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Compaction-induced soil degradation is of growing importance as field machinery continues to increase in power and mass. Approaches to managing the impacts of soil compaction include minimisation (reduce load), remediation (tillage) and confinement (control traffic). Integrated ‘swarms’ of low-mass autonomous machinery have recently been suggested as a means of reducing compaction and an alternative to controlled traffic. In this study, combine and potato harvester machinery relationships were used to predict the specifications of potential low-mass harvesters for use in soil compaction modelling. Results suggested that combine harvester gross vehicle mass (GVM) must be less than 6 Mg to keep the modelled soil bulk density below 1.4 Mg m-3. With this constraint, 6-9 small harvesters (~50 kW) would be required to replace one Class 9 (>300 kW) harvester. A fleet of this size would require access to unloading facilities every 2.5-3 min for the modelled yield conditions. For root and tuber harvesting, which results in a high degree of soil disturbance, no low-mass harvester option was found that would avoid compacting the soil to unacceptable limits. Avoiding soil compaction while maintaining acceptable productivity will pose considerable design and logistics challenges for low-mass grain, root and tuber vegetable harvest machinery. The integration of controlled traffic farming (CTF) and medium-capacity autonomous machines (~10-20 Mg GVM for combine harvesters) may be a better solution for both soil compaction and operational logistics than low-mass swarm technology.

The activities of innovation system actors, particularly the importance of networks, entrepreneurs, and the role of intermediaries have not yet been integrated into a framework that explains innovation system performance at the project level. This study contributes by exploring the role of the innovation system’s actors with respect to its performance. Innovation system performance is studied using multiple cases of projects using statistical inference, network analysis, and fuzzy-set qualitative comparative analysis. The number of actors effectively involved in projects is positively associated with innovation system performance. The network of relationships in the case study innovation system was relatively open, such that the contribution of some actors only became available to the system through the conduit of other actors. Both researchers and intermediaries are highly involved and effective, and the intermediaries’ effectiveness contributes to innovation system performance. However, the perceived involvement or effectiveness of these and other actors did not, alone, ensure that the conditions required for innovation system performance were met. The research method and results apply to any innovation project, particularly those in highly regulated, technological fields. The present study’s findings demonstrate the application of innovation system theory at the project level. The study has important implications for integrating entrepreneurial marketing into innovation system policy and practice.

Innovation systems provide a structured approach to understanding innovation performance and failure. Two innovation system theories, structural and functional, provide the basis for understanding the failures of projects within the single innovation system under investigation. Many indicators of the strength of conditions in the model are important to innovation system performance. Fuzzy set qualitative comparative analysis is suitable for the validation of formative measurement models. The survey instrument meets validity criteria to the extent of this research and is a useful diagnostic tool for innovation system performance.

Innovation systems provide an approach to understanding, and managing, the innovation process. The application of structural theory from the sectoral innovations systems literature and the functional theory from technological systems literature to a series of projects provides an opportunity to explore how weaknesses in the innovation system relate to innovation failure. Findings from fuzzy set qualitative comparative analysis of multiple cases indicate that the weaknesses of the innovation system are recurrent across cases, and therefore, amenable to policy or management intervention to improve innovation outcomes. The weaknesses in structural theory conditions are more consistent than the weaknesses in technological theory conditions.

Large amounts of industrial wastewater, often of high in salt content, are produced by urban activities or industries which require reuse or disposal and thus can be potentially used in agriculture to ease the pressure on freshwater supply for irrigation. At the same time, plant performance in the field may be determined not only by salt concentration per se but also by confounding effects associated with soil physical and chemical properties. The purpose of this study was to investigate the effect of saline water irrigation (0–16 dS/m range) on the performance of two plant species, Atriplex lentiformis (xero halophyte) and Medicago arborea (glycophyte) grown in three soil texture setups – (1) clay, (2) sandy loam and (3) sandy loam over clay (texture-contrast) – under glasshouse conditions. Both plant species yielded higher biomass in the clay texture compared to other soil texture setups under all irrigation treatments. There was no significant variation in chlorophyll fluorescence with salt treatments but stomatal conductance was significantly reduced (up to 70%) by salinity in M. arborea. Overall, leaf ion content (Na+ and Cl _) also increased with increasing salinity treatment in both plants, but significant effects were seen only in sandy loam soil for both species. Both osmotic effect and specific ionic toxicity impacted physiological performance in M. arborea while A. lentiformis plants were insensitive to both components of salt stress. Plant performance in the sandy soil was not as good as in clay, indicating that soil texture and structure may have a significant role in the salt stress process under saline irrigation.

Systematic approaches to understanding innovation are common, but these approaches still need testing as theories. This study aims to fill that gap by constructing sectoral and technological innovation-system failure models as theories and by testing those models using a multiple case study and fuzzy set qualitative comparative analysis. Both theories predict innovation system performance. Qualitative comparative analysis proved useful in both constructing and testing theory.

The use of biochar and compost as soil amendments and their comparative effects on microbial activities and related processes were investigated in an apple orchard site at Mountain River in Tasmania, Australia. Biochar derived from Acacia green waste was applied at a rate of 47 ton ha−1 just before planting and has been in situ for 3.5 years. Compost produced by the Luebke system was also applied separately at 10 ton ha−1 as a top dressing one week after planting. Chemical analysis indicated that there was no significant impact on total ions by either biochar or compost additions. However, organic carbon was significantly increased (p = 0.009) by 23% for biochar and 55% for compost treatments. Soil pH decreased in both biochar and compost treatments. Microbial abundance was improved after the addition of biochar, but the effect of compost addition was greater. There were no significant differences across a panel of enzyme activities among treatments. There were slight increases in alkaline phosphatase while fluorescein diacetate activity and hydrolysis activity slightly decreased. The entire community of the soil was assessed using 16S rRNA and 18S rRNA genes amplicon pyrosequencing. Significant differences in bacterial and fungal but not archaeal or other eukaryota community components were observed. These results indicated that biochar and compost carbon amendments can subtly affect the community structure of the orchard soils despite active application of inorganic and organic fertilizers. The overall effects on fundamental activity is largely neutral, however, likely due to the enormous structural resilience and functional redundancy present.

The world's food production will need to increase by up to 70% by 2050 to match the predicted population growth. Achieving this goal will be challenging due to the decreased availability of arable land, resulting from urbanization and land degradation. Soil salinity is a major factor contributing to the latter process. While some improvement in crop yields in saline soils may be achieved as a consequence of single gene transfers, the real progress may be achieved only via a painfully slow “pyramiding” of essential physiological traits. Given the time constraints, a safer solution to meet the 2050 challenge may be to find alternative crop and forage species for farming in salt-affected conditions and to restore salt-affected areas. This review focuses on the suitability of halophytes to become important components of 21st century farming systems. We provide a comprehensive summary of the current use of halophytes for human food consumption, for forage and animal feeds, as oilseed and energy crops, and for desalination and phytoremediation purposes. We argue that the use of halophytes may be a viable commercial alternative to ease pressure on the requirement of good quality land and water for conventional cropping systems and the utilization of land degraded by salinity.

Knowledge of the soil water characteristic (SWC) and saturated hydraulic conductivity (Ksat) are required for simulation of soil water movement in most Richards’ equation based soil-water models. This study compared van Genuchten (VG) parameter values and Ksat determined by desorption with two rapid approaches, evaporative flux from intact cores, and inverse solution of tension infiltration data. Estimated and measured Ksat varied up to four orders of magnitude depending on parameterisation approach and antecedent soil moisture content. The SWC differed markedly between the laboratory drying and in situ wetting approaches due to the effects of hysteresis, air entrapment, clay swelling and water repellence. The evaporative flux approach was subjected to errors associated with prior saturation of the soil core, lack of K(ψ) data near saturation, and extrapolation of values beyond the measurement range of the upper tensiometer. Inverse solution of cumulative infiltration data from tension infiltrometers was able to discern the effects of antecedent soil moisture on soil structure and water repellence, however the approach had difficulty in obtaining unique local minima when the residual soil water content (θr) was included in the objective function. Both the evaporative flux and inverse solution of tension infiltration data approaches were improved by independent determination of the θr. Researchers should be aware that initial moisture content and methodology may influence VG parameter values, and that laboratory analysis of intact cores may result in Ksat and VG values which do not represent the hydraulic behaviour of field soils.

Many Tasmanian deposits previously described as ‘periglacial’ have been described in more detail, re-interpreted and dated. We suggest that ‘periglacial’ has little meaning when applied locally and the term ‘relict cold-climate deposits’ is more appropriate. In this paper we examine the origin and age of relict cold-climate slope deposits, fan alluvium and aeolian sediments in Tasmania, and infer the conditions under which they accumulated. Fan alluvium dating from the penultimate Glacial (OIS 6) and capped by a prominent palaeosol deduced to date to the Last Interglacial (OIS 5e) is present at Woodstock, south of Hobart. Many fan deposits formed before 40 ka or in a period c. 30–23 ka; only a few deposits date to the Last Glacial Maximum in Tasmania, which is defined as spanning the period 23.5–17.5 ka. Slope deposits indicate widespread instability down to present-day sea level throughout the Last Glacial, probably as a result of freeze–thaw in a sparsely vegetated landscape. Layered fine gravel and coarse sand colluvial deposits resembling grezes litees, produced both by dry deposition and by the action of water, are locally common where jointed siltstone bedrock outcrops. These deposits occur from altitudes of 500 m to near sea level and also in caves and must have formed under sparse vegetation cover, probably by freeze–thaw in extremely dry conditions. They have been radiocarbon dated from 35 to 17.5 cal. ka. Relict dunes and sandsheets are widespread at the margin of the Bassian Plain that once provided a land bridge between Tasmania and the mainland. They are also found in western Tasmania and in areas of inland southern Tasmania that now support wet eucalypt forest and rainforest and receive mean annual rainfall > 1500 mm. In the south they have been dated > 87.5–19 ka and attest to a long period of semi-arid climate in an area extending well to the west and south of the present semiarid zone. We deduce that during most of the Last Glacial anticyclones dominated Tasmania's climate and rain-bearing depressions generally passed south of the land mass. However in the east prominent palaeosols in aeolian deposits, dated between 26.4 ka and 16 ka at different locations, and palaeosols with morphology indicating formation under humid conditions, indicate periods of wetter climate in eastern Tasmania during or close to the LGM, deduced to be the result of easterlies associated with near-coastal depressions in the western Tasman Sea. Such easterlies may also be responsible for short Last Glacial wet periods noted at mainland coastal sites. A plot of ages of all dated deposits reveals an increase of erosion and deposition between 35 and 20 ka, and greater prevalence of aeolian deposits in the 35–15 ka period than earlier in the Last Glacial. There are two possible explanations for this pattern: (1) that aeolian activity increased as the result of climatic effects (e.g. increased windiness); or (2) that shrubland biomass increased after the megafauna were hunted to extinction following human arrival c. 40 ka, causing increased fire frequency, and in the cold dry climate of the late Last Glacial such fires caused increased erosion and increased aeolian accumulation.

Summary The effect of soil moisture status on preferential flow in a texture-contrast soil was investigated by applying 25 mm Brilliant Blue dye tracer to soil profiles at high and low antecedent soil moisture. Differences in soil morphology and chemistry between soil profiles had little effect on the depth of dye infiltration and dye distribution down the profile. Antecedent soil moisture strongly influenced the type, depth and rate of dye tracer movement. In the wet treatment, the dye tracer infiltrated to depths between 0.24 and 0.40 m, at an average rate of 120 mm h −1 . Whilst in the dry treatment, the same volume of dye tracer infiltrated to between 0.85 and 1.19 m depth at an average rate of 1160 mm h −1 . In dry antecedent conditions, finger flow developed in the A1 horizon as a result of water repellency. In the wet treatment, the wetting front developed permutations but did not break into fingers. Despite similar particle size distributions, flow in the A2 e was slower than the A1 horizon, due to the absence of macropores. In the dry treatment, the dye tracer ponded on the upper surface of the B21 horizon, which then spilled down the sides of the large clay columns as rivulets, at rates of between 2000 and 3000 mm h −1 . The dye tracer accumulated at the base of the columns resulting in backfilling of the inter column shrinkage cracks, at an estimated rate of 750 mm h −1 . In the subsoil, water movement occurred via shrinkage cracks which resulted in flow by-passing 99% of the soil matrix in the B21 horizon and 94% of the soil matrix in the B22 horizon. Evidence of rapid and deep infiltration in ‘dry’ texture-contrast soils has implications for water and solute management. This knowledge could be used to: (i) improve irrigation and fertilizer efficiency (ii) explain variations in crop yield (iii) reduce salinity through improved leaching practices, (iv) reduce the risk of agrochemicals contaminating shallow groundwater.

Soil genesis has been examined using field description, particle-size distributions, chemical properties, mineralogy and elemental distributions of five soil profiles developed on dolerite on Mt. Nelson and Tolmans Hill near Hobart in Tasmania. The soils form a sequence ranging from a Black Vertosol (P8) to four texture contrast soils, namely, a Eutrophic Brown Chromosol (P5), two Mottled-Subnatric Grey Sodosols (MN8 and P4), and a Mottled-Mesonatric Grey Sodosol (P7). The soil stratigraphic and pedological relationships of these soils have been investigated to help understand their distribution and improve understanding of soil formation history. The knowledge of the soil stratigraphy and weathering features aided in the determination of the broader landscape history. The field observations show the local dolerite has been subjected to both deep weathering and severe erosional periods. Pockets of deeply weathered dolerite occur adjacent to thin A/C soils or hard outcropping rock. Deeper colluvial soil materials occur on lower slopes. The presence of protruding dolerite columns now buried by transported clayey slope-wash materials indicates partial landscape stripping followed by reburial. The presence of buried stone-lines separating the upper profile from the clayey subsoils supports the idea of a second major erosional–depositional cycle. A pronounced variation between the A and B horizons particle-size distribution, mineralogy and elemental distribution supports the conclusion that the modern soils are composed of several sedimentary layers which cap a variable thickness of in situ weathered dolerite (termed “mealy material”) above fresh dolerite. Bedrock jointing, veins and rock fabric extend upward from the bedrock into the mealy material, but are truncated abruptly at the contact with the clayey subsoil. Soil-forming processes have operated to modify soil colours and mottling, soil structure and cation chemistry. These findings have important implications for landscape history, slope processes and the improved understanding of the distribution of dolerite-derived soils in Tasmania.