Made available in DSpace on 2016-08-12T19:18:43Z (GMT). No. of bitstreams: 1 RomuloMOF_DISSERT.pdf: 1866145 bytes, checksum: 9f9729462fbec5049c6b3e9bb450b4fa (MD5) Previous issue date: 2012-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The cowpea crop has great importance for the Brazilian Northeast, especially for the poorest population. One of the major problems encountered for this crop is drought stress caused by erratic rainfall, coupled with the high temperatures common in this region. The no-tillage system has features, such as reduction of soil water evaporation, higher water retention and lower soil temperature fluctuations, and can be a way to minimize the water stress in a cowpea crop. Thus, this study aims to obtain information on growth, yield components and cowpea yield under moisture stress in no-tillage and conventional crop systems. For this purpose an experiment was conducted at Universidade Federal Rural do Semi-Arido, in a split plot with randomized complete blocks design with four replications, using the cowpea cultivar BRS Guariba, and no-tillage and conventional crop systems treatments. For the dry spells simulation, irrigation systems has been suspended at 34 days after sowing, during the onset of flowering, for periods of 2, 6, 10, 14, 18 and 22 days, after what the irrigation was resumed. To evaluate the effect of the crop systems and moisture stress on growth, samples were taken between 15 and 64 days after sowing, in the treatments with and without irrigation (22 days duration). The evaluation of yield components (pod length, number of grains per pod, number of pods per plant and hundred grains weight) and yield was performed at 70 days after sowing. The tillage systems influenced the leaf area, and stem leaf, pod and plant dry weight. The growth rates were influenced by the plant phenological phase (age) and by water stress. The highest growth rates were achieved in the no-tillage system. Water stress affected negatively all the variables, regardless of tillage system. The no-tillage system was more productive both for the irrigated and the stress treatments. The dry spells periods affected grain yield and all other yield components studied in a negative way, except for the hundred grains weight. Among the systems studied, the no-tillage system provides higher values for the yield components, except for the hundred grains weight / A cultura do feijão-caupi possui grande importância para a região Nordeste, principalmente para a população mais carente. Um dos grandes problemas encontrados para essa cultura é o estresse hídrico, provocado pela irregularidade das chuvas, aliado a altas temperaturas, comuns a esta região. O sistema de plantio direto possui características como redução da evaporação da água do solo, maior retenção do solo e menores oscilações da temperatura, e pode ser uma forma de minimizar o efeito do estresse hídrico para a cultura do feijão-caupi. Deste modo, o presente trabalho se propõe a obter informações relativas ao crescimento, componentes da produção e rendimento de feijão-caupi sob veranico nos sistemas de plantio direto e convencional. Para isso, foi realizado, na Universidade Federal Rural do Semi-Árido, um experimento em delineamento de blocos completos casualizados em parcelas subdivididas com 4 repetições, utilizando-se a cultivar de feijão-caupi BRS Guariba em plantio direto e convencional. Para aplicação do veranico, a irrigação foi suspensa nos sistemas aos 34 dias após a semeadura por períodos de 2, 6, 10, 14, 18 e 22 dias sem irrigação, ocasião em que foi verificado o início do florescimento. Para avaliar o efeito dos sistemas e do veranico no crescimento, foram realizadas coletas entre os 15 e 64 dias após a semeadura, nos tratamentos com e sem irrigação (22 dias de duração). A avaliação dos componentes de produção (comprimento de vagem, número de grãos por vagem, número de vagens por planta e peso de cem grãos) e rendimento de grãos foi realizada aos 70 dias após a semeadura. Os sistemas de plantio influenciam o crescimento da área foliar, da matéria seca do caule, de folhas, de vagens e total do feijão-caupi. Os índices de crescimento são influenciados pela fase fenológica da planta (idade) e pelo estresse hídrico. As maiores taxas de crescimento foram alcançadas no sistema de plantio direto. O estresse hídrico afetanegativamente todas as variáveis avaliadas, independentemente do sistema de plantio. O sistema de plantio direto é mais produtivo do que o convencional quando em irrigação e em condição de estresse. Os períodos de veranico influenciaram o rendimento de grãos e todos os componentes de produção estudados de forma negativa, com exceção do peso de cem grãos. Entre os sistemas estudados, o direto é o que proporciona maiores valores para os componentes de produção, exceto peso de cem grãos

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-06T14:51:07Z No. of bitstreams: 1 Julio Jose do Nascimento Silva.pdf: 1033478 bytes, checksum: b9ad38ecd46c3d8a9eb97e0fce3dcc0b (MD5) / Made available in DSpace on 2016-10-06T14:51:07Z (GMT). No. of bitstreams: 1 Julio Jose do Nascimento Silva.pdf: 1033478 bytes, checksum: b9ad38ecd46c3d8a9eb97e0fce3dcc0b (MD5) Previous issue date: 2012-02-28 / The objective of this study was to evaluate the influence of different irrigation levels in the presence and absence of mulch on soil moisture dynamics in castor bean (Ricinus Comunnis L.) BRS Energy cultivation in communal farming. The experimental design was completely randomized in factorial scheme (4x2) x3, with four primary treatments, which are the irrigation based on crop evapotranspiration (ETc), L1 = 60% ETc, L2 = 80% ETc; 100% ETc = L3, L4 = 120% ETc, and two secondary treatments, is the absence and presence of mulch on density equal to 12 ton ha-1 and three replicates. Altogether 27 measurements were taken along the crop cycle. The mulch kept the soil moisture above field capacity. The increase in humidity due to the presence of mulch was 23.8% and 26% in the 0-20 cm and 20-40 cm layers, respectively, compared to its absence. Irrigation allowed moisture in both covering systems to present optimal levels, above the field capacity moisture and far below saturation. Furthermore, it was also perfomed growth analysis. The experimental design was a completely randomized in a factorial scheme (4x2) x4. Eight measurements were performed in the following periods: 15, 30, 45, 60, 75, 90, 105 and 120 days after germination (DAG) and evaluated three plants per plot. Analyses of non-destructive growth, stem diameter (AD), plant height (PH) and Leaf Area Index (LAI). From the measured data of AP, DC, and IAF, we calculated the absolute growth rate (AGR) and relative growth rate (RGR) for each variable respectively. All growth variables showed significant differences along the crop cycle mainly to the presence of cover, except absolute and relative growth rates of DC. The effects of irrigation levels were only significant for plant height (PH) and the Leaf Area Index (LAI). Finally, the crop yield components of castor bean (Ricinus Comunnis L.) were evaluated. The experimental design was same as above. It was performed a single harvest at 120 days after germination (DAG), and sampled three plants per plot. Analyses of the number of racemes per plant (NRP), length of racemes (CR) in centimeters (cm), productivity of fruits (PF) in kilograms per hectare (kg/ha), yield of berries (PG) in kilograms per hectare (kg/ha), mass of 100 seeds (M100) in grams (g) and water use efficiency (EUA) in kilograms of berries per cubic meter (kg/m³) have been performed. All variables except the M100 showed a significant difference to the adopted treatment. The NRP, the PC and the EUA responded significantly to the presence of ground cover, as the CR, the PF and PB responded significantly to the effects of individual irrigation depths and the soil cover. The irrigation depth of 679.77 mm corresponding to 100% of ETc was the best choise allowing an average yield of 2461.4 kg ha-1 of berries for the crop. / Objetivou-se com o presente estudo, avaliar o efeito de lâminas de irrigação na presença e ausência de cobertura morta sobre a cultura da mamona BRS Energia em Neossolo Flúvico em vale aluvial em Pesqueira, semiárido de Pernambuco, em condições de moderada salinidade. O experimento foi implantado em 08 de setembro de 2010 sendo finalizado em 18 de janeiro de 2011. O início da germinação das plantas se deu no dia 20 de setembro, perfazendo um total de 120 dias úteis. Avaliou-se a influência dos tratamentos na dinâmica de umidade do solo, com delineamento experimental inteiramente casualizado em esquema fatorial (4x2)x3, correspondentes às lâminas de irrigação, baseadas na evapotranspiração de cultura (ETc), sendo L1 = 60% ETc; L2 = 80% ETc; L3 = 100% ETc; L4 = 120% ETc, ausência e presença de cobertura morta na densidade de 12 t ha-1, e três repetições. Foi realizada análise multivariada de medidas repetidas no tempo, ao todo foram realizadas 27 medições ao longo do ciclo da cultura. A cobertura morta preservou a umidade do solo sempre acima da capacidade campo. O incremento na umidade em função da presença de cobertura morta foi de 23,8% e 26% nas camadas de 0 a 20 cm e 20 a 40 cm, respectivamente, em relação à ausência da mesma. A irrigação proporcionou níveis ótimos de umidade em ambos os sistemas de cobertura, acima da capacidade de campo e bem abaixo da umidade de saturação. Outrossim, também foi realizada análise crescimento da cultura, onde foi utilizado o delineamento experimental inteiramente casualizado em esquema fatorial (4x2)x4, bem como análise multivariada de medidas repetidas com o tempo, em que foram conduzidas 8 medições nos seguintes intervalos: 15, 30, 45, 60, 75, 90, 105 e 120 dias após a germinação (DAG), sendo avaliadas 3 plantas por parcela experimental. Realizaram-se análises de crescimento não destrutivas: Diâmetro do Caule (DC), Altura das Plantas (AP) e Índice de Área Foliar (IAF). A partir dos dados medidos de AP, DC e IAF, foram calculados a Taxa de Crescimento Absoluta (TCA) e Taxa de Crescimento Relativo (TCR) para cada variável, respectivamente, exceto para o IAF. Todas as variáveis de crescimento apresentaram diferença significativa ao longo do ciclo da cultura principalmente na presença de cobertura, exceto as taxas de crescimento absoluta e relativa do DC. Os efeitos das lâminas de irrigação apenas foram significativos para altura de plantas (AP) e para o Índice de Área Foliar (IAF). Por fim, foram avaliados os componentes de produção da cultura, utilizando-se o delineamento anterior. Foi realizada uma única colheita aos 120 dias após a germinação (DAG), sendo coletadas amostras de 3 plantas por parcela experimental. Realizaram-se análises do número de racemos por planta (NRP); comprimento de racemos (CR), em centímetros (cm); produtividade de frutos (PF) em quilogramas por hectare (kg/ha); produtividade de bagas (PG), em quilogramas por hectare (kg/ha); massa de 100 sementes (M100) em gramas (g) e eficiência no uso da água (EUA), em quilogramas de bagas por metro cúbico de água (kg/m³). Todas as variáveis, exceto a M100 apresentaram diferença significativa aos tratamentos. O NRP, a PC e a EUA responderam significamente à presença de cobertura do solo. Já o CR, a PF e PB responderam significativamente aos efeitos isolados das lâminas e da cobertura do solo. A lâmina de 679,77 mm correspondente a 100% da ETc foi a que permitiu melhor desempenho da cultura com, uma produtividade média de 2.461,4 kg ha-1 de bagas.

O presente trabalho teve o objetivo de avaliar os efeitos da vegetação intercalar composta por gramíneas e leguminosas perenes e da cobertura morta, obtida pelo manejo mecânico da vegetação intercalar, e herbicidas aplicados em pós-emergência, na linha da cultura, sobre a população de plantas daninhas, características químicas do solo, estado nutricional, desenvolvimento vegetativo e produção de citros. O experimento foi conduzido, durante as safras 2004/2005 e 2005/2006, na Fazenda São Judas, Lucianópolis - SP, em um pomar de laranja Pêra (Citrus sinensis (L.) Osbeck.), plantado em outubro de 2002. O delineamento utilizado foi o de blocos ao acaso, com parcelas subdivididas sendo 7 tratamentos e 2 subtratamentos, com 4 repetições. Os tratamentos foram: 1) vegetação intercalar de Brachiaria ruziziensis R. Germ. & Evrard, sem cobertura morta na linha da cultura; 2) vegetação intercalar de B. ruziziensis, com cobertura morta1 na linha da cultura; 3) vegetação intercalar de B. ruziziensis e Arachis pintoi Krap. & Greg com cobertura morta1 na linha da cultura; 4) vegetação intercalar de B. ruziziensis e Stylosantes spp. com cobertura morta1 na linha da cultura; 5) vegetação intercalar composta por Brachiaria plantagineacom cobertura morta1 na linha da cultura 6) vegetação intercalar de Arachis pintoi com cobertura morta1 na linha da cultura; 7) vegetação intercalar de estilosantes \'mineirão\' (Stylosathes macrocephala (25%), S. capitata (60%) e S. guianensis (15%)) com cobertura morta1 na linha da cultura. Os herbicidas aplicados às subparcelas foram: 1) glyphosate a 1260 g e. a. ha-1 e 2) paraquat a 400 g i. a. ha-1. Pelos dados obtidos pode-se observar que: a vegetação intercalar dos tratamentos 2, 3 e 4 obtiveram as maiores produções de fitomassa e cobertura morta, seguido pelos tratamentos 5 e 7 e a menor produção de fitomassa foi obtida pelo tratamento 6. A cobertura morta de B. ruziziensis proporcionou menor densidade de plantas daninhas por até 90 dias. O teor de matéria orgânica, nas entrelinhas, na camada de 0-0,10 m, nos tratamentos 2 e 4 foi superior em 3,79 e 3,48 g cm-3 em relação ao tratamento 6, enquanto que na camada de 0,20-0,40 m, o teor de matéria orgânica, do tratamento 6, foi superior em 4,6, 5,1 e 3,9 g cm-3 em relação aos tratamentos 1, 3 e 4, respectivamente. Nas linhas da cultura, o tratamento 4 e 3 apresentaram teor de K superior em 1,28 e 0,95 mmolc dm-3, respectivamente, em relação ao tratamento 6, nas camadas de 0-0,10 e 0,10-0,20 m de solo. O estilosantes proporcionou incrementos no teor foliar de N de 2,58 e 2,55 g kg-1, em relação aos tratamentos 1 e 2. O teor foliar de P do tratamento 4 foi superior ao tratamento 1 em 0,31 g kg-1, sendo observada uma correlação entre a densidade do sistema radicular na camada de 0-0,10 m de solo e o teor foliar de P. Não foi verificado efeitos dos tratamentos e herbicidas no desenvolvimento vegetativo, bem como na produção total no período avaliado. / The objective of this research was to evaluate the effects of cover crops from grass and perennial leguminous in the orchard inter-rows, mulch, produced through mechanical management with a lateral rotary mower from inter-row cover crops associated with herbicides applied in pos-emergence, on the rows, on population dynamics of weeds, soil chemical characteristics and development, nutrition and citros production. The experiment was carried out at the São Judas farm, Lucianópolis - SP - Brazil during the harvest of 2004/2005 and 2005/2006 in a citrus orchard of Citrus sinensis L. Osbeck cv. Pera, planted in October, 2002. The experimental design used was of randomized blocks with subdivided plots and 4 replications. The treatments were; 1) Cover crop of Brachiaria ruziziensis R. Germ. & Evrard, without mulch on the row; 2) Cover crop of B. ruziziensis and mulch on the row, produced through mechanical management with a lateral rotary mower (REL) from this cover crop; 3) Cover crop of B. ruziziensis and Arachis pintoi Krap. & Greg and mulch on the row, produced through REL from this cover crop; 4) Cover crop of B. ruziziensis and estilosantes \"mineirão\" (Stylosathes macrocephala (25%), S. capitata (60%) e S. guianensis (15%)) and mulch on the row, produced through REL from this cover crop; 5) Cover crop of Brachiaria plantaginea and mulch on the row, produced through REL from this cover crop; 6) Cover crop of Arachis pintoi and mulch on the row, produced through REL from this cover crop; 7) Cover crop of estilosantes \"mineirão\" and mulch on the row, produced through REL from this cover crop.The herbicides applied into the subplots were: 1) glyphosate at the rate 1260 g a.e. ha-1 and 2) paraquat at the rate 400 a.i. ha-1. In these experiments, it could be observed that: the cover crops from the treatments 2, 3 and 4 got higher wet biomass and mulch than others treatments; B. ruziziensis mulch decrease the weeds density until 90 days after the distribution; in the inter-row, into 0-0,10 m soil layer, the treatments 2 and 4 organic matter, was higher than treatment 6, however, into 0,20-0,40 m soil layer, treatment 6 organic matter was higher than treatments 1, 3 and 4. Into the rows, treatments 4 and 3 achieved K tenor higher than treatment 6 in 1,28 and 0,95 mmolc dm-3, respectively, into 0-0,10 and 0,10-0,20 m soil layers. Estilosantes promoted N foliar increases of 2,58 and 2,55 g kg-1 regarding treatments 1 and 2. Treatment 4 P foliar tenor was higher than treatment 1 in 0,31 g kg-1. It was observed a correlation between root density into superficial layer soil and P foliar tenor. It was not verified any effect of treatment or herbicides on development and total citros production.

Increasing food, feed, fiber, biofuel production on decreasing amounts of arable land while simultaneously enhancing ecosystem services is challenging. Strategic inclusion of winter rye (<i>Secale cereale</i>) for biomass, silage, grain and Kura clover (<i>Trifolium ambiguum</i>) living mulch into existing Midwestern cropping systems may offer alternative economic income for farmers without displacing or reducing yields of primary crops. Research was conducted at the Purdue Water Quality Field Station (WQFS) where net balances of water, carbon, nitrogen, and radiation can be measured, and greenhouse gas (GHG) emissions are monitored. The agronomic performance of a corn-soybean rotation and continuous corn (controls) were compared to novel systems that included the use of rye cover cropping and Kura clover co-cropping. Rye was harvested for biomass/silage at heading immediately followed by corn or soybean planting. Continuous corn receiving 69 kg N ha^-1was planted into an establishment of Kura clover sod. Controls included these same systems without the rye or clover. GHG samples were taken via the static chamber method and tile-drained water sub-samples were collected, analyzed for nitrate, and load losses calculated. Biomass composition was determined and used to calculate herbage theoretical ethanol (EtOH) yields. Cereal rye did not significantly decrease corn or soybean grain yield. Averaged across years, Kura clover significantly depressed corn grain yields by nearly 70%. Kura clover significantly reduced flow-weighted tile drainage nitrate (NO₃^-) concentrations, however cereal rye did not. Reductions in flow-weighted tile drainage nitrate (NO₃^-) concentrations were found to largely occur during Quarter two (April, May, June). Cover crops did not significantly reduce annual tile drained NO₃^- load losses in most cases, however, they did significantly reduce annual N₂O emissions. Cumulative annual CH₄ emissions were not significantly altered. Annual CO₂emissions were higher after the introduction of Kura clover and not significantly altered following the introduction of cereal rye. Averaged across years, theoretical ethanol yields in the Kura clover system produced 2,752 L EtOH ha^-1, whereas EtOH production in cereal rye systems ranged from 3,245 to 4,210 L EtOH ha^-1. Theoretical ethanol yields of continuous corn and rotational controls ranged from 2,982 to 3505 L EtOH ha^-1 for these same systems without the cereal rye of Kura clover. These data suggest that a multipurpose approach to cover crop inclusion can provide both environmental and economic advantages worthy of consideration.

Die Broschüre gibt einen Sachstand aus dem Jahr 2019 zum Einsatz von Transfermulch im sächsischen Ökolandbau basierend auf einer telefonischen Befragung von 200 Ökobetrieben. Die Befragung zeigte, dass vor allem gärtnerische Betriebe pflanzliches Mulchmaterial als Bodenbedeckung und Düngung schon länger nutzen, obwohl auch für sie die trockenen Jahre 2018 und 2019 eine Herausforderung war, ausreichend Mulchmaterial in guter Qualität zu produzieren. Auch wenn einige Betriebe vor dem Arbeitsaufwand zurückschrecken oder es ihnen an geeigneter Technik für das System fehlt, so besteht bei sächsischen Ökobetrieben dennoch ein großes Interesse am Thema Transfermulch. Die Veröffentlichung richtet sich an praktizierende Landwirte, Berater und Verbände. Redaktionsschluss: 04.11.2020

No description available.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free state, 2014 / The main objective of the study was to determine the effect of different potassium concentrations and water quality (salt) compared with the current scientifically accepted potassium threshold level and standardised water quality on the yield, oil composition and leaf morphology of rose geranium (Pelargonium graveolens L.) when grown in different potting-bag sizes and root media under temperature controlled condition. To achieve this objective, two trials were conducted. The first experiment evaluated potassium concentrations at 1.3, 3.3, 5.3 and 7.3 mmol L-1 and potting-bag size of 5 and 10 L. Treatments were arranged in a randomised complete block design assigned in a split plot layout. The main plots consisted of potassium concentration and the pottingbag sizes were allocated to sub-plots. Plant height, potassium content, linalool, geraniol, geranyl formate and the citronellol to geraniol ratio (C:G) were affected by potassium. Plant height, number of branches, the branch to height ratio (B:H), foliar fresh mass (FFM) and oil yield were significantly increased when 5 L potting bags were used. Plant foliar mass was significantly increased by the interaction between 5.3 mmol K L-1 and 5 L potting bags. In the second experiment salt levels applied at 1.6, 2.4, 3.2 and 4.0 mS cm-1 and root media (sand and sawdust) were evaluated. A split plot experimental layout was also used in this trial, with the salt levels allocated to the main plots. The sub-plots were allocated to the root medium. High salt level of 4.0 mS cm-1 reduced the number of leaves, plant height, number of branches, B:H ratio, leaf area, chlorophyll content and foliar fresh mass significantly. The number of leaves, leaf area and FFM were significantly increased where sawdust was used. Time of the day significantly affected stomatal conductance, and the opening of most stomata occurred at 10:00. Geranyl formate and the C:G ratio were significantly affected by salt at 4.0 mS cm-1. Salt induced the development of capitates trichomes. The abaxial leaf surface had a higher number of trichomes than the adaxial leaf surface. A strong polynomial (r2=0.97) relationship was found between capitates trichomes and salt levels. High densities of capitates trichomes were found at high salt level of 4.0 mS cm-1. Although the development of asciiform trichomes was induced, it was at an insignificant level. Trichome densities are therefore not affected by salt. It was therefore concluded that the application of 5.3 mmol K L-1 concentration and the use of 5 L potting bags improves the yield and oil quality of rose geranium. It was evident from this study that rose geranium might Salt induced have some degree of tolerance to salt. It was therefore concluded that rose geranium is a moderately salt-sensitive crop.

Organic mulches and cover crops mulched in situ were assessed for their effects on B. cinerea primary inoculum and disease levels in inflorescences at flowering and/or bunches at harvest. Organic mulches were used to enhance biological degradation of vine debris to reduce levels of B. cinerea primary inoculum the following season. Four mulch types (anaerobically and aerobically fermented marc (grape pressings), inter-row grass clippings and shredded office paper) were applied under ten-year-old Riesling vines in a ten-replicate randomized block design in New Zealand over two consecutive years. Plastic mesh bags, each containing naturally infected vine debris, were placed under vines on bare ground (control) and at the soil-mulch interface, in winter (July) 2003 and 2004. In each year, half the bags were recovered at flowering (December) and the remainder at leaf plucking (February), for assessment of B. cinerea sporulation from the vine debris and debris degradation rate. Bait lamina probes, which measure soil biological activity, were placed in the soil-mulch interface three weeks before each of the two bag-recovery dates in both years and were then removed and assessed at the same times as were the bags. All mulches led to a reduction in B. cinerea sporulation. This reduction was significantly correlated with elevated rates of vine debris decomposition and increased soil biological activity. Over both years, compared with the controls, all treatments gave a 3-20-fold reduction in B. cinerea sporulation, a 1.6-2.6-fold increase in vine debris degradation and in the two marc and the paper treatments, a 1.8-4-fold increase in activity of soil organisms. The mulches also altered vine characteristics and elevated their resistance to B. cinerea through changes to the soil environment. Functional soil biological activity, as measured by Biolog Ecoplates and bait lamina probes, was increased 2-4 times in the two marc and paper treatments, compared with the control, an effect relating to the elevated soil moisture and reduced temperature fluctuations under these mulches. Soil nutrient levels and the C:N ratios were also affected in these treatments. The mulched paper lowered vine canopy density by up to 1.4 times that of the other treatments, an effect which probably led to elevated light penetration into the canopy and consequent increased canopy temperature, photosynthesis and lowered canopy humidity. These changes to soil and vine characteristics increased grape skin strength by up to 10% in the paper treatment and sugar concentrations by 1.2-1.4 °Brix in the two marc and paper treatments. The severity of B. cinerea infections in the anaerobic marc, aerobic marc and paper treatments were reduced to 12%, 3% and 2.2% of the control, respectively, in field assessments averaged over two consecutive harvests. Cover crops mulched in situ had similar effects to those of the organic mulches, increasing soil biological activity and reducing B. cinerea primary inoculum and the severity of B. cinerea infection in grapes at harvest (2006). Inter-row phacelia and ryegrass were mulched in winter 2005 and compared with a bare ground control, under 10-year-old Chardonnay vines in a ten-replicate randomized block design. Functional soil biological activity increased by 1.5-4.5 times in the two cover crop treatments compared with the control, an effect possibly related to elevated soil moisture in these treatments. This increase in soil moisture and soil biological activity increased vine debris degradation, reduced B. cinerea primary inoculum on the debris and decreased B. cinerea severity at flowering (December 2005) and harvest (April 2006). These results show the potential of organic mulches and cover crops mulched in situ to enhance soil ecosystem services and improve the sustainability of viticultural practices.

China's Minqin Oasis once welcomed traders along the ancient Silk Road with rivers, lakes, and lush forests, yet today the region's farmland and grassland are increasingly being engulfed by the sands of the Gobi Desert. The severity of this incremental catastrophe for a declining population of 300,000 residents has brought forth a host of recent water policies to include agronomic water conservation through plastic mulch use, computerized regulation and pricing of groundwater, and water diversions from the Yellow River. This study uses a multi-disciplinary and mixed methods approach to better understand farmer perspectives on why they implement certain water and land use practices in agriculture. The world's farmers currently use the majority of the world's available freshwater and arable land. Modern agriculture and its continued intensification also lead to increases in petroleum based inputs such as agrochemicals and agricultural plastics (plasticulture). Despite the large of impact of the decisions made by the world's farmers on natural resources, little research to date has sought to better understand farmers' perceptions and decision-making processes. Plastic film mulch is a technology that has existed since the 1940's and it has been used in places such as rural China for over five decades. This technology conserves a considerable amount of irrigation water and it increases harvests, however, use of plastic for mulch causes waste disposal problems and is an expenditure of petroleum through plastic manufacturing. Without a fundamental understanding of why farmers perceive plastic mulch to be valuable to their households and communities, we may not fully grasp why its global application continues to increase year after year. Moreover, a focused study of plastic mulch use at the local level may also allow researchers and entrepreneurs to develop a suitable alternative mulch that does not consume non-renewable resources or result in detrimental plastic waste after its utility has been exhausted. This study uses household level interviews, surveys, and participant observation to better understand why Minqin County farmers in rural China continue to use plastic mulch and how it may influence their standard of living. / Graduation date: 2013

Made available in DSpace on 2016-08-12T19:18:23Z (GMT). No. of bitstreams: 1 MariaEHC_TESE.pdf: 1170432 bytes, checksum: 23f945c77b271c8ad86c1d93e1bf0f2c (MD5) Previous issue date: 2011-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Three experiments were carried out in the didactic orchard of the Departamento de Ciências Vegetais of Universidade Federal Rural do Semi-Árido (UFERSA), located in Mossoró-RN. The experiments aimed at assessing the interference of weeds on the soil temperature, on the growth of sweet pepper (Capsicum annuum L.), and on the efficiency as to the use of water in the referred to type of crop when submitted to weed handling strategies within the systems no-trillage and conventional planting. The trials were assembled in a split-plot scheme, distributed within the experimental design , in randomized blocks with four replications. Within the plots, two planting systems were assessed (no-trillage and conventional), and, within the subplots, three weed handling strategies soil covering with black polyethylene film, with regular weeds, and with no weeds, were assessed. Within each subplot, sensors were installed at a depth of 5 cm for the purpose of measuring the soil temperature. Data were collected every 10 minutes and stored in dataloggers. As for the first experiment, the collected data led to the determination the temperature variation throughout the day from 20 to 30 days after transplanting (DAT), the average maximum and minimum temperatures every 5 days, and the daily temperature range during the crop cycle. On the 60th and 147th days after transplanting, the density as well as the dry mass of the weeds were assessed within the treatment with no weeds. Regarding the second experiment, what was assessed was the growth of sweet pepper, submitted to weed handling strategies within no-trillage and conventional planting systems. To attain such an objective, eight assessment times were established (0, 21, 42, 63, 84, 105, 126 e 147 DAT). The assessed features were: leaf area per plant, leaf area index, dry mass of leaves, of stem, of fruits, and the total dry mass per plant, leaf area ratio as well as the rates of absolute and relative growth and of net assimilation. On the 30th and 90th DAT, the weeds density and the dry mass were assessed in the treatments with no weeds. As to the third experiment, the water consumption and the sweet pepper s productivity were assessed. Based upon the relationship between productivity and water consumption, the efficiency as with water use (kg of fruit m-³ of water) was determined. On 0, 21, 42, 63, 84 e 105 DAT, the density and dry mass of weeds were assessed in the treatments with no weeds. Irrigation was done by way of dripping water, with different water supply to each subplot in order that the soil would be maintained with at least 80% of the total available water, based upon water tension in the soil. It was found that the soil temperature was influenced by the covering types, with wider temperature ranges and maximum temperatures in the treatments with weeds and in the treatments with the soil covered by polyethylene film within the conventional planting system as compared to the no trillage direct planting with regular weeds. The no-trillage system proved to be a suitable technique for growing sweet peppers under a high temperature condition. The no-trillage system displayed higher growth rates than those displayed by the conventional planting in all weed handling strategies. The highest rates were observed in the no-trillage with weeds; besides, this type of planting reduces infestation and the weeds dry mass accumulation. Insofar as the third trial is concerned, it was found that the weeds interference increased water consumption and reduced the sweet pepper productivity within the two planting systems; however, the conventional planting displayed stronger effects. The treatment with weeds in the direct planting displayed greater fruit productivity and greater efficiency as for water use as compared to the others. It was concluded that the dead covering in the direct planting lowered the soil temperature, favored the growth and productivity of sweet pepper, reduced infestation by weeds, and increased water use efficiency / Foram conduzidos na horta didática do Departamento de Ciências Vegetais da Universidade Federal Rural do Semi-Árido (UFERSA), no município de Mossoró-RN, três experimentos com o objetivo de avaliar a interferência de plantas daninhas sobre a temperatura do solo, no crescimento e na eficiência do uso da água na cultura do pimentão (Capsicum annuum L.), submetido a estratégias de manejo de plantas daninhas nos sistemas de plantio direto e convencional. Os ensaios foram montados no esquema de parcelas subdivididas, distribuídas no delineamento experimental em blocos casualizados com quatro repetições. Nas parcelas foram avaliados dois sistemas de plantio (direto e convencional) e nas subparcelas, três estratégias de manejo de plantas daninhas (cobertura do solo com filme de polietileno preto, com capinas regulares e sem capinas). Em cada subparcela, foram instalados sensores, a 5 cm de profundidade, para medir a temperatura do solo. Os dados foram coletados a cada 10 minutos e armazenados em dataloggers. No primeiro experimento, a partir dos dados obtidos, determinou-se a variação da temperatura ao longo do dia, no período de 20 a 30 dias após o transplantio (DAT) e a cada 5 dias a média das temperaturas máxima e mínima e a amplitude térmica diária durante o ciclo da cultura e aos 60 e 147 dias após o transplantio foram realizadas avaliações nos tratamentos sem capinas da densidade e massa seca de plantas daninhas. No segundo experimento avaliou-se o crescimento do pimentão submetido a estratégias de manejo de plantas daninhas nos sistemas de plantio convencional e direto. Para tal foram realizadas oito épocas de avaliações (0, 21, 42, 63, 84, 105, 126 e 147 DAT). As características avaliadas foram: área foliar por planta, índice de área foliar, massa seca de folhas, caule, frutos e total por planta, razão de área foliar, as taxas de crescimento absoluto e relativo e taxa de assimilação líquida. Aos 30 e 90 DAT foram realizadas avaliações de densidade e massa seca de plantas daninhas nos tratamentos sem capinas. No terceiro experimento avaliou-se o consumo de água e a produtividade do pimentão. A partir da relação entre a produtividade e o consumo de água determinou-se, para cada tratamento, a eficiência no uso da água (kg de fruto m-³ de água) e aos 0, 21, 42, 63, 84 e 105 DAT foram realizadas avaliações de densidade e massa seca de plantas daninhas nos tratamentos sem capinas. As irrigações foram realizadas por gotejamento com fornecimento de água diferenciado para cada subparcela, de modo a manter o solo com no mínimo de 80% da água disponível total, com base na tensão de água no solo. Verificou-se que a temperatura do solo foi influenciada pelos tipos de cobertura, tendo-se constatado maiores amplitudes térmicas e temperaturas máximas nos tratamentos com capinas e coberto com filme de polietileno no sistema de plantio convencional em relação ao plantio direto com capinas regulares. O sistema de plantio direto mostrou-se como uma técnica adequada para o cultivo do pimentão sob condição de temperatura elevada. O sistema de plantio direto apresentou índices de crescimento superiores aos do plantio convencional em todas as estratégias de manejo de plantas daninhas e as maiores taxas foram verificadas no plantio direto com capinas além de reduzir a infestação e o acúmulo de massa seca de plantas daninhas. No terceiro ensaio, constatou-se que a interferência das plantas daninhas elevou o consumo de água e reduziu a produtividade do pimentão nos dois sistemas de plantio, embora com efeitos mais pronunciados no plantio convencional. O tratamento com capinas no plantio direto apresentou maior produtividade de frutos e eficiência no uso da água em relação aos demais. Concluiu-se que a cobertura morta no sistema de plantio direto diminuiu a temperatura do solo e favoreceu o crescimento e a produtividade do pimentão, reduziu a infestação de plantas daninhas e elevou a eficiência no uso da água