scholarly journals Functional Diversity Of Interseeded Cover Crops And Their Effect On Carabid Activity-Density In Semi-Arid Climates

2020 ◽  
Author(s):  
Sara Capitan

Interseeding cover crops into standing annual crops can promote environmental benefits within agroecosystems. However, seeding method and cover crop diversity may influence biomass production and activity-density of ground beetles (Coleoptera: Carabidae). Carabids abundant in agroecosystems and their granivorous behavior can impact weeds and potentially crops. In a two-year study, six annual cover crop species– planted as either single species or mixtures– were interseeded into standing corn. The seed predation rate of Harpalus, a granivorous carabid, was estimated in a no-choice experiment using weed and crop seed species. Higher crop diversity did not correlate with biomass yield, but cover crop species did. Carabid activity-density was significantly higher later in the season, but was not influenced by diversity or species. Harpalus consumed crop seeds, but preferred weed seed. With further experimentation and analysis, these results can inform farmers in choosing the most effective seeding method and seed type for interseeded cover crop establishment.

2020 ◽  
Vol 12 (5) ◽  
pp. 2058
Author(s):  
Tejendra Chapagain ◽  
Elizabeth A. Lee ◽  
Manish N. Raizada

Cover crops provide a range of well-documented benefits to growers and the environment. However, no single species can deliver all of these benefits, and hence planting mixtures is gaining increasing attention. To the best of our knowledge, there is no comprehensive review on different multi-mix strategies. This article reviews available studies on multi-mixes, focusing on temperate North America, and discusses objective criteria for selecting components of a multi-mix and what future research is needed. Very few peer-reviewed studies on multi-mixes are currently available; a diversity of species compositions is being tested with a wide range of potential benefits but also with various limitations. Selection of species in multi-mixes is based on different criteria that help improve multiple ecosystem services. An emerging concept is the importance of selecting cover crop species with functional complementarity rather than simply increasing the number of species. Based on this concept, objective criteria have been developed to select the species for a multi-mix: grower objectives/primary purpose of planting the cover crop, crop rotation and cropping system compatibility, above and belowground compatibility, complementarity of different ecosystem functions, compatibility with the growing environment, duration for cover crop growth, termination option(s) available, input/labour costs, planting equipment required, persistence/weediness, and potential net economic returns. We propose a step-wise procedure to develop effective multi-species mixtures. The number of species and their ratio in the mixtures will depend on objective criteria, and hence long-term research is required to assess different species compositions and their impacts.


2020 ◽  
Vol 49 (4) ◽  
pp. 865-875 ◽  
Author(s):  
Karly H Regan ◽  
Christina A Voortman ◽  
John M Wallace ◽  
Mary E Barbercheck

Abstract In organic agronomic cropping systems, the use of synthetic insecticides and transgenic varieties are prohibited and producers rely mainly on biological control, tillage, crop rotation, and other cultural practices to manage pests. We measured damage to organic corn (Zea mays L.) from multiple invertebrate pests, including slugs (Gastropoda: Mollusca), European corn borer (Ostrinia nubilalis Hübner), corn earworm (Helicoverpa zea Boddie), and fall armyworm (Spodoptera frugiperda Smith), early and late in the growing season in four cropping systems that varied in tillage frequency and intensity and in winter cover crop species. Specific management tactics included two cover crop mixtures preceding corn, the use of a roller-crimper or tillage to terminate cover crops preceding corn, and the establishment of interseeded cover crops after corn emergence. Prevalence of early-season damage was high, but severity of damage was very low and unrelated to corn yield. The proportion of corn plants affected by chewing pests early in the season was lower in plots in which tillage compared to a roller-crimper was used to terminate cover crops. Cropping system did not affect the numbers of late-season caterpillar pests or corn yield. Predation by natural enemies appeared to effectively maintain damage from chewing pests below yield-damaging levels. These results support the inclusion of winter and interseeded cover crops in organic agronomic crop rotations to gain environmental benefits without increasing risks of damage by insect pests.


2017 ◽  
Vol 32 (6) ◽  
pp. 538-551 ◽  
Author(s):  
Ariel Rivers ◽  
Christina Mullen ◽  
John Wallace ◽  
Mary Barbercheck

AbstractOrganic grain growers rely on cultural practices and biological control to regulate pests, and the implementation and timing of cultural practices can affect many characteristics of the cropping system as a habitat for natural enemies of arthropod pests. Ground beetles (Coleoptera: Carabidae) in particular are important insect and weed-seed predators, and are sensitive to crop rotations, tillage and environmental complexity. In a reduced tillage system in transition to organic management, we evaluated the effect of cover crop species and termination date, crop rotation and high residue cultivation on ground and tiger beetle (Coleoptera: Carabidae) activity-density, community composition and size and trophic groups. The 3-year experiment included a sequence of corn (Zea maysL.), soybean (Glycine max(L.) Merr.) and winter wheat (Triticum aestivumL.). A mixture of hairy vetch (Vicia villosaRoth) and triticale (xTriticosecaleWittmack) preceded corn, and cereal rye (Secale cerealeL.) preceded soybean, and each crop sequence was present in each year (full-entry). We compared three cover crop termination (and cash crop planting) dates by terminating the overwintered cover crops with a roller-crimper, and immediately or soon after, we no-till planted corn and soybean through the mat created by the rolled cover crops. In the corn and soybean phases of the rotation, we also compared inter-row cultivation as a pest management strategy to a control treatment (no inter-row cultivation in corn, and an alternative row-spacing in soybean). Wheat was planted on a single date in each year into tilled soil. Carabids were sampled using pitfall traps 2 weeks after termination of the two cover crop treatments, and in mid-June in wheat. Carabid activity-density and species richness increased across the experimental site during the 3-year transition, and community evenness across the experimental site increased by the third year. Crop species influenced carabid community composition, and by the third year, the carabid community was comparable between wheat and hairy vetch-triticale cover crop. The late cover crop termination date was positively associated with higher activity-densities of large carabids in rolled hairy vetch-triticale and rolled cereal rye; carnivorous beetles in rolled hairy vetch-triticale; and granivorous beetles in rolled cereal rye. Inter-row cultivation occurring in corn and soybean resulted in a significantly higher proportion of small beetles in the wheat phase of the rotation, with a significantly higher proportion of large beetles in wheat treatments, which had not received inter-row cultivation in corn and soybean. Results have strong implications for management during the transition to organic, including the importance of plant residue, reduced tillage and timing of cover crop termination dates for augmenting carabid populations.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 819A-819
Author(s):  
N.G. Creamer ◽  
M.A. Bennett ◽  
J. Cardina ◽  
E.E. Regnier

Little research has been conducted to quantify allelopathic suppression of weeds in the field. The objectives of this study were to develop an adequate control for separating physical from allelochemical effects, use the control to quantify allelochemical suppression in the field, and determine whether a mixture of cover crops would provide a broader spectrum of weed control than single species. Hairy vetch, rye, crimson clover, and barley were cut into 5-cm pieces, shaken in distilled water (pH 6) to leach allelochemicals, and redried. A seed germination bioassay confirmed that leached cover crops were nontoxic to germinating seeds. Physical suppression of Eastern black nightshade by the four cover crop species occurred in the field study, as did allelochemical suppression by crimson clover. Only rye physically suppressed yellow foxtail, and none of the cover crops suppressed yellow foxtail allelochemically.


2004 ◽  
Vol 47 (3) ◽  
pp. 381-386 ◽  
Author(s):  
Júlio C. Franchini ◽  
Marcos A. Pavan ◽  
Mário Miyazawa

The objective of this study was to evaluate if cover crops can absorb P from the upper layers and transport it in their roots to subsoil layers. Samples of an Oxisol were placed in PVC columns. Super phosphate fertilizer was applied to the 0-10 cm soil surface layers. The cover crops tested were: Avena strigosa, Avena sativa, Secale cereale, Pisum sativum subsp arvense, Pisum sativum, Vicia villosa, Vicia sativa, Lupinus angustifoliu, Lupinus albus, and Triticum aestivum. After a growth period of 80 days the cover crop shoots were cut off and the soil was divided into 10cm layers and the roots of each layer were washed out. The roots and shoots were analyzed separated for total P contribution to the soil. Considerable amount of P was present in the roots of cover crops. Vicia sativa contained more than 60% of total plant P in the roots. The contribution of Vicia sativa to soil P bellow the fertilized zone was about 7 kg ha-1. It thus appeared that there existed a possibility of P redistribution into the soil under no tillage by using cover crops in rotation with cash crops. Vicia sativa was the most efficient cover crop species as P carrier into the roots from superficial layer to lower layers.


2020 ◽  
Vol 6 (2) ◽  
pp. 64
Author(s):  
Imtiaz Ahmad ◽  
María del Mar Jiménez-Gasco ◽  
Dawn S. Luthe ◽  
Mary E. Barbercheck

Fungi in the genus Metarhizium (Hypocreales: Clavicipitaceae) are insect pathogens that can establish as endophytes and can benefit their host plant. In field experiments, we observed a positive correlation between the prevalence of M. robertsii and legume cover crops, and a negative relationship with brassicaceous cover crops and with increasing proportion of cereal rye in mixtures. Here, we report the effects of endophytic M. robertsii on three cover crop species under greenhouse conditions. We inoculated seeds of Austrian winter pea (Pisum sativum L., AWP), cereal rye (Secale cereale L.), and winter canola (Brassica napus L.) with conidia of M. robertsii to assess the effects of endophytic colonization on cover crop growth. We recovered M. robertsii from 59%, 46%, and 39% of seed-inoculated AWP, cereal rye, and canola plants, respectively. Endophytic M. robertsii significantly increased height and above-ground biomass of AWP and cereal rye but did not affect chlorophyll content of any of the cover crop species. Among inoculated plants from which we recovered M. robertsii, above-ground biomass of AWP was positively correlated with the proportion of colonized root but not leaf tissue sections. Our results suggest that winter cover crops may help to conserve Metarhizium spp. in annual cropping systems.


2019 ◽  
Vol 35 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Ebony G. Murrell ◽  
Swayamjit Ray ◽  
Mary E. Lemmon ◽  
Dawn S. Luthe ◽  
Jason P. Kaye

AbstractArbuscular mycorrhizal fungi (AMF) can increase plant nutrient uptake and chemical defense production, both of which can improve plants’ ability to resist insect herbivory. Cover crops—non-commercial species planted in between cash crops in a crop rotation—can naturally alter both soil nutrients and AMF. We tested whether different cover crop species alter AMF colonization, plant nutrient status and plant–insect interactions in a subsequent maize crop. Cover crop species were either non-mycorrhizal, non-leguminous (canola, forage radish), mycorrhizal non-leguminous (cereal rye, oats), mycorrhizal leguminous (clover, pea) or absent (fallow). We measured the cascading consequences of cover crop treatment on maize root AMF colonization, maize growth and performance of an herbivorous insect (European corn borer) feeding on the maize. Maize AMF colonization was greater in plots previously planted with mycorrhizal (rye, oats) than non-mycorrhizal (canola, radish) cover crops or no cover crop (fallow). AMF colonization was linked to increased plant phosphorous and nitrogen, and maize growth increased with low plant N:P. Induced jasmonic acid pathway plant defenses increased with increasing maize growth and AMF colonization. European corn borer survivorship decreased with lower plant N:P, and insect development rate decreased with increased induced plant defenses. Our data describe a cascade in which cover crop species selection can increase or decrease mycorrhizal colonization of subsequent maize crop roots, which in turn impacts phosphorus uptake and may affect herbivory resistance in the maize. These results suggest that farmers could select cover crop species to manage nutrient uptake and pest resistance, in order to amend or limit fertilizer and pesticide use.


Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1760
Author(s):  
Paul Cottney ◽  
Lisa Black ◽  
Ethel White ◽  
Paul N. Williams

The aim of this study is to identify species of cover crops that cause an increase in biomass and total nutrient accumulation in response to manure/slurry. This could improve nutrient efficiency and intensify the benefits from over-winter cover crops in arable rotations and improve following commercial crop yields. In a pot experiment, sixteen cover crops were grown for 100 days in response to slurry. Growth and nutrient (N, P, K, Mg and S) accumulation were measured, and then residue was reincorporated into the soil with spring barley (Hodeum vulgare L.) sown and harvested for yield. In response to slurry, tillage radish (Raphanus sativus L.) increased N accumulation by 101% due to a significant increase in biomass and % N (p < 0.05) over its relative control plots. Significant interactions between species and the application of slurry were found in cover crop biomass, cover crop and spring barley nutrient uptake, as well as cover crop carbon accumulation, particularly in the brassica species used. Slurry integrated with cover crops both reduced the cover crop C:N ratio and enhanced nutrient cycling compared to the control when soil mineral nitrogen (SMN) and spring barley crop N offtake were pooled. However, this was not observed in the legumes. This study shows that slurry integration with cover crops is a promising sustainable farming practice to sequester N and other macro-nutrients whilst providing a range of synergistic benefits to spring barley production when compared to unplanted/fallow land rotations. However, this advantage is subject to use of responsive cover crop species identified in this study.


2017 ◽  
Vol 31 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Cody D. Cornelius ◽  
Kevin W. Bradley

The recent interest in cover crops as component of Midwest corn and soybean production systems has led to the need for additional research, including the effects of residual corn and soybean herbicide treatments on fall cover crop establishment. Field studies were conducted in 2013, 2014, and 2015 in Columbia, Missouri to investigate the effects of common residual herbicides applied in corn and soybean on establishment of winter wheat, tillage radish, cereal rye, crimson clover, winter oat, Austrian winter pea, Italian ryegrass, and hairy vetch. Cover crops were evaluated for stand and biomass reduction 28 d after emergence (DAE). Rainfall from herbicide application to cover crop seeding date was much greater in 2014 and 2015, which resulted in less carryover in these years compared to 2013. When averaged across all herbicides evaluated in these experiments, the general order of sensitivity of cover crops to herbicide carryover, from greatest to least was Austrian winter pea=crimson clover>oilseed radish>Italian ryegrass>hairy vetch>wheat >winter oat>cereal rye. Cereal rye had the fewest instances of biomass or stand reduction with only four out of the 27 herbicides adversely effecting establishment. Pyroxasulfone consistently reduced Italian ryegrass and winter oat biomass at least 67% in both the corn and soybean experiments. In the soybean experiment, imazethapyr- and fomesafen-containing products resulted in severe stand and biomass reduction in both years while flumetsulam-containing products resulted in the greatest carryover symptoms in the corn experiment. Results from these experiments suggest that several commonly used corn and soybean herbicides have the potential to hinder cover crop establishment, but the severity of damage will depend on weather, cover crop species, and the specific herbicide combination.


2019 ◽  
Vol 34 (1) ◽  
pp. 48-54
Author(s):  
Kara B. Pittman ◽  
Charles W. Cahoon ◽  
Kevin W. Bamber ◽  
Lucas S. Rector ◽  
Michael L. Flessner

AbstractCover crops provide a number of agronomic benefits, including weed suppression, which is important as cases of herbicide resistance continue to rise. To effectively suppress weeds, high cover crop biomass is needed, which necessitates later termination timing. Cover crop termination is important to mitigate potential planting issues and prevent surviving cover crop competition with cash crops. Field studies were conducted in Virginia to determine the most effective herbicide options alone or combined with glyphosate or paraquat to terminate a range of cover crop species. Results revealed that grass cover crop species were controlled (94% to 98%) by glyphosate alone 4 wk after application (WAA). Overall, legume species varied in response to the single active-ingredient treatments, and control increased with the addition of glyphosate or paraquat. Mixes with glyphosate provided better control of crimson clover and hairy vetch by 7% to 8% compared with mixes containing paraquat 4 WAA. Mix partner did not influence control of Austrian winter pea. No treatment adequately controlled rapeseed in this study, with a maximum of 58% control observed with single active-ingredient treatments and 62% control with mixes. Height reduction for all cover crop species supports visible rating data. Rapeseed should be terminated when smaller, which could negate weed suppressive benefits from this cover crop species. Growers should consider herbicide selection and termination timing in their cover crop plan to ensure effective termination.


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