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Effect of paraplowing on soil properties and crop yield under irrigated management2015 March 1900 (has links)
Limitations on water infiltration and soil aeration through compaction processes have the potential to limit production in irrigated agricultural fields. This project was conducted to determine the impact of sub-soiling with a paraplow (Howard Rotavator) on soil physical properties and processes that are important in affecting soil-water relations and productivity. The paraplow was the subsoiler selected for use in this study because of its ability to loosen the soil at the depth of plowing while producing minimal surface disturbance. The research plots were located on Chernozem and Vertisol soils in the Brown soil zone in the Lake Diefenbaker irrigation district near Birsay, SK. Irrigated and dryland sites were used for comparison. Sub-soiling was able to consistently reduce bulk density of the soil and effects persisted for one to two years under normal precipitation conditions.
Excessively wet conditions (2010 and 2011) reduced the effectiveness of the sub-soiling. Tillage induced porosity in the soil was associated with a greater infiltration capacity measured in the field. Yield benefits in crops grown (canola, flax, wheat) from sub-soiling were variable under the wet conditions of 2010 and 2011. A greater benefit was observed under the normal precipitation conditions of 2012 on sites that were paraplowed in 2011. Subsoiling at a depth of 45cm and a row spacing of 45cm (manufacturer’s recommended configuration) was more effective than shallower depth and wider row spacing treatments. A significant yield benefit was only observed at the dryland site established in 2011, and limited yield benefit was observed in the irrigated sites. Over the three years of the study, annual yields from sub-soiling were on average about 5% higher than the un-tilled control. However, yield benefits were variable depending on crop and year. Given an estimated cost of subsoiling of ~$30 per acre, a benefit of sub-soiling that lasts one year would produce close to break-even conditions, and sub-soiling benefits that are consistent and last longer than one year are needed to be cost effective.
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Sistemas de manejo de um Argissolo dos tabuleiros costeiros de Sergipe cultivado com citros / Tillage systems in Ultisoil under citrus grove of Sergipe coastal tablelandsAnjos, Joézio Luiz dos 28 February 2006 (has links)
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Previous issue date: 2006-02-28 / In spite the social and economic importance of citrus on tablelands ecossistem in
Northeasten Brazil, specially in Sergipe and Bahia States, the citrus yield is yet very lowone
box of 40,8 kg per tree. Among the restrictive factors to the business of Sergipe citrus
area, the second most important in Brazil, are outstanding those related to physical and
chemical characteristics of the tableland soils – high acidity, low natural fertility and
mainly the coercion layers located near by the soil surface. These pedogenetic layers are
typical in tableland soils and cause noticeable limitation to soil water and to root system of
trees. Doing interrow tillages based in intensive utilization of agricultural machines chiefly
harrows, the growers of that region give contribution to increase negative effects of
handsettings, resulting in modification in the physical and hydric soil qualities, impairing
its fertility and then the grove productivity. The aim of this study was the evaluate hydric
and physic properties of the soil under different tillage systems in the interrows to control
weeds. The treatments were as follow: 1) Subsoiling and harrowing all over the year; 2)
No subsbsoiling and harrowing all over the year. 3) Mowing in the rainy season (From
April to September) and harrowing in the dry season (October to March) with subsoiling.
4) Mowing in rainy season and harrowing in the dry one without subsoiling; 5)
Intercropping of jackbean (Canavalia ensiformis D.C.) in the rainy season and harrowing
in the dry one with subsoiling; .6) Intercropping of jackbean in rainy season and
harrowing in dry one without subsoiling. The experiment design was a split-plot
randomized block with the treatments as plots and subsoiling depth as subplots. The assay
was set for in field early in 1994 in a citrus orchard (Pera orange Citrus sinensis, Osbeck
on ‘Rangpure’ lime C. limonia, Osbeck.) and the physical soil properties were assessed in
2003. By the result it was concluded that the tillage systems green cover, mowing and
subsoiling alone or associated with Canavalia ensiformes, D.C.- promoted important
beneficial modification in the physical and hydric attributes evaluated. It was observed
that 80% of the roots were at 0-30 cm in deph and 63% were at 20 cm.The lateral root
distribution was 80% corresponding at plant canopy. The combination C. ensiformis and
subsoiling tended to result longer and deeper in depth citrus roots. / Apesar da importante inserção social e econômica da citricultura nos tabuleiros costeiros
da Região Nordeste, com destaque para os estados da Bahia e Sergipe com 11% da
produção nacional, a produtividade média é considerada muito baixa com cerca de 1 caixa
(40,8kg) por planta. Entre os fatores que limitam o agronegócio dos citros, destacam-se os
problemas relacionados às características químicas e físicas dos solos dos tabuleiros
costeiros, tais como elevada acidez e baixa fertilidade natural, presença de camadas coesas
relacionadas com alterações prejudiciais ao regime hídrico desses solos e limitação do
aprofundamento do sistema radicular dos citros. O manejo do solo na entrelinha dos
pomares visando inibir a competição da vegetação espontânea, tem promovido o uso
intensivo de máquinas, especialmente grade, e vem contribuindo para potencializar os
efeitos negativos das camadas coesas, com reflexos na produtividade dos citros. Portanto,
há demanda de pesquisa sobre sistemas conservacionistas de manejo do solo com
leguminosas, subsolagem e outros que contribuam para a melhoria física, química e
biológica dos solos de tabuleiros visando diminuir a susceptibilidade a perda de água na
época seca, com reflexos no desenvolvimento das plantas, produtividade e qualidade dos
frutos. Essa pesquisa teve como objetivos estudar a influência dos sistemas de manejo nos
atributos físicos e hídricos do solo, na distribuição e aprofundamento do sistema radicular
da plantas cítricas; a fertilidade do solo, estado nutricional, desenvolvimento e
produtividade dos citros. Os tratamentos foram: 1) grade nas águas (abril a setembro) e no
período seco (outubro a março) na presença de subsolagem; 2) grade nas águas (abril a
setembro) e no período seco (outubro a março) na ausência de subsolagem; 3) roçadeira
nas águas e grade no período seco na presença de subsolagem; 4) roçadeira nas águas e
grade no período seco na ausência de subsolagem; 5) plantio de feijão-de-porco nas águas
e grade no período seco na presença de subsolagem; 6) plantio de feijão-de-porco nas
águas e grade no período seco na ausência de subsolagem. A subsolagem promove
melhoria de atributos físicos e hídricos do solo. O sistema radicular das plantas cítricas
(‘Pêra’ sobre ‘Cravo’) é predominantemente superficial (camada 0-20cm) e restrito ao raio
da projeção da copa das plantas. O manejo com feijão-de-porco, na entrelinha do pomar,
associado à subsolagem promove maior comprimento de raízes; o sistema de manejo por
métodos mais conservacionistas (feijão-de-porco e roçagem) comparados ao uso de grade,
promove menor degradação da fertilidade do solo; os sistemas de manejo não influenciam
no crescimento, volume da copa e estado nutricional das plantas cítricas, entretanto, a
melhor produtividade do pomar ocorre com o manejo de feijão-de-porco nas águas
incorporado com grade no final das águas, associado ao uso de grade no início do período
seco, independente da subsolagem.
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Effects of soil management practices on water infiltration and maize yield to improve Mississippi River Valley Alluvial Aquifer sustainabilityRix, Jacob 09 December 2022 (has links) (PDF)
Surface sealing and hardpans in loam soils are problematic in the Mid-South U.S. because of intense tillage. Two experiments quantified the effects of soil management practices on infiltration and maize yield in loam soils. The first study measured the impacts of in-row subsoiling frequency × furrow irrigation frequency. In-row subsoiling significantly improved the infiltration of irrigation but not the infiltration of precipitation. In-row subsoiling with low irrigation frequency is optimal to achieve profitable maize yields while encouraging groundwater conservation. In the second study, six soil management treatments were imposed. For single-ring infiltrometer tests, infiltration rates were different between the two measurement dates but not between measured treatments. In 2022, neutron attenuation data indicated no differences in soil water content between measured treatments. Based on both studies, in-row subsoiling was proven to be an economically viable option in comparison to other Mississippi Delta on-farm conservation practices in the short term.
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Influence of nursery stock, planting practices, fertilization and competition control on initial survival and growth of Nuttall and white oak seedlingsMoree, Joshua Larue 11 August 2007 (has links)
This project evaluates the survival and initial growth response of oak seedlings produced under special nursery protocols (?enhanced? seedlings) compared to nursery-run oak seedlings of the same species, and the influence of various cultural practices on these same nursery stocks. Survival did not differ significantly between nursery stocks. Significant differences in survival among competition control treatments did occur. Intensive competition control regimes using glyphosate can negatively impact seedling survival if seedlings come in contact with herbicide spray drift.Nursery-run seedlings had significantly greater growth and many were larger than enhanced seedlings after two growing seasons. Height growth was typically greater with seedlings receiving less intensive competition control, while groundline diameter (GLD) growth was greatest with seedlings receiving more intensive competition control. Subsoil and auger planting typically resulted in greater growth than normal hand planting. Fertilization improved growth in certain areas, but the effects diminished after the first growing season.
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Desempenho operacional de um subsolador em função da estrutura, do teor de argila e de água em três latossolos. / Operational performance of a subsoiler as a function of the structure, clay and moisture content in three latosols.Sasaki, Cassiano Massakazu 20 April 2005 (has links)
A rápida evolução tecnológica da silvicultura brasileira, verificada na década de 80, culminou com o sistema de cultivo mínimo do solo, implantado em grande escala a partir do início da década de 90. Levantamentos recentes junto a empresas florestadoras de expressão nacional, indicaram que cerca de 77% da área plantada é realizada no sistema de cultivo mínimo do solo. O amplo emprego do subsolador no cultivo mínimo e a falta de estudos científicos no projeto, o empirismo associado à operação e a falta de informações sobre a interação entre o teor de água e o tipo de solo subsolado motivaram a condução do presente estudo, cujos objetivos foram: (i) avaliar o desempenho operacional de um subsolador com haste parabólica em função da estrutura, do teor de argila e de água em três Latossolos, (ii) avaliar o grau de mobilização do solo em função de teores crescentes de argila e de água, (iii) avaliar a duração do efeito desagregador da subsolagem e a relação entre a área mobilizada de solo e o tempo póssubsolagem e, (iv) estabelecer um intervalo ideal de umidade para a subsolagem, em função da mobilização e da densidade máxima do solo. As pesquisas foram desenvolvidas em um Latossolo Vermelho Distrófico textura média (LVd-1), um Latossolo Vermelho Distrófico textura argilosa (LVd-2) e um Latossolo Vermelho Distrófico textura muito argilosa (LVd-3). A avaliação do desempenho operacional do subsolador foi realizada por meio dos parâmetros volume mobilizado de solo (VMS), profundidade efetiva de trabalho (PET), largura efetiva de trabalho (LET), velocidade média de deslocamento (VMD), capacidade teórica de trabalho (CTT) e rendimento (R). O grau de mobilização dos solos e o tempo de duração dos efeitos da subsolagem foram avaliados por meio da área mobilizada de solo (AMS), mensurada em três datas: logo após a subsolagem, 12 e 24 meses pós-subsolagem. O intervalo ideal de umidade para a subsolagem foi baseado na AMS e no teste de Proctor normal. A maioria dos parâmetros usados na avaliação do desempenho operacional indicou que teores de água mais baixos melhoram o desempenho do subsolador. Nos solos com estrutura em blocos, LVd-2, e com alto teor de argila, LVd-3, foram obtidos o maior VMS (com o solo mais seco) e o menor R (com o solo mais úmido); esses atributos também provocaram maior readensamento das partículas de solo no sulco de preparo, diminuindo o efeito desagregador da subsolagem mais rapidamente. Tanto no LVd-2, como no LVd-3, praticamente a metade da área mobilizada inicial foi modificada (56 e 49%, respectivamente). O LVd-1 foi o solo que apresentou a menor resposta aos tratamentos, em função de sua capacidade de suporte ser mais estável que a dos outros Latossolos estudados. O LVd-1 apresentou melhores condições de ser subsolado entre os teores de água de 0,07 a 0,13 cm3 cm-3, o LVd-3, entre 0,14 a 0,27 cm3 cm-3 e, o LVd-2, apresentou a amplitude de subsolagem mais restrita, entre 0,12 a 0,19 cm3 cm-3. / The fast technological development of the Brazilian silviculture, during the 80s decade, culminated with the soil minimum cultivation system, established in large degree from the beginning of the 90s decade. Recent surveys in expressive Brazilian forest companies, indicated that about 77% of the planted area is accomplish under the soil minimum cultivation system. The large use of the subsoiler in the minimum cultivation, the empiricism associated to the operation and the lack of information about the interaction between the moisture content and the subsoiled soil motivated the present study, which objectives were: (i) evaluate the operational performance of a subsoiler with parabolic tine as a function of the soil structure, clay and moisture content of three Latosols, (ii) evaluate the soil disturbance degree as a function of the increasing on the clay and moisture content, (iii) evaluate the length of the subsoiling effect on the soil and the relationship between the soil disturbed area and the time after the subsoiling and, (iv) settle an ideal water interval to the subsoiling, as a function of the soil disturbance and the maximum bulk density. The researchers were developed in a sandy clay loam dystrophic Red Latosol (LVd-1), a clay dystrophic Red Latosol with kaolinit (LVd-2) and a clay dystrophic Red Latosol (LVd-3). The operational performance evaluation was realized by the parameters soil disturbed volume (SDV), work depth (WD), work width (WW), average speed (AS), theoretical work capacity (TWC) and efficiency (E). The soils disturbance degree and the length of the subsoiling effects were evaluated by the soil disturbed area (SDA), which was measured three times: after the subsoiling, 12 and 24 months after the subsoiling. The ideal water interval of the subsoiling was based upon the SDA and the normal Proctors test. Most of the parameters used to the operational performance evaluation indicated that lower moisture contents improve the subsoiler performance. The soils with structure in blocks, LVd-2, and high clay content, LVd-3, presented higher SDV (when the soils were dryer) and lower E (when the soils were damper); these characteristics provoked high age-hardening of the soil particles either, decreasing the subsoiling effect faster. Almost half of the original soil disturbed area was modified in the LVd-2 and in the LVd-3 (56 and 49%, respectively). The LVd-1 was the soil that presented the lower effect to the treatments, as a function of its high stability. The LVd-1 presented better conditions to be subsoiled between the moisture contents of 0,07 and 0,13 cm3 cm-3, the LVd-3, between 0,14 and 0,27 cm3 cm-3 and, the LVd-2, presented the lower subsoiling water range, between 0,12 and 0,19 cm3 cm-3.
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Desempenho operacional de um subsolador em função da estrutura, do teor de argila e de água em três latossolos. / Operational performance of a subsoiler as a function of the structure, clay and moisture content in three latosols.Cassiano Massakazu Sasaki 20 April 2005 (has links)
A rápida evolução tecnológica da silvicultura brasileira, verificada na década de 80, culminou com o sistema de cultivo mínimo do solo, implantado em grande escala a partir do início da década de 90. Levantamentos recentes junto a empresas florestadoras de expressão nacional, indicaram que cerca de 77% da área plantada é realizada no sistema de cultivo mínimo do solo. O amplo emprego do subsolador no cultivo mínimo e a falta de estudos científicos no projeto, o empirismo associado à operação e a falta de informações sobre a interação entre o teor de água e o tipo de solo subsolado motivaram a condução do presente estudo, cujos objetivos foram: (i) avaliar o desempenho operacional de um subsolador com haste parabólica em função da estrutura, do teor de argila e de água em três Latossolos, (ii) avaliar o grau de mobilização do solo em função de teores crescentes de argila e de água, (iii) avaliar a duração do efeito desagregador da subsolagem e a relação entre a área mobilizada de solo e o tempo póssubsolagem e, (iv) estabelecer um intervalo ideal de umidade para a subsolagem, em função da mobilização e da densidade máxima do solo. As pesquisas foram desenvolvidas em um Latossolo Vermelho Distrófico textura média (LVd-1), um Latossolo Vermelho Distrófico textura argilosa (LVd-2) e um Latossolo Vermelho Distrófico textura muito argilosa (LVd-3). A avaliação do desempenho operacional do subsolador foi realizada por meio dos parâmetros volume mobilizado de solo (VMS), profundidade efetiva de trabalho (PET), largura efetiva de trabalho (LET), velocidade média de deslocamento (VMD), capacidade teórica de trabalho (CTT) e rendimento (R). O grau de mobilização dos solos e o tempo de duração dos efeitos da subsolagem foram avaliados por meio da área mobilizada de solo (AMS), mensurada em três datas: logo após a subsolagem, 12 e 24 meses pós-subsolagem. O intervalo ideal de umidade para a subsolagem foi baseado na AMS e no teste de Proctor normal. A maioria dos parâmetros usados na avaliação do desempenho operacional indicou que teores de água mais baixos melhoram o desempenho do subsolador. Nos solos com estrutura em blocos, LVd-2, e com alto teor de argila, LVd-3, foram obtidos o maior VMS (com o solo mais seco) e o menor R (com o solo mais úmido); esses atributos também provocaram maior readensamento das partículas de solo no sulco de preparo, diminuindo o efeito desagregador da subsolagem mais rapidamente. Tanto no LVd-2, como no LVd-3, praticamente a metade da área mobilizada inicial foi modificada (56 e 49%, respectivamente). O LVd-1 foi o solo que apresentou a menor resposta aos tratamentos, em função de sua capacidade de suporte ser mais estável que a dos outros Latossolos estudados. O LVd-1 apresentou melhores condições de ser subsolado entre os teores de água de 0,07 a 0,13 cm3 cm-3, o LVd-3, entre 0,14 a 0,27 cm3 cm-3 e, o LVd-2, apresentou a amplitude de subsolagem mais restrita, entre 0,12 a 0,19 cm3 cm-3. / The fast technological development of the Brazilian silviculture, during the 80s decade, culminated with the soil minimum cultivation system, established in large degree from the beginning of the 90s decade. Recent surveys in expressive Brazilian forest companies, indicated that about 77% of the planted area is accomplish under the soil minimum cultivation system. The large use of the subsoiler in the minimum cultivation, the empiricism associated to the operation and the lack of information about the interaction between the moisture content and the subsoiled soil motivated the present study, which objectives were: (i) evaluate the operational performance of a subsoiler with parabolic tine as a function of the soil structure, clay and moisture content of three Latosols, (ii) evaluate the soil disturbance degree as a function of the increasing on the clay and moisture content, (iii) evaluate the length of the subsoiling effect on the soil and the relationship between the soil disturbed area and the time after the subsoiling and, (iv) settle an ideal water interval to the subsoiling, as a function of the soil disturbance and the maximum bulk density. The researchers were developed in a sandy clay loam dystrophic Red Latosol (LVd-1), a clay dystrophic Red Latosol with kaolinit (LVd-2) and a clay dystrophic Red Latosol (LVd-3). The operational performance evaluation was realized by the parameters soil disturbed volume (SDV), work depth (WD), work width (WW), average speed (AS), theoretical work capacity (TWC) and efficiency (E). The soils disturbance degree and the length of the subsoiling effects were evaluated by the soil disturbed area (SDA), which was measured three times: after the subsoiling, 12 and 24 months after the subsoiling. The ideal water interval of the subsoiling was based upon the SDA and the normal Proctors test. Most of the parameters used to the operational performance evaluation indicated that lower moisture contents improve the subsoiler performance. The soils with structure in blocks, LVd-2, and high clay content, LVd-3, presented higher SDV (when the soils were dryer) and lower E (when the soils were damper); these characteristics provoked high age-hardening of the soil particles either, decreasing the subsoiling effect faster. Almost half of the original soil disturbed area was modified in the LVd-2 and in the LVd-3 (56 and 49%, respectively). The LVd-1 was the soil that presented the lower effect to the treatments, as a function of its high stability. The LVd-1 presented better conditions to be subsoiled between the moisture contents of 0,07 and 0,13 cm3 cm-3, the LVd-3, between 0,14 and 0,27 cm3 cm-3 and, the LVd-2, presented the lower subsoiling water range, between 0,12 and 0,19 cm3 cm-3.
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Modifying soil structure using plant roots /Löfkvist, John, January 2005 (has links) (PDF)
Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.
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Forbedring af jordkvaliteten efter jordpakning : er løsning løsningen?Grossmann, Freya. January 2002 (has links)
Speciale. / Haves kun i elektronisk udg.
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