scholarly journals Predicted climate conditions and cover crop composition modify weed communities in semiarid agroecosystems

Weed Research ◽  
2021 ◽  
Author(s):  
Mary E. DuPre ◽  
Tim Seipel ◽  
Maryse Bourgault ◽  
Darin L. Boss ◽  
Fabian D. Menalled
Keyword(s):  
Cover Crop ◽  
Climate Conditions ◽  
Weed Communities

scholarly journals Effects of winter wheat cover crop desiccation times on soil moisture, temperature and early maize growth

2011 ◽  
Vol 51 (No. 6) ◽  
pp. 255-261 ◽  
Author(s):  
B. Stipešević ◽  
E.J. Kladivko
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Water Conservation ◽  
Cover Crop ◽  
Triticum Aestivum L ◽  
Shoot Biomass ◽  
Tillage Systems ◽  
Climate Conditions ◽  
Maize Growth ◽  
Dominant Soil

Two tillage systems for maize (Zea mays) after soybean (Glycine max), no-till (NT) and conventional till (CT), which consisted of double disking in the spring, were included in the experiment on two sites in Indiana, USA. Each tillage plot had three winter wheat (Triticum aestivum L.) cover crop levels: no cover crop (N), early desiccation (E), 3–4 weeks prior to planting the maize, and regular desiccation (R), within the maize planting week. Due to the mulching effect, both E and R for both tillage systems increased soil moisture, except in the case of spring drought, when E proved dominant. Soil temperature for both tillage systems showed N > E > R order. Young maize plants tended to grow taller and have greater shoot biomass in NT than in CT. Both E and R improved early maize growth. In the case of drought, the E proved significantly better for maize on both tillage treatments, due to the better soil water conservation, therefore the winter wheat cover crop should be desiccated early in given climate conditions.

Cover-Crop Systems Affect Weed Communities in a California Vineyard

Weed Science ◽  
2008 ◽  
Vol 56 (4) ◽  
pp. 596-605 ◽  
Author(s):  
Kendra Baumgartner ◽  
Kerri L. Steenwerth ◽  
Lissa Veilleux
Keyword(s):  
Community Structure ◽  
Cover Crops ◽  
Cover Crop ◽  
Weed Biomass ◽  
Orthogonal Contrasts ◽  
Red Fescue ◽  
The North ◽  
No Till ◽  
Weed Communities ◽  
Carry Over

Vineyard weed communities were examined under four dormant-season cover-crop systems representative of those used in the north-coastal grape-growing region of California: no-till annuals (ANoT) (rose clover, soft brome, zorro fescue), no-till perennials (PNoT) (blue wildrye, California brome, meadow barley, red fescue, yarrow), tilled annual (AT) (triticale), and a no-cover-crop tilled control (NoCT). Treatments were carried out for 3 yr in the interrows of a wine grape vineyard. Glyphosate was used to control weeds directly beneath the vines, in the intrarows. Treatments significantly impacted weed biomass, community structure, and species diversity in the interrows. Orthogonal contrasts showed that tillage, and not the presence of a cover crop, impacted interrow weed biomass. Distance-based redundancy analyses (db-RDA) revealed significant effects of the cover-crop systems and of tillage on weed community structure in the interrows. For scarlet pimpernel and spiny sowthistle, the combination of ANOVA and orthogonal contrasts confirmed their association with the tilled treatments, as revealed by db-RDA. This same approach identified the association between California burclover and the no-till treatments. Our findings of no significant effects of the cover-crop systems on weed biomass, community structure, or diversity in the intrarows demonstrate that the impacts the cover-crop management systems had on the interrows did not carry over to adjacent intrarows. In addition, the fact that the cover crops did not affect vine yield, growth, or nutrition relative to the no-cover-crop control suggests that cover crops are likely to minimize soil erosion from winter rains, which is the primary purpose of vineyard cover cropping in northern California, without adversely affecting vine health or weed control.

Cover-Crop Species as Distinct Biotic Filters in Weed Community Assembly

Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 282-295 ◽  
Author(s):  
Richard G. Smith ◽  
Lesley W. Atwood ◽  
Fredric W. Pollnac ◽  
Nicholas D. Warren
Keyword(s):  
Cover Crops ◽  
Community Assembly ◽  
Cover Crop ◽  
Weed Species ◽  
Seeding Rate ◽  
Crop Species ◽  
Cover Cropping ◽  
Directional Filtering ◽  
Weed Communities ◽  
Sorghum Sudangrass

Cover crops represent a potentially important biological filter during weed community assembly in agroecosystems. This filtering could be considered directional if different cover-crop species result in weed communities with predictably different species composition. We examined the following four questions related to the potential filtering effects of cover crops in a field experiment involving five cover crops grown in monoculture and mixture: (1) Do cover crops differ in their effect on weed community composition? (2) Is competition more intense between cover crops and weeds that are in the same family or functional group? (3) Is competition more intense across weed functional types in a cover-crop mixture compared with cover crops grown in monocultures? (4) Within a cover-crop mixture, is a higher seeding rate associated with more effective biotic filtering of the weed community? We found some evidence that cover crops differentially filtered weed communities and that at least some of these filtering effects were due to differential biomass production across cover-crop species. Monocultures of buckwheat and sorghum–sudangrass reduced the number of weed species relative to the no-cover-crop control by an average of 36 and 59% (buckwheat) and 25 and 40% (sorghum–sudangrass) in 2011 and 2012, respectively. We found little evidence that competition intensity was dependent upon the family or functional classification of the cover crop or weeds, or that cover-crop mixtures were stronger assembly filters than the most effective monocultures. Although our results do not suggest that annual cover crops exert strong directional filtering during weed community assembly, our methodological framework for detecting such effects could be applied to similar future studies that incorporate a greater number of cover-crop species and are conducted under a greater range of cover-cropping conditions.

scholarly journals Weed Community in a Conventionally-Grown Olive Orchard Vs. Weed Community in Consociation with Pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch. Bip.)

Poljoprivreda ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 30-36
Author(s):  
Edita Štefanić ◽  
◽  
Vesna Kovačević ◽  
Lea Jakovljević ◽  
Urška Kosić ◽  
...  
Keyword(s):  
Cover Crop ◽  
Vascular Plants ◽  
Floristic Composition ◽  
Community Diversity ◽  
Weed Species ◽  
Olive Orchard ◽  
Weed Communities ◽  
Tanacetum Cinerariifolium ◽  
The One ◽  
Experimental Plots

On the experimental plots of the Institute of Agriculture and Tourism in Poreč, weed communities were analyzed in a conventionally‐grown olive orchard and in consociation with pyrethrum. Phytocenological surveys were conducted in March, June, and September using the Braun-Blanquet Cover Abundance Scale. Altogether, 54 species of vascular plants were recognized in both orchards. However, in a conventionally‐grown olive orchard, 27 were identified, whereas 42 weed species were identified in consociation with pyrethrum. Only 15 weeds were common to both orchards. Between both olive orchards, significant differences existed regarding the floristic and community diversity metrics. In consociation with pyrethrum as a cover crop, olive orchard had a more stable weed community during the season, while two weed species, Mercurialis annuua L. and Medicago arabica (L.) Huds., dominated in a conventionally‐grown orchard in the fall. The weed communities in both orchards significantly differ considering the appearance season (spring, summer, and fall). An autumnal weed community in a conventionally‐grown olive orchard was more diverse, more abundant, and with a more distinct floristic composition than a weed community in the spring and summer periods. However, an olive‐orchard weed community in consociation with pyrethrum also differed regarding the season, but a Canonical Correspondence Analysis (CCA) demonstrated a clear separation of a more diverse estival weed community than the one observed in the spring and summer.

scholarly journals Weed communities and wheat yield are modified by cropping systems and climate conditions

2020 ◽  
Author(s):  
Tim Seipel ◽  
Suzanne L. Ishaq ◽  
Fabian D. Menalled
Keyword(s):  
Cropping Systems ◽  
Wheat Yield ◽  
Cropping System ◽  
Conventional System ◽  
Organic System ◽  
Weed Biomass ◽  
Climate Conditions ◽  
No Till ◽  
Weed Communities ◽  
The Impact

SummaryUnderstanding the impact of biological and environmental stresses on crop performance is essential to secure the long-term sustainability of agricultural production. How cropping systems modify weed communities and wheat yield in response to predicted climate conditions is unknown. We tested the effect of warmer, and warmer and drier conditions on weed biomass, weed community characteristics, and winter wheat yields in three contrasting cropping systems: a no-till chemically managed system, a tilled organic system, and an organic system that used grazing to reduce tillage. Weed communities in the organic systems were more diverse and more variable than the no-till conventional system, though the grazed organic and no-till conventional systems had more similar relative species abundance. Cropping system affected weed biomass and weed species composition recorded in 0.75 m2 split-plots, with the most biomass recorded in grazed organic system (38 g ±23.4 SE) compared to the tilled-organic (17 g ±10.3 SE) and no-till chemically managed systems (<1 g ±0.02). Climate conditions had relatively minor impacts on weed communities compared with cropping systems. Wheat yield was highest in the no-till conventional system but declined in response to warmer and drier conditions despite its low weed biomass. Yield was lower in the tilled organic and grazed organic cropping system but declines in warmer and drier conditions were more variable among years. In the Northern Great Plains, predicted climate scenarios have the potential to alter weed communities and reduce wheat yield, and designing resilient cropping systems is essential to mitigate these negative impacts.

scholarly journals Resilience of an Integrated Crop–Livestock System to Climate Change: A Simulation Analysis of Cover Crop Grazing in Southern Brazil

2020 ◽  
Vol 4 ◽  
Author(s):  
Caitlin A. Peterson ◽  
Lindsay W. Bell ◽  
Paulo C. de F. Carvalho ◽  
Amélie C. M. Gaudin
Keyword(s):  
Climate Change ◽  
Cover Crop ◽  
Simulation Analysis ◽  
Integrated System ◽  
Sustainable Intensification ◽  
Total System ◽  
Southern Brazil ◽  
System Productivity ◽  
Climate Conditions ◽  
Weather Anomalies

Integrated crop–livestock systems are a form of sustainable intensification of agriculture that rely on synergistic relationships between plant and animal system elements to bolster critical agroecosystem processes, with potential impacts on resilience to weather anomalies. We simulated productivity dynamics in an integrated cover crop grazing agroecosystem typical of southern Brazil to gain a better understanding of the impacts of livestock integration on system performance, including future productivity and resilience under climate change. Long-term historical simulations in APSIM showed that the integrated system resulted in greater system-wide productivity than a specialized control system in 77% of simulated years. Although soybean yields were typically lower in the integrated system, the additional forage and livestock production increased total system outputs. Under simulated future climate conditions [representative concentration pathway 8.5 (RCP8.5) scenario from 2020 to 2060], integrated system productivity exceeded specialized system productivity in 95% of years despite declines in average soybean yield and aboveground cover crop biomass production. While the integrated system provided a productivity buffer against chronic climate stress, its resilience to annual weather anomalies depended on disturbance type and timing. This study demonstrates the utility of process-based models for exploring biophysical proxies for resilience, as well as the potential advantages of livestock integration into cropland as a sustainable intensification strategy.

scholarly journals Weeds in a Sugar Cane Soil Cultivated with Crotalaria juncea

2019 ◽  
Vol 37 ◽  
Author(s):  
J.J. OBRADOR-OLÁN ◽  
E. GARCÍA-LÓPEZ ◽  
L.E. ALMEYDA-SANTOS ◽  
M. CASTELÁN-ESTRADA ◽  
E. CARRILLO-ÁVILA
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Green Manure ◽  
Cyperus Rotundus ◽  
Control Groups ◽  
Importance Value ◽  
Crotalaria Juncea ◽  
Weed Communities ◽  
Production Values ◽  
Weed Diversity

ABSTRACT: Cover crops play an important role in sustainable agriculture, as they decrease soil erosion, promote the incorporation of nitrogen into the soil and reduce or modify weed communities. Aiming at evaluating the changes related to the cultivation and incorporation of sunn crotalaria (Crotalaria juncea L.1753) in a weed community of a soil cultivated with sugarcane, an agro-industrial crop of vital importance to La Chontalpa region, Tabasco, Mexico, an experiment encompassing the cultivation cycle and the incorporation of the dry phytomass of this cover crop was carried out. The treatments included three levels of fertilization and two controls, the plots of the first control were interspersed with those of the treatments, while the second control was placed outside, in order to avoid the shade effect caused by crotalaria. Sampling was carried out monthly, and the data obtained from samplings allowed the calculation of weed diversity and importance value (IVI) indexes, in addition to dry phytomass production values. The results showed that the fertilization did not exert any influence on the composition, diversity or importance of the weeds, factors that were more related to the rainy season, period in which the research on the cultivation, cutting and incorporation of crotalaria into the soil was performed. Although the best represented family was Euphorbiaceae, its species were not among the most important in the community in which Cyperus rotundus L. 1753, Lindernia crustacea (L.) F. Muell. 1882, Scleria setuloso-ciliata Boeckeler 1882, Ageratum houstonianum Mill, 1768 and Acmella repens (Walter) Rich. 1807 stood out. The dry biomass of the weeds showed statistical differences between the plots with and without crotalaria, considering that lower values were observed in the control groups; however, the total dry phytomass production was extremely higher in the cultivated plots, highlighting the importance of using this species as green manure.

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

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