Assessing water quality for cropping management practices: A new approach for dissolved inorganic nitrogen discharged to the Great Barrier Reef

Applications of nitrogen (N) fertiliser to agricultural lands impact many marine and aquatic ecosystems, and improved N fertiliser management is needed to reduce these water quality impacts. Government policies need information on water quality and risk associated with improved practices to evaluate the benefits of their adoption. Policies protecting Great Barrier Reef (GBR) ecosystems are an example of this situation. We developed a simple metric for assessing the risk of N discharge from sugarcane cropping, the biggest contributor of dissolved inorganic N to the GBR. The metric, termed NiLRI, is the ratio of N fertiliser applied to crops and the cane yield achieved (i.e. kg N (t cane)−1). We defined seven classes of water quality risk using NiLRI values derived from first principles reasoning. NiLRI values calculated from (1) results of historical field experiments and (2) survey data on the management of 170,177 ha (or 53%) of commercial sugarcane cropping were compared to the classes. The NiLRI values in both the experiments and commercial crops fell into all seven classes, showing that the classes were both biophysically sensible (c.f. the experiments) and relevant to farmers’ experience. We then used machine learning to explore the association between crop management practices recorded in the surveys and associated NiLRI values. Practices that most influenced NiLRI values had little apparent direct impact on N management. They included improving fallow management and reducing tillage and compaction, practices that have been promoted for production rather than N discharge benefits. The study not only provides a metric for the change in N water quality risk resulting from adoption of improved practices, it also gives the first clear empirical evidence of the agronomic practices that could be promoted to reduce water quality risk while maintaining or improving yields of sugarcane crops grown in catchments adjacent to the GBR. Our approach has relevance to assessing the environmental risk of N fertiliser management in other countries and cropping systems

2017 Scientific Consensus Statement: land use impacts on the Great Barrier Reef water quality and ecosystem condition. Chapter 4: management options and their effectiveness

This chapter seeks to answer the following questions: 1. What are the values of the Great Barrier Reef? 2. How effective are better agricultural practices in improving water quality? 3. How can we improve the uptake of better agricultural practices? 4. What water quality improvement can non-agricultural land uses contribute? 5. How can Great Barrier Reef water quality improvement programs be improved? Each section summarises the currently available peer reviewed literature and comments on implications for management and research gaps. This chapter has a wider scope than previous Scientific Consensus Statements, including, for the first time, the social and governance dimensions of management and the management of non-agricultural land uses. These new sections are constrained by a lack of Great Barrier Reef–specific data and information. The relevance of information from other locations must be carefully considered. In comparison, the agricultural practice change and economics sections provide an update on material compiled as part of the 2013 Scientific Consensus Statement. This report has been confined to peer reviewed literature, which is generally published in books and journals or major reports. There is additional evidence in grey literature, such as project and program reports, that has not been included here. Each section of this chapter has been compiled by a writing team and then revised following a series of review processes

Assessing cost-effectiveness when environmental benefits are bundled: agricultural water management in Great Barrier Reef catchments

Using economic analysis to prioritise improvements in environmental conditions is particularly difficult when multiple benefits are involved. This includes ‘bundling’ issues in agricultural pollution management, where a change in management action or farming systems generates multiple improvements, such as reductions in more than one pollutant. In this study, we conceptualise and compare two different approaches to analysing cost-effectiveness when varying bundles of benefits are generated for a single project investment. Each approach requires data to be transformed in some way to allow the analysis to proceed. The index approach requires the transformation on the benefits side so that the effects of multiple pollutant changes can be combined into a measure for each project which can then be compared to costs. By comparison, the disaggregation approach requires the transformation on the costs side where costs for each project have to be apportioned across the different pollutants involved. The paper provides novel insights with an application to agricultural water quality improvements into the Great Barrier Reef in Australia, demonstrating that while both approaches are effective in prioritising projects by cost-effectiveness, the disaggregation approach provides more insightful results and values that may be relevant for use as upper value guidelines in future project selection

Assessing cost-effectiveness when environmental benefits are bundled: agricultural water management in Great Barrier Reef catchments

Using economic analysis to prioritise improvements in environmental conditions is particularly difficult when multiple benefits are involved. This includes ‘bundling’ issues in agricultural pollution management, where a change in management action or farming systems generates multiple improvements, such as reductions in more than one pollutant. In this study, we conceptualise and compare two different approaches to analysing cost-effectiveness when varying bundles of benefits are generated for a single project investment. Each approach requires data to be transformed in some way to allow the analysis to proceed. The index approach requires the transformation on the benefits side so that the effects of multiple pollutant changes can be combined into a measure for each project which can then be compared to costs. By comparison, the disaggregation approach requires the transformation on the costs side where costs for each project have to be apportioned across the different pollutants involved. The paper provides novel insights with an application to agricultural water quality improvements into the Great Barrier Reef in Australia, demonstrating that while both approaches are effective in prioritising projects by cost-effectiveness, the disaggregation approach provides more insightful results and values that may be relevant for use as upper value guidelines in future project selection

Spatial and temporal monitoring of farm practices in Great Barrier Reef catchments

The Great Barrier Reef (GBR) is under increasing threat from climate change, extreme weather events, and land-based runoff (sediments, nutrients, and pesticides). The major contributor of loads of these pollutants are the agricultural production systems in river catchments adjacent to the GBR. These agricultural land uses comprise approximately 14,000 farms which manage ~370,000 km2 or 80% of the total land area. The governments of Australia and Queensland have invested significant public funds in improving how farms are managed with the aim of decreasing pollutant loads and improving water quality in the GBR lagoon. The Paddock to Reef program monitors the adoption of farm management practices within these catchments, for the five main agricultural land uses (beef cattle grazing, and cropping of grains, sugarcane, bananas, and other horticultural crops). Paddock to Reef manages a geographic information system (GIS) based system to track farm management changes spatially, and over time. Between 2014 and 2021, Paddock to Reef has recorded management attributes on more than 50,000 km2 of farmland in the highest priority areas of the GBR catchments. The purpose of these data is to enable independent, science-based assessment of the potential water quality impacts of the many programs and projects aiming to improve farm management. This paper summarises unique features of Paddock to Reef’s monitoring and evaluation effort, the main limitations, and possible future enhancements

Targeting for pollutant reductions in the Great Barrier Reef river catchments

Rolfe, JC ORCiD: 0000-0001-7659-7040The declining health of the Great Barrier Reef (GBR) from poor water quality has increased the urgency for pollutant reductions at the same time that available financial resources and knowledge regarding the most appropriate interventions are limited. Prioritisation of water quality interventions in the Great Barrier Reefcatchments is the process of identifying which land based actions can achieve the largest environmental benefitsat the lowest cost. For prioritisation to be effective a focus is required on the outcomes of pollution reductiona ctivities as compared to the inputs. In this paper we set out a framework for prioritising actions to improve water quality into the Great Barrier Reef, as well as providing a case study analysis using 47 individual riverbasins across the six large scale catchments, three pollutants and two industries. The results identify the most cost-effective options for water quality improvements aligning to locations of medium risk to reef health. The outcomes of the analysis highlight the importance of seeking pollutant reductions where the most effectiveoutcome can be achieved rather than simply targeting an industry or a catchment

Intoducing the hill "Sxisti Petra"

Αντικείμενο της παρούσας εργασίας αποτελεί η αστική παρέμβαση στο λόφο Σχιστή Πέτρα, στους πρόποδες του Λυκαβηττού, στην Αθήνα. Κύριος στόχος της παρέμβασης είναι η επαναδιαπραγμάτευση της σχέσης της Σχιστής Πέτρας τόσο με το δομημένο περιβάλλον της όσο και με το λόφο του Λυκαβηττού. Πρόκειται για μια αλληλουχία οριακών παρεμβάσεων που συγκροτούν μια υπαίθρια έκθεση γλυπτικής με κύριο εργαλείο υλοποίησης το τοιχίο. Η χρήση του τοιχίου είναι τέτοια ωστέ να συγκρατεί, να κατευθύνει, να εισχωρεί, να παράγει επίπεδα, μεταβατικούς χώρους και περάσματα, να στρέφει το σώμα και το βλέμμα. Αυτές οι χειρονομίες υλοποιούνται με απλές συνθέσεις τοιχίων. Με την ίδια λογική συγκροτείται και μια κτιριακή δομή που φιλοξενεί ένα εργαστήρι γλυπτικής που τροφοδοτεί την υπαίθρια έκθεση. Την παρέμβαση ολοκληρώνουν η διαμόρφωση του εδάφους καθώς επίσης και τα γλυπτά.The subject of the present project is an urban intervention at the hill “Sxisti Petra”, at the foothills of the hill Lycabettus, in Athens. Main goal of our intervention is the renegotiation of Sxisti Petra’s relationship with the built environment as well as the hill of Lycabettus. Our proposal consists of a sequence of limit interventions which form an outdoor sculpture exposition. Main compositional tool is the wall which is used so that it can hold, give direction to the body, penetrate, produce levels and passages and turns both body and gaze. Our intervention as a whole is formed as simple wall compositions. With the same philosophy we develop a building structure which hosts a sculpture workshop. Two extra compositional tools complete the project, the configurations of the ground as well as the sculptures themselves.Ιωάννα Α. ΜπουντουβάΜυρσίνη Πετροπούλο

Identifying chickpea homoclimes using the APSIM chickpea model

Chickpea (Cicer arietinum L.) has been traditionally grown in India but is a relatively new export crop in Australia where its cultivation is expanding into new areas. The objective of this study was to identify homoclimes (i.e. similar chickpea-growing environments) in the major chickpea-growing areas of the 2 countries, using the Agricultural Production Systems Simulator (APSIM) chickpea model. The model, which processes climatic, soil, and plant information on a daily time step, was first validated and then used to simulate flowering, maturity, and grain yield of Amethyst, a mid-season cultivar, and Barwon, a full-season cultivar, on low (100 mm), medium (150 mm), and high (190 mm) water-holding capacity soils, using historical climatic data of 67 Australian and 24 Indian locations. The mean of annual outputs of flowering, maturity, and grain yield of the 2 cultivars on 3 soils was then clustered using Ward's hierarchical complete linkage clustering procedure. At a 90% level of similarity, all the locations could be grouped into 6 homoclime clusters. The Australian locations appeared more diverse as they were present in all the clusters, whereas the Indian locations were present only in clusters 1, 2, and 6. While there were clear geographical patterns of spread of these clusters, in Australia they were not entirely related to latitude. The cluster 1 and 2 locations, which represent the largest chickpea-growing area in Australia, had homoclime locations in common with northern India. The clustering of locations appeared generally consistent with the known adaptation of chickpea in different environments of the 2 countries and therefore suggests that the methodology could be potentially used for complementing conventional approaches of introducing or exchanging germplasm, as well as determining appropriateness of breeding/testing sites