Mustard Cover Crop Growth and Weed Suppression in Organic, Strawberry Furrows in California

Strawberry (Fragaria ×ananassa Duch.) production in California uses plastic mulch–covered beds that provide many benefits such as moisture conservation and weed control. Unfortunately, the mulch can also cause environmental problems by increasing runoff and soil erosion and reducing groundwater recharge. Planting cover crops in bare furrows between the plastic cover beds can help minimize these problems. Furrow cover cropping was evaluated during two growing seasons in organic strawberries in Salinas, CA, using a mustard (Sinapis alba L.) cover crop planted at two seeding rates (1× and 3×). Mustard was planted in November or December after strawberry transplanting and it resulted in average densities per meter of furrow of 54 and 162 mustard plants for the 1× and 3× rates, respectively. The mustard was mowed in February before it shaded the strawberry plants. Increasing the seeding rate increased mustard shoot biomass and height, and reduced the concentration of P in the mustard shoots. Compared with furrows with no cover crop, cover-cropped furrows reduced weed biomass by 29% and 40% in the 1× and 3× seeding rates, respectively, although weeds still accounted for at least 28% of the furrow biomass in the cover-cropped furrows. These results show that growing mustard cover crops in furrows without irrigating the furrows worked well even during years with relatively minimal precipitation. We conclude that 1) mustard densities of ≈150 plants/m furrow will likely provide the most benefits due to greater biomass production, N scavenging, and weed suppression; 2) mowing was an effective way to kill the mustard; and 3) high seeding rates of mustard alone are insufficient to provide adequate weed suppression in strawberry furrows.

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

Weed Science ◽

10.1614/ws-d-14-00071.1 ◽

2015 ◽

Vol 63 (1) ◽

pp. 282-295 ◽

Cited By ~ 20

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.

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Effects of Long-Term Cover Cropping on Weed Seedbanks

Frontiers in Agronomy ◽

10.3389/fagro.2020.591091 ◽

2020 ◽

Vol 2 ◽

Author(s):

Virginia Nichols ◽

Lydia English ◽

Sarah Carlson ◽

Stefan Gailans ◽

Matt Liebman

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Production Systems ◽

Early Spring ◽

Weed Suppression ◽

Winter Rye ◽

Maize Crop ◽

Cover Cropping ◽

Crop Biomass

Cool-season cover crops have been shown to reduce soil erosion and nutrient discharge from maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] production systems. However, their effects on long-term weed dynamics are not well-understood. We utilized five long-term research trials in Iowa to quantify germinable weed seedbank densities and compositions after 10+ years of cover cropping treatments. All five trials consisted of zero-tillage maize-soybean rotations managed with and without the inclusion of a yearly winter rye (Secale cereal L.) cover crop. Seedbank sampling was conducted in the early spring before crop planting at all locations, with three of the five trials having grown a soybean crop the preceding year, and two a maize crop. Two of the trials (both previously soybean) showed significant and biologically relevant decreases (4,070 and 927 seeds m−2, respectively) in seedbank densities in cover crop treatments compared to controls. In another two trials, one previously maize and one previously soybean, no difference was detected in seedbank densities. In the fifth trial (previously maize), there was a significant, but biologically unimportant increase of 349 seeds m−2. All five trials' weed communities were dominated by common waterhemp [Amaranthus tuberculatus (Moq.)], and changes in seedbank composition from cover-cropping were driven by changes in this species. Although previous studies have shown that increases in cover crop biomass are strongly correlated with weed suppression, in our study we did not find a relationship between seedbank changes and the mean amount of cover crop biomass produced over a 10-years period (experiment means ranging from 0.5 to 2.0 Mg ha−1 yr−1), the stability of the cover crop biomass production, nor the amount produced going into the previous crop's growing season. We conclude that long-term use of a winter rye cover crop in a maize-soybean system has the potential to meaningfully reduce the size of weed seedbanks compared to winter fallows. However, identifying the mechanisms by which this occurs requires further research into processes such as seed predation and seed decay in cover cropped systems.

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Weed suppression and early sugar beet development under different cover crop mulches

Plant Protection Science ◽

10.17221/109/2016-pps ◽

2017 ◽

Vol 53 (No. 3) ◽

pp. 187-193 ◽

Cited By ~ 2

Author(s):

Kunz Christoph ◽

Sturm Dominic J ◽

Sökefeld Markus ◽

Gerhards Roland

Keyword(s):

Sugar Beet ◽

Cover Crops ◽

Cover Crop ◽

Raphanus Sativus ◽

Field Experiments ◽

Chenopodium Album ◽

Sinapis Alba ◽

Weed Suppression ◽

Vicia Sativa ◽

Stellaria Media

Field experiments were conducted at two locations in 2014–2015 and 2015–2016 to investigate the weed suppressive ability of cover crop mulches in sugar beets. Three cover crops and two cover crop mixtures were tested in all four experiments. Weed densities ranged from 2 up to 210 plants/m<sup>2</sup> in Chenopodium album L. and Stellaria media (L.) Vill. as predominant species. Sinapis alba grew significantly faster than Vicia sativa, Raphanus sativus var. niger, and both cover crop mixtures. Sinapis alba, Vicia sativa, Raphanus sativus var. niger reduced weed density by 57, 22, and 15% across all locations, respectively. A mixture of seven different cover crops reduced weed emergence by 64% compared to the control plot without cover crop mulch. Early sugar beet growth was enhanced by all mulch treatments in 2015 and decelerated in 2016.

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Developing Cover Crops for Weed Control in Establishment Year for Strawberries

HortScience ◽

10.21273/hortsci.30.4.820a ◽

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.

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183 Influence of Cover Crops on Weed Control and Plant Growth in Strawberry (Fragaria × ananassa Duch.)

HortScience ◽

10.21273/hortsci.34.3.473e ◽

1999 ◽

Vol 34 (3) ◽

pp. 473E-473

Author(s):

Braja B. Datta ◽

Ray D William

Keyword(s):

Plant Growth ◽

Cover Crops ◽

Cover Crop ◽

Crop Residues ◽

Weed Suppression ◽

Root Competition ◽

Control Treatment ◽

Shoot Biomass ◽

Yield Reduction ◽

Weed Biomass

Fall-planted cover crops killed in spring is practiced in strawberry cultivation in different regions of the North America. These systems have shown significant weed suppression and conservation of soil without significant yield reduction in strawberry. During the establishment season, this study was initiated to assess weed suppression with cover crops (`Wheeler' rye and `Micah' and `Steptoe' barley) along with perlite, an artificial plant medium. Strawberry (`Selva' and `Totem') plant growth and weed biomass were measured during 1995-96 season. Small-seeded summer annual weeds were suppressed in cover crop treatments compared to control treatment. `Micah' barley in growth phase suppressed more than 81% of the total weed biomass compared to control plots with no cover crop in early spring. However, in early summer, cover crop residues failed to suppress different types of weeds 60 days after killing of cereal with herbicide (2% glyphosate). Distinct differences in strawberry plant growth were evident between the cover crop treatments and non-cover crop treatments including `Micah' applied on surface. Strawberry growth was doubled during 10 July to 15 Aug. in both cultivars. `Micah' barley applied on surface produced better growth in both strawberry varieties than the growth in other treatments. `Micah' barley applied on soil surface produced 50% more strawberry shoot biomass may indicate the root competition between cover crops and strawberry.

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Relay-cropping and Fallow Programs for Strawberry-based Production System: Effects on Crop Productivity and Weed Control

HortScience ◽

10.21273/hortsci12658-17 ◽

2018 ◽

Vol 53 (4) ◽

pp. 445-450 ◽

Cited By ~ 8

Author(s):

Jialin Yu ◽

Nathan S. Boyd ◽

Zhengfei Guan

Keyword(s):

Cover Crop ◽

Field Experiments ◽

Weed Suppression ◽

Growth And Yield ◽

Plastic Mulch ◽

Weed Density ◽

Growing Seasons ◽

Relay Cropping ◽

Chemical Fallow ◽

Summer Fallow

Many strawberry growers in Florida relay crop vegetables with strawberries or grow multiple crops on the same plastic mulch. The practice can reduce the overall input costs per crop but weed management can be problematic. Field experiments designed as a split plot were conducted in Balm and Dover, FL over two successive strawberry-growing seasons from Oct. 2014 to Mar. 2015 (year 1) and Oct. 2015 to Mar. 2016 (year 2) and two successive muskmelon-growing seasons from March to July 2015 (year 1) and March to July 2016 (year 2). The objectives were to examine the effect of summer fallow programs and the presence or absence of a relay-crop on weed density and strawberry (Fragaria ×ananassa Duchesne) and muskmelon (Cucumis melo L.) yields. Summer fallow programs included leaving the plastic mulch in place and reusing it in year 2, a sunn hemp (Crotalaria juncea L.) cover crop, or a conventional chemical fallow. Relay cropping muskmelon with strawberries had no effect on strawberry yield. Summer fallow programs had no effect on muskmelon growth and yield in Balm and Dover, as well as strawberry growth and yield in Balm. In Dover, the plastic mulch summer fallow had 22% to 34% lower berry yield in year 2 compared with cover crop and chemical fallow, respectively. In year 2, relay-cropping was more effective in reducing total weed density compared with strawberry monoculture in Dover but not in Balm. In year 2 in Dover, averaged overall summer fallow programs, the total weed density was ≈3-fold less in relay-cropping than strawberry monoculture. Of all the summer fallow programs evaluated, leaving the plastic mulch in place combined with glyphosate was the most effective summer fallow program, whereas the conventional chemical fallow was the least effective at weed suppression. We conclude that relay cropping or double use of plastic mulch for successive strawberry crops are viable options for Florida strawberry growers.

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Are cover crop mixtures better at suppressing weeds than cover crop monocultures?

Weed Science ◽

10.1017/wsc.2020.12 ◽

2020 ◽

Vol 68 (2) ◽

pp. 186-194 ◽

Cited By ~ 6

Author(s):

Richard G. Smith ◽

Nicholas D. Warren ◽

Stéphane Cordeau

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Raphanus Sativus ◽

Weed Suppression ◽

Temporal Niche ◽

Cover Cropping ◽

Stable Mixture ◽

Species Mixtures ◽

Spring Planting

AbstractCover crops are increasingly being used for weed management, and planting them as diverse mixtures has become an increasingly popular strategy for their implementation. While ecological theory suggests that cover crop mixtures should be more weed suppressive than cover crop monocultures, few experiments have explicitly tested this for more than a single temporal niche. We assessed the effects of cover crop mixtures (5- or 6-species and 14-species mixtures) and monocultures on weed abundance (weed biomass) and weed suppression at the time of cover crop termination. Separate experiments were conducted in Madbury, NH, from 2014 to 2017 for each of three temporal cover-cropping niches: summer (spring planting–summer termination), fall (summer planting–fall termination), and spring (fall planting–subsequent spring termination). Regardless of temporal niche, mixtures were never more weed suppressive than the most weed-suppressive cover crop grown as a monoculture, and the more diverse mixture (14 species) never outperformed the less diverse mixture. Mean weed-suppression levels of the best-performing monocultures in each temporal niche ranged from 97% to 98% for buckwheat (Fagopyrum esculentum Moench) in the summer niche and forage radish (Raphanus sativus L. var. niger J. Kern.) in the fall niche, and 83% to 100% for triticale (×Triticosecale Wittm. ex A. Camus [Secale × Triticum]) in the winter–spring niche. In comparison, weed-suppression levels for the mixtures ranged from 66% to 97%, 70% to 90%, and 67% to 99% in the summer, fall, and spring niches, respectively. Stability of weed suppression, measured as the coefficient of variation, was two to six times greater in the best-performing monoculture compared with the most stable mixture, depending on the temporal niche. Results of this study suggest that when weed suppression is the sole objective, farmers are more likely to achieve better results planting the most weed-suppressive cover crop as a monoculture than a mixture.

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Buckwheat Species as Summer Cover Crops for Weed Suppression in No-Tillage Vegetable Cropping Systems

Weed Science ◽

10.1614/ws-d-14-00088.1 ◽

2015 ◽

Vol 63 (3) ◽

pp. 690-702 ◽

Cited By ~ 7

Author(s):

Mary T. Saunders Bulan ◽

David E. Stoltenberg ◽

Joshua L. Posner

Keyword(s):

Cover Crops ◽

Soil Compaction ◽

Cover Crop ◽

Nitrogen Availability ◽

Conventional Tillage ◽

Weed Suppression ◽

Tartary Buckwheat ◽

Shoot Biomass ◽

N Availability ◽

No Tillage

Buckwheat is a broadleaved annual species that is often used as a summer cover crop for its quick growth, weed suppressive ability, and ease of management. Tartary buckwheat is a species related to buckwheat, with many of the same traits valued in buckwheat as a cover crop. However, Tartary buckwheat has been reported to grow more vigorously than buckwheat, especially in cool conditions, which might fill a unique niche for vegetable farmers in Wisconsin and other northcentral states. Our research objectives were to determine the effectiveness of Tartary buckwheat relative to buckwheat for weed suppression, both during the cover-cropping phase and after cover-crop termination during cabbage production, and quantify weed suppression, soil compaction, soil nitrogen availability, and cabbage yield in no-tillage (roller-crimped or sickle-bar mowed) and conventional-tillage (rototilled) systems. Across three site-years, we found that buckwheat emerged earlier and produced 64% more shoot dry biomass than Tartary buckwheat. Pretermination weed shoot biomass (predominantlyAmaranthusandSetariaspp.) in Tartary buckwheat treatments was approximately twice that of buckwheat, and did not differ from weed shoot biomass in a control fallow treatment. Cabbage yield did not differ between cover crop species nor did yield differ between conventional-tillage cover cropped and control fallow treatments. However, weed biomass was greater, and cabbage yield was reduced, in no-tillage compared to conventional-tillage treatments. We also found evidence of greater soil compaction and less nitrate–nitrogen (NO3–N) availability in no-tillage than conventional-tillage treatments. These results suggest that Tartary buckwheat is not a suitable summer cover crop alternative to buckwheat for weed suppression prior to cabbage production.

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008 Evaluation of Weed Control in a No-tillage Vegetable Production System

HortScience ◽

10.21273/hortsci.34.3.442b ◽

1999 ◽

Vol 34 (3) ◽

pp. 442B-442

Author(s):

Christine Crosby ◽

Hector Valenzuela ◽

Bernard Kratky ◽

Carl Evensen

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Weed Suppression ◽

Grass Species ◽

No Tillage ◽

Vegetable Crops ◽

Seeding Rate ◽

Crop Species ◽

Weed Growth

In the tropics, weed control is a year-round concern. The use of cover crops in a conservation tillage system allows for the production of a crop biomass that can be killed and mowed, and later used as mulching material to help reduce weed growth. This study compared yields of three vegetable species grown in two conventional tillage systems, one weeded and one unweeded control, and in two no-tillage treatments using two different cover crop species, oats (Avena sativa L. `Cauyse') and rye grain (Secale cereale L.). The cover crops were seeded (112 kg/ha) in Spring 1998 in 4 × 23-m plots in a RCB design with six replications per treatment, and mowed down at the flowering stage before transplanting the seedlings. Data collection throughout the experimental period included quadrant weed counts, biomass levels, and crop marketable yields. Weed suppression was compared with the yields of the vegetable crops. The greatest vegetable yields were in the conventionally hand-weeded control and the worst in the un-weeded controls. Weed species composition varied depending on the cover crop species treatment. The rye better suppressed weed growth than the oats, with greater control of grass species. Rye, however, suppressed romaine and bell pepper yields more than the oat treatments. Similarly greater eggplant yields and more fruit per plant were found in the oat treatment than in the rye. Both cover crops suppressed weed growth for the first month; however, by the second month most plots had extensive weed growth. This study showed that at the given cover crop seeding rate, the mulch produced was not enough to reduce weed growth and provide acceptable yields of various vegetable crops.

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Suitability of peanut residue as a nitrogen source for a rye cover crop

Scientia Agricola ◽

10.1590/s0103-90162007000200012 ◽

2007 ◽

Vol 64 (2) ◽

pp. 181-186 ◽

Cited By ~ 9

Author(s):

Kipling Shane Balkcom ◽

Charles Wesley Wood ◽

James Fredrick Adams ◽

Bernard Meso

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Sandy Loam ◽

Soil Surface ◽

N Application ◽

Growing Seasons ◽

Application Rates ◽

Arachis Hypogaea L ◽

Secale Cereale L ◽

Biomass Yields

Leguminous winter cover crops have been utilized in conservation systems to partially meet nitrogen (N) requirements of succeeding summer cash crops, but the potential of summer legumes to reduce N requirements of a winter annual grass, used as a cover crop, has not been extensively examined. This study assessed the N contribution of peanut (Arachis hypogaea L.) residues to a subsequent rye (Secale cereale L.) cover crop grown in a conservation system on a Dothan sandy loam (fine-loamy, kaolinitic, thermic Plinthic Kandiudults) at Headland, AL USA during the 2003-2005 growing seasons. Treatments were arranged in a split plot design, with main plots of peanut residue retained or removed from the soil surface, and subplots as N application rates (0, 34, 67 and 101 kg ha-1) applied in the fall. Peanut residue had minimal to no effect on rye biomass yields, N content, carbon (C) /N ratio, or N, P, K, Ca and Zn uptake. Additional N increased rye biomass yield, and N, P, K, Ca, and Zn uptakes. Peanut residue does not contribute significant amounts of N to a rye cover crop grown as part of a conservation system, but retaining peanut residue on the soil surface could protect the soil from erosion early in the fall and winter before a rye cover crop grows sufficiently to protect the typically degraded southeastern USA soils.

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