Spatial distribution of root length density and soil water of linear agroforestry systems in sub-humid Kenya: implications for agroforestry models

2004 ◽  
Vol 188 (1-3) ◽  
pp. 77-89 ◽  
Author(s):  
Simone Radersma ◽  
Chin K Ong
Keyword(s):  
Spatial Distribution ◽  
Soil Water ◽  
Root Length ◽  
Root Length Density ◽  
Agroforestry Systems

Root length density and soil water distribution in drip-irrigated olive orchards in Argentina under arid conditions

2009 ◽  
Vol 60 (3) ◽  
pp. 280 ◽  
Author(s):  
Peter S. Searles ◽  
Diego A. Saravia ◽  
M. Cecilia Rousseaux
Keyword(s):  
Water Content ◽  
Root System ◽  
Soil Water ◽  
Soil Water Content ◽  
Root Length ◽  
Root Length Density ◽  
Soil Depth ◽  
Drip Line ◽  
North West ◽  
Intensively Managed

Several studies have evaluated many above-ground aspects of olive production, but essential root system characteristics have been little examined. The objective of our study was to evaluate root length density (RLD) and root distribution relative to soil water content in three commercial orchards (north-west Argentina). Depending on the orchard, the different drip emitter arrangements included either: (1) emitters spaced continuously at 1-m intervals along the drip line (CE-4; 4 emitters per tree); (2) 4 emitters per tree spaced at 1-m intervals, but with a space of 2 m between emitters of neighbouring trees (E-4); or (3) 2 emitters per tree with 4 m between emitters of neighbouring trees (E-2). All of the orchards included either var. Manzanilla fina or Manzanilla reina trees (5–8 years old) growing in sandy soils, although the specific characteristics of each orchard differed. Root length density values (2.5–3.5 cm/cm3) in the upper soil depth (0–0.5 m) were fairly uniform along the drip line in the continuous emitter (CE-4) orchard. In contrast, roots were more concentrated in the E-4 and E-2 orchards, in some cases with maximum RLD values of up to 7 cm/cm3. Approximately 70% of the root system was located in the upper 0.5 m of soil depth, and most of the roots were within 0.5 m of the drip line. For each of the three orchards, significant linear relationships between soil water content and RLD were detected based on 42 sampling positions that included various distances from the trunk and soil depths. Values of RLD averaged over the entire rooting zone and total tree root length per leaf area for the three orchards were estimated to range from 0.19 to 0.48 cm/cm3 and from 1.8 to 3.5 km/m2, respectively. These results should reduce the uncertainty associated with the magnitude of RLD values under drip irrigation as intensively managed olive orchards continue to expand in established and new growing regions.

scholarly journals Tree Roots Anchoring and Binding Soil: Reducing Landslide Risk in Indonesian Agroforestry

Land ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 256 ◽  
Author(s):  
Kurniatun Hairiah ◽  
Widianto Widianto ◽  
Didik Suprayogo ◽  
Meine Van Noordwijk
Keyword(s):  
Shear Strength ◽  
Root Length ◽  
Root Length Density ◽  
Fruit Trees ◽  
Agroforestry Systems ◽  
Horizontal Distribution ◽  
Landslide Risk ◽  
Tree Roots ◽  
Deep Roots ◽  
Coffee Agroforestry

Tree root systems stabilize hillslopes and riverbanks, reducing landslide risk, but related data for the humid tropics are scarce. We tested fractal allometry hypotheses on differences in the vertical and horizontal distribution of roots of trees commonly found in agroforestry systems and on shear strength of soil in relation to root length density in the topsoil. Proximal roots of 685 trees (55 species; 4–20 cm stem diameter at breast height, dbh) were observed across six landscapes in Indonesia. The Index of Root Anchoring (IRA) and the Index of Root Binding (IRB) were calculated as ΣDv2/dbh2 and as ΣDh2/dbh2, respectively, where Dv and Dh are the diameters of vertical (angle > 45°) and horizontal (angle < 45°) proximal roots. High IRA values (>1.0) were observed in coffee and several common shade trees. Common fruit trees in coffee agroforestry had low medium values, indicating modest ‘soil anchoring’. Where root length density (Lrv) in the topsoil is less than 10 km m−3 shear strength largely depends on texture; for Lrv > 10 shear strength was >1.5 kg m−2 at the texture tested. In conclusion, a mix of tree species with deep roots and grasses with intense fine roots provides the highest hillslope and riverbank stability.

Growth and yield of rice cultivars under sprinkler irrigation in south-eastern Queensland. 3. Water extraction and plant water relations dash comparison with maize and grain sorghum

1988 ◽  
Vol 28 (2) ◽  
pp. 249 ◽  
Author(s):  
S Fukai ◽  
P Inthapan
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Leaf Water Potential ◽  
Osmotic Potential ◽  
Root Length ◽  
Dry Matter ◽  
Root Length Density ◽  
Leaf Water

Several physiological responses were compared, under irrigated and water-stressed conditions, in an attempt to explain the reasons for the greater reduction in dry matter production of rice compared with maize and sorghum in a water-limiting environment. Leaf water potential and leaf rolling were determined weekly, soil water profiles and root length density twice, and leaf osmotic potential once during a long dry period. Root length density of rice was at least as high as that of maize and sorghum in the top 0.6 m layer of soil in both the wet and dry trials. There was no difference in water extraction among the 3 species from this layer, while rice extracted less water than did the other species from below 0.6 m. High variability among replicates precluded any conclusion being drawn regarding root length in the deeper layer. Leaf water potential, measured in the early afternoon, was consistently lower in rice than in maize and sorghum, even when soil water content was high, indicating high internal resistance to the flow of water in the rice plants. The low leaf water potential in rice was accompanied by low osmotic potential, and this assisted in maintenance of turgor and dry matter growth when soil water content was relatively high. As soil water content decreased, however, leaf water potential became very low (less than - 2.5 MPa) and, for rice, leaves rolled tightly.

scholarly journals Trickle irrigation systems affect spatial distribution of roots of banana crop

2020 ◽  
Vol 24 (5) ◽  
pp. 325-331
Author(s):  
Edvaldo B. Santana Junior ◽  
Eugênio F. Coelho ◽  
Jailson L. Cruz ◽  
João B. R. da S. Reis ◽  
Diego M. de Mello ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Flow Rate ◽  
Root Length ◽  
Root Length Density ◽  
Soil Profiles ◽  
Trickle Irrigation ◽  
Irrigation Systems ◽  
Sprinkler Systems ◽  
Lateral Lines ◽  
Distribution Of Roots

ABSTRACT Trickle irrigation has been largely used for banana in Brazil, mainly due to the increase in water and fertilizer use efficiency. These irrigation systems have different options concerning number, type and flow rate of emitters as well as for hydraulics, number and location of lateral lines. The small area of soil wetted by these systems limits root spatial distribution of crops. This study aimed to evaluate the effect of different trickle irrigation systems on the root spatial growth and root spatial distribution of banana cv. Prata Gorutuba. Root length density and root length were evaluated in soil profiles of three micro-sprinkler systems, with emitter flow rates of 35, 53 and 70 L h-1 and of two drip irrigation systems, with one and two lateral lines per crop row. Trickle irrigation systems influence root spatial distribution, favoring a greater or smaller distribution of roots at different depth and distance from the plant according to micro-sprinkler flow rate and to the number of lateral lines per crop row. The effect on root spatial distribution is more accentuated for micro-sprinkler systems than for drip systems. The majority of the total root length (80%) was observed in the soil profiles from 0.33 to 0.57 m depth and at distances from the plants of 0.75 to 0.83 m.

Banding phosphorus and ammonium enhances nutrient uptake by maize via modifying root spatial distribution

2013 ◽  
Vol 64 (10) ◽  
pp. 965 ◽  
Author(s):  
Qinghua Ma ◽  
Hongliang Tang ◽  
Zed Rengel ◽  
Jianbo Shen
Keyword(s):  
Spatial Distribution ◽  
Nutrient Uptake ◽  
Root Length ◽  
Root Length Density ◽  
Soil Column ◽  
Calcareous Soils ◽  
Ammonium Phosphate ◽  
P Uptake ◽  
Uptake Rates ◽  
P Uptake Rates

Localised supply of phosphorus (P) plus ammonium improves root proliferation and nutrient uptake by plants grown on calcareous soils, but how nitrogen (N) forms (ammonium and urea) and placements affect maize (Zea mays L.) root distribution and nutrient uptake is not fully understood. A soil column study was conducted with four N and P combinations including P plus urea (UP), mono-ammonium phosphate (MAP), di-ammonium phosphate (DAP) and P plus ammonium sulfate (ASP), and two fertiliser application methods (banding in the 10–25 cm layer or mixing throughout the 45-cm soil profile). Shoot N and P content increased by 11–31% and 14–37% in the treatments with banding P plus ammonium (MAP, DAP or ASP) compared with banding UP and the mixing treatments. Shoot N and P uptake rates per root dry weight or root length were higher with banding P plus ammonium than their respective mixing treatments. Banding P plus ammonium increased root-length density in the fertiliser-banded layer compared with banding UP and the mixing treatments. The results show that modifying root spatial distribution by banding P plus ammonium leads to an increase in N and P uptake rates, and consequently enhances nutrient accumulation by maize.

Growth and yield response of barley and chickpea to water stress under three environments in southeast Queensland. II. Root growth and soil water extraction pattern

1995 ◽  
Vol 46 (1) ◽  
pp. 35 ◽  
Author(s):  
s Thoma ◽  
S Fukai ◽  
GL Hammer
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Root Length ◽  
Root Length Density ◽  
Water Extraction ◽  
Barley Cultivars ◽  
Early Stages ◽  
Matter Production ◽  
Early Maturing ◽  
Extractable Soil

Root growth and water extraction of two barley cultivars, Corvette (early maturing), Triumph (late maturing) and one cultivar of chickpea (Amethyst at Redland Bay and Borwen at Hermitage) were compared under three environments: April sowing and July sowing at Redland Bay and June sowing at Hermitage Research Station, south-east Queensland. This work was designed to explain differences in dry matter production in terms of root growth and water uptake during the crop growth, which relied only on stored soil moisture. In the April sowing where all crops grew well during the early stages of growth, decline in soil water with time for the whole profile was similar among all crops. In the winter sowings (June, July), total water use was less in chickpea than in barley, particularly during early stages when chickpea growth was poor. Water extraction patterns of two barley cultivars were similar in all experiments, though the late-maturing Triumph extracted slightly more water than early maturing Corvette towards maturity. Water extraction front velocities of the three crops were similar in each experiment. At Redland Bay, the water extraction front velocities varied from 1.4 to 1.6 cm day-1 in the April sowing and 2.3 to 2.4 cm day-1 in the July sowing, while they varied from 2.0 to 2.3 cm day-1 at Hermitage. However, descent of the water extraction front commenced later in chickpea than in barley when sown in winter months, and this resulted in lower total water use in chickpea, particularly at Hermitage. In both sowings at Redland Bay total root length increased rapidly to about 60 days after sowing in barley, whereas the increase was slower in chickpea. Root length density was high in the upper soil layers, and this was associated with high extractable soil water. In deeper layers both root length density and extractable soil water decreased. For a given root length density chickpea extracted more water than barley. These results indicate that the differences in root growth and water extraction by the two barley crops were rather small and were unlikely to be the reason for the differences in total dry matter production. Chickpea on the other hand appeared to be susceptible to low temperatures during early stages of growth, and this caused poor growth of both shoots and roots.

scholarly journals Seasonal Growth and Spatial Distribution of Apple Tree Roots on Different Rootstocks or Interstems

2013 ◽  
Vol 138 (2) ◽  
pp. 79-87 ◽  
Author(s):  
Li Ma ◽  
Chang Wei Hou ◽  
Xin Zhong Zhang ◽  
Hong Li Li ◽  
De Guo Han ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Root System ◽  
Root Length ◽  
Shoot Growth ◽  
Root Length Density ◽  
Small Region ◽  
Growth Patterns ◽  
Root Dynamics ◽  
Tree Roots ◽  
Root Stock

Understanding of root growth patterns and architecture of apple (Malus ×domestica Borkh.) trees is very important for commercial apple production. Most commercial apple trees are usually a grafted complex consisting of the scion and the rootstock, each of which is a different genotype. Recently, rootstocks of dwarf tree species have been used extensively to meet the convenience in management; however, this practice appears to negatively impact root development. Using minirhizotrons, we investigated root dynamics, root spatial distribution, and shoot growth in ‘Red Fuji’ scion grown: 1) directly on dwarf and vigorous root stocks and 2) on a dwarf root stock placed in between the non-dwarf scion and non-dwarf rootstock (hereinafter referred to as an interstem). The results showed that: 1) one or two peaks in total root length density (TRLD) were observed in each scion/rootstock combinations every year; 2) the greatest TRLD peaks were always observed in between May and December. The peaks of shoot growth were always asynchronous with that of white root length density; 3) compared with scion/vigorous rootstock combinations, inserting a dwarfing interstem between the scion and vigorous seedling rootstock reduced the TRLD; 4) scion/vigorous rootstock combinations had a relatively deep, widespread and large root system. Scion/dwarfing rootstock combinations had a root system distributed in a small region; and the root systems of scion/dwarfing interstem/vigorous rootstock combinations tended to be intermediate between those of scion/vigorous rootstock and scion/dwarfing rootstock. This implies that the insertion of interstems altered the root architecture by not only the quantity of roots, but also the spatial distribution.

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

Irriga ◽  
2007 ◽  
Vol 12 (1) ◽  
pp. 14-26 ◽  
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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