Showing papers in "Agricultural and Forest Meteorology in 1987"

TL;DR: In this paper, a net-radiation-based empirical model for soil heat flux (G) is analyzed for inclusion in a canopy-temperature-based energy balance equation to estimate evaporation from a growing wheat crop.

TL;DR: In this paper, a canopy microenvironment turbulence model, based on higher-order closure principles, is presented, which consists of equations for the mean quantities and their vertical turbulent fluxes, with good agreement between modelled and measured mean temperature, specific humidity, net radiation and mean wind speed profiles.

TL;DR: In this article, a linear regression is determined for contact numbers (derived from the logarithm of the transmittance) as a function of the angle, in radians, of the sun's beam to the vertical.

TL;DR: The ability of the CERES-Maize model to estimate annual fluctuations in maize production for the U.S. Cornbelt was tested for the years 1982-1985.

TL;DR: During two growing seasons (1980–1982), the influence of nitrogen fertilizer on the growth of winter and spring wheat was assessed and a linear approximation proved useful in producing a seasonal constant.

TL;DR: The area where the average extinction probability exceeds some arbitrary value is greatest for umbrella-like, horizontally extended crowns and for a forest stand where the total horizontal projection area of crown cones is high, the spatial distribution of trees should be systematic for effective light interception.

TL;DR: In this article, a model is developed of the penetration, absorption and transmission of direct and diffuse solar radiation and that scattered by the foliage in an irregularly shaped hedgerow canopy.

TL;DR: A better understanding of the action of the climate forcing factors is required before possible climatic change can be included in determining reliability of cropping.

TL;DR: Radiation, soil temperature at several depths and soil heat flux were measured in the U.K. and Syria and the relationship between the daily rise in soil temperature and the energy absorbed at the soil surface is illustrated.

TL;DR: In this article, a method of computerizing this procedure to improve speed and accuracy, by digitizing photographic silhouettes of the windbreak, was proposed, which was found to be capable of estimating porosity to within 2% in a very time-efficient manner.

TL;DR: In this paper, it was shown that very small amounts of radial lens distortion produce relatively large changes in projected areas on the image plane and describes the projection of image regions for several commonly available fisheye lenses.

TL;DR: In this paper, the accuracy of a daily solar radiation model for horizontal or sloping sites in terrain where surrounding ridges and tall trees block both direct beam and diffuse sky short wave radiation was evaluated.

TL;DR: Agave tequilana (Weber), whose stem is commercially harvested for the production of the distilled alcoholic beverage tequila, exhibited Crassulacean acid metabolism (CAM), as do other agaves, and was accompanied by an increase in tissue acidity at night.

TL;DR: In this article, a regression model based on a radiation and temperature dependent conversion coefficient between intercepted solar radiation and dry matter production was developed and validation was carried out in 1984-1985.

TL;DR: In this paper, a multiple regression model is used which includes an interaction term for windspeed and net radiation to predict the change in minimum air temperature with elevation (d T /d z ) at 31 sites in a 170 km 2 region of undulating grazing land.

TL;DR: In this paper, a grid matching method was used to assist the selection of Australian tree species and provenances for trial at other target sites in a half-degree latitude-longitude grid across Australia.

TL;DR: In this paper, the authors measured and compared several microclimatic variables in a cleared area and under a high rain forest in the humid tropic belt of Nigeria, and made measurements were made consecutively from July to December for the years 1984 and 1985.

TL;DR: It is suggested that, in contrast to the responses observed in several native annual plant species, leaf solar tracking in cotton does not enhance photosynthetic rates of fully exposed sun-lit leaves.

TL;DR: In this paper, the influence of the distribution of radiation in an orange canopy on transpiration and photosynthesis was examined by developing a model of these processes, which combined the leaf energy balance, microclimate relationships and climatic data with radiation, leaf conductance, and leaf carbon uptake models to simulate orchard photosynthesis and transpiration over two days.

TL;DR: In this article, it is shown that lead time is the most important variable distinguishing between subscribers to a National Oceanic and Atmospheric Administration (NOAA) prediction who use the prediction in decision making from those who do not.

TL;DR: Making a comparison between the modeling method and the traditional temperature summation method, the former reduced the errors by about 3 days for early rice, 6–9 days for medium rice and 18–20 days for late rice varieties.

TL;DR: In this article, a method to compute the angular distribution of multiply scattered radiation in and from a vegetative canopy is described, where the single scattering albedos are treated as dependent on the incident beam direction.

TL;DR: In this paper, an algorithm which employs Newton's iterative method for solving the non-linearized surface energy balance equation (SEBE) is offered as an alternative method, which is capable of dealing with the general form of the SEBE which accounts for any degree of surface wetness and with few iterations one can obtain surface temperature to any desired degree of accuracy.

TL;DR: Cylindrical surface wetness duration sensors were constructed and tested for use in onions in this article, and their potential for use as wetness sensors in flat-leaved crops was also investigated.

TL;DR: In this article, a model to predict the trajectories of water droplets in still air is presented and its application to the study of splash dispersed plant pathogens is briefly discussed and compared with the observed and predicted ranges of droplets were compared.

TL;DR: In this paper, the authors proposed the Successive Orders of Scattering Approximation (SOSA) method, which involves computation of photons scattered once, twice, three times, etc., with the total intensity obtained as the sum over all orders.

TL;DR: In this paper, a model which simulates the drying of water drops on plant leaves has been tested in a field of maize, based on laboratory simulations of evaporation from isolated large drops (Leclerc et al., 1985, 1986), augmented with equations to describe the contribution of radiation to drying.

TL;DR: In this article, the authors measured the aerial spore concentration by small suction traps placed on sticky strips held at angles of 0, 30, 60 and 90° with respect to the horizontal and oriented to face the mean wind direction and on sticky, vertical glass rods.

TL;DR: In this article, the photosynthetic light curves of eight Scots pine (Pinus sylvestris L.) shoots, each with a different structure, were measured in a direct radiation field at different positions relative to the radiation beam.