Weed species diversity in spring barley varies with crop rotation and tillage, but not with nutrient source

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 DMGand 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−2occurred in the moldboard-plowed monoculture compared with three to six species and densities of 51 to 832 plants m−2in 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.

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Taxonomic diversity and distinctness indices in assessment of weed communities

Acta Agrobotanica ◽

10.5586/aa.2011.067 ◽

2012 ◽

Vol 64 (4) ◽

pp. 251-258

Author(s):

Magdalena Jastrzębska ◽

Maria Wanic ◽

Wiesław P. Jastrzębski ◽

Marta K. Kostrzewska

Keyword(s):

Crop Rotation ◽

Spring Barley ◽

Taxonomic Diversity ◽

Diversity Indices ◽

Barley Grain ◽

Taxonomic Distinctness ◽

Weed Species ◽

Winter Triticale ◽

Weed Communities ◽

Barley Crop

This paper contains an analysis of taxonomic weed biodiversity in the cultivation of spring barley in the period of 1990-2004, grown in crop rotation after potato with a 25% share of this cereal (potato - spring barley - field pea - winter triticale) as well as in crop rotation with its 75% share (potato - spring barley - spring barley - spring barley) in which barley was grown once and twice after the same barley crop. No weed control was used in the present experiment. Every year in the spring (at full emergence of the cereal crop) and before harvest, the species composition and the numbers of individual weed species were determined, as well as weed biomass before harvest. On this basis, the taxonomic diversity and distinctness indices were calculated. Potato/barley crop rotation with a 25% share of this cereal and growing spring barley once and twice after the same barley crop did not differentiate taxonomic weed biodiversity. However, it was positively correlated with rainfall abundance during the growing season and negatively correlated with mean temperature. The taxonomic diversity indices were positively correlated with species richness and species diversity, whereas the taxonomic distinctness indices did not generally show any relationship with these measures. Spring barley grain yield did not depend on taxonomic biodiversity of weed communities.

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Diversity of segetal weeds in pea (Pisum sativum L.) depending on crops chosen for a crop rotation system

Acta Agrobotanica ◽

10.5586/aa.2014.008 ◽

2014 ◽

Vol 67 (1) ◽

pp. 55-66 ◽

Cited By ~ 1

Author(s):

Marta K. Kostrzewska ◽

Magdalena Jastrzębska ◽

Kinga Treder ◽

Maria Wanic

Keyword(s):

Species Diversity ◽

Species Composition ◽

Crop Rotation ◽

Spring Barley ◽

Chenopodium Album ◽

Research Station ◽

Weed Species ◽

Rotation System ◽

Density And Biomass ◽

Dominance Indices

This study, lasting from 1999 to 2006, was conducted at the Research Station in Tomaszkowo, which belongs to the University of Warmia and Mazury in Olsztyn. The experiment was set up on brown rusty soil classified as good rye complex 5 in the Polish soil valuation system. The analysis comprised weeds in fields sown with pea cultivated in two four-field crop rotation systems with a different first crop: A. potato – spring barley – pea – spring barley; B. mixture of spring barley with pea – spring barley – pea – spring barley. Every year, at the 2–3 true leaf stage of pea, the species composition and density of individual weed species were determined; in addition, before harvesting the main crop, the dry matter of weeds was weighed. The results were used to analyze the constancy of weed taxa, species diversity, and the evenness and dominance indices, to determine the relationships between all biological indicators analyzed and weather conditions, and to calculate the indices of similarity, in terms of species composition, density and biomass of weeds, between the crop rotations compared.The species richness, density and biomass of weeds in fields with field pea were not differentiated by the choice of the initial crop in a given rotation system. In the spring, the total number of identified taxa was 28 and it increased to 36 before the harvest of pea plants. Chenopodium album and Echinochloa crus-galli were the most numerous. Chenopodium album, Echinochloa crus-galli, Sonchus arvensis, Fallopia convolvulus and Viola arvensis were constant in all treatments, regardless of what the first crop in rotation was or when the observations were made.The species diversity and the evenness and species dominance indices varied significantly between years and dates of observations. Species diversity calculated on the basis of the density of weed species was higher in the rotation with a mixture of cereals and legumes, while that calculated on the basis of weed biomass was higher in the system with potato. The similarity indices, which express the convergence of floristic composition as well as of the density and biomass of weeds growing in pea fields in the two crop rotation systems compared, were within a broad range (42–86%). The biodiversity of weed communities was more closely correlated to total precipitation than to air temperature.

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Weed infestation of a cereal-legume mixture depending on its concentration and position in a crop rotation

Acta Agrobotanica ◽

10.5586/aa.2012.013 ◽

2012 ◽

Vol 65 (3) ◽

pp. 99-108

Author(s):

Marta K. Kostrzewska ◽

Maria Wanic ◽

Magdalena Jastrzębska

Keyword(s):

Species Composition ◽

Crop Rotation ◽

Spring Barley ◽

Similarity Index ◽

Floristic Composition ◽

Field Pea ◽

Total Biomass ◽

Weed Species ◽

Weed Communities ◽

Weed Infestation

A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson’s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Elymus repens, Polygonum convolvulus, and Sonchus arvensis were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

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An attempt to use functional diversity indices for the assessment of weed communities

Acta Agrobotanica ◽

10.5586/aa.2012.051 ◽

2012 ◽

Vol 65 (1) ◽

pp. 129-140 ◽

Cited By ~ 1

Author(s):

Magdalena Jastrzębska ◽

Maria Wanic ◽

Marta K. Kostrzewska ◽

Kinga Treder ◽

Janusz Nowicki

Keyword(s):

Crop Rotation ◽

Functional Diversity ◽

Spring Barley ◽

Diversity Indices ◽

Weed Species ◽

Winter Triticale ◽

Weed Communities ◽

Functional Diversity Indices ◽

Barley Crop

This paper presents an analysis of changes in functional diversity of weeds in spring barley grown in the period 1990-2004 in crop rotation after potato with a 25% share of this cereal (potato - spring barley - field pea - winter triticale) as well as in crop rotation with its 75% share (potato - spring barley - spring barley - spring barley) in which barley was grown once and twice after the same barley crop. No weed control was used in the present experiment. Every year in the spring (at full emergence of barley) and before harvest, the species composition and numbers of individual weed species were determined, as well as their weed biomass before harvest. On this basis, the selected functional diversity indices were calculated. Multidimensional techniques were used for dividing weeds into functional groups and for the determination of some of the indices. Potato/barley crop rotation with a 25% share of barley and growing spring barley once and twice after the same barley crop did not differentiate weed functional biodiversity. The weed functional diversity indices showed different variations over time. Higher variation was usually observed for the indices calculated for the summer communities compared to the spring ones. The strength and significance of the positive correlation between weed functional diversity and precipitation in the growing season and of the negative correlation with mean temperature for the period from April to August were dependent on the measure of diversity. The functional diversity indices showed high convergence. The FD and FAD indices proved to be interchangeable.

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Environmental factors including management practices as correlates of weed community composition in spring seeded crops

Canadian Journal of Botany ◽

10.1139/b92-240 ◽

1992 ◽

Vol 70 (10) ◽

pp. 1931-1939 ◽

Cited By ~ 58

Author(s):

M. R. T. Dale ◽

A. G. Thomas ◽

E. A. John

Keyword(s):

Community Composition ◽

Correspondence Analysis ◽

Canonical Correspondence Analysis ◽

Environmental Variables ◽

Management Practices ◽

Geographic Region ◽

Climatic Conditions ◽

Weed Species ◽

Weed Communities ◽

Seed Crops

The relationship between the weed communities and environmental variables such as soil, crop, and management was investigated in two provinces of Canada. The frequencies of weed species were recorded in cereal and oilseed fields in Saskatchewan (2244 fields over 4 years) and Manitoba (864 fields over 3 years), Canada. Information on some of the physical characteristics of the fields and on the management practices imposed on them was also collected, in part by questionnaire. The two kinds of data were ordinated together using canonical correspondence analysis to assess the relationships between the species and the environmental variables. In the Saskatchewan data, there was a clear and consistent separation of the species into groups along an axis correlated with soil zone and the associated climatic gradient. In the Manitoba data, the same groups of species did not separate as clearly or as consistently, although geographic region was a major determinant of the weed communities. The greater variability may be due to the fact that the gradient of soil types is much more restricted in Manitoba and not as closely correlated with climatic conditions. In both provinces, culture practices were less important as correlates of the weed community composition than soil type or, to a certain extent, the previous crop. Key words: canonical correspondence analysis, cereal crops, oil seed crops.

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Agroecological service crops managed with roller crimper reduce weed density and weed species richness in organic vegetable systems across Europe

Agronomy for Sustainable Development ◽

10.1007/s13593-019-0597-8 ◽

2019 ◽

Vol 39 (6) ◽

Cited By ~ 2

Author(s):

David Navarro-Miró ◽

José M. Blanco-Moreno ◽

Corrado Ciaccia ◽

Lourdes Chamorro ◽

Elena Testani ◽

...

Keyword(s):

Species Richness ◽

Weed Species ◽

Weed Density ◽

Weed Species Richness

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Weed infestation during the transition phase from conventional to conservation agriculture

10.5194/egusphere-egu2020-9838 ◽

2020 ◽

Author(s):

Felice Sartori ◽

Donato Loddo ◽

Ilaria Piccoli ◽

Antonio Berti

Keyword(s):

Species Richness ◽

Seed Bank ◽

Conservation Agriculture ◽

Soil Disturbance ◽

Transition Phase ◽

Effective Control ◽

Silty Clay ◽

Weed Species ◽

Number Of Species ◽

Weed Species Richness

Despite conservation agriculture and, overall, the reduction of soil disturbance are considered soil improving cropping systems, these practices could conflict with weed control. Indeed, reduced tillage is usually linked to increased weed species richness and abundance and, thus, it could increase the dependence on chemical treatments. Weed management is one of the reasons behind the distrust of European farmers in the conservation agriculture, that is still not widespread, despites European subsidies. In fact, conservation agriculture is implemented only in the 2.8% of European cropland.The aim of this study is to evaluate the effect of different tillage intensities on spring-summer weeds richness and abundance in a maize monoculture, during the transition phase from conventional to conservation agriculture.The weed survey was conducted in June 2019 on an experiment comparing three levels of tillage management: conventional agriculture (CT), which represents the most common choice in Veneto region, involving deep ploughing and harrowing in spring; minimum tillage (MT), consisting only in harrowing at 20 cm; and no tillage (NT), namely sod seeding. The experiment started in 2018, at Padova University experimental farm, in a sub-humid area, with a silty clay loam soil. The survey was conducted with a set of random throws of a 30&#215;30 cm square frame in each plot (ca. 3300 m2). &#160;Weed plants found within the frame were classified and counted. Subsequently, data analysis assessed which botanical families were promoted by each treatment.The NT resulted the treatment with the highest weed density (915 plant/m2): 6% higher than MT (823 plant/m2) and four-fold more than CT (209 plant/m2). The latter showed to be the treatment with higher diversity, according to both Shannon and Simpson indices. The survey evidenced higher weed species richness in MT, where both annual and perennial species were identified, while the lowest number of species were detected in NT. Plantago major and Chenopodium album were the species with the highest density in CT (>32 plant/m2) while they are negligible in NT and MT (7 plant/m2, on average). Digitaria sanguinalis was instead the dominant species in MT and NT (>600 plant/m2) while a lower density was observed in CT (11 plant/m2). Low levels of Asteraceae weeds were measured in all treatments. These results shows that the actual flora rapidly changes depending on tillage intensity, with an increase of both dominance and number of species in MT. Differently, only a limited number of adapted species germinated in NT, despite higher infestations if compared with the other treatments.It should be expected that other species more adapted to conservation agriculture (namely Asteraceae), still marginally present in the seed bank, will spread in the next years. This stresses the importance of a continuous monitoring and effective control of weeds to avoid uncontrolled evolutions of the weed flora and increase of seed bank in the transition phase from conventional to conservation agriculture.

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Biodiversity of weed communities in common wheat and spelt following various forecrops

Acta Agrobotanica ◽

10.5586/aa.1751 ◽

2018 ◽

Vol 71 (4) ◽

Cited By ~ 1

Author(s):

Maria Wanic ◽

Mariola Parzonka ◽

Dariusz Załuski

Keyword(s):

Species Diversity ◽

Common Wheat ◽

Oilseed Rape ◽

Dry Weight ◽

Wiener Index ◽

Weed Species ◽

Spelt Wheat ◽

Weed Communities ◽

Weed Infestation ◽

Heading Stage

Environmentally-friendly solutions are increasingly often applied in crop cultivation technologies. These include, among others, the return of old crops (e.g., spelt wheat) and crop rotation. Ensuring a proper forecrop is essential, especially in the cultivation of winter wheat, which is susceptible to infestation by weeds. However, there is only sparse information on infestation by weeds in the cultivation of winter spelt. In this study, it was assumed that this crop is invaded by weeds to a lesser extent than wheat, especially after unfavorable forecrops. The study was based on a field experiment conducted in the east part of Poland. The aim was to compare the weed infestation of common wheat and spelt wheat grown after peas, oilseed rape, and after itself. Analyses of weed infestation were conducted in 2014–2016. The weed species composition and population size were determined as well as their dry weight. The following indices were calculated: index of species richness, Simpson’s domination index, Shannon–Wiener index of species diversity, and Pielou’s index of evenness. The weed infestation of spelt wheat was higher than that of common wheat during the tillering stage. It was similar in both species during the heading stage. The lowest weed infestation in both cereals was observed on a field where peas had grown. Growing after oilseed rape and after themselves contributed to an increase in weed infestation. Biomass of weeds in a field of spelt was similar after all forecrops, unlike that in wheat, where more biomass was observed after oilseed rape and wheat. A greater share of Apera spica-venti and Viola arvensis was observed in common wheat and spelt grown after oilseed rape and after themselves. Weed communities in spelt were more diverse than in wheat. The forecrops did not differentiate the species diversity in either crop.

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ASSESSMENT OF THE HERBOLOGICAL SITUATION OF AGRO-PHYTOCENOSES OF SPRING BARLEY DURING THE USE OF VARIOUS PRECURSORS IN THE EXPERIMENTAL FIELD

Agriculture and Forestry ◽

10.37128/2707-5826-2019-3-15 ◽

2019 ◽

pp. 172-183

Author(s):

Ludmila Pelekh

Keyword(s):

Species Diversity ◽

Growth And Development ◽

Spring Barley ◽

General Structure ◽

Cultivated Plants ◽

Weed Species ◽

Previous Crop ◽

Cultivation Technology ◽

Biological Group ◽

Phenological Phases

The article reflects the results of many years of studying the peculiarities of the formation of the number of weeds in the agrophytocenosis of spring barley, depending on the previous culture. The general structure of weed species and their genus are estimated taking into account the features of the precursor. Species diversity has been assessed depending on the nature of the previous culture. A grouping of recorded weeds into biological groups was carried out, taking into account the type of the previous crop and the peculiarities of its cultivation technology. The general patterns of the formation of the structure of weeds are formulated taking into account typological predecessors and the dynamics of the formation of each biological group of weeds in the general structure of vegetation is evaluated. Peculiarities of the conjugate formation of weed are determined taking into account the duration of phenological phases of growth and development of spring barley, and an analysis is made of the features of increasing the total weediness of the field taking into account the competitive features of cultivated plants as precursors of spring barley.

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