COTTON ROOT VOLUME AND ROOT DRY MATTER AS A FUNCTION OF HIGH SOIL BULK DENSITY AND SOIL WATER STRESS

COTTON ROOT VOLUME AND ROOT DRY MATTER AS A FUNCTION OF HIGH SOIL BULK DENSITY AND SOIL WATER STRESS Charles Duruoha1; Cassio Roberto Piffer2; Paulo Roberto Arbex Silva21United States Department of Agriculture (USDA-ARS), National Soil Dynamics Laboratory, Auburn, AL, U.S.A,. [email protected] 2Rural Engineering Departament, School of Agronomic Sciences, São Paulo State University, Botucatu, SP 1 ABSTRACT Soil compaction reduces root growth, affecting the yield, especially in the Southern Coastal Plain of the USA. Simulations of the root restricting layers in greenhouses are necessary to develop mechanisms which alleviate soil compaction problems. The selection of three distinct bulk densities based on the Standard Proctor Test is also an important factor to determine which bulk density restricts root penetration. This experiment was conducted to evaluate cotton (Gossypium hirsutum L.) root volume and root dry matter as a function of soil bulk density and water stress. Three levels of soil density (1.2, 1.4, and 1.6 g cm-3), and two levels of water content (70 and 90% of field capacity) were used. A completely randomized design with four replicates in a 3x2 factorial pattern was used. The results showed that mechanical impedance affected root volume positively with soil bulk density of 1.2 and 1.6 g cm-3, enhancing root growth (P>0.0064). Soil water content reduced root growth as root and shoot growth was higher at 70% field capacity than that at 90% field capacity. Shoot growth was not affected by the increase in soil bulk density and this result suggests that soil bulk density is not a good indicator for measuring mechanical impedance in some soils. KEY WORDS: soil density, water stress, root growth. DURUOHA, C.; PIFFER, C. R.; SILVA, P. R. A. VOLUME E MATÉRIA SECA RADICULAR DE ALGODÃO EM FUNÇÃO DA DENSIDADE DO SOLO ELEVADA E DO ESTRESSE HÍDRICO 2 RESUMO A compactação do solo reduz o crescimento radicular e, conseqüentemente, afeta a produção, especialmente no sudoeste do EUA. Simulações de camadas de restrição de raízes em casa de vegetação são necessárias para desenvolver mecanismos que reduzam problemas de compactação dos solos. A seleção de três diferentes densidades de solo baseadas no ensaio de Proctor é também um fator importante para determinar qual densidade restringe a penetração da raiz. O presente trabalho foi realizado para avaliar o volume e matéria seca radicular em função da densidade do solo e da disponibilidade hídrica em algodão (Gossypium hirsutum L.). Foram utilizados três níveis de densidade do solo (1,2; 1,4 e 1,6 g.cm-3) e dois níveis de teor de água no solo (70 e 90% da capacidade de campo). Os tratamentos foram inteiramente casualizados com quatro repetições em arranjo fatorial (3 x 2). Os resultados mostraram que o impedimento mecânico afetou o volume radicular com densidade do solo de 1,2 a 1,6 g.cm-3, proporcionando aumento do crescimento radicular (P>0,0064). A compactação subsuperficial restringiu a matéria seca radicular com densidade do solo de 1,2 cm.cm-3, aumentando a quantidade de matéria seca radicular na camada compactada (P<0,0291). O teor de água reduziu o crescimento radicular onde, na capacidade de campo de 70 %, houve aumento de raízes e da parte aérea, em relação à capacidade de campo de 90%. O crescimento da parte aérea não foi afetado pela densidade do solo, este resultado sugere que a densidade do solo não é um bom indicador de impedimento mecânico em alguns solos. UNITERMOS: densidade do solo, estresse hídrico, crescimento radicular.

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ROOT VOLUME AND DRY MATTER OF PEANUT PLANTS AS A FUNCTION OF SOIL BULK DENSITY AND SOIL WATER STRESS.

Irriga ◽

10.15809/irriga.2008v13n2p170-181 ◽

2008 ◽

Vol 13 (2) ◽

pp. 170-181 ◽

Cited By ~ 1

Author(s):

Charles Duruoha ◽

Cassio Roberto Piffer ◽

Paulo Roberto Arbex Silva

Keyword(s):

Water Stress ◽

Root Growth ◽

Water Content ◽

Bulk Density ◽

Soil Water ◽

Soil Water Content ◽

Soil Compaction ◽

Field Capacity ◽

Soil Bulk Density ◽

Root Volume

ROOT VOLUME AND DRY MATTER OF PEANUT PLANTS AS A FUNCTION OF SOIL BULK DENSITY AND SOIL WATER STRESS. Charles Duruoha1; Cassio Roberto Piffer2; Paulo Roberto Arbex Silva21United States Department of Agriculture (USDA-ARS), National Soil Dynamics Laboratory, Auburn, AL - U.S.A., [email protected] de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, São Paulo 1 ABSTRACT Soil compaction may be defined as the pressing of soil to make it denser. Soil compaction makes the soil denser, decreases permeability of gas and water exchange as well as alterations in thermal relations, and increases mechanical strength of the soil. Compacted soil can restrict normal root development. Simulations of the root restricting layers in a greenhouse are necessary to develop a mechanism to alleviate soil compaction problems in these soils. The selection of three distinct bulk densities based on the standard proctor test is also an important factor to determine which bulk density restricts the root layer. This experiment aimed to assess peanut (Arachis hypogea) root volume and root dry matter as a function of bulk density and water stress. Three levels of soil density (1.2, 1.4, and 1.6g cm-3), and two levels of the soil water content (70 and 90% of field capacity) were used. Treatments were arranged as completely randomized design, with four replications in a 3x2 factorial scheme. The result showed that peanut yield generally responded favorably to subsurface compaction in the presence of high mechanical impedance. This clearly indicates the ability of this root to penetrate the hardpan with less stress. Root volume was not affected by increase in soil bulk density and this mechanical impedance increased root volume when roots penetrated the barrier with less energy. Root growth below the compacted layer (hardpan), was impaired by the imposed barrier. This stress made it impossible for roots to grow well even in the presence of optimum soil water content. Generally soil water content of 70% field capacity (P<0.0001) enhanced greater root proliferation. Nonetheless, soil water content of 90% field capacity in some occasions proved better for root growth. Some of the discrepancies observed were that mechanical impedance is not a good indicator for measuring root growth restriction in greenhouse. Future research can be done using more levels of water to determine the lowest soil water level, which can inhibit plant growth. KEY WORDS: Soil compaction; water stress; soil bunk; root volume; root growth DURUOHA, C.; PIFFER, C. R.; SILVA, P. R. A. MATÉRIA SECA E VOLUME DE RAÍZES DE PLANTAS DE AMENDOIMEM FUNÇÃO DADENSIDADEE DO DÉFICIT DE ÁGUA DO SOLO. 2 RESUMO O conceito de compactação do solo não inclui apenas a redução do solo, mas também no resultante decréscimo em permeabilidade para trocas gasosas e água, assim como alterações em relação térmica e aumento na resistência mecânica do solo. Um solo compactado pode restringir o desenvolvimento radicular normal da planta. Simulações de camadas de restrição de raízes em casa de vegetação são necessárias para desenvolver mecanismos que reduzam problemas de compactação dos solos. A seleção de três diferentes densidades de solo, baseadas no ensaio de Proctor, é também um fator importante para determinar qual densidade restringe a penetração da raiz. O presente trabalho foi realizado para avaliar o volume e matéria seca radicular em função da densidade do solo e da disponibilidade hídrica em amendoim (Arachis hypogea). Foram utilizados três níveis de densidade do solo (1,2; 1,4 e1,6 gcm-3) e dois níveis de teor de água no solo (70 e 90% da capacidade de campo). Os tratamentos foram inteiramente casualizados com quatro repetições em arranjo fatorial (3 x 2). Os resultados sugerem que a produção de amendoim geralmente responde favoravelmente à compactação subsuperficial, na presença de impedância mecânica elevada. Este resultado claramente indica a habilidade da raiz em penetrar na camada de impedimento com menor densidade. O volume radicular não foi afetado pelo aumento da densidade do solo e esta impedância mecânica aumentou o volume radicular quando as raízes penetraram em barreiras com menor compactação. O crescimento radicular abaixo da camada compactada foi afetado pela barreira imposta. Esta compactação impossibilitou que as raízes crescessem mesmo na presença de teor de água ótimo. O teor de água de 70 % da capacidade de campo (P<0,0001) proporcionou maior proliferação radicular. Foi observado que a impedância mecânica não é um bom indicador para a avaliação da restrição de crescimento radicular no trabalho em casa de vegetação. UNITERMOS: compactação do solo, capacidade de campo e crescimento radicular.

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Effect of combined soil water and external load on soil compaction

Soil Research ◽

10.1071/sr09144 ◽

2011 ◽

Vol 49 (2) ◽

pp. 135 ◽

Cited By ~ 10

Author(s):

M. A. Hamza ◽

S. S. Al-Adawi ◽

K. A. Al-Hinai

Keyword(s):

Bulk Density ◽

Soil Water ◽

Soil Compaction ◽

External Load ◽

Field Capacity ◽

Infiltration Rate ◽

Soil Bulk Density ◽

Soil Strength ◽

Water Infiltration ◽

Soil Water Infiltration

Reducing soil compaction is now an important issue in agriculture due to intensive use of farm machinery in different farm operations. This experiment was designed to study the influence of combinations of external load and soil water on soil compaction. Four soil water levels were combined with four external loads as follows: soil water—air-dry, 50% of field capacity, field capacity, and saturation; external load using different-sized tractors—no load (0 kg), small tractor (2638 kg), medium tractor (3912 kg), and large tractor (6964 kg). Soil bulk density, soil strength, and soil water infiltration rate were measured at 0–100, 100–200, and 200–300 mm soil depths. The 16 treatments were set up in a randomised block design with three replications. Combined increases in soil water and external load increased soil compaction, as indicated by increasing soil bulk density and soil strength and decreasing soil water infiltration rate. There was no significant interaction between soil water and external load for bulk density at all soil depths, but the interaction was significant for soil strength and infiltration rates at all soil depths. The ratio between the weight of the external load and the surface area of contact between the external load and the ground was important in determining the degree of surface soil compaction. Least compaction was produced by the medium tractor because it had the highest tyre/ground surface area contact. In general, the effects of soil water and external load on increasing soil bulk density and soil strength were greater in the topsoil than the subsoil.

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Impact of Intensive Forest Management Practices on the Bulk Density of Lower Coastal Plain and Piedmont Soils

Southern Journal of Applied Forestry ◽

10.1093/sjaf/9.1.44 ◽

1985 ◽

Vol 9 (1) ◽

pp. 44-48 ◽

Cited By ~ 4

Author(s):

J. A. Gent ◽

R. Ballard

Keyword(s):

Root Growth ◽

Bulk Density ◽

Coastal Plain ◽

Soil Compaction ◽

Management Practices ◽

Soil Surface ◽

Mechanical Impedance ◽

Soil Bulk Density ◽

Intensive Forest Management ◽

Lower Coastal Plain

Abstract Trafficking during harvesting significantly increased soil bulk density to depths of 3 to 6 inches in areas outside of primary skid trails and 9 to 12 inches in primary skid trails. On the Coastal Plain site, bedding was effective in offsetting soil compaction in areas outside of primary skid trails, forming a new soil surface, 7 to 8 inches in height, over the surface trafficked during harvest. Bedding may not be so effective in the skid trails, because the original soil surface under the bed was so compacted that root growth may be inhibited. On the Piedmont site, disking was effective in restoring bulk density to preharvest levels in the upper 3 to 5 inches of soil, but soil compaction in the upper 3 to 9 inches of drum-chopped areas may result in reduced root growth, because of mechanical impedance.

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CORN ROOT LENGTH DENSITY AND ROOT DIAMETER AS AFFECTED BY SOIL COMPACTION AND SOIL WATER CONTENT

Irriga ◽

10.15809/irriga.2007v12n1p14-26 ◽

2007 ◽

Vol 12 (1) ◽

pp. 14-26 ◽

Cited By ~ 2

Author(s):

Charles Duruoha ◽

Cassio Roberto Piffer ◽

Paulo Arbex Silva

Keyword(s):

Root Growth ◽

Water Content ◽

Bulk Density ◽

Soil Water ◽

Soil Water Content ◽

Root Length ◽

Soil Compaction ◽

Root Length Density ◽

Field Capacity ◽

Root Diameter

CORN ROOT LENGTH DENSITY AND ROOT DIAMETER AS AFFECTED BY SOIL COMPACTION AND SOIL WATER CONTENT Charles Duruoha1; Cassio Roberto Piffer2; Paulo Arbex Silva2(1) United States Department of Agriculture (USDA-ARS), National Soil Dynamics Laboratory, Auburn, AL - U.S.A, [email protected] (2) Universidade Estadual Paulista, Faculdade de Ciências Agronômicas, Departamento de Engenharia Rural, Botucatu, SP 1 ABSTRACT Negative effects of soil compaction have been recognized as one of the problems restricting the root system and consequently impairing yields, especially in the Southern Coastal Plain of the USA. Simulations of the root restricting layers in green house studies are necessary for the development of mechanism which alleviates soil compaction problems in these soils. The selection of three distinct bulk densities based on the standard proctor test is also an important factor to determine which bulk density restricts the root layer. The experiment was conducted to assess the root length density and root diameter of the corn (Zea mays L.) crop as a function of bulk density and water stress, characterized by the soil density (1.2; 1.4, and 1.6 g cm-3), and two levels of the water content, approximately (70 and 90% field capacity). The statistical design adopted was completely randomized design, with four replicates in a factorial pattern of (3 x 2). The PVC tubes were superimposed with an internal diameter of 20 cm with a height of 40 cm (the upper tube 20 cm, compacted and inferior tube 10 cm), the hardpan with different levels of soil compaction were located between 20 and 30 cm of the depth of the pot. Results showed that: the main effects of subsoil mechanical impedance were observed on the top layer indicating that the plants had to penetrate beyond the favorable soil conditions before root growth was affected from 3.16; 2.41 to 1.37 cm cm-3 (P<0.005). There was a significant difference at the hardpan layer for the two levels of water and 90% field capacity reduced the root growth from 0.91 to 0.60 cm cm-3 (P<0.005). The root length density and root diameter were affected by increasing soil bulk density from 1.2 to 1.6 g cm-3 which caused penetration resistance to increase to 1.4 MPa. Soil water content of 70% field capacity furnished better root growth in all the layers studied. The increase in root length density resulted in increased root volume. It can also be concluded that the effect of soil compaction impaired the root diameter mostly at the hardpan layer. Soil temperature had detrimental effect on the root growth mostly with higher bulk densities. KEYWORDS: Soil compaction, water, bulk density, soil strength, root growth. DURUOHA, C.; PIFFER, C. R.; SILVA, P. A. COMPRIMENTO E DIÂMETRO RADICULAR DO MILHO, EM FUNÇÃO DA COMPACTAÇÃO E DO TEOR DE ÁGUA NO SOLO 2 RESUMO Os efeitos negativos da compactação do solo vêm sendo reconhecidos como um dos problemas que restringe o sistema radicular e conseqüentemente, impede a produção agrícola, especialmente no sudoeste dos Estados Unidos. Simulações de camadas de restrição de raízes, em casa de vegetação, são necessárias para desenvolver mecanismos que reduzam problemas de compactação dos solos. A seleção de três diferentes densidades de solo, baseadas no ensaio de Proctor é também um fator importante para determinar qual densidade restringe a penetração da raiz. O experimento foi conduzido para avaliar o comprimento e diâmetro radicular da cultura do milho (Zea mays L.), em função da densidade do solo e do estresse hídrico, caracterizado pelas densidades (1,2; 1,4 e 1,6 cm-3) e dois níveis de teor de água (70 e 90 % da capacidade de campo). O método estatístico utilizado foi inteiramente casualizado, com quatro repetições, em arranjo fatorial (3 x 2). Os vasos foram montados em tubos de PVC, com diâmetro interno de 20 cm, sobrepostos, totalizando 40 cm de altura (anel superior com 20 cm e anéis compactado e inferior com 10 cm), a camada com diferentes níveis de solo compactado foi instalada entre 20 e 30 cm de profundidade nos vasos. Os resultados indicaram, através da resistência mecânica que na camada superior as raízes conseguiram penetrar até onde havia condições favoráveis do solo, antes que o sistema radicular fosse afetado de 3,16; 2,41 e 1,37 cm cm-3 (P<0.005). Ocorreu diferença significativa na camada compactada para os dois níveis de teor de água, sendo que a 90 % da capacidade de campo houve uma redução do crescimento radicular de 0,91 para 0,60 cm cm-3 (P<0,005). O comprimento e o diâmetro radicular foram afetados pelo aumento da densidade do solo de 1,2 a 1,6 g cm-3, com resistência à penetração de 1.4 MPa. O teor de água de 70 % da capacidade de campo proporcionou maior comprimento radicular em todas as densidades estudadas. O aumento no comprimento radicular resultou em maior volume radicular. Concluiu-se também que os efeitos da compactação do solo prejudicaram o diâmetro radicular, principalmente na camada compactada. A temperatura do solo afetou o crescimento radicular, principalmente nas camadas com densidade elevada. UNITERMOS: compactação do solo, teor de água, densidade do solo, resistência à penetração, crescimento radicular.

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WATER TRANSPORT AND GROWTH OF CASHEW (Anacardium occidentale L.) UNDER SOIL MECHANICAL IMPEDANCE

Jurnal Penelitian Tanaman Industri ◽

10.21082/littri.v21n3.2015.117-124 ◽

2016 ◽

Vol 21 (3) ◽

pp. 117

Author(s):

JOKO PITONO ◽

TSUDA MAKOTO ◽

YOSHIHIKO HIRAI

Keyword(s):

Root Growth ◽

Bulk Density ◽

Water Transport ◽

Mechanical Impedance ◽

Soil Bulk Density ◽

Hydraulic Conductance ◽

Anacardium Occidentale ◽

Specific Response ◽

Root Area ◽

Four Levels

ABSTRACTThe ability to adapt to soil mechanical impedance was considered to support cashew growing in drought prone areas, since those areas are sometimes aggravated by problem on soil mechanical impedance. The response of water transport and growth under soil mechanical impedance was evaluated at two productive cashew accessions. Two cashew accessions, A3-1, that adapt well to drought stress, and a local accession Pangkep, and four levels of soil bulk densities of 0.75 g cm-3, 0.90 g cm-3, 1.00 g cm-3 and 1.24 g cm-3 under sufficient soil moisture conditions, were arranged in factorially completely randomized design with five replications. The response of shoot and root growth, transpiration and hydraulic conductance were evaluated. The results showed that the accession of A3-1 indicated a better to maintain root growth under soil mechanical impedance that produced thick root/total root length ratio and xylem area/transvesal root area ratio more than Pangkep. On the other hand, A3-1 was faster in reducing leaf area than Pangkep when subjected to increased level of soil bulk density treatments. Although the hydraulic conductance was not varied among the cashew accessions and had not a specific response trend to soil bulk density treatments, however, the increase of diurnal transpiration induced by increased level of soil bulk density treatment in A3-1 was higher than it in Pangkep. It is suggested that the ability to regulate the root and shoot growth and water transport under soil mechanical impedance condition was better in A3-1 than in Pangkep. Moreover, it might be a part attribute of drought tolerance on A3-1 accession.Keywords: cashew, soil mechanical impedance, growth, water transport ABSTRAKTransportasi Air dan Pertumbuhan Jambu Mente (Anacardium occidentale L.) pada Berbagai Hambatan Mekanik TanahKemampuan adaptasi terhadap hambatan mekanik tanah diper- kirakan membantu pengembangan jambu mente di wilayah berlahan kering, mengingat kondisi wilayah tersebut sering diperparah oleh masalah hambatan mekanik tanah. Respon transportasi air tanaman dan pertum- buhan terhadap hambatan mekanik tanah dievaluasi pada dua aksesi jambu mente. Dua aksesi jambu mete, A3-1 yang adaptif terhadap stres kekeringan dan aksesi lokal, Pangkep, serta 4 level padatan tanah 0.75 g.cm-3, 0.90 g.cm-3, 1.00 g.cm-3, dan 1.24 g.cm-3 dengan kondisi lengas tanah dijaga selalu cukup, disusun dalam rancangan faktorial acak lengkap dengan lima ulangan. Respon pertumbuhan akar dan tajuk, transpirasi, dan daya hantar air tanaman dievaluasi. Hasil penelitian menunjukkan bahwa A3-1 lebih mampu menjaga pertumbuhan akar pada kondisi hambatan mekanik tanah dengan nilai rasio panjang akar tebal/panjang total akar dan rasio luas xylem/luas melintang akar lebih lebih besar daripada Pangkep. Pada sisi lain, A3-1 mengurangi luas daun lebih cepat dibanding Pangkep saat diberikan kenaikan perlakuan berat isi tanah. Meskipun tidak ada perbedaan daya hantar air tanaman di antara kedua aksesi dan tidak adanya pola respon spesifik terhadap perlakuan padatan tanah, namun terjadi kenaikan transpirasi harian lebih besar pada A3-1 daripada Pangkep. Hasil ini mengindikasikan bahwa kemampuan A3-1 mengatur pertumbuhan dan transportasi air saat mengalami hambatan mekanik tanah lebih baik daripada Pangkep. Hal ini mungkin merupakan bagian dari sifat toleransi terhadap kekeringan pada aksesi A3-1.Kata kunci: jambu mente, hambatan mekanik tanah, pertumbuhan, transportasi air

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Initial Growth and Roots Development of Soybean as Function of Water Availability and Soil Bulk Density

Journal of Agricultural Science ◽

10.5539/jas.v11n16p213 ◽

2019 ◽

Vol 11 (16) ◽

pp. 213

Author(s):

Pâmela de Andrades Timm ◽

Marília Alves Brito Pinto ◽

José Maria Barbat Parfitt ◽

Germani Concenço ◽

Alexssandra Dayanne Soares de Campos ◽

...

Keyword(s):

Bulk Density ◽

Soil Water ◽

Water Availability ◽

Soil Compaction ◽

Soil Bulk Density ◽

Initial Growth ◽

Initial Development ◽

Soybean Crop ◽

Soil Water Tension ◽

Soybean Plants

Soil compaction is preponderant in soil physical-hydric relationships, which in turn, exert direct effect on plant development. In this context, this work aimed to evaluate the initial development of shoot and roots of soybean plants (Glycine max (L.) Merril), cv. BMX Ícone, cultivated in different combinations of soil bulk densities and water availability. A greenhouse experiment was carried out at the EMBRAPA Lowland Experimental Station, Rio Grande do Sul, Brazil. Soybean plants were grown in seven levels of soil bulk density (1.4, 1.5, 1.6, 1.7, 1.8, 1.9 and 2.0 kg dm-3) coupled to two soil water tensions (10 and 50 kPa). Plant height and leaf area, as well as root volume, decreased when soybean was cultivated at 50 kPa, associated to soil bulk densities above 1.8 kg dm-3. Soybean crop showed to be most sensitive to water deficit than to soil compaction, and soil water tension around the field capacity (10 kPa) should be associated to soil bulk density lower than 1.8 kg dm-3 to allow adequate soybean crop development.

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The effects of soil water content and bulk density on the compactibility and soil penetration resistance of some Western Australian sandy soils

Soil Research ◽

10.1071/sr9880391 ◽

1988 ◽

Vol 26 (2) ◽

pp. 391 ◽

Cited By ~ 46

Author(s):

C Henderson ◽

A Levett ◽

D Lisle

Keyword(s):

Water Content ◽

Bulk Density ◽

Soil Water ◽

Soil Water Content ◽

Soil Compaction ◽

Field Capacity ◽

Penetration Resistance ◽

Coarse Sand ◽

Soil Penetration Resistance ◽

Compactive Effort

Quantitative models to predict the effects of soil compaction on wheat yields are being developed for the northern sandplains of Western Australia. An understanding of the relationships between soil water content (W), bulk density (p), compactibility and soil penetration resistance (P) is required. Thirteen subsoils from W.A. sandplain soils were tested for compactibility. As the amounts of very coarse sand or clay in the soil increased, the maximum density (�max.) achieved with a standard compactive effort also increased, while the critical soil water content (Wcrit,.) for maximum compactibility declined. The effects of p and W on P were investigated for five of the soils. The value of P was only slightly affected as W was reduced to less than 70% of the field capacity water content. As the soils were dried further, P increased exponentially. At all water contents, an increase in p was found to markedly increase P. Particle size distribution could be used to predict �max. and Wcrit., but could not be related to the effects of changes in p and W on P. The implications for the measurement and effects of soil compaction in the field are discussed.

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Critical soil bulk density for soybean growth in Oxisols

International Agrophysics ◽

10.1515/intag-2015-0050 ◽

2015 ◽

Vol 29 (4) ◽

pp. 441-447 ◽

Cited By ~ 3

Author(s):

Michel Keisuke Sato ◽

Herdjania Veras de Lima ◽

Pedro Daniel de Oliveira ◽

Sueli Rodrigues

Keyword(s):

Root Growth ◽

Bulk Density ◽

Clayey Soil ◽

Sandy Loam ◽

Field Capacity ◽

Penetration Resistance ◽

Soil Bulk Density ◽

Dry Mass ◽

Soybean Root ◽

Soil Penetration Resistance

Abstract The aim of this study was to evaluate the critical soil bulk density from the soil penetration resistance measurements for soybean root growth in Brazilian Amazon Oxisols. The experiment was carried out in a greenhouse using disturbed soil samples collected from the northwest of Para characterized by different texture. The treatments consisted of a range of soil bulk densities for each soil textural class. Three pots were used for soybean growth of and two for the soil penetration resistance curve. From the fitted model, the critical soil bulk density was determined considering the penetration resistance values of 2 and 3 MPa. After sixty days, plants were cut and root length, dry mass of root, and dry mass of shoots were determined. At higher bulk densities, the increase in soil water content decreased the penetration resistance, allowing unrestricted growth of soybean roots. Regardless of soil texture, the penetration resistance of 2 and 3 MPa had a slight effect on root growth in soil moisture at field capacity and a reduction of 50% in the soybean root growth was achieved at critical soil bulk density of 1.82, 1.75, 1.51, and 1.45 Mg m-3 for the sandy loam, sandy clay loam, clayey, and very clayey soil.

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EFFECTS OF SUBSOIL BULK DENSITY, NUTRIENT AVAILABILITY AND SOIL MOISTURE ON CORN ROOT GROWTH IN THE FIELD

Canadian Journal of Soil Science ◽

10.4141/cjss87-026 ◽

1987 ◽

Vol 67 (2) ◽

pp. 293-308 ◽

Cited By ~ 9

Author(s):

M. STYPA ◽

A. NUNEZ-BARRIOS ◽

D. A. BARRY ◽

M. H. MILLER ◽

W. A. MITCHELL

Keyword(s):

Root Growth ◽

Water Potential ◽

Bulk Density ◽

Soil Water ◽

Soil Water Potential ◽

Soil Bulk Density ◽

Corn Root ◽

Penetrometer Resistance ◽

Loam Soil ◽

Distribution Of Roots

In a 4-yr study, root growth in the upper 50 cm of a silt loam soil (Gleyed Melanic Brunisol) was equal to or greater than that in a low-density artificial medium (soil:peat:perlite) in spite of a high bulk density in the soil (1.5 Mg m−3 in the 15-to 45-cm depth). We suggest that, due to the natural structure of the Bm horizon, the resistance to root growth is much less than would be expected from bulk density or penetrometer resistance measurements. Marked increases in P and K fertility in the surface soil had only minor effects on either the total length or distribution of roots although the shoot growth was markedly increased. Neither total root length nor root distribution were altered by irrigation during 1981, the only year a moisture variable was included. During a 2-wk dry period in July, prior to anthesis, soil water potential on the nonirrigated plots decreased to −1.5 MPa in the upper 15 cm and to −0.5 MPa in the 15- to 30-cm layer. Leaf water potential, stomatal conductance and rate of growth during the period were lower on the nonirrigated treatment although final dry matter production was not. The results indicate that corn root growth and distribution in the field are not as sensitive to environmental factors as one would expect from short-term laboratory studies. Key words: Corn, root growth, soil bulk density, fertility, soil water

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Effect of Smashing Ridge Tillage Depth on Soil Water, Salinity, and Yield in Saline Cotton Fields in South Xinjiang, China

Water ◽

10.3390/w13243592 ◽

2021 ◽

Vol 13 (24) ◽

pp. 3592

Author(s):

Zhentao Bai ◽

Hongguang Liu ◽

Tangang Wang ◽

Ping Gong ◽

Huiqin Li ◽

...

Keyword(s):

Bulk Density ◽

Soil Water ◽

Dry Matter ◽

Salt Content ◽

Soil Layer ◽

Soil Bulk Density ◽

Dry Matter Production ◽

Matter Production ◽

Opening Stage ◽

Ridge Tillage

To explore the potential of smashing ridge tillage irrigation, it is necessary to investigate how smashing ridge tillage technology with mulched drip irrigation affects soil water, salinity, and cotton yield in saline fields. We conducted a two-year (2020–2021) field experiment to study the effects of different smashing ridge tillage depths on soil bulk density, moisture, salinity, dry matter production, yield, and its constituents (effective bolls, 100-bell weight). There were three smashing ridge tillage depths: A (20 cm), B (40 cm), and C (60 cm), with traditional tillage as the CT. The results showed that all of the smashing ridge tillage could reduce soil bulk density, improve the utilization and uptake of deep soil water during the rapid growth period, and reduce the soil salt content. Compared with the CT treatment, the average soil bulk density of the 0–60 cm soil layer in treatments A, B, and C in 2020 and 2021 decreased by 3.05%, 5.87%, 10.09%, and 1.65%, 4.48%, and 8.49%, respectively. The average soil water content in the 0–120 cm soil layer at the flowering and boll stage decreased by 3.68%, 6.28%, 9.04%, and 3.59%, 6.52%, and 9.98%, respectively; the soil salt content in the 0–120 cm soil layer at the boll opening stage decreased by 4.21%, 6.75%, 11.95%, and 5.47%, 24.25%, and 54.13%, respectively. Cotton dry matter production and yield tended to increase with an increasing depth of smash ridge tillage. Treatment C obtained the maximum dry matter production, seed cotton yield, effective bolls, and 100-boll weight. The dry matter production at the boll opening stage was significantly increased by 17.16% and 15.91%, and the yield was significantly increased by 65.24% and 84.14% in treatments C in 2020 and 2021, respectively, compared to CT. The smashing ridge tillage of 60 cm can optimize the structure of the soil tillage layer and also reduce soil salinity and increase yield, which is the suitable depth of smashing ridge tillage for saline cotton fields in the south of Xinjiang. The findings of the study can provide some theoretical basis and practical experience for the improvement of saline soils and sustainable agricultural development in South Xinjiang, China.

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