scholarly journals Nutrient Cycling, Weed Suppression, and Onion Yield Following Brassica and Sorghum Sudangrass Cover Crops

2008 ◽  
Vol 18 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Guangyao Wang ◽  
Mathieu Ngouajio ◽  
Darryl D. Warncke

The effects of cover crops on nutrient cycling, weed suppression, and onion (Allium cepa) yield were evaluated under a muck soil with high organic matter in Michigan. Four brassica cover crops, including brown mustard (Brassica juncea ‘Common brown’), oilseed radish (Raphanus sativus ‘Daikon’), oriental mustard (B. juncea ‘Forge’), and yellow mustard (Sinapis alba ‘Tilney’), as well as sorghum sudangrass (Sorghum bicolor × S. sudanense ‘Honey Sweet’) produced similar amount of biomass and recycled similar amounts of nitrogen, phosphorus, and potassium. The brassica cover crop biomass contained more calcium, sulfur, and boron, but less magnesium, iron, manganese, copper, and zinc than sorghum sudangrass. However, soil fertility was generally similar regardless of whether a cover crop was used. This was mainly because the soil was sampled when most of the cover crop residue was not yet decomposed. Weed density during onion growth was reduced by all cover crops compared with the control with no cover crop, with yellow mustard treatment having the lowest weed density among the cover crops. Weed species composition was also significantly affected by the cover crops. Yellow mustard treatment had the lowest density of common purslane (Portulaca oleracea) and redroot pigweed (Amaranthus retroflexus), whereas sorghum sudangrass had the highest yellow nutsedge (Cyperus esculentus) density among all the treatments. However, weed suppression was not enough to eliminate normal control strategies. The brassica cover crops, especially oilseed radish and yellow mustard, increased onion stand count and marketable yield. These results suggest that brassica and sorghum sudangrass cover crops could provide multiple benefits if incorporated into short-term onion rotations under Michigan growing conditions.

Author(s):  
Silvia Fogliatto ◽  
Lorenzo Patrucco ◽  
Fernando De Palo ◽  
Barbara Moretti ◽  
Marco Milan ◽  
...  

A field study was carried out in 2017 and 2018 in two Italian rice farms (at Livorno Ferraris and Rovasenda) to assess the effect of using cover crops as green mulching on weed control and rice yield. In each site, three different rice fields were sown after rice harvest with either Vicia villosa, Lolium multiflorum, or a mixture of both (V. villosa 40% + L. multiflorum 60%); at Rovasenda a small percentage of Brassica napus and Triticale was also present in the mixture. An additional field at both sites without cover crop was considered as a control reference. Rice was broadcasted sown within the cover crop in May. After few days, the cover crop was terminated in half of each field using a roller-crimper, while in the other half it was terminated by shredding. Within 10 days, the fields were flooded for about a week to promote the degradation of the cover crop biomass. Then, the fields were cultivated in flooding conditions without further weed control. Weed density and weed cover were evaluated thrice during the growing season. At harvest, rice yield and harvest index were determined. Mixed nested ANOVAs were performed for each site to assess the effect of cover crop species, termination technique, and the interaction between cover crop and year. L. multiflorum showed a high biomass before termination, while V. villosa had a more variable development. At Rovasenda, V. villosa growth was limited because of the combination of scarce emergence due to sod-seeding and frost damage. In general, green mulching significantly affected weed density. The best weed suppression was observed with L. multiflorum and mix at Rovasenda, with values of weed density <40 plants m-2 recorded in 2018. At both sites, rice yield was variable in the two years. The highest rice yield (>5 t ha-1) was observed in 2018 in the shredded mixture at Rovasenda and in V. villosa at Livorno Ferraris in 2017. Generally, control fields showed lower yields (1-3 t ha-1) at both sites. The termination methods did not significantly affect both weed density and rice yield. The results highlighted that green mulching could reduce weed infestations, even though alone is not able to completely avoid weed development. Some critical issues of the technique were observed, such as the need of a good cover crop establishment, that eventually results in abundant biomass production and significant weed suppression.   Highlights - Green mulching reduces weed pressure but it should be integrated with other weed control techniques. - Hairy vetch showed poor establishment because of the combination of scarce emergence due to sod-seeding and low temperatures. - Italian ryegrass was more tolerant to low temperatures and showed a good cover that contained weed growth. - Cover crop mixture showed variable results with higher suppression probably related to the number of cover crop species present in the mixture. - The termination methods (crimping and shredding) did not affect weed density and rice yield.


2016 ◽  
Vol 26 (4) ◽  
pp. 409-416 ◽  
Author(s):  
Raymond Kruse ◽  
Ajay Nair

Cover crops can be used as a sustainable weed management tool in crop production systems. Cover crops have the ability to suppress weeds, reduce soil erosion, increase soil organic matter, and improve soil physical, chemical, and biological properties. In the north-central region of the United States, including Iowa, much cover crop research has been conducted in row crop systems, mainly with corn (Zea mays) and soybean (Glycine max) where cover crops are planted at the end of the growing season in September or October. There is little information available on the use of cover crops in vegetable cropping systems, particularly on the use of summer cover crops for fall vegetable production. The choice of the cover crop will significantly impact the entire fall vegetable production enterprise. Vegetable growers need information to identify the right cover crop for a particular slot in the cropping system and to understand how cover crops would affect weed suppression, soil properties, and successive vegetable crop yield. The time interval between cover crop termination and vegetable planting critically affects the growth and successive yield of the vegetable crop. This study investigated how short-duration summer cover crops impact weed suppression, soil properties, and ‘Adriana’ lettuce (Lactuca sativa) yield. The study also examined appropriate planting times of lettuce transplants after soil incorporation of cover crops. The experimental design was a randomized complete block split-plot design with four replications. Whole plots consisted of cover crop treatments: ‘Mancan’ buckwheat (Fagopyrum esculentum), ‘Iron & Clay’ cowpea/southernpea (Vigna unguiculata), black oats (Avena strigosa), ‘Grazex II’ sorghum-sudangrass (Sorghum bicolor ssp. drummondii), and a control (no-cover crop) where weeds were left to grow unchecked. The subplot treatment consisted of two lettuce transplanting times: planted immediately or 8 days after cover crop soil incorporation. Fall-planted butterhead lettuce was used. Data were collected on cover crop biomass, weed biomass, soil nutrient concentration, lettuce growth, and yield. All cover crops significantly reduced weed biomass during the fallow period as compared with the control treatment. Highest degree of weed suppression (90% as compared with the no-cover crop control treatment) was provided by buckwheat. Southernpea, a legume, increased soil nitrogen (N) concentration and contributed to higher lettuce yield and improved quality. Southernpea also enhanced lettuce growth and led to an earlier harvest than other treatments. Sorghum-sudangrass showed evidence of detrimental effects to the marketable lettuce crop. This was not due to N immobilization but presumably due to alleopathic properties. There is no clear pattern within any cover crop treatment that lettuce planting time following cover crop termination affects plant growth; however, planting early or soon after cover crop incorporation ensures more growing degree days and daylight, thus leading to timely harvest of a higher quality product. This study demonstrates that cover crops can successfully be integrated into vegetable cropping systems; however, cover crop selection is critical.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 807B-807
Author(s):  
Lydia Stivers-Young

Vegetable growers in the northeastern United States who want to use cover crops are limited by the relatively short growing season and by a lack of cover crop species options. Seven cover crops that winter-kill under NE US conditions were evaluated in on-farm trials for their suitability for following early harvested vegetables. Plots of oilseed radish (Raphanus sativus), white senf mustard (Brassica hirta), phacelia (Phacelia tanacetifolia), oats (Avena sativa), and a bare control were planted on 25 Aug. and 8 Sept. 1993, following a lettuce crop. In the early planting, oilseed radish, white senf mustard, and phacelia produced more than 3000 kg·ha–1 dry matter in 11 weeks, while oats produced just more than 2000 kg·ha–1. A smaller proportion of the accumulated biomass from these cover crops remained on the surface in the spring compared to oats. In the first planting, 80–107 kg·ha–1 N were accumulated in the above-ground biomass of the cover crops. On 3 and 16 Sept. 1994, plots of oilseed radish, white senf mustard, oats, yellow mustard (Brassica hirta), forage kale (Brassica oleracea), forage turnip (Brassica rapa), canola (Brassica napus cv. Sparta), and a bare control were established following potatoes. All cover crops except kale produced more than 3800 kg·ha–1 dry matter by late November in the early planting.


1996 ◽  
Vol 10 (4) ◽  
pp. 893-899 ◽  
Author(s):  
Nilda R. Burgos ◽  
Ronald E. Talbert

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.


2011 ◽  
Vol 25 (3) ◽  
pp. 374-384 ◽  
Author(s):  
Kelsey A. O'Reilly ◽  
Darren E. Robinson ◽  
Richard J. Vyn ◽  
Laura L. Van Eerd

The effectiveness of cover crops as an alternative weed control strategy should be assessed as the demand for food and fiber grown under sustainable agricultural practices increases. This study assessed the effect of fall cover crops on weed populations in the fall and spring prior to sweet corn planting and during sweet corn growth. The experiment was a split-plot design in a pea cover–cover crop–sweet corn rotation with fall cover crop type as the main plot factor and presence or absence of weeds in the sweet corn as the split-plot factor. The cover crop treatments were a control with no cover crop (no-cover), oat, cereal rye (rye), oilseed radish (OSR), and oilseed radish with rye (OSR+rye). In the fall, at Ridgetown, weed biomass in the OSR treatments was 29 and 59 g m−2lower than in the no-cover and the cereal treatments, respectively. In the spring, OSR+rye and rye reduced weed biomass, density, and richness below the levels observed in the control at Bothwell. At Ridgetown in the spring, cover crops had no effect on weed populations. During the sweet corn season, weed populations and sweet corn yields were generally unaffected by the cover crops, provided OSR did not set viable seed. All cover crop treatments were as profitable as or more profitable than the no-cover treatment. At Bothwell profit margins were highest for oat at almost Can$600 ha−1higher than the no-cover treatment. At Ridgetown, compared with the no-cover treatment, OSR and OSR+rye profit margins were between Can$1,250 and Can$1,350 ha−1and between Can$682 and Can$835 ha−1, respectively. Therefore, provided that OSR does not set viable seed, the cover crops tested are feasible and profitable options to include in sweet corn production and provide weed-suppression benefits.


Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 702-708 ◽  
Author(s):  
Erin R. Haramoto ◽  
Eric R. Gallandt

Field studies have shown that weed density and biomass were lower in crops following incorporation of brassica cover crops compared with fallow but have not determined whether weed-suppressive effects are solely a consequence of reduced establishment, as evidenced in our companion paper, reduced growth of established plants, or both. In 2002 and 2003, canola and yellow mustard were seeded in early May, mowed in early July, and the residues incorporated. Green bean and redroot pigweed were then planted at fixed densities. Plant height and biomass were measured weekly; leaf area and biomass of component plant parts were measured at three harvests. Based on analysis of variance (ANOVA) at discreet sampling points, growth of redroot pigweed and green bean in monoculture or mixture were similar following fallow and incorporated brassica cover crops. However, based on aboveground biomass fitted to a Richards function, redroot pigweed growth in monoculture was reduced by the yellow mustard cover crop compared with fallow in both years (P = 0.007), but the magnitude of this effect was small; the canola cover crop did not affect growth (P = 0.179). Brassica cover crops did not reduce redroot pigweed growth when it was grown in mixture with green bean (P ≥ 0.382). Redroot pigweed competition reduced green bean yield, but incorporated brassica cover crops did not affect green bean growth and yield, nor did they confer a competitive advantage to the crop. Thus, brassica cover crops may suppress the growth of established weed and crop plants, but the magnitude of suppression was less than previously documented for effects on weed establishment.


2011 ◽  
Vol 25 (3) ◽  
pp. 473-479 ◽  
Author(s):  
Daniel C. Brainard ◽  
Robin R. Bellinder ◽  
Virender Kumar

Summer leguminous cover crops can improve soil health and reduce the economic and environmental costs associated with N fertilizers. However, adoption is often constrained by poor weed suppression compared to nonlegume cover crops. In field experiments conducted in organic vegetable cropping systems in north-central New York, two primary hypotheses were tested: (1) mixtures of legume cover crops (cowpea and soybean) with grasses (sorghum–sudangrass and Japanese millet) reduce weed seed production and increase cover crop productivity relative to legume monocultures and (2) higher soil fertility shifts the competitive outcome in favor of weeds and nonlegume cover crops. Cover crops were grown either alone or in grass–legume combinations with or without composted chicken manure. Under hot, dry conditions in 2005, cowpea and soybean cover crops were severely suppressed by weeds in monoculture and by sorghum–sudangrass in mixtures, resulting in low legume biomass, poor nodulation, and high levels of Powell amaranth seed production (> 25,000 seeds m−2). Under more typical temperature and rainfall conditions in 2006, cowpea mixtures with Japanese millet stimulated cowpea biomass production and nodulation compared to monoculture, but soybeans were suppressed in mixtures with both grasses. Composted chicken manure shifted competition in favor of weeds at the expense of cowpea (2005), stimulated weed and grass biomass production (2006), and suppressed nodulation of soybean (2006). In a complementary on-farm trial, cowpea mixtures with sorghum–sudangrass suppressed weed biomass by 99%; however, both common purslane and hairy galinsoga produced sufficient seeds (600 seeds m−2) to replenish the existing weed seedbank. Results suggest that (1) mixtures of cowpeas with grasses can improve nodulation, lower seed costs, and reduce the risk of weed seed production; (2) soybean is not compatible with grasses in mixture; and (3) future costs of weed seed production must be considered when determining optimal cover crop choices.


HortScience ◽  
1997 ◽  
Vol 32 (6) ◽  
pp. 1040-1043 ◽  
Author(s):  
Bruce P. Bordelon ◽  
Stephen C. Weller

Use of in-row cover crops for weed management in first-year vineyards was investigated in two studies. In the first study, rye (Secale cereal L. 'Wheeler') was fall-planted, overwintered, then managed by three methods before vine planting. Rye was either herbicide-desiccated with glyphosate and left on the surface as a mulch, mowed, or incorporated into the soil (cultivated). Weed density and growth of grapevines (Vitis spp.) were evaluated. Herbicide desiccation was superior to the other methods for weed suppression, with weed densities 3 to 8 times lower than for mowed or cultivated plots. Vine growth was similar among treatments, but the trend was for more shoot growth with lower weed density. In a second study, four cover crops, rye, wheat (Triticum aestivum L. 'Cardinal'), oats (Avena sativa L. 'Ogle'), and hairy vetch (Vicia villosa Roth), were compared. Wheat and rye were fall- and spring-planted, and oats and vetch were spring-planted, then desiccated with herbicides (glyphosate or sethoxydim) after vine planting and compared to weed-free and weedy control plots for weed suppression and grapevine growth. Cover crops provided 27% to 95% reduction in weed biomass compared to weedy control plots. Total vine dry mass was highest in weed-free control plots, was reduced 54% to 77% in the cover crop plots, and was reduced 81% in the weedy control. Fall-planted wheat and rye and spring-planted rye plots produced the highest vine dry mass among cover crop treatments. Spring-planted rye provided the best combination of weed suppression and vine growth. Chemical names used: N-(phosphonomethyl) glycine (glyphosate isopropylamine salt); 2-[l-(ethoxyimino)butyl]5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one (sethoxydim).


2021 ◽  
pp. 1-9
Author(s):  
Thierry E. Besançon ◽  
Maggie H. Wasacz ◽  
Joseph R. Heckman

Cover crops included in a crop rotation can help increase nitrogen (N) availability to subsequent crops, raise soil organic matter, and suppress emergence and growth of various weed species. However, weed suppression by cover crops has mostly been investigated shortly after cover crop termination and not over a longer period spanning into the next cropping season. The effects of sunn hemp (Crotalaria juncea) and sorghum-sudangrass (Sorghum ×drummondi) planted the previous year on N availability before transplanting of late summer cabbage (Brassica oleracea), weed germination and growth, and cabbage yield was examined in field studies conducted in 2018 and 2019 at Pittstown, NJ. Results established that there was little evidence for a functional difference in soil N availability for fall cabbage production because of previous cover crop type. Heavy rainfall events both years may have caused major losses of available N that might otherwise be expected to come from N mineralization of residues of legume cover crop like sunn hemp. During the cover crop season, smooth pigweed (Amaranthus hybridus) and common lambsquarters (Chenopodium album) dry biomass was 77% and 82% lower, respectively, in sorghum-sudangrass compared with sunn hemp plots. The subsequent season following sorghum-sudangrass cover crop, dry biomass of broadleaf weeds was lower by 74% and 56% in June and July, respectively, compared with preceding sunn hemp. Smooth pigweed, common lambsquarters, and hairy galinsoga (Galinsoga quadriradiata) were the weed species most consistently affected by preceding sorghum-sudangrass cover crop with biomass decreased by up to 80%, 78%, and 64%, respectively. Thus, it appears that sorghum-sudangrass can provide suppression of some broadleaf species over a relatively long period and is indicative of sorghum-sudangrass allelopathic activity. On the contrary, density and biomass of grassy weeds as well as commercial yield of transplanted cabbage were unaffected by the preceding cover crop. These results suggest that sorghum-sudangrass cover crop could be integrated to transplanted cole crop rotation for providing weed suppression benefits without altering crop yield in New Jersey organic vegetable cropping systems.


Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 346-352 ◽  
Author(s):  
Nicholas E. Korres ◽  
Jason K. Norsworthy

Cover crops are becoming increasingly common in cotton as a result of glyphosate-resistant Palmer amaranth; hence, a field experiment was conducted in 2009 and 2010 in Marianna, AR, with a rye cover crop used to determine its effects on the critical period for weed control in cotton. Throughout most of the growing season, weed biomass in the presence of a rye cover crop was lesser than that in the absence of a rye cover crop. In 2009, in weeks 2 through 7 after planting, weed biomass was reduced at least twofold in the presence of a rye cover compared with the absence of rye. In 2009, in both presence and absence of a rye cover crop, weed removal needed to begin before weed biomass was 150 g m−2, or approximately 4 wk after planting, to prevent yield loss > 5%. Weed density was less in 2010 than in 2009, so weed removal was not required until 7 wk after planting, at which point weed biomass values were 175 and 385 g m−2in the presence and absence of a cover crop, respectively.


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