Cropping system diversification does not always beget weed diversity

2022 ◽  
Vol 133 ◽  
pp. 126438
Author(s):  
Guillaume Adeux ◽  
Séverin Yvoz ◽  
Luc Biju-Duval ◽  
Emilie Cadet ◽  
Pascal Farcy ◽  
...  
Keyword(s):  
Cropping System ◽  
Weed Diversity

Weed diversity and weed management

Weed Science ◽  
1997 ◽  
Vol 45 (3) ◽  
pp. 357-363 ◽  
Author(s):  
Jack Dekker
Keyword(s):  
Weed Management ◽  
Phenotypic Diversity ◽  
Management Strategies ◽  
Physical Space ◽  
Cropping System ◽  
Weed Species ◽  
Plant Parts ◽  
Weed Diversity ◽  
Diversity Enhancement

The story of agriculture is the story of weed interference. After millennia of weed control we still have weeds. This situation has led many growers to observe that “the weeds always win.” One of the most important reasons weeds are so successful is their biodiversity. Biodiversity is an inevitable consequence of the struggle an individual weed species undergoes in the presence of neighbors, and by occupying a physical space in an agroecosystem. Weeds have evolved in response to cropping system practices by adapting and occupying niches left available in agroecosystems. Forces created by our cropping practices over evolutionary time have led to the weed diversity we observe today. Diversity underlies weed management in several important ways. A plant experiences diversity among its neighbors in at least five different ways. Weeds have adapted to selection in agroecosystems in several ways: (1) genetic variants within a species; (2) somatic polymorphism of plant parts; (3) success in diverse habitat microsites; (4) temporal adaptations within the community; and (5) floristic diversity of a community at higher levels than the species. Herein, weed diversity is discussed in this broader context, in terms of population behaviors that emerge as a consequence of the activities of individual components at lower levels of organization. Diversity is also discussed in terms of its implications for weed management. The potential exists to develop management strategies based on differences in weed and crop diversity. These strategies might be developed by characterization of weedy genetic and phenotypic diversity; enhancement of crop, cropping system, and agroecosystem diversity; and characterization of the spatial distribution of weed populations.

Agricultural Weeds in Glyphosate-Resistant Cropping Systems in the United States

Weed Science ◽  
2013 ◽  
Vol 61 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Bryan G. Young ◽  
David J. Gibson ◽  
Karla L. Gage ◽  
Joseph L. Matthews ◽  
David L. Jordan ◽  
...  
Keyword(s):  
United States ◽  
Crop Rotation ◽  
Cropping System ◽  
The United States ◽  
Agricultural Landscapes ◽  
Large Field ◽  
Categorical Variables ◽  
Weed Flora ◽  
Weed Diversity ◽  
History Of

A segment of the debate surrounding the commercialization of genetically engineered (GE) crops, such as glyphosate-resistant (GR) crops, focuses on the theory that implementation of these traits is an extension of the intensification of agriculture that will further erode the biodiversity of agricultural landscapes. A large field-scale study was conducted in 2006 in the United States on 156 different field sites with a minimum 3-yr history of GR corn, cotton, or soybean in the cropping system. The impact of cropping system, crop rotation, frequency of using the GR crop trait, and several categorical variables on emerged weed density and diversity was analyzed. Species richness, evenness, Shannon's H′, proportion of forbs, erect growth habit, and C3species diversity were all greater in agricultural sites that lacked crop rotation or were in a continuous GR crop system. Rotating between two GR crops (e.g., corn and soybean) or rotating to a non-GR crop resulted in less weed diversity than a continuous GR crop. The composition of the weed flora was more strongly related to location (geography) than any other parameter. The diversity of weed flora in agricultural sites with a history of GR crop production can be influenced by several factors relating to the specific method in which the GR trait is integrated (cropping system, crop rotation, GR trait rotation), the specific weed species, and the geographical location. The finding that fields with continuous GR crops demonstrated greater weed diversity is contrary to arguments opposing the use of GE crops. These results justify further research to clarify the complexities of crops grown with herbicide-resistance traits, or more broadly, GE crops, to provide a more complete characterization of their culture and local adaptation.

scholarly journals Diversity and Spatial Heterogeneity of Weed Communities in a Sugarcane Cropping System in the Dry Tropics of Costa Rica

Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Ramon G. Leon ◽  
Renán Agüero ◽  
Diego Calderón
Keyword(s):  
Costa Rica ◽  
Weed Control ◽  
Soil Texture ◽  
Cropping System ◽  
Weed Species ◽  
Ecological Processes ◽  
Dry Tropics ◽  
Weed Communities ◽  
Management Area ◽  
Weed Diversity

Weed diversity, structure, and distribution within and outside agricultural fields affect not only ecological processes but also weed management strategies. We studied how areas managed differently within and outside the field determine weed communities in a sugarcane cropping system in the dry tropics of Costa Rica. A total of 120 weed species were detected, which was similar to surveys conducted in subtropical and temperate conditions. Weed species richness was highest in undisturbed field borders and lowest in rows and furrows. The area where tractors turn within the field (turn area) had similar richness compared with the borders, despite being one of the most disturbed management areas studied. The most predominant weed species were divided between generalists and species that exhibited clear preferences for management area or soil texture. Soil texture was more important for determining weed community structure than management area when considering weed species affecting weed control decisions. The results indicated that disturbance in the management area and, especially, weed control practices are critical factors affecting weed diversity, but availability of resources for weed growth such as nutrients, soil moisture, and light can mitigate some of the limitations imposed by weed control on weed diversity, especially in the turn area. Differences in weed communities between management areas within fields indicated the existence of conditions that favor key weed species, and this information can be used to anticipate their population growth and help determine when and where more intensive control should be implemented.

scholarly journals Weeds on Soybeans Crop After the Application of the Association of the Herbicides Imazapic + Imazapyr on Different Liming Rates in a No-till Cropping System

2018 ◽  
Vol 10 (6) ◽  
pp. 238 ◽  
Author(s):  
Lucas Rizzon Ferreira ◽  
Taísa Dal Magro ◽  
Elaine Damiani Conte ◽  
Marco Thúlio Monego ◽  
Lucas de Ross Marchioretto
Keyword(s):  
Raphanus Sativus ◽  
Chemical Properties ◽  
Cropping System ◽  
Soil Parameters ◽  
Resistant Species ◽  
No Till ◽  
Chemical Soil ◽  
Weed Diversity ◽  
Repeated Use ◽  
Herbicide Glyphosate

The repeated use of the herbicide glyphosate has selected weed resistant species to this molecule. The combination of the tank-mix imazapic + imazapyr (Cultivance® technology) turns out being an alternative on the management of glyphosate resistant weeds. The interaction of these molecules with the soil’s chemical properties with the spraying frequency, and the weed diversity are yet unknown. This study evaluated the effects of liming at the weed incidence on the soybeans crop treated with the association of herbicides imazapic + imazapyr in a no-till cropping system. The experiment was installed at the field in a RCBD with four replications. The experiment was conducted in a factorial arrangement 5 × 2 with five rates of calcitic limestone (0, 2.5, 5, 12.5, and 30 ton/ha) and two corresponding to the presence or absence of the herbicides imazapic + imazapyr (rate of 100 g/ha of the commercial product Soyvance®) sprayed in a spray-plant system. After 40 months of surface-liming, the soybean cultivar Lancer® was planted in a no-till field, and it was evaluated: frequency and abundance of weeds, and the chemical soil parameters: pH, Ca, H+Al, and Mg at the depth of 0-10 cm. The most abundant weeds observed were: Desmodium spp., Schlechtendalia luzulifolia, Digitaria horizontalis, Raphanus sativus and Cyperus spp., with predominance of dicot species. In conclusion, as the surface-liming rate was increased, the greater the frequency of dicot weeds, and the lesser the monocots were found in the area.

Improved Plant Diversity as a Strategy to Increase Available Soil Phosphorus

2019 ◽  
Vol 103 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Carlos Crusciol ◽  
João Rigon ◽  
Juliano Calonego ◽  
Rogério Soratto
Keyword(s):  
Crop Yields ◽  
Soil Phosphorus ◽  
Cropping System ◽  
P Availability ◽  
P Fractions ◽  
Crop Species ◽  
Soil P ◽  
Residue Decomposition ◽  
Available Soil Phosphorus ◽  
Crop Residue Decomposition

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.

ALLEY CROPPING SYSTEM UNDER CONSERVATION AGRICULTURE PRACTICES IN TAJIKISTAN

2020 ◽  
pp. 48-51
Author(s):  
A. Nurbekov ◽  
L. Xalilova ◽  
B. Isroilov ◽  
U. Xalilov
Keyword(s):  
Alley Cropping ◽  
Cropping System ◽  
Conservation Agriculture

APPLICATION OF THE INTENSIVE CROP GROWING TECHNOLOGIES IN CROP ROTATION IS THE STABILITY CONDITION OF THE HUMUS CONTENT OF SOIL

1970 ◽  
pp. 52-56
Author(s):  
V. А. Shchedrin
Keyword(s):  
Soil Fertility ◽  
Crop Rotation ◽  
Humus Content ◽  
Arable Land ◽  
Weighted Average ◽  
Cropping System ◽  
Investment Project ◽  
Crop Rotations ◽  
High Productivity ◽  
Labile Phosphorus

In OOO “Dubovitskoe” which was organized in 2006 as investment project of the AO “Shchelkovo Agrokhim” for 2010 – 2012 three advanced crop rotations have been developed. Before their introduction the grain crops fraction in the cropping system was 62%, then it fell to 49%. At the same time the portion of raw crops increased from 15 to 20%, legumes from 6 to 8%, others (buckwheat, grain maize, etc.) - up to 23%. As of 2017, the crops of leguminous crops have increased noteworthily. There are two predominant soil types here heavy clay loam podzolized chernozem (6615 ha) and grey forest soil (856 ha). Weighted average indicators (as of 2017): humus content in the soils of arable land is 5, 34%; acidity pH is 4.92; labile phosphorus - 111.8 mg / kg soil; exchange potassium - 144 mg / kg soil. The coefficient of the soil fertility in the enterprise (weighted average) is 0.66. This means that maintaining and increasing the soil fertility for arable land of the enterprise is critical task. As a result of the research, it has been established that the technologies introduced in the crop vegetation management (CVS) in the crop rotation conditions ensure high productivity of cultivated crops and stability of humus content in soils as an energy basis and a guarantor of increasing fertility. The indicators of the labile phosphorus Р205 and exchange potassium К20 in the soils depending on the crop rotation vary from a certain decrease to expressed steady growth. Therefore it is necessary to specify seeding rates based on actual data. Sustainable soil acidification in the crop rotations under crop cultivation in OOO “Dubovitskoe” it is the result of the acid feterlizers high rates application, during studying period did not carried out required agromelioration with calcium contenting elements.

Urbanization and Changes in Cropping Patterns at Kathmandu Valley

2007 ◽  
Vol 7 ◽  
pp. 113 ◽  
Author(s):  
Raj Man Shrestha
Keyword(s):  
Urban Areas ◽  
Cropping System ◽  
Considerable Change ◽  
Rapid Expansion ◽  
Leafy Vegetables ◽  
Kathmandu Valley ◽  
Rapid Urbanization ◽  
Average Growth ◽  
Cropping Patterns ◽  
Agriculture Land

The increase of population in Kathmandu valley is bringing a considerable change in cropping system. Rapid urbanization and introduction of new agriculture technology have encouraged the valley’s farmers to change their cropping patterns from traditional (low value crops) to new crops (high value crops). According to numerous studies made in Nepal, the change is seen considerably in winter crops than in summer crops and the land under cultivation of green leafy vegetables is increasing rapidly in the urban and semi-urban areas. An average growth of population at 3 % in the valley during the period 1951-2001 has resulted in the rapid expansion of area under urban coverage (24.6 % growth per year from 1984 - 2000) has made agriculture land of Katmandu valley to decline per year by 2.04 % (836.27 ha per year). If this trend of decline in agriculture land in Kathmandu valley continues in future too, it is expected that there will be no agriculture land left over by two and half decades in the valley. The planners should take note of this fact that if fertile land of Katmandu valley is to be preserved for agriculture necessary planning is urgently needed. <i>Nepal Journal of Science and Technology</i> Vol. 7, 2006

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