scholarly journals Undersown cover crops have limited weed suppression potential when reducing tillage intensity in organically grown cereals

2019 ◽  
Vol 10 (1) ◽  
pp. 107-121 ◽  
Author(s):  
J. Salonen ◽  
E. Ketoja
Keyword(s):  
Winter Wheat ◽  
Spring Wheat ◽  
Cover Crops ◽  
Weed Management ◽  
Spring Barley ◽  
Wheat Yield ◽  
Weed Suppression ◽  
Reduced Tillage ◽  
Perennial Weeds ◽  
Weed Infestation

Abstract Adoption of reduced tillage in organic cropping has been slow, partly due to concerns about increasing weed infestation. Undersown cover crops (CCs) are considered to be a feasible option for weed management but their potential for weed suppression is insufficiently investigated in low-till organic cropping. The possibilities to reduce primary tillage by introducing CCs to maintain weed infestation at a level that does not substantially jeopardize crop yield were studied in a field experiment in southern Finland during 2015–2017. Eight different CC mixtures were undersown in cereals and the response in weed occurrence was consecutively assessed in spring barley, winter wheat, and finally, as a subsequent effect, in spring wheat. Growth of CCs was too slow to prevent the flush of early emerging weeds in spring barley whereas in winter wheat, CCs succeeded in hindering the growth of weeds. However, CCs could not prevent the increase of perennial weeds in a reduced tillage system in which the early growth of spring wheat was retarded in cool 2017. Consequently, after 2 years of reduced tillage, weed biomass was about 2.6 times higher and spring wheat yield was 30% lower than in plowed plots, respectively. No major differences in weed control efficacy among CC treatments were evident. A grain yield benefit was recorded after repeated use of leguminous CCs. The need for long-term field studies remains of particular interest regarding post-harvest performance and influence of CCs on perennial weeds before the inversion tillage.

scholarly journals Impact of site-specific weed management on herbicide savings and winter wheat yield  

2013 ◽  
Vol 59 (No. 3) ◽  
pp. 101-107 ◽  
Author(s):  
P. Hamouz ◽  
K. Hamouzová ◽  
J. Holec ◽  
L. Tyšer
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Wheat Yield ◽  
The Other ◽  
Herbicide Application ◽  
Site Specific ◽  
Treatment Thresholds ◽  
Patch Spraying ◽  
Winter Wheat Yield ◽  
Weed Infestation

An aggregated distribution pattern of weed populations provides opportunity to reduce the herbicide application if site-specific weed management is adopted. This work is focused on the practical testing of site-specific weed management in a winter wheat and the optimisation of the control thresholds. Patch spraying was applied to an experimental field in Central Bohemia. Total numbers of 512 application cells were arranged into 16 blocks, which allowed the randomisation of four treatments in four replications. Treatment 1 represented blanket spraying and the other treatments differed by the herbicide application thresholds. The weed infestation was estimated immediately before the post-emergence herbicide application. Treatment maps for every weed group were created based on the weed abundance data and relevant treatment thresholds. The herbicides were applied using a sprayer equipped with boom section control. The herbicide savings were calculated for every treatment and the differences in the grain yield between the treatments were tested using the analysis of variance. The site-specific applications provided herbicide savings ranging from 15.6% to 100% according to the herbicide and application threshold used. The differences in yield between the treatments were not statistically significant (P = 0.81). Thus, the yield was not lowered by site-specific weed management.

Efficacy of Cover Crops on Weed Suppression, Wheat Yield, and Water Conservation in Winter Wheat–Sorghum–Fallow

Crop Science ◽  
2019 ◽  
Vol 59 (4) ◽  
pp. 1745-1752 ◽  
Author(s):  
Abdel Mesbah ◽  
Abdelaziz Nilahyane ◽  
Binod Ghimire ◽  
Leslie Beck ◽  
Rajan Ghimire
Keyword(s):  
Winter Wheat ◽  
Cover Crops ◽  
Water Conservation ◽  
Wheat Yield ◽  
Weed Suppression

Cereal cover crops for weed suppression in a summer fallow-wheat cropping sequence

2000 ◽  
Vol 80 (2) ◽  
pp. 441-449 ◽  
Author(s):  
J. R. Moyer ◽  
R. E. Blackshaw ◽  
E. G. Smith ◽  
S. M. McGinn
Keyword(s):  
Winter Wheat ◽  
Weed Control ◽  
Cover Crops ◽  
Soil Conservation ◽  
Cover Crop ◽  
Wheat Yield ◽  
Weed Suppression ◽  
Wheat Crop ◽  
Weed Growth ◽  
Summer Fallow

Cropping systems in western Canada that include summer fallow can leave the soil exposed to erosion and require frequent weed control treatments. Cover crops have been used for soil conservation and to suppress weed growth. Experiments were conducted under rain-fed conditions at Lethbridge, Alberta to determine the effect of short-term fall rye (Secale cereale L.), winter wheat (Triticum aestivum L.) and annual rye cover crops in the fallow year on weed growth and subsequent wheat yield. Under favorable weather conditions fall rye was as effective as post-harvest plus early spring tillage or herbicides in spring weed control. Winter wheat and fall rye residues, after growth was terminated in June, reduced weed biomass in September by 50% compared to no cover crop in 1993 but had little effect on weeds in 1995. Fall-seeded cover crops reduced the density of dandelion (Taraxacum officinale Weber in Wiggers) and Canada thistle [Cirsium arvense (L.) Scop.] but increased the density of downy brome (Bromus tectorum L.), wild buckwheat (Polygonum convolvulus L.), and thyme-leaved spurge (Euphorbia serpyllifolia Pers.) in the following fall or spring. Wheat yields after fall rye and no cover crop were similar but yields after spring-seeded annual rye were less than after no cover crop. Spring-seeded annual rye did not adequately compete with weeds. Cover crops, unlike the no cover crop treatment, always left sufficient plant residue to protect the soil from erosion until the following wheat crop was seeded. Key words: Allelopathies, fall rye, nitrogen, soil conservation, soil moisture, weed control, spring rye, winter wheat

scholarly journals Effects of Reduced Tillage on Weed Pressure, Nitrogen Availability and Winter Wheat Yields under Organic Management

Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 180 ◽  
Author(s):  
Merel Hofmeijer ◽  
Maike Krauss ◽  
Alfred Berner ◽  
Joséphine Peigné ◽  
Paul Mäder ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Nitrogen Availability ◽  
Negative Impact ◽  
Stem Elongation ◽  
Conventional Tillage ◽  
Reduced Tillage ◽  
Soil Mineral Nitrogen ◽  
Tillage System ◽  
Weed Infestation

Reduced tillage reduces soil erosion and increases topsoil organic matter compared with conventional tillage. However, yields are often reported to be lower, presumably, due to increased weed pressure and a slower N mineralization under organic farming conditions. The effects of reduced tillage compared with ploughing on weed infestation and winter wheat performance at four different crop stages, i.e., tillering, stem elongation, flowering, and harvest, was monitored for a single season in an eleven-year-old organic long-term tillage trial. To disentangle the effects of weed presence on crop yield and potential crop performance, subplots were cleaned from weeds during the whole cropping season. Weed biomass was consistently higher under reduced tillage. Soil mineral nitrogen contents under reduced tillage management were higher, which could be explained by the earlier ley termination in autumn compared with the conventional tillage system. Nitrogen status of wheat assessed with SPAD measurements was consequently higher under reduced tillage throughout the season. At harvest, wheat biomass and grain yield were similar in both tillage systems in the presence of weeds, but 15–18% higher in the reduced tillage system when weeds were removed. The negative impact of weeds on yields were not found with conventional tillage with a low weed infestation. Results suggest that reduced tillage can provide equivalent and even higher yields to conventional tillage in organically managed winter wheat if weed management is improved and good nutrient supply is assured.

scholarly journals Developing Cover Crops for Weed Control in Establishment Year for Strawberries

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 820A-820
Author(s):  
Charlotte Herman ◽  
David Larson ◽  
Emily Hoover
Keyword(s):  
Winter Wheat ◽  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Plant Material ◽  
Weed Suppression ◽  
First Year ◽  
Growing Seasons ◽  
Stage Of Development ◽  
Soil Area

The goal of our program is to learn how to effectively establish first-year strawberry plantings without using herbicides. Before strawberry transplanting, four treatments were established: winter wheat, a dwarf Brassica sp., napropamide (2.24 kg·h–1) plus hand hoeing and rototilling, and no weed management. `Honeyoye' transplants were set into plots measuring 6.1 × 7.32 m on 21 May 1993 and 10 May 1994. Weekly data was taken on the percentage of soil area covered with plant material, height, and stage of development of plants, and weeds present. Weed transects and plant dry weights were done periodically during the growing seasons. The most promising cover crop treatment was the dwarf Brassica sp. for early season weed suppression because of rapid germination and short stature. Winter wheat was very competitive with the strawberry plants. The herbicide treatment had the largest inputs; however, it did produce the largest strawberry plants at the end of the season.

Effects of missing-row sowing supplemented with row spacing and nitrogen on weed competition and growth and yield of wheat

2011 ◽  
Vol 62 (1) ◽  
pp. 48 ◽  
Author(s):  
T. K. Das ◽  
N. T. Yaduraju
Keyword(s):  
Weed Management ◽  
Wheat Yield ◽  
Weed Suppression ◽  
Growth And Yield ◽  
Weed Competition ◽  
Row Spacing ◽  
Weed Growth ◽  
Spatial Uniformity ◽  
Weed Infestation ◽  
Ecological Weed Management

Crop husbandry practices, i.e. sowing method, row spacing, and nitrogen (N) fertilisation, influence weed competition in a crop and play a role in ecological weed management. Missing-row sowing is a novel method of sowing wheat, with one row left unsown after several rows of continuous sowing. It affects density and spatial uniformity of wheat, which may influence the wheat plants’ competitiveness and weed suppression. It may have interactions with row spacing and N, which may further improve crop–weed balance, but is rarely studied in India or elsewhere. We undertook this study to optimise the method of missing-row sowing of wheat in combination with row spacing and N application. The results revealed that leaving 20% of rows unsown significantly reduced weed populations and dry weights, and increased the competitiveness of wheat plants through greater leaf area, numbers of ear-bearing tillers, and uptake of N. Leaving 20% of rows unsown increased wheat yield by 10.9%, 17.3%, and 8.2%, respectively, during the first, second, and third year compared with conventional sowing (no missing rows). An 18.5-cm row spacing resulted in a more weed suppression than 22.5-cm row spacing, but the latter gave higher yield. Application of N at 120 kg/ha resulted in higher yield than N at 60 kg/ha, due to a significant reduction in weed growth. A practice that combines 20% of rows unsown, 22.5-cm row spacing, and 120 kg N/ha will yield more through better suppression of a moderate weed infestation.

Suppressing weed growth after wheat harvest with underseeded red clover in organic farming

2015 ◽  
Vol 31 (3) ◽  
pp. 185-190 ◽  
Author(s):  
Randy L. Anderson
Keyword(s):  
Winter Wheat ◽  
Spring Wheat ◽  
Weed Management ◽  
Cover Crop ◽  
Block Design ◽  
Wheat Yield ◽  
Red Clover ◽  
Downy Brome ◽  
Alternative Tactics ◽  
Weed Growth

AbstractOrganic producers are seeking alternative tactics for weed control so that they can reduce their need for tillage. In this study, we examined cover crop strategies for suppressing weed growth after harvest of wheat. Three cover crop treatments, red clover (mammoth type), a mixture of oat and dry pea, and a control were compared. Treatments were established in both winter and spring wheat, resulting in six treatments arranged in a randomized complete block design. Red clover was underseeded in wheat by drilling in the spring, and the oat/pea mixture was planted in August. Oat was planted uniformly across all treatments in the following growing season. The red clover treatment effectively suppressed weeds, reducing post-harvest weed biomass, density of volunteer winter wheat, and seed production of downy brome by more than 99% compared with the control. Oat/pea was not effective for weed management, likely because of less fall growth and competition compared with red clover. Underseeding red clover did not affect winter wheat yield, but reduced spring wheat yield by 17%. Oat yield, however, was reduced by volunteer crop plants and downy brome infestations in all treatments. Underseeding clovers in winter wheat may effectively manage weeds and, if they winterkill, can replace the need for tillage to control weeds after wheat harvest.

scholarly journals Effects of disk tillage on soil condition, crop yield and weed infestation

2011 ◽  
Vol 48 (No. 1) ◽  
pp. 20-26
Author(s):  
M. Birkás ◽  
T. Szalai ◽  
C. Gyuricza ◽  
M. Gecse ◽  
K. Bordás
Keyword(s):  
Winter Wheat ◽  
Crop Yield ◽  
Field Experiments ◽  
Soil Layer ◽  
Soil Condition ◽  
Perennial Weeds ◽  
Weed Infestation ◽  
Set Up ◽  
Different Levels

This research was instigated by the fact that during the last decade annually repeated shallow disk tillage on the same field became frequent practice in Hungary. In order to study the changes of soil condition associated with disk tillage and to assess it is consequences, long-term tillage field experiments with different levels of nutrients were set up in 1991 (A) and in 1994 (B) on Chromic Luvisol at Gödöllö. The effects of disk tillage (D) and disk tillage combined with loosening (LD) on soil condition, on yield of maize and winter wheat, and on weed infestation were examined. The evaluation of soil condition measured by cone index and bulk density indicated that use of disking annually resulted in a dense soil layer below the disking depth (diskpan-compaction). It was found, that soil condition deteriorated by diskpan-compaction decreased the yield of maize significantly by 20 and 42% (w/w), and that of wheat by 13 and 15% (w/w) when compared to soils with no diskpan-compaction. Averaged over seven years, and three fertilizer levels, the cover % of the total, grass and perennial weeds on loosened soils were 73, 69 and 65% of soils contained diskpan-compaction.

scholarly journals Spring-planted cover crops for weed control in soybean

2021 ◽  
pp. 1-8
Author(s):  
Katja Koehler-Cole ◽  
Christopher A. Proctor ◽  
Roger W. Elmore ◽  
David A. Wedin
Keyword(s):  
Weed Control ◽  
Biomass Production ◽  
Cover Crops ◽  
Weed Management ◽  
Block Design ◽  
Weed Suppression ◽  
Crop Species ◽  
Cold Temperatures ◽  
Weed Biomass ◽  
Small Grains

Abstract Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%. Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

An experiment begun in 1958 measuring effects of N, P and K fertilizers on yield and N, P and K contents of grass:2. Residual effects on arable crops, 1968–76

1980 ◽  
Vol 95 (3) ◽  
pp. 583-595 ◽  
Author(s):  
A. Penny ◽  
F. V. Widdowson
Keyword(s):  
Winter Wheat ◽  
Spring Wheat ◽  
Spring Barley ◽  
Residual Effects ◽  
Wheat Grain ◽  
K Uptake ◽  
Arable Crops ◽  
Soil P ◽  
K Fertilizer ◽  
K Depletion

SUMMARYAn experiment at Rothamsted during 1958–67 measured effects on yield, on K uptake and on soil K of applying all combinations of 38, 75 and 113 kg N and 0, 31 and 62 kg K/ha per cut to grass leys, which were cut and removed. Soil K was depleted most where most N and least K were given. Annual applications of 0, 33 and 66 kg P/ha were also tested; soil P was not depleted. The grass was then ploughed.In 1968, residual effects were measured by spring wheat. In 1969 and in 1970 104 kg/ha of fresh K was applied on half of each plot; potatoes (1969) and spring wheat (1970) valued residual and fresh effects of K.In 1971 potatoes tested 0, 104 and 208 kg/ha of fresh K, cumulatively with the three amounts given to the grass and also extra K (104 kg/ha) on half-plots, cumulatively with that given in 1969 and 1970. In 1972 winter wheat, and in 1974 and 1975 spring barley, measured residues of all treatments previously applied (the site was fallowed in 1973).Finally, in 1976, potatoes tested 0, 156 and 312 kg/ha of fresh K on whole plots, cumulatively with the previous dressings of K, and also 156 kg/ha of extra K on half-plots, again cumulatively. All these test crops were given basal N.Yields and K contents of wheat at ear emergence and yields of wheat grain were largest after grass given 38 kg N and 62 kg K/ha per cut, because here soil K depletion was least. Wheat grain yields benefited consistently from fresh K. K content of the wheat at ear emergence was a good indicator of the need for K, but K content of grain was not, because it was unaltered by K fertilizer. Barley was a poor test crop for K, because yields of grain were little affected by previous treatments.Percentage K in potato leaves (in July in 1969 and 1971, in August in 1976) and yield of tubers were well correlated. Largest yields in 1969, 1971 and 1976 came where the leaves contained 3·43, 3·76 and 2·82% K, respectively, i.e. from soil containing most exchangeable K, plus most fresh K. There was no indication that maximum yields had been obtained, so the largest amounts (kg/ha) of fresh K tested (104 in 1969, 312 in 1971 and 468 in 1976) were insufficient to counteract depletion of soil K by the grass. Because the grass did not deplete soil P, the test crops benefited only little from either residual or fresh P.

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