Abstract
The aim of the present work was to investigate the use of low and medium temperature active solar energy systems for the disinfestation of greenhouse soils. Four flat plate solar collectors (low-temperature solar thermal energy devices) and six parabolic trough concentrators (medium-temperature solar thermal energy devices) were used to heat water, which, via a buried heat exchange system, was used to heat the soil of greenhouse plots. These treatments were compared to no solar (control) and solarized (using a 50 micro m-thick transparent polyethylene sheet) plots. Experiments performed in the summers of 2004 and 2005 showed that: 1) the temperatures reached and the energy accumulated in the soil - and therefore the disinfestation capacity - were greater with either of the active solar treatments (40-60 deg C and 10.222.438-18.102.054 J, respectively) than with solarization (< 40 deg C and 6.628.760 J, respectively) and 2) the temperatures reached using the parabolic trough concentrators (50-60 deg C) were higher than those achieved with the flat plate solar collectors (40-50 deg C). The soil temperatures reached suggest these systems could be used to disinfest greenhouse soils.
Highlights
Agricultural applications of solar energy technology first began to appear in the second half of the 20th century with the aim of reducing the consumption of fossil fuels, limiting atmospheric pollution, and bringing down production costs (Solar Energy Society, 1965)
Experiments performed in the summers of 2004 and 2005 showed that: 1) the temperatures reached and the energy accumulated in the soil - and the disinfestation capacity - were greater with either of the active solar treatments (40-60oC and 10.222.438–18.102.054 J, respectively) than with solarization (< 40oC and 6.628.760 J, respectively) and 2) the temperatures reached using the parabolic trough concentrators (50 - 60oC) were higher than those achieved with the flat plate solar collectors (40-50oC)
The temperature reached in the solarized soil was higher than that reached in the control soil, but lower than that reached in the soils heated by the active solar energy systems
Summary
Agricultural applications of solar energy technology first began to appear in the second half of the 20th century with the aim of reducing the consumption of fossil fuels, limiting atmospheric pollution, and bringing down production costs (Solar Energy Society, 1965). Since 1977 the use of passive solar thermal energy (solar energy captured without the help of mechanical systems) for the control of soil pathogens has spread widely, a consequence of the development of the soil solarization method. This entails the spreading of a transparent plastic sheet, exposed to the sun, over a moist, uncultivated soil. This causes a change in the energy balance of the soil, leading to an increase in temperature of between 7 and 10oC over that reached in control soil (Katan et al, 1976; Katan, 1981). Several authors report that such pathogen control is effective if maintained for one or two months (Martínez et al, 1986; Cenis, 1991; Soriano et al, 1998)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
