To make agricultural systems sustainable in terms of their greenness and efficiency,optimizing the tillage and fertilization practices is essential.To assess the effects of tilling and fertilization practices in wheat...To make agricultural systems sustainable in terms of their greenness and efficiency,optimizing the tillage and fertilization practices is essential.To assess the effects of tilling and fertilization practices in wheat-maize cropping systems,a three-year field experiment was designed to quantify the carbon footprint(CF)and energy efficiency of the cropping systems in the North China Plain.The study parameters included four tillage practices(no tillage(NT),conventional tillage(CT),rotary tillage(RT),and subsoiling rotary tillage(SRT))and two fertilizer regimes(inorganic fertilizer(IF)and hybrid fertilizer with organic and inorganic components(HF)).The results indicated that the most prominent energy inputs and greenhouse gas(GHG)emissions could be ascribed to the use of fertilizers and fuel consumption.Under the same fertilization regime,ranking the tillage patterns with respect to the value of the crop yield,profit,CF,energy use efficiency(EUE)or energy productivity(EP)for either wheat or maize always gave the same sequence of SRT>RT>CT>NT.For the same tillage,the energy consumption associated with HF was higher than IF,but its GHG emissions and CF were lower while the yield and profit were higher.In terms of overall performance,tilling is more beneficial than NT,and reduced tillage practices(RT and SRT)are more beneficial than CT.The fertilization regime with the best overall performance was HF.Combining SRT with HF has significant potential for reducing CF and increasing EUE,thereby improving sustainability.Adopting measures that promote these optimizations can help to overcome the challenges posed by a lack of food security,energy crises and ecological stress.展开更多
High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial asp...High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m^(2) for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m^(2) in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.展开更多
Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plan...Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term evolution.In order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa L.cv.Lvdie and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,respectively.The results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,respectively.Addition of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,respectively.Spectral absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin contents.White plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white LEDs.Fresh weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue LEDs.In conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(cv.Lvdie and Ziya)production in plant factories with artificial lighting.展开更多
A comparative study of the needle-to-liquid plasma in the continuous mode with DC and AC excitations is detailed in this paper. All plasmas studied here are shown to be glow discharges. This study is based on measurem...A comparative study of the needle-to-liquid plasma in the continuous mode with DC and AC excitations is detailed in this paper. All plasmas studied here are shown to be glow discharges. This study is based on measurements of several key parameters, including electrical energy, optical emission intensities of active species, rotational and vibrational temperatures, and temperatures of the needle and liquid electrodes. AC plasmas can produce 1.2～5 times higher excited state active species than DC plasmas under the same dissipated power. AC excited liquid plasmas have the highest energy utilization efficiency among the three systems （AC excited plasmas, DC excited plasmas with water anode and DC excited plasmas with water cathode）; most of the energy is used to produce useful species rather than to heat the electrodes and plasmas.展开更多
This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnai...This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnaires,observations and field works were performed in 134 garlic farms in the region through simple random method.In garlic cultivation,energy input was calculated as 32103.20 MJ/hm^(2)and energy output was calculated as 30096 MJ/hm^(2).With regards to the three highest inputs in garlic production,46.66%of the energy inputs consisted of chemical fertilizers energy(14979.26 MJ/hm^(2)),11.29%consisted of farmyard manure energy(3625.71 MJ/hm^(2))and 10.48%consisted of human labour energy(3363.36 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy in garlic cultivation were calculated as 0.94,1.71 MJ/kg,0.59 kg/MJ,and−2007.20 MJ/hm^(2),respectively.The total energy input consumed in garlic cultivation was classified as 27.19%direct energy,72.81%indirect energy,35.17%renewable energy and 64.87%nonrenewable energy.Total GHG emissions and GHG ratio were calculated as 8636.60 kg CO_(2)-eq/hm^(2)and 0.46 kg CO_(2)-eq/kg,respectively.展开更多
To enhance the transplants’growth and reduce energy use efficiency,Eggplant(Solanum melongena L.)transplants(cv.Jingqie 21)were cultivated in a plant factory laboratory under different LED light spectrums.The experim...To enhance the transplants’growth and reduce energy use efficiency,Eggplant(Solanum melongena L.)transplants(cv.Jingqie 21)were cultivated in a plant factory laboratory under different LED light spectrums.The experimental treatments included white plus blue LED lights(R:B=0.5,WB0.5),white LED lights(R:B=0.9,W0.9),white plus red LED lights(R:B=2.7,WR2.7),white plus red plus UV lights(R:B=3.8,WRUV3.8),and red plus blue plus green LED lights(R:B=5.4,RBG5.4).The transplants were grown for 30 d under a light intensity of 250μmol/m2·s and a photoperiod of 16 h/d.The morphological indicators and biomass accumulation of eggplant transplants were significantly higher in the W0.9 treatment compared to the other experimental treatments.The photosynthetic quantum yield in the W0.9 treatment exhibited an increase of over 22%compared to that in the WR2.7 treatment.The shoot dry weight of the W0.9 treatment reached(381±41)mg/plant and the leaf area was(113.3±8.9)cm^(2),indicating a higher health index compared to the other treatments.However,there were no significant differences in the net photosynthetic rate of the leaves among all treatments.The energy yield(EY)of the W0.9 treatment was(37.7±1.8)g/kW·h,which was higher than others.Therefore,considering the high quality of transplants and the maximization of energy use efficiency,the LED light spectrum in the eggplant transplants production was recommended to the white LED light with an R:B ratio of 0.9.展开更多
The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This st...The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This study included calculations of energy input,energy output,energy use efficiency,specific energy,energy productivity,net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2020-2021 production season.The data obtained from the study were collected from 16 different farms(reachable)through face-to-face surveys with full count method.Energy input and energy output were calculated as 19570.58 MJ/hm^(2) and 19471.94 MJ/hm^(2),respectively.With regards to production inputs,55.70% of the energy inputs consisted of chemical fertilizers energy(10900.03 MJ/hm^(2)),9.46% consisted of chemicals energy(1852.10 MJ/hm^(2)),9.32% consisted of human labour energy(1823.13 MJ/hm^(2)),7.65% consisted of electricity energy(1497.28 MJ/hm^(2)),6.91% consisted of diesel fuel energy(1351.52 MJ/hm^(2)),4.73% consisted of irrigation water energy(926.10 MJ/hm^(2)),3.43% consisted of machinery energy(671.98 MJ/hm^(2)),1.88% consisted of transportation energy(367.72 MJ/hm^(2)),0.88% consisted of farmyard manure energy(171.80 MJ/hm^(2))and 0.05%consisted of lime energy(8.94 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 0.99,1.91 MJ/kg,0.52 kg/MJ and-98.64 MJ/hm^(2),respectively.The consumed total energy input in production was classified as 28.60% direct energy,71.40% indirect energy,14.93% renewable energy and 85.07% non-renewable.Total GHG emissions and GHG ratio were calculated as 1683.24 kgCO_(2)-eq/hm^(2) and 0.16 kg CO_(2)-eq/kg,respectively.展开更多
Recently, triboelectric nanogenerators （TENGs）, as a collection technology with characteristics of high reliability, high energy density and low cost, has attracted more and more attention. However, the energy comin...Recently, triboelectric nanogenerators （TENGs）, as a collection technology with characteristics of high reliability, high energy density and low cost, has attracted more and more attention. However, the energy coming from TENGs needs to be stored in a storage unit effectively due to its unstable ac output. The traditional energy storage circuit has an extremely low energy storage efficiency for TENGs because of their high internal impedance. This paper presents a new power management circuit used to optimize the energy using efficiency of TENGs, and realize large load capacity. The power management circuit mainly includes rectification storage circuit and DC-DC management circuit. A rotating TENG with maximal energy output of 106 mW at 170 rpm based on PCB is used for the experimental verification. Experimental results show that the power energy transforming to the storage capacitor reach up to 53 mW and the energy using efficiency is calculated as 50%. When different loading resistances range from 0.82 to 34.5 k^2 are connected to the storage capacitor in parallel, the power energy stored in the storage capacitor is all about 52.5 mW. Getting through the circuit, the power energy coming from the TENGs can be used to drive numerous conventional electronics, such as wearable watches.展开更多
Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are res...Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are restricting the wide application of this technology.In order to design an optimal artificial lighting environment for lettuce production,effects of different combinations of light intensity,photoperiod,and light quality on growth,quality,photosynthesis,and energy use efficiency of lettuce(Lactuca sativa L.cv Ziwei)were investigated under a closed plant factory.Lettuce transplants were grown under photosynthetic photon flux density(PPFD)at 150μmol/m^(2)·s,200μmol/m^(2)·s,250μmol/m^(2)·s,and 300μmol/m^(2)·s provided by fluorescent lamps(FL)with a red to blue ratio(R:B ratio)of 1.8 and light-emitting diode(LED)lamps with R:B ratio of 1.2 and 2.2,in combination with photoperiod of 12 and 16 h/d.In order to examine the“long term”photosynthetic characteristics,net photosynthetic rates of hydroponic lettuce leaves were continuously measured for 2 d(15^(th) and 16^(th) day after transplanting)before harvest.There was no difference in leaf fresh weight(FW)between PPFD of 250μmol/m^(2)·s and 300μmol/m^(2)·s with photoperiod of 16 h/d,regardless of light quality,and same results showed in contents of nitrate,soluble sugar,and vitamin C,respectively.The results of continuous measurements of net photosynthetic rate of lettuce leaves before harvest indicated that plants grown at PPFD of 250μmol/m^(2)·s had consistently higher compared to those grown at PPFD of 300μmol/m^(2)·s.Combining the results from growth,photosynthesis,quality,and energy consumption,it can be concluded that PPFD at 250μmol/m^(2)·s with photoperiod of 16 h/d under LED with R:B ratio of 2.2 is a suitable light environment for maximum growth and high quality of commercial lettuce(cv.Ziwei)production under indoor controlled environment.展开更多
The extensive environment,especially low temperature and weak lighting in winter and spring,which limits the growth of pepper(Capicum annuum L.)seedlings,the use of plant factory with artificial lighting technology ca...The extensive environment,especially low temperature and weak lighting in winter and spring,which limits the growth of pepper(Capicum annuum L.)seedlings,the use of plant factory with artificial lighting technology can effectively control the lighting environment to produce high-quality seedlings.In this study,white LED lamps with R:B ratio of 0.7(L0.7)and 1.5(L1.5)and red-blue LED lamps with R:B ratio of 3.5(L3.5)were used to cultivate seedlings of“CAU-24”pepper in the light intensity of 250μmol/m^(2)·s and photoperiod of 12 h/d,white fluorescent lamps with R:B ratio of 1.7(F1.7)was used as control.The results showed that plant height,stem diameter,hypocotyl length,biomass accumulation,light energy use efficiency(LUE)and electric energy use efficiency(EUE)of pepper seedling under L1.5 were the highest.After 36 days of sowing,the dry weight of shoot reached 302.8±45.2 mg/plant.Leaf area reached maximum value of 153.5±22.0 cm^(2) under L0.7.The contents of chlorophyll a,chlorophyll b and total chlorophyll of pepper seedling leaves under all kinds of LED light were greater than F1.7,but there was no significant difference in net photosynthetic rate.The total dry weight with lamp electric power consumption of L1.5 were 3.0 g/(kW·h)which was 1.5,2,and 3 times greater than that of L3.5,L0.7,and F1.7,respectively.Therefore,compared with fluorescent lamp and other LED lamps,the white LED light quality with R:B ratio of 1.5 is suitable for pepper seedling production in plant factory because of the high LED lighting efficiency,greater LUE and EUE.展开更多
Pakchoi,a popular leafy vegetable in China,is expected to be planted in plant factories with artificial lighting(PFALs).In order to examine the effects of different red and blue light ratios(R:B ratio)on growth,photos...Pakchoi,a popular leafy vegetable in China,is expected to be planted in plant factories with artificial lighting(PFALs).In order to examine the effects of different red and blue light ratios(R:B ratio)on growth,photosynthesis,and absorption spectrum of plant leaves,and to analyze the energy use efficiency,the pakchoi(Brassica Chinensis L.cv.Xiazhijiao)was cultivated hydroponically under white LEDs with R:B ratios of 0.9(L0.9)and 1.8(L1.8),white plus red LEDs with R:B ratios of 2.7(L2.7)and 4.0(L4.0)for 40 d,respectively.The results showed that the leaf length and width were significantly greater in the L0.9 treatment than in other treatments,and the dry weight per plant increased by over 33%when R:B ratio decreased from 4.0 to 0.9.The net photosynthesis rates of pakchoi leaves ranged from 9.2 to 9.6μmol/(m2·s)under different lighting conditions,which had no significant difference.The biggest difference in the spectrum absorptance of pakchoi leaves was expressed in green light waveband,and the highest absorption of plant leaves was under L0.9 and L1.8 treatments.The light energy use efficiency(LUE),photon yield(PY),and energy yield(EY)in L0.9 were over 25%higher than that in the other treatments,while there was no significant difference in the electrical energy use efficiency(EUE).In conclusion,an optimal light quality to cultivate pakchoi in PFALs was the white LEDs with R:B ratio of 0.9,and this finding could provide a promising lighting environment to hydroponic pakchoi yield and energy use efficiency.展开更多
As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of ...As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of vascular tissue in grafted seedlings.The effect of daily light integral(DLI)on the healing process and seedling quality of tomato(Solanum lycopersicum L.)was analyzed in this study,with the comparison of grafted seedlings treated in dark for 7 d after grafting.The results showed that the height increment of scion and rootstock,adhesion of graft union,stem flow,total chlorophyll content,and net photosynthesis rate increased gradually with increasing light intensity,and no longer increased significantly when the DLI was higher than 5.04 mol/m^(2)·d.The contents of auxin(IAA)and gibberellin(GA)in tomato leaves increased and abscisic acid(ABA)decreased with the increase of DLI.However,there was no significant difference between the treatments with DLI higher than 6.48 mol/m^(2)·d.Both the biomass and energy use efficiency(EUE)of grafted seedlings increased with DLI in a certain range and then decreased.The biomass was the largest when DLI was 5.04 mol/m^(2)·d.However,EUE was highest when DLI was 7.46 mol/m^(2)·d.In conclusion,a suitable DLI is beneficial to cultivate high-quality grafted tomato seedlings,and increasing DLI within a certain range can promote biomass accumulation,connection of vascular tissue,and endogenous hormone biosynthesis in tomato grafted seedlings during the healing period.The lighting environment with DLI of 5.04 mol/m^(2)·d(light intensity of 100μmol/m^(2)·s and light time of 14 h/d)is recommended for the healing treatment in high-quality production,which also improves EUE during the healing period of tomato grafted seedlings.展开更多
基金supported by research grants from the Natural Science Foundation of Shandong Province,China(ZR2020MC092)the Key Research and Development Project of Shandong Province,China(2019TSCYCX-33)the Key Research and Development Project of Shandong Province,China(LJNY202025).
文摘To make agricultural systems sustainable in terms of their greenness and efficiency,optimizing the tillage and fertilization practices is essential.To assess the effects of tilling and fertilization practices in wheat-maize cropping systems,a three-year field experiment was designed to quantify the carbon footprint(CF)and energy efficiency of the cropping systems in the North China Plain.The study parameters included four tillage practices(no tillage(NT),conventional tillage(CT),rotary tillage(RT),and subsoiling rotary tillage(SRT))and two fertilizer regimes(inorganic fertilizer(IF)and hybrid fertilizer with organic and inorganic components(HF)).The results indicated that the most prominent energy inputs and greenhouse gas(GHG)emissions could be ascribed to the use of fertilizers and fuel consumption.Under the same fertilization regime,ranking the tillage patterns with respect to the value of the crop yield,profit,CF,energy use efficiency(EUE)or energy productivity(EP)for either wheat or maize always gave the same sequence of SRT>RT>CT>NT.For the same tillage,the energy consumption associated with HF was higher than IF,but its GHG emissions and CF were lower while the yield and profit were higher.In terms of overall performance,tilling is more beneficial than NT,and reduced tillage practices(RT and SRT)are more beneficial than CT.The fertilization regime with the best overall performance was HF.Combining SRT with HF has significant potential for reducing CF and increasing EUE,thereby improving sustainability.Adopting measures that promote these optimizations can help to overcome the challenges posed by a lack of food security,energy crises and ecological stress.
文摘High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner(AC)in warm and humid regions.This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled(EV-cooled)greenhouse in winter and summer seasons.Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University,Oman,with dimensions of 6.0 m long and 3.0 m wide.The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes(LED)lights were used as a source of light,while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source.Three cultivars of high-value lettuce were grown for experimentation.To evaluate the technical efficiency of greenhouse performance,we conducted measures on land use efficiency(LUE),water use efficiency(WUE),gross water use efficiency(GWUE)and energy use efficiency(EUE).Financial analysis was conducted to compare the profitability of both greenhouses.The results showed that the LUE in winter were 10.10 and 14.50 kg/m^(2) for the AC-and EV-cooled greenhouses,respectively.However,the values reduced near to 6.80 kg/m^(2) in both greenhouses in summer.The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8%in winter and 26.8%in summer.The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water;it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%.The EUE in the EV-cooled greenhouse was higher in both seasons.Financial analysis showed that in winter,gross return,net return and benefit-to-cost ratio were better in the EVcooled greenhouse,while in summer,those were higher in the AC-cooled greenhouse.The values of internal rate of return in the AC-and EV-cooled greenhouses were 63.4%and 129.3%,respectively.In both greenhouses,lettuce investment was highly sensitive to changes in price,yield and energy cost.The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter.Finally,more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.
基金This work was supported by the National Key Research and Development Program of China(2017YFB0403901)This manuscript was presented at 2019 International Symposium on Environment Control Technology for Value-added Plant Production hold in Beijing from Aug.27-29,2019.
文摘Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the spectrum.However,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term evolution.In order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa L.cv.Lvdie and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,respectively.The results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,respectively.Addition of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,respectively.Spectral absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin contents.White plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white LEDs.Fresh weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue LEDs.In conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(cv.Lvdie and Ziya)production in plant factories with artificial lighting.
基金supported by National Natural Science Foundation of China(No.51207027)Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China
文摘A comparative study of the needle-to-liquid plasma in the continuous mode with DC and AC excitations is detailed in this paper. All plasmas studied here are shown to be glow discharges. This study is based on measurements of several key parameters, including electrical energy, optical emission intensities of active species, rotational and vibrational temperatures, and temperatures of the needle and liquid electrodes. AC plasmas can produce 1.2～5 times higher excited state active species than DC plasmas under the same dissipated power. AC excited liquid plasmas have the highest energy utilization efficiency among the three systems （AC excited plasmas, DC excited plasmas with water anode and DC excited plasmas with water cathode）; most of the energy is used to produce useful species rather than to heat the electrodes and plasmas.
文摘This study has been conducted with the purpose of determining energy use efficiency and greenhouse gas emissions of garlic cultivation during the 2020-2021 cultivation season in Adıyaman province of Turkey.Questionnaires,observations and field works were performed in 134 garlic farms in the region through simple random method.In garlic cultivation,energy input was calculated as 32103.20 MJ/hm^(2)and energy output was calculated as 30096 MJ/hm^(2).With regards to the three highest inputs in garlic production,46.66%of the energy inputs consisted of chemical fertilizers energy(14979.26 MJ/hm^(2)),11.29%consisted of farmyard manure energy(3625.71 MJ/hm^(2))and 10.48%consisted of human labour energy(3363.36 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy in garlic cultivation were calculated as 0.94,1.71 MJ/kg,0.59 kg/MJ,and−2007.20 MJ/hm^(2),respectively.The total energy input consumed in garlic cultivation was classified as 27.19%direct energy,72.81%indirect energy,35.17%renewable energy and 64.87%nonrenewable energy.Total GHG emissions and GHG ratio were calculated as 8636.60 kg CO_(2)-eq/hm^(2)and 0.46 kg CO_(2)-eq/kg,respectively.
基金This work was financially supported by the Key Research and Development Project of Shandong Province(Grant No.2022 CXGC020708)Chinese Universities Scientific Fund(2023TC087).
文摘To enhance the transplants’growth and reduce energy use efficiency,Eggplant(Solanum melongena L.)transplants(cv.Jingqie 21)were cultivated in a plant factory laboratory under different LED light spectrums.The experimental treatments included white plus blue LED lights(R:B=0.5,WB0.5),white LED lights(R:B=0.9,W0.9),white plus red LED lights(R:B=2.7,WR2.7),white plus red plus UV lights(R:B=3.8,WRUV3.8),and red plus blue plus green LED lights(R:B=5.4,RBG5.4).The transplants were grown for 30 d under a light intensity of 250μmol/m2·s and a photoperiod of 16 h/d.The morphological indicators and biomass accumulation of eggplant transplants were significantly higher in the W0.9 treatment compared to the other experimental treatments.The photosynthetic quantum yield in the W0.9 treatment exhibited an increase of over 22%compared to that in the WR2.7 treatment.The shoot dry weight of the W0.9 treatment reached(381±41)mg/plant and the leaf area was(113.3±8.9)cm^(2),indicating a higher health index compared to the other treatments.However,there were no significant differences in the net photosynthetic rate of the leaves among all treatments.The energy yield(EY)of the W0.9 treatment was(37.7±1.8)g/kW·h,which was higher than others.Therefore,considering the high quality of transplants and the maximization of energy use efficiency,the LED light spectrum in the eggplant transplants production was recommended to the white LED light with an R:B ratio of 0.9.
文摘The purpose of this study was to determine the energy use efficiency and greenhouse gas(GHG)emissions in peach production that took place in Kırklareli province of Turkey during the 2020-2021 production season.This study included calculations of energy input,energy output,energy use efficiency,specific energy,energy productivity,net energy,energy input types,GHG emissions and GHG ratio.Survey,observation and data calculations are related to the 2020-2021 production season.The data obtained from the study were collected from 16 different farms(reachable)through face-to-face surveys with full count method.Energy input and energy output were calculated as 19570.58 MJ/hm^(2) and 19471.94 MJ/hm^(2),respectively.With regards to production inputs,55.70% of the energy inputs consisted of chemical fertilizers energy(10900.03 MJ/hm^(2)),9.46% consisted of chemicals energy(1852.10 MJ/hm^(2)),9.32% consisted of human labour energy(1823.13 MJ/hm^(2)),7.65% consisted of electricity energy(1497.28 MJ/hm^(2)),6.91% consisted of diesel fuel energy(1351.52 MJ/hm^(2)),4.73% consisted of irrigation water energy(926.10 MJ/hm^(2)),3.43% consisted of machinery energy(671.98 MJ/hm^(2)),1.88% consisted of transportation energy(367.72 MJ/hm^(2)),0.88% consisted of farmyard manure energy(171.80 MJ/hm^(2))and 0.05%consisted of lime energy(8.94 MJ/hm^(2)).Energy use efficiency,specific energy,energy productivity and net energy were calculated as 0.99,1.91 MJ/kg,0.52 kg/MJ and-98.64 MJ/hm^(2),respectively.The consumed total energy input in production was classified as 28.60% direct energy,71.40% indirect energy,14.93% renewable energy and 85.07% non-renewable.Total GHG emissions and GHG ratio were calculated as 1683.24 kgCO_(2)-eq/hm^(2) and 0.16 kg CO_(2)-eq/kg,respectively.
文摘Recently, triboelectric nanogenerators （TENGs）, as a collection technology with characteristics of high reliability, high energy density and low cost, has attracted more and more attention. However, the energy coming from TENGs needs to be stored in a storage unit effectively due to its unstable ac output. The traditional energy storage circuit has an extremely low energy storage efficiency for TENGs because of their high internal impedance. This paper presents a new power management circuit used to optimize the energy using efficiency of TENGs, and realize large load capacity. The power management circuit mainly includes rectification storage circuit and DC-DC management circuit. A rotating TENG with maximal energy output of 106 mW at 170 rpm based on PCB is used for the experimental verification. Experimental results show that the power energy transforming to the storage capacitor reach up to 53 mW and the energy using efficiency is calculated as 50%. When different loading resistances range from 0.82 to 34.5 k^2 are connected to the storage capacitor in parallel, the power energy stored in the storage capacitor is all about 52.5 mW. Getting through the circuit, the power energy coming from the TENGs can be used to drive numerous conventional electronics, such as wearable watches.
基金supported by the National High Technology Research and Development Program(“863”Program)of China(2013AA103005).
文摘Leafy vegetable production under controlled environment using artificial lighting has many advantages over conventional greenhouses and open-field production.However,high initial investment and operation costs are restricting the wide application of this technology.In order to design an optimal artificial lighting environment for lettuce production,effects of different combinations of light intensity,photoperiod,and light quality on growth,quality,photosynthesis,and energy use efficiency of lettuce(Lactuca sativa L.cv Ziwei)were investigated under a closed plant factory.Lettuce transplants were grown under photosynthetic photon flux density(PPFD)at 150μmol/m^(2)·s,200μmol/m^(2)·s,250μmol/m^(2)·s,and 300μmol/m^(2)·s provided by fluorescent lamps(FL)with a red to blue ratio(R:B ratio)of 1.8 and light-emitting diode(LED)lamps with R:B ratio of 1.2 and 2.2,in combination with photoperiod of 12 and 16 h/d.In order to examine the“long term”photosynthetic characteristics,net photosynthetic rates of hydroponic lettuce leaves were continuously measured for 2 d(15^(th) and 16^(th) day after transplanting)before harvest.There was no difference in leaf fresh weight(FW)between PPFD of 250μmol/m^(2)·s and 300μmol/m^(2)·s with photoperiod of 16 h/d,regardless of light quality,and same results showed in contents of nitrate,soluble sugar,and vitamin C,respectively.The results of continuous measurements of net photosynthetic rate of lettuce leaves before harvest indicated that plants grown at PPFD of 250μmol/m^(2)·s had consistently higher compared to those grown at PPFD of 300μmol/m^(2)·s.Combining the results from growth,photosynthesis,quality,and energy consumption,it can be concluded that PPFD at 250μmol/m^(2)·s with photoperiod of 16 h/d under LED with R:B ratio of 2.2 is a suitable light environment for maximum growth and high quality of commercial lettuce(cv.Ziwei)production under indoor controlled environment.
基金supported by the National Key Research and Development Program of China(2017YFB0403901).
文摘The extensive environment,especially low temperature and weak lighting in winter and spring,which limits the growth of pepper(Capicum annuum L.)seedlings,the use of plant factory with artificial lighting technology can effectively control the lighting environment to produce high-quality seedlings.In this study,white LED lamps with R:B ratio of 0.7(L0.7)and 1.5(L1.5)and red-blue LED lamps with R:B ratio of 3.5(L3.5)were used to cultivate seedlings of“CAU-24”pepper in the light intensity of 250μmol/m^(2)·s and photoperiod of 12 h/d,white fluorescent lamps with R:B ratio of 1.7(F1.7)was used as control.The results showed that plant height,stem diameter,hypocotyl length,biomass accumulation,light energy use efficiency(LUE)and electric energy use efficiency(EUE)of pepper seedling under L1.5 were the highest.After 36 days of sowing,the dry weight of shoot reached 302.8±45.2 mg/plant.Leaf area reached maximum value of 153.5±22.0 cm^(2) under L0.7.The contents of chlorophyll a,chlorophyll b and total chlorophyll of pepper seedling leaves under all kinds of LED light were greater than F1.7,but there was no significant difference in net photosynthetic rate.The total dry weight with lamp electric power consumption of L1.5 were 3.0 g/(kW·h)which was 1.5,2,and 3 times greater than that of L3.5,L0.7,and F1.7,respectively.Therefore,compared with fluorescent lamp and other LED lamps,the white LED light quality with R:B ratio of 1.5 is suitable for pepper seedling production in plant factory because of the high LED lighting efficiency,greater LUE and EUE.
基金This research was funded by the China Agriculture Research System of MOF and MARA(CARS-21)the National Key Research and Development Program of China(2017YFB0403901).
文摘Pakchoi,a popular leafy vegetable in China,is expected to be planted in plant factories with artificial lighting(PFALs).In order to examine the effects of different red and blue light ratios(R:B ratio)on growth,photosynthesis,and absorption spectrum of plant leaves,and to analyze the energy use efficiency,the pakchoi(Brassica Chinensis L.cv.Xiazhijiao)was cultivated hydroponically under white LEDs with R:B ratios of 0.9(L0.9)and 1.8(L1.8),white plus red LEDs with R:B ratios of 2.7(L2.7)and 4.0(L4.0)for 40 d,respectively.The results showed that the leaf length and width were significantly greater in the L0.9 treatment than in other treatments,and the dry weight per plant increased by over 33%when R:B ratio decreased from 4.0 to 0.9.The net photosynthesis rates of pakchoi leaves ranged from 9.2 to 9.6μmol/(m2·s)under different lighting conditions,which had no significant difference.The biggest difference in the spectrum absorptance of pakchoi leaves was expressed in green light waveband,and the highest absorption of plant leaves was under L0.9 and L1.8 treatments.The light energy use efficiency(LUE),photon yield(PY),and energy yield(EY)in L0.9 were over 25%higher than that in the other treatments,while there was no significant difference in the electrical energy use efficiency(EUE).In conclusion,an optimal light quality to cultivate pakchoi in PFALs was the white LEDs with R:B ratio of 0.9,and this finding could provide a promising lighting environment to hydroponic pakchoi yield and energy use efficiency.
基金supported by Postdoctoral Fund in Jiangsu Province(2020Z308)Project Funded by the National Key Research and Development Program of China(2018YFF0213601)+1 种基金Project Funded by the Key Laboratory of Modern Agricultural Equipment and Technology of the Ministry of Education(JNZ201909)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD-2018-87).
文摘As the source of energy and biological signals,light can influence the healing process of grafted seedlings by regulating the synthesis of the endogenous hormone,regeneration of wound-healing tissue,and connection of vascular tissue in grafted seedlings.The effect of daily light integral(DLI)on the healing process and seedling quality of tomato(Solanum lycopersicum L.)was analyzed in this study,with the comparison of grafted seedlings treated in dark for 7 d after grafting.The results showed that the height increment of scion and rootstock,adhesion of graft union,stem flow,total chlorophyll content,and net photosynthesis rate increased gradually with increasing light intensity,and no longer increased significantly when the DLI was higher than 5.04 mol/m^(2)·d.The contents of auxin(IAA)and gibberellin(GA)in tomato leaves increased and abscisic acid(ABA)decreased with the increase of DLI.However,there was no significant difference between the treatments with DLI higher than 6.48 mol/m^(2)·d.Both the biomass and energy use efficiency(EUE)of grafted seedlings increased with DLI in a certain range and then decreased.The biomass was the largest when DLI was 5.04 mol/m^(2)·d.However,EUE was highest when DLI was 7.46 mol/m^(2)·d.In conclusion,a suitable DLI is beneficial to cultivate high-quality grafted tomato seedlings,and increasing DLI within a certain range can promote biomass accumulation,connection of vascular tissue,and endogenous hormone biosynthesis in tomato grafted seedlings during the healing period.The lighting environment with DLI of 5.04 mol/m^(2)·d(light intensity of 100μmol/m^(2)·s and light time of 14 h/d)is recommended for the healing treatment in high-quality production,which also improves EUE during the healing period of tomato grafted seedlings.
