scholarly journals Effects of lighting, semi-closed greenhouse and split-root fertigation on energy use and CO2 emissions in high latitude cucumber growing

2014 ◽  
Vol 23 (3) ◽  
pp. 220-235 ◽  
Author(s):  
Timo Kaukoranta ◽  
Juha Näkkilä ◽  
Liisa Särkkä ◽  
Kari Jokinen
Keyword(s):  
Light Intensity ◽  
Co2 Emissions ◽  
High Latitude ◽  
Energy Use ◽  
Energy Use Efficiency ◽  
Split Root ◽  
Electricity Use ◽  
Use Efficiency ◽  
Supplemental Lighting ◽  
Seasonal Heat

Effects of supplemental lighting, semi-closed greenhouse and split-root fertigation on weekly to seasonal heat and electricity use and CO2 emissions in cucumber growing were estimated in Finland. With moderate lighting (170 W m-2 above rows, 60 W m-2 inter-row) in a ventilated greenhouse, seasonal electricity and heat use (MJ kg-1 cucumber) were 20–50 and 10–25, 17–30 and 3–8, 38–55 and 10–18 in spring, summer and autumn to mid-winter, respectively. In summer, a semi-closed greenhouse improved energy use efficiency by 20–30% and split-root fertigation by 0–15%. Raising light intensity and applying inter- row lighting allowed higher yields in autumn to mid-winter without affecting electricity use efficiency. In other seasons, increasing the lighting decreased the efficiency. The emissions largely resulted from electricity use. Direct emissions (kg CO2-eq kg-1) based on propane and electricity from the national grid were 2.5, 1.5 and 3.3 in spring, summer and autumn to mid-winter, respectively. Efficiency of using solar and supplemental PAR was markedly lower in summer than in other seasons. The results provide profile of energy use and emissions and point to ways to reduce them.

scholarly journals Investigation of Input and Output Energy for Wheat Production: A Comprehensive Study for Tehsil Mailsi (Pakistan)

2020 ◽  
Vol 12 (17) ◽  
pp. 6884
Author(s):  
Muhammad N. Ashraf ◽  
Muhammad H. Mahmood ◽  
Muhammad Sultan ◽  
Narges Banaeian ◽  
Muhammad Usman ◽  
...  
Keyword(s):  
Grain Yield ◽  
Co2 Emissions ◽  
Energy Use ◽  
Output Energy ◽  
Energy Productivity ◽  
Energy Use Efficiency ◽  
Wheat Production ◽  
Input And Output ◽  
Energy Indices ◽  
Use Efficiency

The global increasing food demand can be met by efficient energy utilization in mechanized agricultural productions. In this study, input–output energy flow along with CO2 emissions for different wheat production cases (C-I to C-V) were investigated to identify the one that is most energy-efficient and environment-friendly case. Data and information about input and output sources were collected from farmers through questionnaires and face-to-face interviews. Input and output sources were converted into energy units by energy equivalents while CO2 emissions were calculated by emission equivalents. Data envelopment analysis (DEA) was conducted to compare technical efficiencies of the developed cases for optimization of inputs in inefficient cases. Results revealed that case C-Ⅴ (higher inputs, larger fields, the tendency of higher fertilizer application and tillage operations) has the highest energy inputs and outputs than the rest of the cases. Moreover, it possesses the lowest energy use efficiency and energy productivity. The highest CO2 emissions (1548 kg-CO2/ha) referred to C-Ⅴ while lowest emissions per ton of grain yield were determined in C-Ⅳ (higher electricity water pumping, moderate energy input). The grain yield increases directly with input energy in most of the cases, but it does not guarantee the highest values for energy indices. C-Ⅲ (moderate irrigations, educated farmers, various fertilizer applications) was found as an optimum case because of higher energy indices like energy use efficiency of 4.4 and energy productivity of 153.94 kg/GJ. Optimum input and better management practices may enhance energy proficiency and limit the traditionally uncontrolled CO2 emissions from wheat production. Therefore, the agricultural practices performed in C-Ⅲ are recommended for efficient cultivation of wheat in the studied area.

scholarly journals Chinaʼs Economic Growth, Energy Efficiency, and Industrial Development: Nonlinear Effects on Carbon Dioxide Emissions

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Donghai Zhou ◽  
Binxia Chen ◽  
Jiahui Li ◽  
Yuanying Jiang
Keyword(s):  
Economic Growth ◽  
Carbon Dioxide ◽  
Energy Efficiency ◽  
Co2 Emissions ◽  
Industrial Development ◽  
Energy Use ◽  
Energy Use Efficiency ◽  
Use Efficiency ◽  
Growth Energy ◽  
The Impact

This paper analyzes the time-varying impacts of Chinaʼs economic growth, energy efficiency, and industrial development on carbon dioxide (CO2) emissions from 1970 to 2019. First, we examined and found that there are two significant structural changes in the CO2 sequence over the years, and there was a significant nonlinear relationship among the four. The first nonlinear structural model constructed is the TVP regression model. According to the Bayesian model comparison criterion, TVP-SV-VAR was selected as the second constructed model from four types of VAR models containing nonlinear structures. The results show that the conduction intensity value of energy use efficiency to CO2 emissions has increased year by year, from 0.45 in 1971 to 0.97 in 2019. The short-term transmission mechanism of energy use efficiency to carbon emissions is the most significant. The conduction intensity of Chinaʼs economic growth on CO2 emissions increases year by year. Chinaʼs economic growth plays a major role in long-term CO2 emission reduction. The impact of industrial development on CO2 emissions reached a peak of 0.34 in 1977, and the intensity of the impact has basically stabilized at 0.26.

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