Conventional- and conservation-tillage systems influence emergence periodicity of annual weed species in canola

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 886-897 ◽  
Author(s):  
W. John Bullied ◽  
Anastasia M. Marginet ◽  
Rene C. Van Acker

Variation in spring emergence periodicity (both before and after crop seeding) of summer annual weeds is a potentially exploitable attribute that may be applied to weed management in canola. Tillage intensity, which is decreasing in the Great Plains of North America, may influence emergence periodicity of summer annual weeds. Emergence periodicity of common lambsquarters, field pennycress, green foxtail, redroot pigweed, wild buckwheat, wild mustard, and wild oat were monitored during the spring of 2000 in 17 producers' canola fields across southern Manitoba, Canada. The fields represented a region of approximately 2 million ha and included a broad range of soil types, agronomic practices, environmental conditions, and seedbank distributions. Fields were grouped into one of two broad tillage classifications (conventional or conservation). For most species, except redroot pigweed and wild mustard, conservation tillage promoted earlier emergence than conventional tillage in terms of both thermal and chronological time. The differences were significant even though there was only a limited range of tillage intensity for the two tillage classes within this region. Onset of canola crop emergence preceded that of all but one weed species in the conservation-tillage fields and five weed species in the conventional-tillage fields. This suggests that canola seeded in conservation- vs. conventional-tillage systems may have a competitive advantage by way of an earlier relative time of crop emergence. The influence of tillage system on weed emergence periodicity is likely due to the influence of tillage on the vertical origin of weed seedling recruitment because measurements of soil temperature and soil moisture did not help to fully explain the differences in emergence periodicity between tillage systems. The results from this study will facilitate weed control timing decisions in canola and provide validation data for weed emergence models.

2004 ◽  
Vol 84 (1) ◽  
pp. 319-326 ◽  
Author(s):  
R. C. Van Acker ◽  
W. J. Bullied ◽  
M. J. du Croix Sissons

The influence of tillage on the depth of weed seedling recruitment has implications for species competitive ability, weed management strategy development, and the modeling of weed emergence; characterization of this relationship could aid in the creation of field-specific models of weed seedling recruitment. A tillage index based on the percentage of residue cover remaining on the soil surface after tillage events was assessed for 44 zero-tillage and 44 conventional-tillage fields across Manitoba, Canada. This index was related to in situ measurements of seedling recruitment depth from the same fields for five annual weed species. The modeled relationship was linear and unique for each species (R2 values ranged from 0.38 to 0.71). The relationship did not differ between pre- and post-seeding measurements, or between years, except for green foxtail. Slopes of the regression lines were greater for species such as volunteer wheat, which can recruit from a great range of depths. The results of this study show that recent tillage strongly influences mean weed seedling recruitment depth, and that the recruitment depth of summer annual weed seedlings is related in a continuous and reliable manner to a simple estimation of the relative level of tillage (including seeding) applied in one season. Key words: Recruitment depth, tillage index, weed emergence, weed seedlings


2006 ◽  
Vol 46 (12) ◽  
pp. 1557 ◽  
Author(s):  
B. S. Chauhan ◽  
G. S. Gill ◽  
C. Preston

In the past few years, there has been a growing trend towards reducing tillage in cropping systems to allow stubble retention, earlier planting and improved soil structure. However, the adoption of conservation tillage systems will change weed control practices. Different tillage systems interact with the micro-environment of weed seeds and can influence the pattern of recruitment from the weed seed bank. Here, we present a review of the effect of different tillage systems on weed ecology, herbicide activity and herbicide persistence. Tillage systems can have a major influence on the vertical distribution of weed seeds in the soil seed bank. However, the impact of the changes in the vertical seed distribution on weed seedling recruitment is not well understood. Usually weed seedling recruitment increases if tillage equipment brings buried seed to, or close to, the soil surface, and seedling recruitment decreases if surface seed is buried deeper in the soil. However, tillage responses have a tendency to be species specific and can also be influenced by the intensity of tillage. Any weed species in which germination is stimulated by exposure to light is likely to become more prevalent under reduced tillage systems. Similarly, species that require burial for germination may become less prevalent. Crop residue present on the soil surface can also influence weed seedling recruitment by modifying the physical environment (mainly temperature) of weed seeds. Weed responses to plant residue could also be influenced by the allelopathic activity of the residue and the sensitivity of the weed species present. Few studies have investigated the fate of weed seeds that fail to germinate under any tillage system. Further research is needed to determine whether the weed seeds that fail to germinate decay before the start of the next growing season or become part of a persistent seed bank. Crop residues present on the soil surface can intercept a considerable amount of the applied herbicide and, depending on the herbicide, this intercepted component is susceptible to losses. Therefore, conservation tillage systems are expected to have lower efficacy of soil active herbicides. However, there has been little investigation of rate of loss of soil active herbicides under reduced tillage systems and the results reported have been inconsistent. Much of the research on these effects is from overseas and may not be true in Australian conditions. Therefore, further work is needed to clearly understand the impact of changing tillage systems on weed ecology, herbicide performance and persistence.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 494f-495 ◽  
Author(s):  
Amy M. Johnson ◽  
Greg D. Hoyt

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.


Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 904-913 ◽  
Author(s):  
Robert H. Gulden ◽  
Steven J. Shirtliffe ◽  
A. Gordon Thomas

In western Canada, little is known about the seedbank ecology of volunteer canola. Therefore, integrated recommendations for the management of this weed are limited. In this study, we investigated the seedbank persistence and seedling recruitment of two spring canola genotype groups with different secondary seed dormancy potentials under contrasting tillage systems. The study was conducted at two locations with different soils in the Mixed Moist Grassland ecoregion of Saskatchewan. A single cohort seedbank was established in 1999 and was followed for 3 yr in successive wheat crops. In a separate laboratory study, the six canola genotypes examined were classified as those with high and those with medium potentials for the development of secondary seed dormancy (HD and MD, respectively). After one, two, and three winters, maximum persistence of 44, 1.4, and 0.2% of the original seedbank was observed among the treatments, respectively. In 2001, HD canola genotypes tended to exhibit 6- to 12-fold greater persistence than MD canola genotypes, indicating lower seedbank mortality in HD canola. Seedling recruitment of HD canola also was higher than MD canola when differences were observed between these genotype groups. Therefore, long-term seedbank persistence of canola can be reduced by growing genotypes with low inherent potential for the development of secondary seed dormancy. The proportion of persisting seeds tended to be higher under conventional tillage than under zero tillage because of lower seedbank mortality, but no clear distinction in seedbank persistence in terms of absolute time could be made between these two tillage systems. Volunteer canola seedling recruitment followed the pattern of a typical summer-annual weed, where seedling emergence was observed only during May and June.


2005 ◽  
Vol 53 (1) ◽  
pp. 53-57 ◽  
Author(s):  
T. Rátonyi ◽  
L. Huzsvai ◽  
J. Nagy ◽  
A. Megyes

The cultivation technologies for the dominant crops in Hungary need to be improved both in the interests of environmental protection and to reduce cultivation costs. A long-term research project was initiated in order to determine the feasibility of conservation tillage systems. The aim of the experiments was to evaluate conservation farming systems in Hungary in order to achieve more economical and more environment-friendly agricultural land use. Four tillage systems, namely conventional tillage (mouldboard plough), conservation tillage I (primary tillage with a J.D. Disk Ripper), conservation tillage II (primary tillage with a J.D. Mulch Finisher) and no tillage (direct drilling), were compared on a clay loam meadow soil (Vertisol). The physical condition of the experimental soils was evaluated using a hand-operated static cone penetrometer. Parallel with the measurement of penetration resistance, the moisture content of the soil was also determined. The grain yield of maize hybrids (Kincs SC [1999], Occitán SC [2000], Pr 37M34 SC [2001], DeKalb 471 SC [2002]) was measured using a plot combine-harvester. The analysis of soil conditions confirmed that if the cultivation depth and intensity are reduced the compaction of soil layers close to the surface can be expected. The decrease in yields (8-33%) in direct drilling (NT) and shallow, spring cultivated (MF) treatments, despite the higher available water content, can be explained partly by the compacted status of the 15-25 cm soil layer.


1999 ◽  
Vol 31 (1) ◽  
pp. 133-147 ◽  
Author(s):  
Keith O. Fuglie

AbstractAdoption of conservation tillage can lead to substantial environmental benefits from reduced soil erosion. But benefits may be partially offset if adoption increases reliance on agricultural chemicals. Using area study data from the Cornbelt, this study examines factors affecting adoption of no-till and other conservation tillage systems and their effect on chemical use and corn yield. The results find no evidence that herbicide or fertilizer application rates are higher on fields with conservation tillage systems compared with conventional tillage. However, insecticide use may increase somewhat and yield may be lower. Current demographic trends in U.S. agriculture favor continued diffusion of conservation tillage.


2021 ◽  
Vol 9 (7) ◽  
pp. 407-421
Author(s):  
Nawal Al-Hajaj

In this study, we reviewed weed seed bank dynamic and main agriculture operations to come up with the weed seed management modeling designed to increase crop productivity by removing weed competition. Weed contributing with 10% loss of total global grain production. Weed seed bank regulate by five demographic processes seedling recruitment and survival, seed production, dispersal and seed survival in soil. The main agriculture operations that interference with weed seed bank are crop rotation and primary tillage. Tillage systems affect weed emergence, management, and seed production; therefore, changing tillage practices changes the composition, vertical distribution, and density of weed seed bank in agricultural soils. Weed species vary in their response to various crop rotations, due to the variability of weed-crop competition in their relative capacity to capture growth–limiting resources. Crop rotations affect weed emergence, management, composition, and density of weed seed bank. Finally, the study suggests elevating crop competitiveness against weeds, through a combination of crop rotation and reduce_ zero tillage, has strong potential to reduce weed-induced yield losses in crop.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 471B-471
Author(s):  
D.J. Makus

In Spring 1998, two sweet corn (Zea mays var. rugosa) cultivars were grown under three tillage systems, conventional cultivation, ridge tillage (RT), and no tillage (NT), which had been in continuous management since Fall 1994. Nitrogen (as NH4NO3), the only fertilizer used, was applied twice at 60 kg/ha. Sweet corn yields were not influenced by tillage system, but average ear weights tended to be smaller under NT (P < 0.17). Ear quality attributes, which included ear weight, length, diameter, dry matter, and incidence of earworm damage, were greater in the later-maturing `G-90' cultivar than in `Sensor'; but tillage system had no influence on these attributes. Cultivars supported different weed species underneath their canopies. `Sensor' allowed more light penetration and sustained higher weed biomass than did the taller `G-90' plants. Weed biomass was higher under RT and NT. Seasonal soil moisture was lowest in the RT plots, but only in the 0- to 15-cm profile. Soil temperatures (unreplicated) at the 15-cm depth were similar between cultivars and tillage treatments over the growing season. The earlier-maturing `Sensor' generally accumulated more ear mineral nutrients (P, S, NO3, Ca, Na, Zn, Mn, Al, and B; dry weight basis), but had lower dry matter (percentage) than did `G-90'. Cumulative nutrient levels tended to be lowest in NT-grown ears (P < 0.08). Soil sampled at 0- to 5-, 10- to 15-, and 25- to 30-cm depths generally had higher concentrations of nutrients toward the surface, and NT soils had the steepest nutrient gradients, with the exception of Na and NO3. Total soil salts were reduced by RT and NT, but C: N ratio remained unchanged between tillage systems.


2021 ◽  
pp. 181-186
Author(s):  
Shilpa Manhas ◽  
Janardan Singh ◽  
Ankit Saini ◽  
Tarun Sharma ◽  
Parita K.

A field experiment was conducted during kharif season of 2019 at the Research Farm, Department of Agronomy, CSKHPKV, Palampur to study the effect of tillage and fertilizer doses on growth and growth indices of soybean under conservation tillage systems. The experiment consisted of twelve treatment combinations which included three tillage systems minimum tillage, minimum tillage with crop residue and conventional tillage and four fertility levels viz; 25 % recommended dose of fertilizer (RDF) , 50 %(RDF) , 75 % RDF and 100% RDF and which were tested in split plot design with tillage system in main plots and fertility levels in sub plots.The soil texture of experimental site was silty clay loam. Minimum tillage along with crop residues (T2)recorded significantly taller plants and higher dry matter accumulation followed by conventional tillage. Absolute growth rate, crop growth rate, dry matter efficiency, relative growth rate and unit area efficiency were significantly higher with minimum tillage + crop residue treatment. Application of 100 % followed by 75 % recommended dose of fertilizer resulted in significantly higher growth parameters and growth indices.


2011 ◽  
Vol 48 (No. 6) ◽  
pp. 249-254 ◽  
Author(s):  
S. Husnjak ◽  
D. Filipović ◽  
S. Košutić

An experiment with five different tillage systems and their influence on physical properties of a&nbsp;silty loam soil (Albic Luvisol) was carried in northwest Slavonia in the period of 1997&ndash;2000. The compared tillage systems were: 1. conventional tillage (CT), 2. reduced tillage (RT), 3. conservation tillage I&nbsp;(CP), 4. conservation tillage II (CM), 5. no-tillage system (NT). The crop rotation was soybean (Glycine max L.) &ndash; winter wheat (Triticum aestivum L.) &ndash; soybean &ndash; winter wheat. Differences between tillage systems in bulk density, total porosity, and water holding capacity and air capacity were not significant in winter wheat seasons. In soybean seasons, significant differences between some tillage systems were recorded in bulk density, total porosity, air capacity and soil moisture. The deterioration trend of physical properties was generally increasing in the order CM, CT, CP, NT and RT. The highest yield of soybean in the first experimental year was achieved under CT system and the lowest under CP system. In all other experimental years, the highest yield of winter wheat and soybean was achieved under CM system, while the lowest under RT system.


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