Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Irrigation science 18 (1999), S. 205-211 
    ISSN: 1432-1319
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Evaporation from the soil (E s) beneath an olive orchard was characterised in a semi-arid Mediterranean climate (Córdoba, Spain). First, the microlysimeter method was modified to measure accurately E s beneath tree orchards. The variability in irradiance reaching the soil beneath the orchard caused spatial variations in E s during both evaporation stages. In the first days of the drying cycle, E s was higher for high irradiance locations but the opposite occurred the subsequent days, although daily differences in E s between locations progressively declined. For the energy-limiting stage, linear relationships between E s values and incident photosynthetically active radiation were found for different times throughout the season. The slopes of the relationships were similar, but their intercepts differed substantially, showing the importance of a variable aerodynamic component in determining E s. A simple functional model was formulated to estimate E s at daily time steps. During the energy-limiting stage, E s is calculated as the sum of the equilibrium evaporation at the soil surface and an aerodynamic term, derived from the Penman equation. For the falling rate stage, Ritchie's (1972) approach is adopted for the E s calculations. The model was successfully tested in an orchard of 6×6 m spacing, typical of intensive olive orchards, under a wide range of evaporative demand conditions. Trees covered around 36% of the soil surface. The model predicted an average seasonal E s of 286 mm, which represents around one third of the estimated olive evapotranspiration and about 50% of the average seasonal rainfall of the area.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 183 (1996), S. 239-251 
    ISSN: 1573-5036
    Keywords: cereal roots ; forage ; grain ; minirhizotron ; soil core ; soil water depletion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Root systems of one triticale (× triticosecale Witt.) and one barley (Hordeum vulgare L.) cultivar grown for grain or for the dual purpose of winter forage-plus-grain were studied in a Mediterranean climate (Granada, Spain). The aim was to assess the effect of winter forage removal on root systems and to improve the knowledge of cereal root systems under Mediterranean conditions in relation to soil water use. After the forage was removed by clipping at the end of the winter period, cereal roots were shallower and lower in length densities, compared to the unclipped treatment. The largest differences occurred during the clipping-anthesis period and in the upper soil layers. At the end of the life cycle, the differences between the two systems regarding depth, density and dry matter of roots were small or nil. Moreover, there were no differences in total water use between clipped and unclipped cereals. Under both production systems (grain and forage plus grain), cereals demonstrated variable downward root extension (0.9 to 1.8 m) as a response to the wetting depth. Triticale roots continued growing after anthesis, especially in the deeper soil layers. In spite of that, root systems were not able to extract a notable amount of residual water (25 to 50 mm) apparently available from the subsoil. In semi-arid Mediterranean drylands, cereal root systems with greater phenotypic plasticity (deeper or larger in the subsoil) in response to subsoil water should be of interest in wetter areas or seasons. This does not necessarily imply a larger root system, but rather a root growth pattern with greater root growth in the subsoil.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...