Weed Succession under Conservation Tillage: A Hierarchical Framework for Research and Management

1993 ◽  
Vol 7 (2) ◽  
pp. 286-297 ◽  
Author(s):  
Clarence J. Swanton ◽  
David R. Clements ◽  
Douglas A. Derksen
Keyword(s):  
Species Composition ◽  
Conservation Tillage ◽  
Management Strategies ◽  
Research Approach ◽  
Weed Species ◽  
Ecological Processes ◽  
Succession Management ◽  
Hierarchical Framework ◽  
Species Performance

The awareness and adoption of conservation tillage is one of the most important changes taking place in agriculture today. There are, however, concerns regarding weed species shifts under conservation tillage. Under conservation tillage, shifts toward grass, perennial, wind-disseminated weeds and volunteer crop plants have been observed. Shifts in weed species composition may either represent long-term ecological succession or temporary fluctuations in species composition; few long-term studies have examined the ecology of these shifts in detail. Further studies are needed to identify mechanisms driving these shifts to determine whether they are fluctuational or successional and to develop more sophisticated management strategies. In this paper, we present a research approach for studying ecological processes such as competition within a hierarchical framework of all possible causes, processes, and defining factors related to weed succession under conservation tillage. Succession management strategies can be developed to act at the causal level in the successional hierarchy. Three primary causes are site availability, colonization, and species performance. Site availability may be controlled through “designed disturbance”, while differential species availability may be regulated through “controlled colonization” and species performance may be regulated through “controlled species performance”. In general, the goals of succession management would involve reducing populations of the weed species most likely to proliferate under conservation tillage. Comprehensive ecological research, within the hierarchical framework outlined here, would identify potential problems and enable management strategies to account for the numerous factors that may be influencing fluctuations and succession of weeds under conservation tillage.

Soil Nitrogen Movement under Sustainable Vegetable Production Systems

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 494f-495 ◽  
Author(s):  
Amy M. Johnson ◽  
Greg D. Hoyt
Keyword(s):  
Pest Management ◽  
Soil Nitrogen ◽  
Conservation Tillage ◽  
Management Strategies ◽  
Conventional Tillage ◽  
Plant Diseases ◽  
Vegetable Production ◽  
Beneficial Arthropods ◽  
Weed Species ◽  
Available Nitrogen

An experiment was established to determine the effect of different tillage practices, vegetable crop rotations, and pest management strategies on crop yield, plant diseases, pest and beneficial arthropods, weed species changes over time, and soil environmental consequences. This poster describes nitrogen movement from the various treatments over a 3-year rotation. The treatments are: 1) conventional tillage with chemically based IPM; 2) conventional tillage with biologically based IPM; 3) conservation tillage with chemically based IPM; 4) conservation tillage with biologically based IPM; and 5) conventional tillage with no fertilizer or pest management. Mid-season soil analyses with depth showed chemical-fertilized plowed and conservation-tilled treatments with more soil available nitrogen at most depths compared to the biological-based IPM systems (soybean meal was used as a nitrogen source). However, the biological-based systems did supply enough soil nitrogen to produce similar yield results as the chemical-based systems. Less soil nitrate was measured in the 30- to 90-cm depths at harvest from the biological-based systems than chemical-based systems. Conservation-tilled systems had greater nitrate with depth compared to conventional-tilled systems.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Keyword(s):  
Evolutionary Biology ◽  
Species Concept ◽  
Management Strategies ◽  
Cutthroat Trout ◽  
Ecological Processes ◽  
Oncorhynchus Clarkii ◽  
Voucher Specimens ◽  
Captive Propagation ◽  
Analytical Tools

<em>Abstract</em>.—The broad distribution and regional variation of Cutthroat Trout <em>Oncorhynchus clarkii </em>across western North America has led to considerable interest in the different forms from both scientific and recreational perspectives. This volume represents an attempt to describe this observed diversity with the most current information available and suggests a revised taxonomy for Cutthroat Trout. However, what is proposed in this volume will be subject to change or refinement as new techniques and analytical tools become available. In particular, remaining uncertainty would benefit from a comparison of all described lineages with a common set of morphological and genetic markers. A range-wide collection of voucher specimens will help to document variation in these characteristics, and we encourage field biologists to prioritize these collections. Future revisions will benefit from agreement on a species concept and explicitly state the assumptions of the chosen species concept. We encourage collaboration between managers and taxonomists to accurately delineate units of conservation that can be used by decision makers tasked with ensuring the long-term persistence of Cutthroat Trout lineages. The proposed taxonomic revisions herein validate many of the ongoing management strategies to conserve Cutthroat Trout, but we advise additional consideration of life-history diversity as an attainable management target. For long-term persistence of all Cutthroat Trout, maintaining and expanding the availability of high quality, well-connected stream and lake habitats will be a necessary first step to achieving desired conservation outcomes. Moreover, restoring and protecting ecological processes are key to conserving the diversity found within and among lineages of Cutthroat Trout. In systems where native Cutthroat Trout have been extirpated or suppressed, captive propagation and translocation are two potentially available tools to re-establish or reinvigorate populations. Last, we encourage fisheries managers and taxonomists to embrace the challenges that come with conserving locally unique forms of wide-ranging species like Cutthroat Trout.

Augmentative Restoration: Repairing Damaged Ecological Processes During Restoration of Heterogeneous Environments

2009 ◽  
Vol 2 (1) ◽  
pp. 10-21 ◽  
Author(s):  
Roger L. Sheley ◽  
Jeremy J. James ◽  
Erin C. Bard
Keyword(s):  
Species Composition ◽  
Native Species ◽  
Plant Performance ◽  
Meadow Vole ◽  
Heterogeneous Environments ◽  
Ecological Processes ◽  
Additional Advantage ◽  
Factors Affecting ◽  
Ephemeral Wetland ◽  
Species Performance

AbstractHeterogeneity in disturbance regimes, propagule pools, and factors affecting plant performance are a ubiquitous feature of wildlands. We tested a conceptual framework, termed augmentative restoration, aimed at identifying and selectively repairing or replacing damaged processes based on their predicted influence on the three causes of succession: site availability, species availability, and species performance. This framework was tested at three sites each with a different cause of succession naturally occurring in an ephemeral wetland dominated by invasive plants that had varying levels of disturbance (site availability), remnant native plants (species availability), and water availability (species performance). Our hypotheses were (1) seeding combined with watering would augment meadow vole disturbance to increase desired species composition, (2) shallow tilling combined with watering would augment remnant native species, and (3) shallow tilling combined with seeding would augment mesic soils to increase desired species composition. Shallow tilling, watering, and seeding were applied in a factorial arrangement at all three sites. These eight treatment combinations were applied in a split-plot design with four replications to generate 32 whole plots (2 m2). The herbicide 2,4-D was applied on half of each whole plot to influence relative species performance. In two of the three sites, using augmentative restoration to guide our management approaches improved our decision as to the treatment combinations that would maximize seedling establishment. Selectively augmenting successional processes that remain intact by repairing or replacing processes occurring at inadequate levels can improve implementation of successional management and provide a refined process-based framework for restoration across heterogeneous landscapes. Besides the clear economic advantages of lower management inputs associated with augmentative restoration, avoiding unnecessary management inputs has the additional advantage of minimizing unintended negative impacts on ecosystem processes.

scholarly journals Managing glyphosate resistance in Australian cotton farming: modelling shows how to delay evolution and maintain long-term population control

2013 ◽  
Vol 64 (8) ◽  
pp. 780 ◽  
Author(s):  
David Thornby ◽  
Jeff Werth ◽  
Steven Walker
Keyword(s):  
Weed Control ◽  
Population Control ◽  
Management Strategies ◽  
Farming Systems ◽  
Glyphosate Resistance ◽  
Weed Species ◽  
Barnyard Grass ◽  
Resistance Evolution ◽  
Seed Bank Dynamics

Glyphosate resistance is a rapidly developing threat to profitability in Australian cotton farming. Resistance causes an immediate reduction in the effectiveness of in-crop weed control in glyphosate-resistant transgenic cotton and summer fallows. Although strategies for delaying glyphosate resistance and those for managing resistant populations are qualitatively similar, the longer resistance can be delayed, the longer cotton growers will have choice over which tactics to apply and when to apply them. Effective strategies to avoid, delay, and manage resistance are thus of substantial value. We used a model of glyphosate resistance dynamics to perform simulations of resistance evolution in Sonchus oleraceus (common sowthistle) and Echinochloa colona (awnless barnyard grass) under a range of resistance prevention, delaying, and management strategies. From these simulations, we identified several elements that could contribute to effective glyphosate resistance prevention and management strategies. (i) Controlling glyphosate survivors is the most robust approach to delaying or preventing resistance. High-efficacy, high-frequency survivor control almost doubled the useful lifespan of glyphosate from 13 to 25 years even with glyphosate alone used in summer fallows. (ii) Two non-glyphosate tactics in-crop plus two in-summer fallows is the minimum intervention required for long-term delays in resistance evolution. (iii) Pre-emergence herbicides are important, but should be backed up with non-glyphosate knockdowns and strategic tillage; replacing a late-season, pre-emergence herbicide with inter-row tillage was predicted to delay glyphosate resistance by 4 years in awnless barnyard grass. (iv) Weed species’ ecological characteristics, particularly seed bank dynamics, have an impact on the effectiveness of resistance strategies; S. oleraceus, because of its propensity to emerge year-round, was less exposed to selection with glyphosate than E. colona, resulting in an extra 5 years of glyphosate usefulness (18 v. 13 years) even in the most rapid cases of resistance evolution. Delaying tactics are thus available that can provide some or many years of continued glyphosate efficacy. If glyphosate-resistant cotton cropping is to remain profitable in Australian farming systems in the long-term, however, growers must adapt to the probability that they will have to deal with summer weeds that are no longer susceptible to glyphosate. Robust resistance management systems will need to include a diversity of weed control options, used appropriately.

scholarly journals Efficacy of the herbicide GF-2581 (penoxsulam + florasulam) against broadleaf weeds in olives

2014 ◽  
Vol 60 (No. 12) ◽  
pp. 574-579 ◽  
Author(s):  
Travlos IS ◽  
M. Lysandrou ◽  
V. Apostolidis
Keyword(s):  
Weed Control ◽  
Management Strategies ◽  
Growing Season ◽  
Field Trials ◽  
Conyza Canadensis ◽  
Weed Species ◽  
Stellaria Media ◽  
Excellent Control ◽  
Control Management

Effective weed control in perennial crops is a challenge due to the limited availability of registered herbicides and herbicide resistance. The objective of the study was to evaluate the efficacy of the herbicide GF-2581 (penoxsulam + florasulam) on broadleaf weeds in comparison with other commonly used herbicides. Field trials were conducted in olives, in Etoloakarnania (Agrinio region) for two years (2012 and 2013). Efficacy assessments were made at 30, 60, 90 and 120 days after treatment. The GF-2581 formulation provided excellent control of a broad spectrum of broadleaf weed species. The long-term control of Sonchus oleraceous, Conyza canadensis and Stellaria media, provided by GF-2581 during the growing season was significantly greater than that using flumioxazin. When combined with glyphosate or diquat, the level of control of these three weeds was improved. The GF-2581 agent applied pre-emergence followed 14 days later by application of glyphosate provided 100% control in 2012. Lower efficacy levels were observed in 2013 and may have been the result of higher rainfall when compared to 2012. GF-2581 is an effective herbicide product to control broadleaf weeds, as a part of integrated weed control management strategies in olives.

scholarly journals Conservation Agriculture: An Eco-Friendly System of Weed Management in Field Crops

2014 ◽  
Vol 3 (4) ◽  
pp. 91-100
Author(s):  
Tika Bahadur Karki ◽  
Jiban Shrestha
Keyword(s):  
Weed Management ◽  
Management Strategies ◽  
Conservation Agriculture ◽  
Grass Species ◽  
Weed Species ◽  
Conventional Agriculture ◽  
Perennial Weeds ◽  
Weed Dynamics ◽  
Agriculture Systems

Since the conservation agriculture (CA) is spreading across the globe, information on weed dynamics and their management under CA is needed. Here, an attempt has been made to summarize the recent research on weed dynamics and their management aspects in the CA systems. Changes in patterns of tillage, planting systems, and other management strategies can alter the soil environment and lead to shifts in weed populations. Weed patterns and populations are not always stable but vary with location, crop, and herbicides use. However, in many long-term conservation management studies, a general increase in perennial weeds and grass species has been observed. No tillage increased the weed population during first season and there after decreased. Residue has significantly reduced the number of weed species and population compared to conventional agriculture systems. The development of low-dose of non-selective pre and selective post emergence herbicides, and transgenic crops has greatly improved the feasibility of CA systems.DOI: http://dx.doi.org/10.3126/ije.v3i4.11733 International Journal of Environment Volume-3, Issue-4, Sep-Nov 2014Page: 91-100

scholarly journals Control of Conyza spp. with glyphosate – a review of the situation in Europe

2013 ◽  
Vol 49 (No. 1) ◽  
pp. 44-53 ◽  
Author(s):  
M. Sansom ◽  
A.A. Saborido ◽  
M. Dubois
Keyword(s):  
Weed Management ◽  
Management Strategies ◽  
Agricultural Practices ◽  
Current Control ◽  
Weed Species ◽  
Resistance Development ◽  
Perennial Crops ◽  
Herbicide Resistant ◽  
Sublethal Doses

In Europe, glyphosate resistant populations have developed in some weed species in perennial crops, including three species of the genus Conyza documented by the International Survey of Herbicide Resistant Weeds. Conyza spp. biology is reviewed in this paper and related to population dynamics and the development of resistant populations. Suboptimal growth stage at application, improper agricultural practices such as overreliance on glyphosate and long-term use of sublethal doses are identified as the most important factors of resistance development. Current control methods in perennial crops including mixtures of glyphosate with other active ingredients are discussed and effective weed management strategies are described to manage the development and spread of glyphosate resistant Conyza spp. in Europe.

scholarly journals Effects of Narrow-Windrow Burning on Weed Dynamics in Soybean in Louisiana

2021 ◽  
Vol 3 ◽  
Author(s):  
Katie M. Patterson ◽  
Lauren M. Schwartz-Lazaro ◽  
Gabrielle LaBiche ◽  
Daniel O. Stephenson
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Production Systems ◽  
Management Strategies ◽  
Weed Seed ◽  
Weed Species ◽  
Cultural Management ◽  
Soil Seedbank ◽  
Weed Dynamics

The soil seedbank allows for long-term persistence of weed species in agricultural fields. Some weed species can persist in the soil seedbank for extended periods. Restricting inputs into the weed seedbank has a large impact on future population density and influences management practices of these weeds in soybean production systems. Harvest weed seed control (HWSC) tactics incorporate mechanical and cultural management strategies to target weed seeds present at harvest. A 3-year trial was initiated to determine if continual use of the HWSC method, narrow windrow burning, selects for earlier seed set and shattering in Louisiana soybean. No shifts in weed populations or shattering time were observed. However, there was a significant reduction in weed density and the weed seed present in the soil seedbank when HWSC and robust herbicide programs were used in combination. Therefore, utilizing multiple effective weed management strategies is imperative in reducing the soil seedbank.

Influence of NPK fertilization on weed flora in maize field

2014 ◽  
Vol 63 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Éva Lehoczky ◽  
M. Kamuti ◽  
N. Mazsu ◽  
J. Tamás ◽  
D. Sáringer-Kenyeres ◽  
...  
Keyword(s):  
Plant Nutrition ◽  
Crop Production ◽  
N Availability ◽  
Weed Species ◽  
Negative Effects ◽  
Production Factors ◽  
Maize Field ◽  
Weed Flora ◽  
Npk Fertilization

Plant nutrition is one of the most important intensification factors of crop production. The utilization of nutrients, however, may be modified by a number of production factors, including weed presence. Thus, the knowledge of occurring weed species, their abundance, nutrient and water uptake is extremely important to establish an appropriate basis for the evaluation of their risks or negative effects on crops. That is why investigations were carried out in a long-term fertilization experiment on the influence of different nutrient supplies (Ø, PK, NK, NPK) on weed flora in maize field.The weed surveys recorded similar diversity on the experimental area: the species of A. artemisiifolia, S. halepense and D. stramonium were dominant, but C. album and C. hybridum were also common. These species and H. annuus were the most abundant weeds.Based on the totalized and average data of all treatments, density followed the same tendency in the experimental years. It was the highest in the PK treated and untreated plots, and significantly exceeded the values of NK fertilized areas. Presumably the better N availability promoted the development of nitrophilic weeds, while the mortality of other small species increased.Winter wheat and maize forecrops had no visible influence on the diversity and the intensity of weediness. On the contrary, there were consistent differences in the density of certain weed species in accordance to the applied nutrients. A. artemisiifolia was present in the largest number in the untreated control and PK fertilized plots. The density of S. halepense and H. annuus was also significantly higher in the control areas. The number of their individuals was smaller in those plots where N containing fertilizers were used. Contrary to them, the density of D. stramonium, C. album and C. hybridum was the highest in the NPK treatments.

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

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