(14) Establishment of Buckwheat as a Summer Cover Crop after Early Vegetables

Buckwheat has historically been used to suppress weeds and improve soil condition, but many of the tricks to success have been lost to history. Buckwheat is inexpensive and particularly effective in short windows between crops. We are documenting the techniques of existing experts and complementing that with research. We surveyed northeastern vegetable and strawberry growers to identify what information they need in order to feel confident that they could succeed with a buckwheat cover crop. Top questions include seed availability, types of weeds controlled, relation to other cover crops, volunteer management, and herbicide tolerance. One question tested experimentally was how to establish a full stand with minimum cost. We tested the minimum tillage requirement following pea harvest. No-till resulted in good emergence but slow growth, and dominance by weeds. Disk incorporating the pea residue resulted in excellent growth, which was not further enhanced by chisel plowing before disking. Buckwheat seedlings are intolerant of waterlogging, so deeper tillage may be important in wet years. Sowing buckwheat immediately after tillage resulted in emergence of 35%, leaving gaps large enough for weeds to grow. Waiting 1 week gave an 80% stand and complete weed suppression. Waiting 2 weeks also gave an 80% stand, but weed growth was advanced enough that weed suppression was incomplete. Therefore, a buckwheat cover crop following early vegetables requires light tillage to permit root growth, and up to a week of decomposition. If those provisions are made, complete weed suppression is obtainable.

Download Full-text

Investigating tarps to facilitate organic no-till cabbage production with high-residue cover crops

Renewable Agriculture and Food Systems ◽

10.1017/s1742170518000509 ◽

2018 ◽

Vol 35 (3) ◽

pp. 227-233 ◽

Cited By ~ 1

Author(s):

Natalie P Lounsbury ◽

Nicholas D Warren ◽

Seamus D Wolfe ◽

Richard G Smith

Keyword(s):

Biological Activity ◽

Soil Temperature ◽

Biomass Production ◽

Nutrient Availability ◽

Cover Crops ◽

Cover Crop ◽

Weed Suppression ◽

Winter Rye ◽

No Till ◽

Crop Biomass

AbstractHigh-residue cover crops can facilitate organic no-till vegetable production when cover crop biomass production is sufficient to suppress weeds (>8000 kg ha−1), and cash crop growth is not limited by soil temperature, nutrient availability, or cover crop regrowth. In cool climates, however, both cover crop biomass production and soil temperature can be limiting for organic no-till. In addition, successful termination of cover crops can be a challenge, particularly when cover crops are grown as mixtures. We tested whether reusable plastic tarps, an increasingly popular tool for small-scale vegetable farmers, could be used to augment organic no-till cover crop termination and weed suppression. We no-till transplanted cabbage into a winter rye (Secale cereale L.)-hairy vetch (Vicia villosa Roth) cover crop mulch that was terminated with either a roller-crimper alone or a roller-crimper plus black or clear tarps. Tarps were applied for durations of 2, 4 and 5 weeks. Across tarp durations, black tarps increased the mean cabbage head weight by 58% compared with the no tarp treatment. This was likely due to a combination of improved weed suppression and nutrient availability. Although soil nutrients and biological activity were not directly measured, remaining cover crop mulch in the black tarp treatments was reduced by more than 1100 kg ha−1 when tarps were removed compared with clear and no tarp treatments. We interpret this as an indirect measurement of biological activity perhaps accelerated by lower daily soil temperature fluctuations and more constant volumetric water content under black tarps. The edges of both tarp types were held down, rather than buried, but moisture losses from the clear tarps were greater and this may have affected the efficacy of clear tarps. Plastic tarps effectively killed the vetch cover crop, whereas it readily regrew in the crimped but uncovered plots. However, emergence of large and smooth crabgrass (Digitaria spp.) appeared to be enhanced in the clear tarp treatment. Although this experiment was limited to a single site-year in New Hampshire, it shows that use of black tarps can overcome some of the obstacles to implementing cover crop-based no-till vegetable productions in northern climates.

Download Full-text

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

Canadian Journal of Plant Science ◽

10.4141/p99-099 ◽

2000 ◽

Vol 80 (2) ◽

pp. 441-449 ◽

Cited By ~ 19

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

Download Full-text

Evaluating Cover Crop Mulches for No-till Organic Production of Onions

HortScience ◽

10.21273/hortsci.45.1.61 ◽

2010 ◽

Vol 45 (1) ◽

pp. 61-70 ◽

Cited By ~ 11

Author(s):

Emily R. Vollmer ◽

Nancy Creamer ◽

Chris Reberg-Horton ◽

Greg Hoyt

Keyword(s):

Soybean Meal ◽

Cover Crops ◽

Cover Crop ◽

N Uptake ◽

Organic Production ◽

Weed Suppression ◽

Soil Mineral N ◽

Soil Mineral ◽

Mineral N ◽

No Till

Cover crops of foxtail millet ‘German Strain R’ [Setaria italica (L.) Beauv.] and cowpea ‘Iron & Clay’ [Vigna unguiculata (L.) Walp.] were grown as monocrops (MIL, COW) and mixtures and compared with a bare ground control (BG) for weed suppression and nitrogen (N) contribution when followed by organically managed no-till bulb onion (Allium cepa L.) production. Experiments in 2006–2007 and 2007–2008 were each conducted on first-year transitional land. Mixtures consisted of cowpea with high, middle, and low seeding rates of millet (MIX-70, MIX-50, MIX-30). During onion production, each cover crop treatment had three N rate subplots (0, 105, and 210 kg N/ha) of surface-applied soybean meal [Glycine max (L.) Merrill]. Cover crop treatments COW and BG had the greatest total marketable onion yield both years. Where supplemental baled millet was applied in 2006–2007, onion mortality was over 50% in MIL and MIX and was attributed to the thickness of the millet mulch. Nitrogen rates of 105 and 210 kg N/ha increased soil mineral N (NO3– and NH4+) on BG plots 2 weeks after surface application of soybean meal each year, but stopped having an effect on soil mineral N by February or March. Split applications of soybean meal could be an important improvement in N management to better meet increased demand for N uptake during bulb initiation and growth in the spring.

Download Full-text

Weed Control and Sweet Corn (Zea maysvar.rugosa) Response in a No-till System with Cover Crops

Weed Science ◽

10.1017/s0043174500094005 ◽

1996 ◽

Vol 44 (2) ◽

pp. 355-361 ◽

Cited By ~ 50

Author(s):

Nilda R. Burgos ◽

Ronald E. Talbert

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Sweet Corn ◽

Weed Suppression ◽

Growth And Yield ◽

Hairy Vetch ◽

Yellow Nutsedge ◽

No Till ◽

Agricultural Experiment ◽

And Control

Studies were conducted at the Main Agricultural Experiment Station in Fayetteville and the Vegetable Substation in Kibler, Arkansas, in 1992 and 1993 on the same plots to evaluate weed suppression by winter cover crops alone or in combination with reduced herbicide rates in no-till sweet corn and to evaluate cover crop effects on growth and yield of sweet corn. Plots seeded to rye plus hairy vetch, rye, or wheat had at least 50% fewer early season weeds than hairy vetch alone or no cover crop. None of the cover crops reduced population of yellow nutsedge. Without herbicides, hairy vetch did not suppress weeds 8 wk after cover crop desiccation. Half rates of atrazine and metolachlor (1.1 + 1.1 kg ai ha−1) reduced total weed density more effectively in no cover crop than in hairy vetch. Half rates of atrazine and metolachlor controlled redroot pigweed, Palmer amaranth, and goosegrass regardless of cover crop. Full rates of atrazine and metolachlor (2.2 + 2.2 kg ai ha−1) were needed to control large crabgrass in hairy vetch. Control of yellow nutsedge in hairy vetch was marginal even with full herbicide rates. Yellow nutsedge population increased and control with herbicides declined the second year, particularly with half rates of atrazine and metolachlor. All cover crops except hairy vetch alone reduced emergence, height, and yield of sweet corn. Sweet corn yields from half rates of atrazine and metolachlor equalled the full rates regardless of cover crops.

Download Full-text

Weed suppression and soybean yield in a no-till cover-crop mulched system as influenced by six rye cultivars

Renewable Agriculture and Food Systems ◽

10.1017/s1742170515000344 ◽

2015 ◽

Vol 31 (5) ◽

pp. 429-440 ◽

Cited By ~ 16

Author(s):

M. Scott Wells ◽

Carrie M. Brinton ◽

S. Chris Reberg-Horton

Keyword(s):

Biomass Production ◽

Cover Crops ◽

Cover Crop ◽

Weed Suppression ◽

Early Flowering ◽

Planting Dates ◽

Soybean Yield ◽

Late Flowering ◽

No Till ◽

Termination Date

AbstractCover crop mulches have been successful in reducing weed severity in organic soybeans. This study examined six rye cultivars (SRCs) used as cover crops to determine which were most adapted for use with a roller–crimper in the southeastern U.S. To be an effective mulch, a rye cultivar must produce high biomass and reach reproductive growth stage to facilitate mechanical termination via the roller–crimper prior to soybean planting. Rye cultivars were planted at three locations in North Carolina over the 2009 and 2010 growing seasons. Each rye cultivar was mechanically terminated via a roller–crimper implement. Rye cover crops were terminated on two dates and soybeans were immediately no-till planted into the mulch. In 2009, all rye cultivars produced greater than 9000 kg ha−1 rye biomass dry matter (DM) with the exception of Rymin at Plymouth (2009), but in 2010 only the early flowering cultivars produced in excess of 9000 kg ha−1 DM. There were no detectable soybean yield differences between the SRCs and the weed-free checks, and weed control was excellent across all SRCs at both Plymouth and Salisbury (2009). After an unseasonably cold and wet winter in 2010, the late flowering rye cultivars were not fully controlled by the early termination date due to delayed maturation (less than 65% control at 2 WAP) whereas the early flowering cultivars were fully controlled (100% control at 2 WAP). Rye biomass production was below 9000 kg ha−1 DM for the late flowering and dough development rye cultivars. The early-terminated rye plots had greater weed coverage across all SRCs than those from the late termination date (P < 0.01). However, weeds did not impact soybean yield for either of the termination dates. Soybean yield in 2010 was modeled with rye biomass and soybean population used as covariates, and for both termination dates, soybean yield was proportional to rye biomass production. Early flowering rye cultivars offer producers the widest range of termination opportunities that best coincide with their cash crop planting dates.

Download Full-text

Integration of cover crops with postemergence herbicides in no-till corn and soybean

Weed Science ◽

10.1614/p2002-062 ◽

2003 ◽

Vol 51 (6) ◽

pp. 995-1001 ◽

Cited By ~ 16

Author(s):

Robert S. Gallagher ◽

John Cardina ◽

Mark Loux

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Crop Productivity ◽

Weed Suppression ◽

Hairy Vetch ◽

Grain Yields ◽

No Till ◽

Full Rate ◽

Postemergence Herbicides ◽

Corn Grain

The integration of cover crops with selected postemergence herbicides was evaluated on the basis of weed control and grain yields in no-till soybean and corn. Soybean was planted into wheat residue, whereas corn was planted into hairy vetch residue. Full, half, and quarter rates and sequential herbicide applications were made. The wheat cover crop did not increase weed suppression but increased soybean grain yields. Half rates of thifensulfuron plus quizalofop-P as single or split applications were as effective as full rates in reducing weed weight in soybean. Soybean grain yields were similar in the half- and full-rate treatments in 1994, but yield was highest in the full-rate treatment in 1995. The hairy vetch cover crop did not increase weed suppression but lowered corn stands and grain yields in 1995 and enhanced corn grain yields in 1996. Full, half, and quarter rates (1996 only) of nicosulfuron plus primisulfuron were equally effective in reducing weed weight. Corn grain yields were similar at all herbicide rates in 1995 but were inversely related to herbicide rate in 1996. Split herbicide applications did not improve weed suppression over single applications of the same herbicide rate in either crop. Results indicate that cover crops can improve crop productivity and reduced rates of environmentally benign herbicides can minimize the herbicide requirements in no-till corn and soybean.

Download Full-text

Weed Control by Spring Cover Crops and Imazethapyr in No-till Southern Pea (Vigna unguiculata)

Weed Technology ◽

10.1017/s0890037x00040987 ◽

1996 ◽

Vol 10 (4) ◽

pp. 893-899 ◽

Cited By ~ 16

Author(s):

Nilda R. Burgos ◽

Ronald E. Talbert

Keyword(s):

Weed Control ◽

Cover Crops ◽

Cover Crop ◽

Palmer Amaranth ◽

Weed Suppression ◽

Italian Ryegrass ◽

No Till ◽

Sorghum Sudangrass ◽

Reduced Rate ◽

Large Crabgrass

Studies were conducted at the Vegetable Substation in Kibler, AR, in 1992 and 1993, in the same plots, to evaluate weed suppression by spring-seeded cover crops and to determine the effects of cover crop and imazethapyr on no-till southern pea. A plot without cover, conventionally tilled before planting southern pea, served as control. Weed control treatments, applied as subplots in each cover crop, included a weedy check, handweeded check, and half and full rates of imazethapyr (0.035 and 0.07 kg/ha) followed by sethoxydim (0.22 kg/ha). Biomass of Palmer amaranth 6 WAR without herbicides, was less in Italian ryegrass and sorghum-sudangrass residues than in oat residue and no cover crop. Over the years, Palmer amaranth density increased 333% without cover crops and 28% with cover crops. Rice flatsedge density increased four to five times in oat and sorghum-sudangrass residues but remained the same in Italian ryegrass residue. In general, Italian ryegrass residue suppressed the most weeds. Oat residue was least suppressive. Italian ryegrass and sorghum-sudangrass also reduced southern pea stand. Regardless of cover crop and year, half and full rates of imazethapyr followed by sethoxydim equally reduced density of Palmer amaranth, goosegrass, large crabgrass, southwestern cupgrass, and rice flatsedge compared with the untreated check. Residual control of Palmer amaranth by imazethapyr was higher at the full rate than the reduced rate, regardless of cover crop. Half rate of imazethapyr followed by sethoxydim controlled 94 to 100% of Palmer amaranth, rice flatsedge, large crabgrass, and southwestern cupgrass late in the season, regardless of cover crop in 1992 and 1993. Southern pea yield in untilled plots with cover crops was two to three times lower than yield in plots with preplant tillage and no cover crops mostly because of reduction in crop stand in the presence of cover crops.

Download Full-text

Rolled Mixtures of Barley and Cereal Rye for Weed Suppression in Cover Crop–based Organic No-Till Planted Soybean

Weed Science ◽

10.1017/wsc.2016.23 ◽

2017 ◽

Vol 65 (3) ◽

pp. 426-439 ◽

Cited By ~ 10

Author(s):

Jeffrey A. Liebert ◽

Antonio DiTommaso ◽

Matthew R. Ryan

Keyword(s):

Cover Crops ◽

Cover Crop ◽

Block Design ◽

Weed Suppression ◽

Management Tool ◽

Weed Biomass ◽

Cereal Rye ◽

No Till ◽

Lower Cover ◽

Crop Biomass

Maximizing cereal rye biomass has been recommended for weed suppression in cover crop–based organic no-till planted soybean; however, achieving high biomass can be challenging, and thick mulch can interfere with soybean seed placement. An experiment was conducted from 2012 to 2014 in New York to test whether mixing barley and cereal rye would (1) increase weed suppression via enhanced shading prior to termination and (2) provide acceptable weed suppression at lower cover crop biomass levels compared with cereal rye alone. This experiment was also designed to assess high-residue cultivation as a supplemental weed management tool. Barley and cereal rye were seeded in a replacement series, and a split-block design with four replications was used with management treatments as main plots and cover crop seeding ratio treatments (barley:cereal rye, 0:100, 50:50, and 100:0) as subplots. Management treatments included high-residue cultivation and standard no-till management without high-residue cultivation. Despite wider leaves in barley, mixing the species did not increase shading, and cereal rye dominated cover crop biomass in the 50:50 mixtures in 2013 and 2014, representing 82 and 93% of the biomass, respectively. Across all treatments, average weed biomass (primarily common ragweed, giant foxtail, and yellow foxtail) in late summer ranged from 0.5 to 1.1 Mg ha−1in 2013 and 0.6 to 1.3 Mg ha−1in 2014, and weed biomass tended to decrease as the proportion of cereal rye, and thus total cover crop biomass, increased. However, soybean population also decreased by 29,100 plants ha−1for every 1 Mg ha−1increase in cover crop biomass in 2013 (P=0.05). There was no relationship between cover crop biomass and soybean population in 2014 (P=0.35). Soybean yield under no-till management averaged 2.9 Mg ha−1in 2013 and 2.6 Mg ha−1in 2014 and was not affected by cover crop ratio or management treatment. Partial correlation analyses demonstrated that shading from cover crops prior to termination explained more variation in weed biomass than cover crop biomass. Our results indicate that cover crop management practices that enhance shading at slightly lower cover crop biomass levels might reduce the challenges associated with excessive biomass production without sacrificing weed suppression in organic no-till planted soybean.

Download Full-text

Use of Cover Crop Mulches in a No-till Furrow-irrigated Processing Tomato Production System

HortTechnology ◽

10.21273/horttech.11.1.43 ◽

2001 ◽

Vol 11 (1) ◽

pp. 43-48 ◽

Cited By ~ 21

Author(s):

E.V. Herrero ◽

J.P. Mitchell ◽

W.T. Lanini ◽

S.R. Temple ◽

E.M. Miyao ◽

...

Keyword(s):

Cover Crops ◽

Cover Crop ◽

N Fertilization ◽

Weed Suppression ◽

Tomato Production ◽

Tomato Seedlings ◽

Processing Tomato ◽

No Till ◽

Medicago Scutellata ◽

Legume Cover Crop

No-till processing tomato (Lycopersicum esculentum Mill.) production in four winter cover crop-derived mulches was evaluated in 1997 and 1998 in Five Points, Calif. The effectiveness of two medics, `Sava' snail medic (Medicago scutellata Mill.) (sava), and `Sephi' barrel medic (Medicago truncatula Gaertn.) (sephi), and two cereal/legume cover crop mixtures, triticale/`Lana' woolypod vetch (X Triticosecale Wittm./Vicia dasycarpa Ten.) (triticale/vetch) and rye/`Lana' woolypod vetch (Secale cereale L./V. dasycarpa) (rye/vetch), was compared with two conventionally tilled fallow controls (with and without herbicide) (fallow+h and fallow-h) in suppressing weeds and maintaining yields with reduced fertilizer inputs. The comparison was conducted as a split plot, with three N fertilization rates (0, 100, and 200 lb/acre; 0, 112, and 224 kg·ha-1) as main plots and cover crops and fallow controls as subplots. Tomato seedlings were transplanted 3 weeks after the cover crops had been mowed and sprayed with herbicide. There were no significant differences in weed cover in the no-till cover crop treatments relative to the fallow controls in 1997. Early season weed suppression in rye/vetch and triticale/vetch plots was similar to herbicide-treated fallow (fallow+h) in 1998, however, later in the 1998 season weed suppression was best in the fallow+h. Tissue N was highest in the fallow treatments in both 1997 and 1998. Yields were highest in the triticale/vetch and fallow and lowest in sephi treatments in 1997, but there were no differences among treatments in 1998. These results demonstrate the feasibility of no-till mulch production of furrow irrigated processing tomatoes and identify opportunities for further optimization of the system.

Download Full-text

Cover Crop and Herbicide Influence on Row Crop Seedling Establishment in No-Tillage Culture

Weed Science ◽

10.1017/s0043174500056320 ◽

1990 ◽

Vol 38 (2) ◽

pp. 166-171 ◽

Cited By ~ 44

Author(s):

Leslie A. Weston

Keyword(s):

Cover Crops ◽

Tall Fescue ◽

Cover Crop ◽

Weed Suppression ◽

Pasture Grass ◽

Red Fescue ◽

Crop Establishment ◽

Weed Growth ◽

Row Crop ◽

Cereal Grain

The establishment and management of nine cover crops in Kentucky production systems were evaluated in field experiments over a 2-yr period. ‘Wheeler’ rye, ‘Barsoy’ barley, and ‘Tyler’ wheat cereal grains produced greater biomass (180 to 260 g/m2) than the pasture species tall fescue, creeping red fescue, and white clover (55 to 110 g/m2). ‘Kentucky 31’ tall fescue, creeping red fescue, and white clover proved most difficult to control, and significant regrowth occurred regardless of herbicide or rate applied. HOE-39866 (1.7 kg ai/ha) was effective in rapidly controlling all cover crops except tall fescue by 30 days after application. Sethoxydim and fluazifop (0.4 and 0.3 kg ai/ha, respectively) effectively controlled the cereals and two ryegrass species. Glyphosate applied at 1.1 and 2.2 kg ai/ha was also effective, while 0.6 kg ai/ha controlled only cereal grain growth adequately. After chemical control, pasture grass plots contained fewest weeds/m2with some reductions likely due to density and regrowth of the sods. Cover crops were effective in suppressing weed growth at 45 days after chemical control. However, significant weed growth existed in all cover crop plots by 60 days after kill. Row crop establishment increased linearly with increasing glyphosate rate. Cereal grain covers provided the most compatible planting situations for greatest seedling establishment, with rye and wheat providing greatest weed suppression. Generally, increased weed suppression provided by a cover crop was accompanied by reduced row crop establishment, with greatest reductions observed in pasture grass plots. Cucumber was most easily established while snap pea was most difficult.

Download Full-text