussions can highlight a diversity of viewpoints and the importance of local knowledge and context-specific strategies for sustainable land management. Similarly, although scientific studies clearly link anthropogenic climate change to land degradation as both cause and consequence, the connection may not be so clear for local rangelands communities due to the complex temporal and spatial scales of change and management in such environments. In research conducted in October 2015, we interviewed 18 stakeholders in the far west of New South Wales about their perspectives on sustainable land management. The results revealed highly variable views on what constitutes land degradation, its causes and appropriate responses. For the pastoral land managers, the most important sign of good land management was the maintenance of groundcover, through the management of total grazing pressure. Participants viewed overgrazing as a contributor to land degradation in some cases and they identified episodes of land degradation in the region. However, other more contentious factors were also highlighted, such as wind erosion, grazing by goats and kangaroos and the spread of undesired 'invasive native scrub' at the expense of more desirable pasture, and alternative views that these can offer productive benefits. Although few participants were concerned about anthropogenic climate change, many described their rangeland management styles as adaptive to the fluctuations of the climate, regardless of the reasons for these variations. Rather than focusing on whether landholders 'believe in' climate change or agree on common definitions or measurement approaches for land degradation, these results suggest that their culture of adaptation may provide a strong basis for coping with an uncertain future. The culture of adaption developed through managing land in a highly variable climate may help even if the specific conditions that landholders need to adapt to are unlike those experienced in living memory. Such an approach requires scientific and expert knowledge to be integrated alongside the context-specific knowledge, values and existing management strategies of local stakeholders

Comparison of Alternative Strategies for Invasive Species Distribution Modeling

Species distribution models (SDMs) can provide useful information for managing biological invasions,such as identification of priority areas for early detection or for determining containment boundaries.However, prediction of invasive species using SDMs can be challenging because they typically violatethe core assumption of being at equilibrium with their environment, which may lead to poorly guidedmanagement resulting from high levels of omission. Our goal was to provide a suite of potential decisionstrategies (DSs) that were not reliant on the equilibrium assumption but rather could be chosento better match the management application, which in this case was to ensure containment throughadequate surveillance. We used presence-only data and expert knowledge for model calibration andpresence/absence data to evaluate the potential distribution of an introduced mesquite (Leguminoseae:Prosopis) invasion located in the Pilbara Region of northwest Western Australia. Five different DSs withvarying levels of conservatism/risk were derived from a multi-criteria evaluation model using orderedweighted averaging. The performance of DSs over all possible thresholds was examined using receiveroperating characteristic (ROC) analysis. DSs not on the convex hull of the ROC curves were discarded. Twothreshold determination methods (TDMs) were compared on the two remaining DSs, one that assumedequilibrium (by maximizing overall prediction success) and another that assumed the invasion was ongoing(using a 95% threshold for true positives). The most conservative DS fitted the validation data mostclosely but could only predict 75% of the presence data. A more risk-taking DS could predict 95% of thepresence data, which identified 8.5 times more area for surveillance, and better highlighted known populationsthat are still rapidly invading. ThisDSandTDMcoupling was considered to be the most appropriatefor our management application. Our results show that predictive niche modeling was highly sensitiveto risk levels, but that these can be tailored to match specified management objectives. The methodsimplemented can be readily adapted to other invasive species or for conservation purposes

Linking changes in land cover and land use of the lower Mekong Basin to instream nitrate and total suspended solids variations

Population growth and economic development are driving changes in land use/land cover (LULC) of the transboundary Lower Mekong River Basin (LMB), posing a serious threat to the integrity of the river system. Using data collected on a monthly basis over 30 years (1985–2015) at 14 stations located along the Lower Mekong river, this study explores whether spatiotemporal relationships exist between LULC changes and instream concentrations of total suspended solids (TSS) and nitrate—as proxies of water quality. The results show seasonal influences where temporal patterns of instream TSS and nitrate concentrations mirror patterns detected for discharge. Changes in LULC influenced instream TSS and nitrate levels differently over time and space. The seasonal Mann–Kendall (SMK) confirmed significant reduction of instream TSS concentrations at six stations (p < 0.05), while nitrate levels increased at five stations (p < 0.05), predominantly in stations located in the upper section of the basin where forest areas and mountainous topography dominate the landscape. Temporal correlation analyses point to the conversion of grassland (r = −0.61, p < 0.01) to paddy fields (r = 0.63, p < 0.01) and urban areas (r = 0.44, p < 0.05) as the changes in LULC that mostly impact instream nitrate contents. The reduction of TSS appears influenced by increased forest land cover (r = −0.72, p < 0.01) and by the development and operation of hydropower projects in the upper Mekong River. Spatial correlation analyses showed positive associations between forest land cover and instream concentrations of TSS (r = 0.64, p = 0.01) and nitrate (r = 0.54, p < 0.05), indicating that this type of LULC was heavily disturbed and harvested, resulting in soil erosion and runoff of nitrate rich sediment during the Wet season. Our results show that enhanced understanding of how LULC changes influence instream water quality at spatial and temporal scales is vital for assessing potential impacts of future land and water resource development on freshwater resources of the LMB

Agency shifts in agricultural land governance and their implications for land degradation neutrality

Given current land degradation trends, Land Degradation Neutrality (LDN, SDG Target 15.3) by 2030 could be difficult to attain. Solutions to avoid, reduce, and reverse land degradation are not being implemented at sufficiently large scales, pointing to land governance as the main obstacle. In this paper, we review dynamics in agricultural land governance, and the potential this may have to enable land degradation or provide solutions towards LDN. The literature reveals agency shifts are taking place, where value chain actors are given increasing decision-making power in land governance. These agency shifts are manifested in two interrelated trends: First, through agricultural value chain coordination, such as contract farming, value chain actors increasingly influence land management decisions. Second, international large-scale land acquisitions and domestic larger-scale farms, both instances of intensified direct involvement of value chain with land management, are overtaking significant areas of land. These new arrangements are associated with agricultural expansion, and are additionally associated with unsustainable land management due to absent landowners, short-term interests, and high-intensity agriculture. However, we also find that value chain actors have both the tools and business cases to catalyze LDN solutions. We discuss how governments and other LDN brokers can motivate or push private actors to deploy private governance measures to avoid, reduce, and reverse land degradation. Successful implementation of LDN requires refocusing efforts to enable and, where necessary, constrain all actors with agency over land management, including value chain actors

From importing innovations to co-producing them: Transdisciplinary approaches to the development of online land management tools

While traditional approaches to innovation diffusion often assume that innovations come from outside a local system, transdisciplinary co-production offers an alternative paradigm in which local stakeholders are engaged as co-producers of innovations. The use of digital online tools for agriculture, conservation, and citizen science is an area of expanding opportunities, but landholders are often dependent on tools developed outside their local communities. This article looks at the potential for transdisciplinary co-production to be used as a framework for more participatory development of digital online land management tools, with a case study from the Central Tablelands of New South Wales, Australia. This research has implications beyond rural land management to other industries and contexts where reflexive and integrative strategies are needed to overcome barriers to stakeholder participation and engagement with new technologies

Developing online tools for increased landholder collaboration in landscape scale conservation and production

This research is part of a two-year project that aims to develop models and tools for incentivising on-ground collaboration on cross-property conservation and production activities. The focus of the study is the NSW Central Tablelands and Central West, particularly the areas around Mudgee-Rylstone and Cowra-Boorowa. The project involves: - Social analysis to identify types of activities and organisational structures that foster collaboration - Spatial analysis to determine how these activities could be linked strategically to deliver landscape-scale impacts outcomes -The development of an online GIS-based tool for use by landholders and other stakeholders in identifying opportunities for collaboration