Rye (<i>Secale cereale</i> L.) used as a winter cover crop was killed by paraquat or by mowing with a bushog. In subsequent no-till corn, early season armyworm, <i>Pseudaletia unipuncta</i> (Lepidoptera: Noctuidae) abundance was lower in the mowed treatment compared with the sprayed treatment. Total cumulative armyworm-days in the sprayed treatment were greater than in the mowed treatment and were significantly greater in the sprayed treatment in two fields. Lower armyworm populations may have resulted from a combination of mowing which physically destroyed some larvae, and predation by generalist predators attracted to the moist conditions provided by the mulch of mowed rye. Twelve species of parasitoids attacked armyworm. <i>Glyptapanteles 111ilitaris</i> (Walsh) (Hymenoptera: Braconidae) and <i>Periscepsia laevigata</i> (Wulp) (Diptera: Tachinidae) were the most abundant parasitoids. Seasonal parasitization rates ranged from 36-45%. Parasitism did not differ significantly between treatments. Mowing the cover crop was 40% less expensive than spraying. Corn silage yields did not differ significantly between treatments, but the average increase in net benefit from mowing compared to spraying was $91-113/ha. / Master of Science

Conservation tillage tobacco production has gained little producer acceptance since introduction in the late 1960's. Yield reductions, tobacco quality issues, unacceptable weed control, and inadequate planting equipment limited practice adoption and substantiated the need for continued research. The recent developments of a Subsurface Tiller-TransplanterTM and the herbicide SpartanTM renewed producer interest in conservation tillage and led to an investigation with both flue-cured and Virginia dark-fired tobacco. Flue-cured tobacco was transplanted into rye mulch on bedded rows and subsequently cultivated at various timings. Conservation tillage significantly reduced soil erosion approximately 92 percent and tobacco yield approximately 23 percent when row cultivation was not applied. Row cultivation significantly increased tobacco yield without increasing soil erosion. The yield of conservation tillage tobacco receiving a minimum of two cultivations was similar to conventional tobacco. The second study evaluated wheat, rye, crimson clover, and mixtures of crimson clover with either wheat or rye as cover crop mulches for conservation tillage production of Virginia dark-fired tobacco. Conservation tillage, regardless of cover crop, reduced dark-fired tobacco yields approximately 779 and 488 pounds per acre in 1996 and 1997, respectively. The removal of cover crop residue for hay did not lower tobacco yield compared to leaving residue on the soil surface. Row cultivation increased conservation tillage tobacco yield approximately 247 pounds in 1997 regardless of cover crop. The nitrogen contribution of crimson clover was minimal in both years of the study and did not affect tobacco performance. / Master of Science

Master of Science / Department of Biological and Agricultural Engineering / Philip L. Barnes / The world’s population has passed 7 billion and is expected grow to more alarming numbers by the year 2050. The increase in human life on the planet ushers the need to responsibly and sustainably grow more food. In order to meet the demand necessary, it is crucial that soil remains healthy and crop yields continue to increase in efficiency. Irresponsible or ill-informed practices can lead to depleted resources and degradation of fertile soils that may limit a producers’ ability to sustainably grow food. Cover crops are a tool that can be used to address issues the modern producer may face. Cover crops have been shown to increase cash crop productivity, improve soil health by improving soil physical and chemical properties as well as providing protection from soil erosion runoff or nutrient leaching. A study was conducted in 2014 to examine the short term effects associated with cover cropping systems. The effects of ryegrass, red clover and a cover crop cocktail (mixture of ryegrass, red clover and hairy vetch) compared to bare tilled and bare control plots were studied. The five treatments were replicated three times in a completely randomized study and analyzed. Soil physical health indicators such as bulk density and porosity were calculated. Soil and cover crop nutrient use, as well as, soil moisture content data was collected and analyzed using excel and ANOVA statistical procedures. In the short term, the study found that there was only statistically significant differences between cover cropping regimens, tilled and control plots in regards to biomass production and biomass nutrient concentrations (α=0.05). The cocktail mix provided more biomass, N and P than the ryegrass and clover plots alone. Observable differences in cover crop volumetric soil moisture and water used between plots demonstrated that cover crops utilize soil moisture in the short term, which must be considered in areas experiencing water stress. Although more long-term data is needed to truly quantify how cover crops effect various aspects of soil health, this study demonstrated how cover crops have the potential for providing numerous benefits such as increased erosion control, lower reliance on anthropogenically created nutrients and the reduction of weeds. Overall the benefits associated with cover crops are still being researched and while adoption of cover cropping systems has been slow, a push towards agricultural sustainability while increasing food production will increase the amount of producers utilizing cover crops in the coming years.

Master of Science / Department of Agronomy / Johanna A. Dille / No-till producers can manage weeds by including cover crops during the fallow phase as part of an integrated weed management plan. Field experiments were conducted between 2007 and 2009 to quantify the influence of cover crops on weed emergence, biomass accumulation, and seed production. Field experiments were established near Garden City, KS with winter wheat or fallow as main plots and cover crop treatments as subplots including five spring- and five fall-sown individual or mixtures of crop species and a no-cover chemical fallow. Separate1-m2 quadrats were seeded with kochia or downy brome at 500 seed/m2. Kochia density was reduced by 75% and biomass reduced by 88% in fall-sown cover crops compared to chemical fallow across growing seasons. Spring-sown cover crop mixtures reduced kochia biomass in 2009 when kochia emergence was delayed. Downy brome biomass decreased exponentially as cover crop biomass increased. A second field experiment was established near Manhattan, KS with soybean, winter wheat, or grain sorghum phases of the rotation as main plots and six cover crop treatments as subplots sown after winter wheat harvest. Paired Palmer amaranth 1-m2 quadrats were seeded with 500 seed/m2 in each cover crop subplot. One quadrat was protected from any herbicide application made to the cover crop or to the grain sorghum. Combining burndown application with high biomass-producing cover crops reduced Palmer amaranth emergence and biomass. Influence of cover crop presence reduced early season Palmer amaranth emergence in the subsequent grain sorghum phase. Optimal seeding rate of forage soybean sown in winter wheat stubble and its impact on Palmer amaranth and downy brome emergence and growth were evaluated in field studies established near Manhattan and Hesston, KS in 2008 and 2009. Soybean was no-till drilled after wheat harvest at five rates ranging from 100,000 to 600,000 seeds/ha. A no-cover chemical fallow treatment was included. Separate 0.5-m2 quadrats were seeded with Palmer amaranth at 100 seed/0.5 m2 or with downy brome at 250 seed/0.5 m2. Three termination methods evaluated were killing frost, glyphosate application, or crop rolling. Palmer amaranth density was not affected by treatments but biomass decreased as soybean seeding rate and crop biomass increased. Downy brome emergence was less with rolled or sprayed termination methods in one site year as timing of termination was optimal. High biomass producing cover crops sown during the fallow phase of a crop rotation reduced weed emergence, density, and biomass accumulation. Cover crops can be part of an integrated weed management plan in Kansas.

Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2007. / This study forms part of an ARC Nietvoorbij research project on the long-term effect of different groundcover management practices in vineyards. This study concentrated on the root distribution of the vines after different groundcover practices were used for one decade. The vineyard on the research farm of the Agricultural Research Council at Robertson, South Africa, was divided into 56 equally distributed trail blocks, 14 treatments with four replicas each. For the study Chardonnay cultivar on 99 Richter rootstock was used. This study concentrated on only eight treatments. The eight different cover crop practices consisted of the mechanical treatment, chemical treatment, straw mulch treatment, permanent cover crop treatment and four annual cover crop treatments. The annual cover crop treatments consisted of triticale cover crop that was sprayed with an herbicide before bloom, a triticale cover crop that was left to die naturally, a grazing vetch cover crop that was sprayed with an herbicide before bloom and a grazing vetch cover crop that was left to die naturally. The vineyard was established in November 1992 while the different treatments started in April 1993. Root studies were conducted during the 2002/2003 season. In this study the auger method was used to determine root density (mm/cm³). The root density was correlated with data from the penetrometer studies, yield and shoot mass collected during the same season.

Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2007 / A selection of species suitable for cover crop management in the different wine grape regions is required to enable more producers to apply this environment friendly practice in a sustainable manner as part of an integrated production strategy. The correct management practice(s) to be applied to these species over both the short and long term in a cooler and warmer wine grape region needed clarification. The effect of seeding date on the dry matter production (DMP) and weed control efficacy of seven grasses and sixteen legumes, as well as varieties of three of these species, was determined during 1991 and 1992. The decomposition rate of the mulches was determined. In the cooler climate of Stellenbosch (33o55'S, 18o52'E), the Medicago species, subterranean clovers, pink Seradella and three Vicia species did not compete effectively with the winter weeds if the weekly precipitation from mid-March to mid-May (autumn) exceeded 18 mm. The two oat species, as well as rye and triticale produced more than five t/ha of dry matter if the precipitation exceeded 18 mm per week. The DMP of the above-mentioned species indicated that these species could be considered for cover crop management in Lutzville (31o35'S, 18o52'E), if full surface irrigation of 18 mm per week could be applied for 10 weeks directly after sowing, followed by 18 mm fortnightly. Seeding date had a significant effect on DMP in both regions. A highly significant correlation (r = 0.85, p ≤ 0.0001) existed between the decomposition rate of the mulches and the initial amount of dry matter present on the soil surface.

<p>Cover crop use, especially in no-till systems, is an evolving practice to maintain or improve soil health. There are many possible indicators of soil health, but this study focuses on the analysis of soil aggregate stability, soil active carbon, and soil organic matter. Soil aggregate stability is related to water infiltration and potential for soil erosion, while active carbon serves as an indicator of a readily-available food source for microbial activity, and soil organic matter serves as a mediator for the soil physical, chemical, and biological processes. The sites include: three Purdue Agricultural Centers, two soil and water conservation district sites, 12 farmer sites with conservation cropping systems, and seven conventional comparison sites. The treatments consisted of cover crop versus no cover crop use, or cover crop use with different tillage systems or nitrogen rates. In 2016 and 2017, soil samples were collected at a depth of 0-5 cm, air-dried, and separated into two soil size fractions: 0-2 mm and 2-8 mm. The wet sieve method was used to measure the mean weight diameter of the water stable soil aggregates from the 2-8 mm size fraction in both years. The potassium permanganate method was used to measure the soil active carbon from both size fractions in both years. The dry combustion method was used to measure the soil organic matter from both soil size fractions in 2017 only. Results showed relatively small improvements in soil active carbon and aggregate stability with the addition of three to four years of cover crops to the long-term no-till systems. However, these improvements were greater when comparing the cover crops plus no-till treatments to the conventional-till without cover crops. More work is needed to understand the dynamics of soil aggregate stability, soil active carbon, and soil organic matter in relation to soil health and cover crop use. Cover crops will likely have more impact on soil aggregate stability, active carbon, and organic matter with a longer duration of use.</p><p></p>

Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-06-23T21:12:08Z No. of bitstreams: 1 DISSERTAÇÃO-LEANDRO AMORIM DAMASCENO.pdf: 621723 bytes, checksum: 8b19f60c0dc2740d6f819fb37b1fc067 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-09T15:09:27Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO-LEANDRO AMORIM DAMASCENO.pdf: 621723 bytes, checksum: 8b19f60c0dc2740d6f819fb37b1fc067 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-09T15:14:44Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO-LEANDRO AMORIM DAMASCENO.pdf: 621723 bytes, checksum: 8b19f60c0dc2740d6f819fb37b1fc067 (MD5) / Made available in DSpace on 2015-07-09T15:14:44Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO-LEANDRO AMORIM DAMASCENO.pdf: 621723 bytes, checksum: 8b19f60c0dc2740d6f819fb37b1fc067 (MD5) Previous issue date: 2013-12-13 / Não Informada / The productivity of citric plants has not reach their maximum potential due to the action of various biotic factors that directly affect agricultural profitability. These factors have great importance interference from infesting plants. The objective of this study was to evaluate the growth and periods of decomposition of plant cover and its effects in the management of weeds in the orange orchard of Amazonas. The research was performed in Citrus Farm IMF, road of Procopius, located at km 112 on highway AM 010, city of Rio Preto da Eva-AMs. The experimental design was a randomized block design with 6 treatments and 4 replications. Treatments with plant covers were as follows: millet, pork beans, turnip, brachiaria millet mixture over and pork bean producer (control) management. The weed community, growth and dry matter production for coverage and the rate of degradation of the vegetation cover by the methodology of litter bags were evaluated. Cover crops showed good dry matter production except the turnip. The highest rates of decomposition occurred in the first 28 days, especially the turnip that had large losses in the initial stage and after these periods, there was a stabilization in the rate of decomposition of the remaining biomass. Brachiaria, pork bean and mixing showed higher half-lives proving to be good alternatives for ground cover. / A produtividade das plantas cítricas não tem atingido seu potencial máximo devido a ação de vários fatores bióticos que afetam diretamente a rentabilidade agrícola. Dentre estes fatores tem grande importância a interferência de plantas infestantes. O objetivo desse trabalho foi avaliar o crescimento e os períodos de decomposição de plantas de coberturas e seus efeitos o manejo de plantas infestantes em pomar de laranjeira no Amazonas. A pesquisa foi realizada na Fazenda FMI Citros, ramal do Procópio, localizada no km 112, na AM 010, município de Rio Preto da Eva-AM. O delineamento experimental foi em blocos ao acaso com 6 tratamentos e 4 repetições. Os tratamentos com plantas de coberturas foram os seguintes: milheto, feijão de porco, nabo forrageiro, braquiária, mistura milheto mais feijão de porco e manejo do produtor (controle). Foram avaliados a comunidade infestante, crescimento e produção de matéria seca por cobertura e a velocidade de degradação das coberturas vegetais pela metodologia de litter bags. As plantas de cobertura apresentaram boa produção de matéria seca exceto o nabo forrageiro. As maiores taxas de decomposição ocorreram nos primeiros 28 dias, principalmente o nabo forrageiro que apresentou grandes perdas na fase inicial e após estes períodos, houve estabilização da taxa de decomposição da fitomassa remanescente. A braquiária, feijão de porco e mistura destas apresentaram maiores tempos de meia vida mostrando ser boas alternativas para cobertura do solo.

Made available in DSpace on 2017-07-10T17:36:54Z (GMT). No. of bitstreams: 1 2014_Diss_Poliana_Ferreira_Costa.pdf: 1338360 bytes, checksum: 1c523ddb26369e2486b4cb15ce0647dc (MD5) Previous issue date: 2014-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study was conducted to evaluate different management of winter cultures in a no-till system, assessing their influence on soil physical properties, dynamics of weeds, content and and nutrient accumulation on soybean in summer crop in Marechal Cândido Rondon - Paraná. The study was conducted in the experimental area of the State University of West Paraná - Campus Rondon in EUTRUSTOX (LVe). The experimental design was randomized blocks in band layout with three replications. The treatments consisted of four different winter crops (oats IPR 126, wheat BRS Tarumãt crambe FMS Bright and forage turnip cultivar common) and two management (chemical and mechanical). With respect to soil physical properties (macroporosity, microporosity, total porosity and density), it was found that only the macroporosity was altered due to interaction between the winter crops and systems of management that occurred in the 0 - 10 cm in the assessment after the harvest of soybean crop. As to the values obtained for the penetration resistance of the soil, it was found that the oat (0.91 MPa) and crambe (1.43 MPa) provided significant differences in the 0 - 5 cm depth. Sixteen weed species were identified in the area, distributed in eleven plant families, especially the families Poaceae and Asteraceae. The presence of weeds in chemical handlings was lower when compared to mechanical handling. In relation to nutrient content were no significant differences for the quantities of N, C and C / N ratio of the materials. As for the accumulation of nutrients wheat BRS showed higher for Mg absorption with 9,15 kg ha-1 / O estudo foi conduzido com o objetivo de avaliar diferentes manejos de culturas de inverno em um sistema de plantio direto, verificando a sua influência sobre as propriedades físicas do solo, dinâmica de plantas daninhas, teor e acúmulo de nutrientes e sobre a cultura da soja no cultivo de verão, em Marechal Cândido Rondon - Paraná. O trabalho foi desenvolvido em área experimental da Universidade Estadual do Oeste Paraná - Campus Marechal Cândido Rondon, em LATOSSOLO VERMELHO Eutrófico (LVe). O delineamento experimental utilizado foi o de blocos casualizados em esquema de faixas, com três repetições. Os tratamentos foram constituídos de quatro diferentes culturas de inverno (aveia IPR 126, crambe FMS Brilhante, Nabo forrageiro cultivar comum e trigo BRS Tarumã) e por dois manejos (químico e mecânico). Com relação às propriedades físicas do solo (macroporosidade, microporosidade, porosidade total e densidade), constatou-se que apenas a macroporosidade sofreu alterações, devido a interação entre as culturas de inverno e os sistemas de manejo empregados, ocorrido na camada de 0 10 cm na avaliação após a colheita da cultura da soja. Quanto aos valores obtidos para a resistência à penetração do solo, verificou-se que a aveia (0,91 Mpa) e o crambe (1,43 Mpa) ofereceram diferenças significativas, na camada de 0 5 cm de profundidade. Foram identificadas dezesseis espécies de plantas daninhas na área, distribuídas em onze famílias botânicas, destacando-se as famílias Poaceae e Asteraceae. A presença de plantas daninhas nos manejos químicos foi menor quando comparada ao manejo mecânico. Em relação aos teores de nutrientes houve diferenças significativas para as quantidades de N, C e relação C/N dos materiais. Já para o acúmulo de nutrientes o trigo BRS apresentou maior acúmulo para o Mg com 9,15 kg ha-1

Orientador: Salatier Buzetti / Banca: Marco Eustaquio de Sa / Banca: Edson Lazarini / Banca: Helder Barbosa Paulino / Banca: Aguinaldo José Freitas Leal / Resumo: A produtividade média das culturas de milho, feijão e trigo no Brasil é considerada atualmente baixa, uma vez que, utilizando técnicas mais adequadas de cultivo, existe possibilidade, de em curto prazo, aumentar a produtividade dessas culturas. O objetivo deste trabalho foi estudar o efeito do consórcio de Brachiaria ruziziensis e Crotalaria spectabilis no desenvolvimento e produtividade do milho cultivado na primeira safra e, restos culturais dessas culturas e doses de nitrogênio no desenvolvimento e produtividade do feijoeiro "de inverno" e trigo em sistema plantio direto. Os experimentos foram conduzidos no município de Selvíria - MS, durante os anos agrícolas 2010/11 e 2011/12 em Latossolo Vermelho distrófico álico típico argiloso (20° 20' S e 51° 24' W, com altitude de 340 m). Foram estabelecidos 40 tratamentos com quatro repetições em blocos casualizados resultantes da combinação entre coberturas vegetais (milho, milho em consórico com Brachiaria ruziziensis, milho em consórcio com Crotalaria spectabilis, Brachiaria ruziziensis e Crotalaria spectabilis) e doses de N (0, 40, 80 e 120 kg ha -1 - fonte Ureia) nas culturas de feijão e trigo de inverno. Os efeitos de cobertura vegetal foram analisados pelo teste de Tukey e de dose pela análise de regressão. Os consórcios não interferiram no desenvolvimento e produtividade da cultura do milho; tanto o feijão quanto o trigo apresentaram resposta linear à adubação nitrogenada em ambos os anos agrícolas; o feijoeiro quando semeado sobre restos culturais de B. ruziziensis e C. spectabilis e o trigo sobre restos culturais de B. ruziziensis e milho, apresentaram maiores produtividades / Abstract: The average productivity of maize, common bean and wheat in Brazil is currently considered low, since using more appropriate cultivation techniques, there is possibility of short-term, increase the productivity of these crops. The aim of this work was to study the effect of the consortium Brachiaria ruziziensis and Crotalaria spectabilis in the development and productivity of maize grown in the first crop and crop residues of these crops and nitrogen levels in the development and productivity of winter common bean and wheat in no tillage. The experiments were conducted in Selvíria - MS, during the years 2010/11 and 2011/12 in an alic typical clayey Oxisol (20 ° 20 'S and 51 ° 24' W, with an altitude of 340 m). We established 40 treatments with four replications in a randomized block design resulting from the combination of cover crops (corn, corn consorptium with Brachiaria ruziziensis, maize intercropped with Crotalaria spectabilis and Crotalaria spectabilis and Brachiaria ruziziensis) and N rates (0, 40, 80 and 120 kg ha-1 - source Urea) in crops of winter common bean and wheat. The effects of vegetation were analyzed by Tukey test and N doses by regression analysis. Consortia not interfere with the development and productivity of maize, both the corn and the wheat showed linear response to nitrogen fertilization in both years; the common corn when sown over residue of B. ruziziensis and C. spectabilis and wheat crop over B. ruziziensis and maize, showed greater productivity / Doutor