Integrated Weed Management Strategies in Cover Crop–based, Organic Rotational No-Till Corn and Soybean in the Mid-Atlantic Region

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 94-108 ◽  
Author(s):  
John M. Wallace ◽  
Clair L. Keene ◽  
William Curran ◽  
Steven Mirsky ◽  
Matthew R. Ryan ◽  
...  

Cover crop–based, organic rotational no-till (CCORNT) corn and soybean systems have been developed in the mid-Atlantic region to build soil health, increase management flexibility, and reduce labor. In this system, a roller-crimped cover crop mulch provides within-season weed suppression in no-till corn and soybean. A cropping system experiment was conducted in Pennsylvania, Maryland, and Delaware to test the cumulative effects of a multitactic weed management approach in a 3-yr hairy vetch/triticale–corn–cereal rye–soybean–winter wheat CCORNT rotation. Treatments included delayed planting dates (early, intermediate, late) and supplemental weed control using high-residue (HR) cultivation in no-till corn and soybean phases. In the no-till corn phase, HR cultivation decreased weed biomass relative to the uncultivated control by 58%, 23%, and 62% in Delaware, Maryland, and Pennsylvania, respectively. In the no-till soybean phase, HR cultivation decreased weed biomass relative to the uncultivated treatment planted in narrow rows (19 to 38 cm) by 20%, 41%, and 78% in Delaware, Maryland, and Pennsylvania, respectively. Common ragweed was more dominant in soybean (39% of total biomass) compared with corn (10% of total biomass), whereas giant foxtail and smooth pigweed were more dominant in corn, comprising 46% and 22% of total biomass, respectively. Common ragweed became less abundant as corn and soybean planting dates were delayed, whereas giant foxtail and smooth pigweed increased as a percentage of total biomass as planting dates were delayed. At the Pennsylvania location, inconsistent termination of cover crops with the roller-crimper resulted in volunteer cover crops in other phases of the rotation. Our results indicate that HR cultivation is necessary to achieve adequate weed control in CCORNT systems. Integration of winter grain or perennial forages into CCORNT systems will also be an important management tactic for truncating weed seedbank population increases.

Weed Science ◽  
2012 ◽  
Vol 60 (4) ◽  
pp. 624-633 ◽  
Author(s):  
Eric A. Nord ◽  
Matthew R. Ryan ◽  
William S. Curran ◽  
David A. Mortensen ◽  
Steven B. Mirsky

Knowledge of weed emergence periodicity can inform the timing and choice of weed management tactics. We tested the effects of weed management system (conventional [CNV] and herbicide-free [HF]), timing of rye sowing (two dates), timing of soybean planting (5 planting dates, 3 in each system), and supplemental control (with and without) on weed suppression and weed community composition in soybean no-till planted into a cereal rye cover crop. Cereal rye was terminated with a roller-crimper and herbicide (CNV) or with a roller-crimper alone (HF), and supplemental weed control was achieved with a postemergence glyphosate application (CNV) or with interrow high-residue cultivation (HF). Supplemental control with glyphosate in CNV was more effective than high-residue cultivation in HF. When soybean was planted on the same date, CNV resulted in less weed biomass and a more even community composition, whereas HF resulted in greater weed biomass, dominated by common ragweed. When we controlled for cereal rye biomass and compared the effects of cereal rye sowing and termination timing within each system, earlier management reduced weed biomass in HF, but tended to increase weed biomass in CNV. Our results suggest the ability to control emerged weeds prior to soybean planting is an important factor that influences the optimal cereal rye cover crop management timing for weed suppression.


1992 ◽  
Vol 6 (4) ◽  
pp. 838-846 ◽  
Author(s):  
Rex Liebl ◽  
F. William Simmons ◽  
Loyd M. Wax ◽  
Edward W. Stoller

A four-year experiment was conducted near Urbana, IL to evaluate the effect of a rye cover crop on weed control, soybean yield and soil moisture. Soybeans were planted into either a rye mulch or corn stubble (with and without spring tillage). Giant foxtail, velvetleaf, smooth pigweed and common lambsquarters control in the rye mulch plots was generally greater than 90% and better than the corn residue treatments five weeks after planting. Weed control was generally better, except for lambsquarters, in the corn residue without spring tillage plots compared to the spring-tilled plots. Herbicides improved weed control in the corn residue plots but not in the no-till rye treatment, due to the excellent control by the rye mulch. Soil water content was lowest during June under the late-killed (killed at planting) rye during dry periods due to water depletion caused by the growing rye. During wet periods the rye mulch resulted in a wetter soil profile compared to the corn residue treatments. Soybean yields were reduced in late-killed rye compared to early-killed rye (killed 2 wk prior to planting) due to soybean stand reductions in the late killed rye. Yields in early-killed rye and spring-tilled treatments were similar to or better than soybeans planted in corn residue without spring tillage.


Weed Science ◽  
2015 ◽  
Vol 63 (2) ◽  
pp. 477-490 ◽  
Author(s):  
John R. Teasdale ◽  
Steven B. Mirsky

Insufficient weed control is a major constraint to adoption of reduced-tillage practices for organic grain production. Tillage, cover crop management, and crop planting date are factors that influence emergence periodicity and growth potential of important weed species in these systems. We assessed two hairy vetch cover crop management practices, disk-kill and roll-kill, across a range of corn planting dates from early May to late June in three experiments in Beltsville, MD. Patterns of seed dormancy, emergence, and early weed growth were determined for overseeded populations of common ragweed, giant foxtail, and smooth pigweed, three important species in the Mid-Atlantic states that represent early to late emergence. Common ragweed emergence was lowest and dormancy was highest of the three species across all planting dates. Giant foxtail emergence was higher than the other species in roll-killed hairy vetch and included a significant number of seeds that germinated before rolling operations in late June. Smooth pigweed had the highest emergence and lowest dormancy in disk-killed hairy vetch in June. Individual giant foxtail plant weight was higher in roll-killed than disk-killed hairy vetch in 2 of 3 yr, whereas that of smooth pigweed plants was higher in disk-killed than roll-killed vetch in 2 of 3 yr. Giant foxtail was the dominant species in roll-killed hairy vetch (averaged 79% of total weed biomass at corn silking), probably because of early germination and establishment before rolling operations. Smooth pigweed was the dominant species in disk-killed hairy vetch at June planting dates (averaged 77% of total weed biomass), probably because of high growth rates under warm conditions in tilled soil. This research demonstrated that cover crop management practices and the timing of planting operations can shift the dominant species of weed communities in organic farming systems and must be considered in long-term weed management planning.


Weed Science ◽  
2010 ◽  
Vol 58 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Adam S. Davis

Termination of cover crops prior to no-till planting of soybean is typically accomplished with burndown herbicides. Recent advances in cover-crop roller–crimper design offer the possibility of reliable physical termination of cover crops without tillage. A field study within a no-till soybean production system was conducted in Urbana, IL, from 2004 through 2007 to quantify the effects of cover crop (cereal rye, hairy vetch, or bare soil control), termination method (chemical burndown or roller–crimper), and postemergence glyphosate application rate (0, 1.1, or 2.2 kg ae ha−1) on soybean yield components, weed–crop interference, and soil environmental variables. Biomass of weeds surviving management within a soybean crop following either a vetch or rye cover crop was reduced by 26 and 56%, respectively, in the rolled system compared to the burndown system. Soybean yield loss due to weed interference was unaffected by cover-crop termination method in soybean following a rye cover crop, but was higher in the rolled than burndown treatment in both hairy vetch and bare soil treatments. In soybean following a rye cover crop, regardless of termination method, yield loss to weed interference was unaffected by glyphosate rate, whereas in soybean following a vetch cover crop or bare soil, yield loss decreased with glyphosate rate. Variation in soybean yield among cover crops and cover-crop termination treatments was due largely to differences in soybean establishment, rather than differences in the soil environment. Use of a roller–crimper to terminate a cover crop preceding no-till soybean has the potential to achieve similar yields to those obtained in a chemically terminated cover crop while reducing residual weed biomass.


2014 ◽  
Vol 28 (2) ◽  
pp. 298-306 ◽  
Author(s):  
Kris J. Mahoney ◽  
Christy Shropshire ◽  
Peter H. Sikkema

Eleven field experiments were conducted over a 3-yr period (2010, 2011, and 2012) in conventional- and no-till soybean with a flumioxazin and pyroxasulfone premix. PRE and preplant applications were evaluated for soybean injury, weed control, and yield compared to standard herbicides. Early-season soybean injury from flumioxazin/pyroxasulfone ranged from 1 to 19%; however, by harvest, soybean yields were similar across labeled rates (160 and 200 g ai ha−1), standard treatments, and the nontreated control. Flumioxazin/pyroxasulfone provided excellent control (99 to 100%) of velvetleaf, pigweed species (redroot pigweed and smooth pigweed), and common lambsquarters across almost all rates tested (80 to 480 g ai ha−1). Common ragweed, green foxtail, and giant foxtail control increased with flumioxazin/pyroxasulfone rate. The biologically effective rates varied between tillage systems. The flumioxazin/pyroxasulfone rate required to provide 80% control (R80) of pigweed was 3 and 273 g ai ha−1under conventional- and no-till, respectively. For common ragweed, the R80was 158 g ai ha−1under conventional tillage; yet, under no-till, the rate was nonestimable. The results indicate that flumioxazin/pyroxasulfone can provide effective weed control as a setup for subsequent herbicide applications.


2010 ◽  
Vol 20 (4) ◽  
pp. 764-771 ◽  
Author(s):  
Sanjeev K. Bangarwa ◽  
Jason K. Norsworthy ◽  
Ronald L. Rainey ◽  
Edward E. Gbur

The phase-out of methyl bromide required an effective and economically viable alternative for weed management in polyethylene-mulched tomato (Solanum lycopersicum). A field experiment was conducted to compare economics of tomato production associated with crucifer (Brassicaceae) cover crops under low-density polyethylene mulch (LDPE) and virtually impermeable film (VIF) mulch with a standard treatment of methyl bromide:chloropicrin (67:33) at 350 lb/acre. Three crucifer cover crops, ‘Seventop’ turnip (Brassica rapa), ‘Pacific Gold’ oriental mustard (Brassica juncea), and Caliente [a blend of brown mustard (B. juncea) and white mustard (Sinapis alba)], were evaluated in combination with hand-weeding. Because of marginal weed control from crucifer cover crops, hand-weeding cost in all cover crop plots, regardless of mulch type, increased from $380.54/acre to $489.10/acre over that in methyl bromide plots. However, total weed management costs in the untreated control and cover crops with LDPE treatments were $17.82/acre to $111.33/acre lower than methyl bromide. Because of mulch expenses, VIF mulch increased the total weed management cost by $328.16/acre over LDPE mulch in the untreated control and cover crop treatments. Because of equivalent marketable yield, gross returns ($21,040.43/acre) were identical in all treatments. Preplant fumigation with methyl bromide provided $6260.90/acre of net returns in tomato production. The untreated control, ‘Seventop’ turnip, ‘Pacific Gold’ oriental mustard, and Caliente mustard under LDPE treatment were $54/acre, $54/acre, $98/acre, and $147/acre more profitable, respectively, than methyl bromide. However, in all other treatments under VIF, net returns relative to methyl bromide were reduced from $181/acre to $274/acre. Therefore, regardless of soil amendment with crucifer cover crops, hand-weeding can serve as an economically viable alternative to methyl bromide for weed control in LDPE-mulched tomato production, depending on the nature and level of pest infestation, labor availability, and wages.


1999 ◽  
Vol 13 (3) ◽  
pp. 478-483 ◽  
Author(s):  
Jimmy D. Wait ◽  
William G. Johnson ◽  
Raymond E. Massey

Field studies were conducted at two locations in 1997 and 1998 to evaluate crop injury, weed control, yield, and net economic returns of single and sequential postemergence applications of labeled and reduced rates of glyphosate to no-till, glyphosate-resistant soybean planted in narrow rows. Sequential applications provided at least 91% control of giant foxtail, while single applications provided at least 86% control with labeled rates and 68–93% control with reduced rates. Common waterhemp control was slightly higher with sequential vs. single treatments and with labeled rates vs. reduced rates. Velvetleaf control was greater than 96% with all treatments. Common cocklebur control was 90% or higher with all treatments except a single application of glyphosate at 210 g/ha. Lower control of giant foxtail and common waterhemp with single-application, reduced-rate treatments in two of the four trials resulted in lower yields. Overall, sequential applications, regardless of rate, provided greater weed control, yield, and net income and lower coefficients of variation (C.V.s) of net income than reduced-rate single applications. Single-application treatments showed a trend of decreased weed control, yield, and net income and higher C.V.s of net income with reduced rates of glyphosate.


2015 ◽  
Vol 31 (5) ◽  
pp. 429-440 ◽  
Author(s):  
M. Scott Wells ◽  
Carrie M. Brinton ◽  
S. Chris Reberg-Horton

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.


2015 ◽  
Vol 31 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Corrado Ciaccia ◽  
Stefano Canali ◽  
Gabriele Campanelli ◽  
Elena Testani ◽  
Francesco Montemurro ◽  
...  

AbstractIntegrating cover crops into vegetable cropping systems can provide a wide range of ecological services, of which weed management is a key component. Cover crop effects on weed control, however, are dependent on termination methods and weed species present in specific cropping seasons. A 2-year weed management experiment with two cultivars of organic zucchini (Cucurbita pepo L.) in central Italy was carried out to compare the effect of a barley (Hordeum distichum L.) cover crop terminated with a modified roller-crimper (RC) to incorporated barley as green manure (GM) and a tilled control left fallow (FA) in the off-season. The effects of cover-crop management on crop competitiveness, yields and weed populations were evaluated by direct measurement, visual estimation and competition index methods. Results showed a significant reduction in weed biomass (>80%) and weed abundance with the RC compared to the GM and FA treatments. Moreover, the RC barley mulch maintained weed control in zucchini plots even under high weed pressure, as determined by the agronomic tolerance to competition (ATC) value of 67% in the RC treatment compared to 40 and 34% in the FA and GM treatments, respectively, averaged over both years of the experiment. The competitive balance (Cb), which quantified the ability of the zucchini crop to compete with weed populations, was also greater (+0.37) in the RC treatment compared to FA (−0.87) and GM (−0.69) treatments over the same period. Zucchini crop biomass was greatest in the RC treatment in 2011. Zucchini fruit yields varied from an average over both years of 1.4 Mg ha−1 in the RC treatment to 0.7 Mg ha−1 in the GM treatment, but yields in the FA treatment, 1.2 Mg ha−1, did not differ from the RC treatment. No differences in yield between ‘Dietary’ and ‘Every’ zucchini, or any significant interactions between cultivar and cover management related to fruit biomass, were observed. Our findings suggested the viability of the modified RC in creating a barley cover-crop mulch to effectively manage weeds and enhance yields in transplanted zucchini.


2017 ◽  
Author(s):  
◽  
Ricardo Costa Silva

Effective weed control is one of the most yield-limiting factors in organic corn and soybean production. Additionally, the amount of tillage needed to control weeds in organic practice is often criticized for its negative impacts on soil quality. This research was conducted in central Missouri from 2016-2017 to compare cultivation, flame application, between-row mowing, and hot water spray for in-season weed control in organic corn and soybeans. Between-row mowing and hot water application were paired with notillage and a crimped winter cover crop of cereal rye (Secale cereale L.). When weeds reached 10.2 cm, weed control practices were implemented and repeated as necessary until canopy closure. Grass and broadleaf weed biomass between crop rows was determined at multiple dates throughout the 2016 and 2017 seasons and in-row weed levels were determined at the final collection date for each crop each year. Broadleaf weed biomass at the end of the soybean season in 2016 was lower in the two treatments utilizing no-till and cover crops as primary weed control and hot water and mowing as secondary control. Soybean yield was adversely affected by flaming but not significantly different for the cultivation, mowing and hot water treatments. In 2017, soybean had less between-row grass biomass in the cultivation and flaming treatments than in hot water and mowing, but broadleaf levels were the same in the mowed treatment as the cultivated and flamed treatments. In 2016, grass biomass was lower in the no-till treatments between corn rows and higher in the crop rows than the other two treatments. Weed control treatments led to no significant differences in corn yield in 2016 and higher yields in the no-till treatments in 2017. In-row weed levels were significantly higher in corn in 2017 for the hot water treatment. Hot water at the levels applied in this research was not an effective weed control method. Since the overuse of cultivation can decrease soil organic matter levels and increase soil erosion, alternatives techniques are important to grant farmers the possibility to use their land for a long time. The crimped cover crop used in the no-till treatments limited weed growth in early-season corn and soybean and when coupled with between-row mowing is a potential alternative to cultivation in organic crop production. Flaming is also a potential alternative to cultivation in corn production.


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