Bian Z.-H.,Northwest University, China |
Bian Z.-H.,Chinese Academy of Agricultural Sciences |
Bian Z.-H.,Key Laboratory for Energy Saving and Waste Disposal of Protected Agriculture |
Wang Y.,Northwest University, China |
And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2013
Taking the tomato (Solanum lycopersicum) cultivar "Kuiguan108" as test object, a comparative study was made on the effects of outer type and built-in type straw bio-reactors on the CO2 concentration, air relative humidity, air vapor pressure deficit in the solar greenhouse during the tomato growth over autumn-delayed cultivation as well as the effects of the bio-reactors on the tomato growth and photosynthetic performance. As compared with that in CK, the average CO2 concentration in the greenhouse with outer type straw bio-reactor at 9:30-11:30 and 14:30-15:00 on sunny days was increased significantly by 207.3 and 103 μmol · mol-1, respectively, and the ave-rage CO2 concentration in the greenhouse with built-in straw bio-reactor at 9:30-11:30 on sunny days was raised by 19.0 μmol · mol-1. Both the outer type and the built-in type straw bio-reactors promoted the tomato plant height growth and early flowering, enhanced the plant net photosynthetic rate and the yield per plant and per unit area significantly, and decreased the plant transpiration rate at the stages of vegetative growth and fruit-bearing significantly. Nevertheless, as compared with built-in type straw bio-reactor, outer type straw bio-reactor was more suitable for the autumn-delayed cultivation of tomato in solar greenhouse.
Wang J.,Chinese Academy of Agricultural Sciences |
Wang J.,Key Laboratory for Energy Saving and Waste Disposal of Protected Agriculture |
Yang Q.,Chinese Academy of Agricultural Sciences |
Yang Q.,Key Laboratory for Energy Saving and Waste Disposal of Protected Agriculture |
And 4 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013
In recent years, the use of plant factory with artificial light (PF) for plant production is gradually increasing in many countries due to its incomparable advantages compared with other plant production systems, such as improving the utilization efficiencies of water and land, improving work conditions. However, the higher initial construction and operation costs limit the further use of the PF. The main electric-energy consumption by air conditioner (AC) for cooling accounts for 15%-25% of the total energy consumption in the PF. In this experiment, the objective of this study is to reduce the electric-energy consumption for cooling in the PF. The air temperature inside the two PFs (floor area: 10.5 m2) was maintained at 25°C and 15°C during photoperiod and dark period, respectively. In one PF, an air exchanger (AE, air quantity: 250 m3/h) was used along with an AC to maintain the inside air temperature at the set-point. The air exchanger was used to exchange the air inside with that outside when the air temperature outside was lower than a certain degree. When the inside air temperature could not maintained at the set-point, the AC would start. In another PF only an AC was used. The results showed that the electric-energy consumption in the PF with AE reduced by 24.6%~63.0% and 2.3%~33.6% when the outside air temperature ranged from -4°C to 12°C, and the runtime of air conditioner reduced by 36.6%~82.0% and 16.3%~64.2% when the outside air temperature ranged from -4°C to 6°C, during photoperiod and dark period, respectively, compared with the electric-energy consumption in the PF only with AC. And the reduction rates of electric consumption and the runtime of air conditioner increased with the decrease of the air temperature outside. Moreover, the air temperature inside the PF with AE could be maintained at the set-point. The above results indicate that the electric-energy consumption for cooling can be reduced by using the AE compared with the AC. Thus, the use of AE in the PF will be an effective way to reduce electric-energy consumption for cooling and the operation cost.