The development of sustainable farming systems depends on our ability to predict and manage the response of weed communities to changes in cropping practices. A study was established at Normandin, Québec, Canada, to investigate the influence of liquid dairy manure and mineral fertilizer, as well as chisel and moldboard plow tillage systems, in a spring barley monoculture and a 3-yr spring barley-forage rotation that included red clover and timothy. Weed species richness (Margalef's DMG), evenness (Shannon's E), and diversity (Shannon's H') were examined in these treatments from 1992 to 1995. Nutrient source had no effect on any of the three diversity indices. Evenness values were extremely low in all years, suggesting dominance of a few weed species in most treatments. Weed species richness and diversity generally were greater in the barley-forage rotation compared with the monoculture. Tillage effects on richness and diversity varied with crop rotation. Margalef's DMG and Shannon's H' were greater in 1993 and 1995, but they were lower in 1994 when chisel was compared with moldboard plowing in the monoculture. In 1994, chickweed density was about five times greater in the chisel-plowed monoculture compared with other treatment combinations of rotation and tillage. In 1995, only one species with a density of six plants m−2 occurred in the moldboard-plowed monoculture compared with three to six species and densities of 51 to 832 plants m−2 in the other rotation by tillage treatments. Climatic conditions and herbicide use patterns in the different crop rotation treatments may have contributed to the more dynamic nature of weed species diversity in the barley monoculture. Reduced frequency of tillage and herbicide application; management of the forage stands, especially with regard to their termination; and improved soil resource availability likely explained the increased but more stable diversity of the weed communities in the barley-forage rotation.

Over 90% of Canadian kochia populations are resistant to acetolactate synthase (ALS)– inhibiting herbicides. We questioned whether the target site–based resistance could affect plant growth and competitiveness. Homozygous F2 herbicide-resistant (HR) kochia plants with an amino acid substitution at Trp574 (sources: Alberta [AB], Saskatchewan [SK], and Manitoba [MB]), or Pro197 (MB, AB with two populations) were grown in replacement series with homozygous F2 herbicide-susceptible (HS) plants from the corresponding heterogeneous population (total: six populations). In pure stands, growth of HR plants from AB and SK was similar to that of HS plants, regardless of mutation; conversely, MB2-HR plants (Trp574Leu) developed more slowly and were taller than MB2-HS plants. Final dry weight of HR plants in pure stands was similar across all six populations, whereas that for HS plants in pure stands and HR–HS plants in mixed stands (50–50%) varied with population. Results for AB and SK populations suggest little impact of either ALS mutation on kochia growth, whereas those for MB lines would suggest an unidentified factor (or factors) affecting the HS, HR, or both biotypes. The variable response within and between lines, and across HS biotypes highlights the importance of including populations of various origins and multiple susceptible controls in HR biotype studies.

A survey conducted across agricultural ecoregions of Saskatchewan in 1996 revealed that wild oat (Avena fatua) populations resistant to acetyl-CoA carboxylase (ACCase) inhibitors were present in approximately 10% of Saskatchewan fields (2.4 million ha). In the Aspen Parkland and Boreal Transition ecoregions, this increased to 17%. The objective of this study was to determine if agronomic practices promoted or delayed resistance and to assess producer awareness of herbicide resistance. Weed resistance and management questionnaire data from the 1996 resistance survey and management questionnaire data from the 1995 Saskatchewan weed survey were submitted to multiway frequency analysis. The frequency of occurrence of herbicide-resistant wild oat was related directly to ACCase inhibitor use. Resistance to cyclohexanedione (CHD) herbicides was not related to CHD use but to frequency of ACCase inhibitor use (i.e., CHD + aryloxyphenoxypropanoate [AOPP]), suggesting that the pressure imposed by AOPPs contributed to the selection of CHD resistance in wild oat. ACCase inhibitor use was more extensive in the Aspen Parkland and Boreal Transition ecoregions than in the Mixed and Moist Mixed Grassland ecoregions. Crop rotations were not conducive to rotation of herbicides with different sites of action. Frequency of ACCase inhibitor use increased with frequency of annual crops, in spite of the inclusion of cereal and dicot crops in the rotation. Producers utilizing conservation tillage practices in the Grassland ecoregions used proportionally more ACCase inhibitors than those using conventional tillage practices. This increase in ACCase use in conservation tillage systems did not result in an increased incidence of wild oat populations resistant to ACCase inhibitors. Producers reporting troublesome wild oat populations tended to have proportionally more ACCase-resistant wild oat. Producers who reported practicing weed sanitation were less likely to have resistant wild oat than those who were less careful. Increased awareness and implementation of management practices that will reduce the dependency on ACCase herbicides are required to better enable producers to prevent, delay, or manage herbicide-resistant wild oat populations.

Few studies report animal grazing effects on weed populations. A study was conducted to assess weed populations in annual and perennial forage grasses grazed at various intensities by cattle over a 4-yr period. The perennial forages were Bromus inermis and Bromus riparius, and the annual forages were winter Triticosecale and a mixture of Hordeum vulgare and winter Triticosecale. With few exceptions, results from the two annual pastures could be adequately described as a group, as could the results from the two perennial pastures. The two most prevalent weed species were Capsella bursa-pastoris and Taraxacum officinale; other species encountered over the course of the study were analyzed as a group. Tillage (seedbed preparation) in the annual system supported a proliferation of annual weeds in the spring. In the perennial pasture system, a lack of tillage and spring MCPA allowed T. officinale to increase as the study progressed, especially at the highest grazing intensity. In the perennial pastures, each unit increase in grazing intensity led to 51 more C. bursa-pastoris m−2 and 4 more T. officinale m−2. At lower levels of grazing intensity, C. bursa-pastoris and other species were most abundant in the annual pastures. Weed population shifts in response to grazing pressure in the annual pasture systems were restricted because of annual tillage and MCPA. Therefore, pasture managers may subject annual pastures to heavy grazing pressure with less negative weed population consequences than perennial pastures where herbicides are not applied.

A conservation tillage study provided the opportunity to test whether tillage effects on the germinable weed seedbank would be consistent across different crop rotations and to investigate the potential residual effects of herbicide treatments terminated 12 yr earlier. Our objective was to measure the effects of tillage (moldboard plow [MP] vs. chisel plow [CP] vs. no-till [NT]), crop rotation (2-yr barley–red clover followed by 4-yr barley–canola–wheat–soybean rotation, compared to a cereal monoculture), and of a prior weed management factor (three intensity levels of herbicide use) on the density, diversity, and community structure of weed seedbanks. Species richness, evenness (Shannon's E), and diversity (Shannon's H′) of spring seedbanks varied little across treatments and over time. Total seedbank density generally increased as tillage was reduced, with some variations due to weed management in 1993 and crop rotation in 2006. Crop rotations generally had smaller seedbanks with fewer species than the monoculture. In 1993, seedbanks with minimum weed management were twice as dense as those with intensive or moderate weed management (approximately 6,000 vs. 3,000 seed m−2). By 2006, seed density averaged 6,838 seed m−2 across intensive and moderate weed management regardless of tillage, but was nearly twice as large in NT (12,188 seed m−2) compared to MP (4,770 seed m−2) and CP (7,117 seed m−2) with minimum weed management (LSD0.005 = 4488). Species with abundant seedbanks responded differently to treatments. Barnyardgrass and green foxtail had larger seedbanks in the monoculture than in the rotation. Common lambsquarters and pigweed species had large seedbanks in tilled treatments in the rotation, whereas yellow foxtail and field pennycress contributed to the large seedbanks observed in NT treatments. The latter two species were also associated with residual effects of weed management treatments (terminated 12 yr earlier) in NT. The differential seedbank response of weed species, attributed in part to contrasting weed emergence patterns and agronomic practice effects on seed rain, explained some of the weak treatment effects observed for total seedbank density and diversity. The large weed seedbanks observed in NT plots after 18 yr confirms the importance of seed rain and seedbank management for the sustainability of NT systems.

Minimizing inputs such as fertilizers, herbicides, or tillage may be sought by producers to satisfy economic as well as environmental goals. One of the challenges in reducing inputs, whether synthetic fertilizers or herbicides, or substituting a synthetic nutrient with an organic source, is to identify practices that will provide optimum growing conditions for the crop while maintaining an adequate level of weed control. Our objective was to measure the cumulative effects of 12 yr of nitrogen (N) and phosphorus (P) fertilization treatments applied to two tillage systems [conventional tillage (CT) vs. no tillage (NT)] in a corn–soybean rotation on weed communities and crop yields. Residual (postherbicide treatment) weed species assembly was determined by multivariate analysis and was influenced mainly by tillage, with weeds more strongly associated with NT than with CT. Diversity of weed communities as measured by richness, evenness (E), and a diversity index (H′), and total weed biomass were greater for NT than for CT. Nutrient treatments had little or no effect on these parameters. Corn yields were reduced by 70% in the absence of N and by 25% in NT compared to CT treatments. Soybean yields were reduced in NT with increasing P rates compared to other treatments, but reductions never exceeded 10%. Overall, corn and soybean had different responses to treatments, with corn yields being far more affected by fertilization and tillage than soybean yields. Conversely, the absence of tillage had a much greater effect than the absence of nutrient input on weed community assembly and biomass, suggesting the importance of a weed management program specifically tailored for NT systems.

The objective of this study was to examine the effects of crop rotation (spring barley monoculture vs. spring barley–red clover 2-yr rotation), tillage (moldboard plow, chisel plow, no-till), and weed management (intensive, moderate, minimum) on plant–seedbank relationships for 19 weed species. Plant and seedbank density data were collected over 4 yr and analyzed by analysis of variance and correlation analysis to confirm treatment effects on plant–seedbank relationships. The relative frequency (difference between aboveground and seedbank frequency) of many species was more influenced by rotation, whereas species density appeared regulated more by weed management than by other factors. Frequency data confirmed that very few species were ubiquitous over time or treatment, aboveground or in the seedbank. The perennial species, field horsetail, quackgrass, white clover, and perennial sowthistle were more frequent aboveground than in the seedbank. This was also observed for annuals such as common hempnettle, sun spurge, catchweed bedstraw, and annual grasses. Treatment effects on abundance were inconsistent aboveground and in the seedbank across time for 12 of 19 species. The seven species that showed more consistent treatment response for abundance were frequent species present in 50% of the plots both aboveground and in the seedbank. For most species, plant density was correlated with either the previous or current year seedbank, but correlations were rarely of the same magnitude and significance over the years. Common chickweed was the only species for which treatment effects on the plant–seedbank relationship were confirmed for all 4 yr. Correlations between midseason plant populations and subsequent seedbanks confirmed the role of residual populations in replenishing the seedbanks, including those of perennials like quackgrass and dandelion. Overall, plant–seedbank relationships were tenuous for many weed species and varied over time with cropping practices and environment.

Phenoxy herbicides are frequently used to control volunteer canola populations. However, there have been claims that poor control could be due to cold acclimation of canola plants in the spring. The objective of this study was to determine whether cold acclimation or growth stage affected the response of canola volunteers to herbicides. In a growth room experiment, canola plants were prehardened and cold acclimated or were grown at 20/12 C and treated with one of six 2,4-D doses. Cold acclimation as achieved by this experiment affected upper and lower asymptotes of the dose–response curve but not the herbicide dose required to reduce canola weight by 50% relative to the nontreated control (GR50), indicating limited cold-related effects on canola tolerance to 2,4-D. Field experiments, conducted in the provinces of Québec and Saskatchewan, examined the effects of canola growth stage on the efficacy of 2,4-D, MCPA, and carfentrazone. Comparisons of the estimates from the dose–response curves confirmed that herbicide efficacy was consistently greater when canola plants were treated at an early growth stage, regardless of cultivar or herbicide used. The GR50 estimates for canola plants treated at a later growth stage exceeded the recommended rates. Some canola plants grown as volunteers in a wheat crop survived 2,4-D or MCPA treatments at 0.5× and 1× rates and produced up to 148 seeds/m2. Efficient control of canola volunteers will be obtained when plants are sprayed at an early growth stage, but near-total control will be highly desirable in order to restrict seedbank buildup, particularly when dealing with canola cultivars with different herbicide-resistant traits.

Crop rotations, particularly those that include legumes, often result in improved soil quality and crop yields. A study was conducted to confirm the presence and persistence of the residual effects of crop rotation and weed management on a test crop and weeds in three tillage systems (moldboard plow [MP]; chisel plow [CP]; no tillage [NT]). Rotation (spring barley monoculture and spring barley–red clover rotation) and weed management (intensive, moderate, minimum) treatments, initiated in 1987, were terminated, and a test crop of spring wheat was grown in 1995 and 1996. Tillage treatments were maintained throughout. Multivariate analysis showed that weed communities were more affected by treatment termination in the rotation NT treatment with minimum weed management than in all other treatments. The former treatment was dominated by perennial broadleaf weeds but sustained adequate wheat yields (3.3 Mg ha−1) compared with the monoculture (1.0 Mg ha−1) one year after termination. Weed communities in CP and MP plots were less affected by treatment termination. Yet, changes in herbicide use at termination caused the virtual elimination of quackgrass from tilled plots and allowed field pennycress to become ubiquitous across treatments. Residual effects from crop rotation were more important than those from weed management in increasing wheat yields in tilled systems. Differences in wheat yield in NT systems 2 yr after treatment termination were attributed to residual effects from previous weed management rather than from crop rotation. Beneficial effects of crop rotation and weed management may persist for 2 yr but will vary according to tillage system.

This article reports on the fourth stage of an evolving study to develop a systems model for embedding education for sustainability (EfS) into preservice teacher education. The fourth stage trialled the extension of the model to a comprehensive state-wide systems approach involving representatives from all eight Queensland teacher education institutions and other key policy agencies and professional associations. Support for trialling the model included regular meetings among the participating representatives and an implementation guide. This article describes the first three stages of developing and trialling the model before presenting the case study and action research methods employed, four key lessons learned from the project, and the implications of the major outcomes for teacher education policies and practices. The Queensland-wide, multi-site case study revealed processes and strategies that can enable institutional change agents to engage productively in building capacity for embedding EfS at the individual, institutional, and state levels in preservice teacher education. Collectively, the project components provide a system-wide framework that offers strategies, examples, insights, and resources that can serve as a model for other states and/or territories wishing to implement EfS in a systematic and coherent fashion.

The first research symposium, organised in conjunction with the Australian Association for Environmental Education (AAEE) biennial conference, began with a dialogue between scholars at three different academic career stages. As we all entered the field at different periods in its development, the first part of our presentation and this article provide our perspectives on the context, approaches and issues that characterised the field at the time we became involved in environmental education (EE) and EE research. The second part of this article presents the lessons we have learnt from EE research, and where we see the field headed in the future.

Over the last decade, the explosion in research and Development associated with nanoscalar materials has continued apace. In parallel with this has been the rapid rise of both sustainable materials and, as a consequence, Natural, Cellular and Responsive material systems. Many of these originate from inorganic, inorganic-organic hybrid composites and polymeric and bio-nano polymeric systems which exhibit intrinsic physico-chemical properties that can be classed as ‘soft’. That is flexible, malleable, lightweight, transparent or semi-transparent and stretchable in character and which can also offer both biocompatible and bioresorbable characteristics essential to useable and sustainable material systems.

This paper describes some of the ways in which we are beginning to understand, explain and exploit ‘soft’ technology. In particular the interactive role of creative design and innovative material science linked through new fabrication methodologies that have, as their common purpose, a focus on compelling Human centred needs. Examples are health, wellness, ambient assistance and urgent improvements in cleanliness, hygiene and nutrition.

Agricultural practices affect the biotic and abiotic conditions that determine food and shelter for carabid beetles (Coleoptera: Carabidae). We hypothesised that carabid communities would respond differently to 18 years of contrasted cropping practices in cereal-based rotations. We measured the effects of tillage (MP: moldboard plough; CP: chisel plough; NT: no-till) and previous crop sequence (cereal monoculture versus cereal–forage/cereal–oilseed rotation) on carabid beetle activity density, diversity, and community structure in corn (Zea mays Linnaeus, Poaceae) at La Pocatière, Québec, Canada. Carabid beetles were sampled monthly from May to September 2006, using pitfall traps. Although 19 carabid species were observed, assemblages were dominated by Harpalus rufipes (De Geer), particularly in the second half of the season. Multivariate analyses indicated a strong affinity of carabid species for the NT treatment throughout the season. Crop sequence and tillage had no effect on diversity (Shannon's H′ ≤ 1.3) and evenness of carabid assemblage, but species richness and activity density were greater in NT than in tilled systems. Peak activity density of dominant species occurred at different times during the season, generally in accordance with preferred breeding season. Many species had greater activity density in NT than in tilled treatments. Because of their granivorous feeding habit, carabid populations such as that of H. rufipes could be an important asset to NT, given the limited weed management options available for this system.