Effects of soil water content and initial root volume on the nutrient status of 2+0 Douglas-fir seedlings

New Forests ◽  
1994 ◽  
Vol 8 (3) ◽  
pp. 265-277 ◽  
Author(s):  
Diane L. Haase ◽  
Robin Rose
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Nutrient Status ◽  
Douglas Fir ◽  
Root Volume ◽  
Initial Root

Belowground competition influences growth of natural regeneration in thinned Douglas-fir stands

2008 ◽  
Vol 38 (12) ◽  
pp. 3085-3097 ◽  
Author(s):  
Warren D. Devine ◽  
Timothy B. Harrington
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Nitrogen Concentration ◽  
Nitrogen Deficiency ◽  
Douglas Fir ◽  
Understory Vegetation ◽  
Detectable Effect ◽  
Belowground Competition ◽  
Overstory Trees

Using a factorial combination of understory removal and trenching treatments, we examined the influences of belowground competition from understory and overstory vegetation on growth of naturally established Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) saplings in thinned stands of Douglas-fir on moderately productive, glacially derived soils near Tacoma, Washington. Under limited light (26% ± 16% of full sun), sapling height and diameter growth were significantly reduced by belowground competition from overstory trees. Regardless of presence or absence of belowground competition from trees, understory vegetation did not have a detectable effect on sapling growth. Nitrogen deficiency in saplings was not detected in the presence of belowground competition: where tree roots were excluded, foliar nitrogen concentration and content increased without an increase in foliar mass. Belowground competition from overstory trees had a greater negative effect on growing season soil water content than did understory vegetation. Under the conditions of restricted light availability in this study, limitations in soil water content from competition had a strong growth-limiting effect on Douglas-fir regeneration. As potential canopy trees in a future uneven-aged stand, this sapling cohort would benefit from root gaps created during harvests.

Transport of Nutrients to Tree Root Systems

1974 ◽  
Vol 4 (4) ◽  
pp. 563-565 ◽  
Author(s):  
T. M. Ballard ◽  
D. W. Cole
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Mass Flow ◽  
Nutrient Transport ◽  
Root Systems ◽  
Douglas Fir ◽  
Nitrogen Transport ◽  
Ca Uptake ◽  
Glacial Outwash

Calculations suggest that nutrient transport through the soil to roots by mass flow accounts for less than 22, 37, and 80%, respectively, of the N, K, and Ca uptake by a Douglas-fir stand growing on a nitrogen-deficient soil derived from glacial outwash. Diffusion and dispersion, though limited by soil water content, are evidently especially important in nitrogen transport to root systems in this soil.

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

Irriga ◽  
2008 ◽  
Vol 13 (2) ◽  
pp. 170-181 ◽  
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.

SOIL WATER CONTENT AFFECTS THE AVAILABILITY OF PHOSPHATE

1985 ◽  
pp. 185-189
Author(s):  
M.C.H.Mouat Pieter Nes
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Solution ◽  
Equivalent Reduction

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.

Effect of inter-row cultivation on soil carbon dioxide emission in a peach plantation

2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Carbon Dioxide Emission ◽  
Nutrient Content ◽  
Soil Disturbance ◽  
Biological Properties ◽  
Soil Tillage ◽  
Favourable Effect ◽  
Volumetric Soil Water Content

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.

Evaluation of a Multi-Rod Probe Performance for Accurate Measurements of Soil Water Content

2020 ◽  
Author(s):  
Justyna Szerement ◽  
Aleksandra Woszczyk ◽  
Agnieszka Szyplowska ◽  
Marcin Kafarski ◽  
Arkadiusz Lewandowski ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content

Effects of soil water content and temperature on Bt protein degradation in leaves at thinning stage and buds of Bt cotton

2014 ◽  
Vol 22 (3) ◽  
pp. 300-307
Author(s):  
Meijun ZHANG ◽  
Wude YANG ◽  
Meichen FENG ◽  
Yun DUAN ◽  
Mingming TANG ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Bt Cotton ◽  
Bt Protein

Evapotranspiration Measurement and Irrigation Scheduling for Several Tropical Fruit Crops Using the EnviroScan System

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 549f-550
Author(s):  
Mongi Zekri ◽  
Bruce Schaffer ◽  
Stephen K. O'Hair ◽  
Roberto Nunez-Elisea ◽  
Jonathan H. Crane
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
National Parks ◽  
Quantitative Information ◽  
Irrigation Scheduling ◽  
Management Tool ◽  
Fruit Crops ◽  
Tropical Fruit

In southern Florida, most tropical fruit crops between Biscayne and Everglades National Parks are irrigated at rates and frequencies based on experience and observations of tree growth and fruit yield rather than on reliable quantitative information of actual water use. This approach suggests that irrigation rates may be excessive and could lead to leaching of agricultural chemicals into the groundwater in this environmentally sensitive area. Therefore, a study is being conducted to increase water use efficiency and optimize irrigation by accurately scheduling irrigation using a very effective management tool (EnviroScan, Sentek Environmental Innovations, Pty., Kent, Australia) that continuously monitors soil water content with highly accurate capacitance multi-sensor probes installed at several depths within the soil profile. The system measures crop water use by monitoring soil water depletion rates and allows the maintenance of soil water content within the optimum range (below field capacity and well above the onset of plant water stress). The study is being conducted in growers' orchards with three tropical fruit crops (avocado, carambola, and `Tahiti' lime) to facilitate rapid adoption and utilization of research results.

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