scholarly journals Energy Balance and Energy Use Efficiency of Annual Bioenergy Crops in Field Experiments in Southern Germany

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1835
Author(s):  
Robert Oliver Simon ◽  
Kurt-Jürgen Hülsbergen

The main objective of the cultivation of energy crops is the production of renewable energy, the substitution of fossil energy resources, and a substantial contribution to energy supply. Thus, energy yield and energy efficiency are the most important criteria for the assessment of energy crops and biomass-based renewable energy chains. Maize is the energy crop with the highest cultivation acreage in Germany because of its high energy yields, but is the subject of controversial debate because of possible detrimental effects on agro-ecosystems. This raises the question as to which energy crops and production systems could be used instead of maize, in order to increase crop diversity and lower environmental impacts. We examined yields, energy inputs, energy outputs, and energy efficiency of alternative energy crops (combinations of catch crops and main crops) compared to maize in four-year field experiments at three southern German sites by means of process analyses. Maize showed moderate energy inputs (11.3–13.2 GJ ha−1), with catch crops ranging from 6.2 to 10.7 GJ ha−1 and main crops ranging from 7.6 to 24.8 GJ ha−1. At all three sites, maize had the highest net energy output compared to the other crops (x¯ = 354–493 GJ ha−1), but was surpassed by combinations of catch and main crops at some sites (winter rye/maize: x¯ = 389–538 GJ ha−1). Although some combinations yielded higher net energy outputs than maize, no other crop or combination of crops outperformed maize regarding energy use efficiency (energy output/energy input: x¯ = 32–45).

2021 ◽  
Vol 67 (No. 3) ◽  
pp. 137-146
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

Sustainable cropping systems require efficient usage of fossil energy. This study performed on a long-term field experiment in the Pannonian Basis investigated the energy efficiency of four tillage systems (mouldboard plough (MP), deep conservation tillage (CT<sub>d</sub>), shallow conservation tillage (CT<sub>s</sub>) and no-tillage (NT)) for sugar beet and soybean production, taking fuel consumption, total energy input (made up of both direct and indirect inputs), crop yield, energy output, net-energy output, energy intensity and energy use efficiency into account. The input rates of fertiliser, chemical plant protection, and seeds were set constant across years; whereas measured values of fuel consumption were used for all tillage treatments. NT required a considerably lower energy input than MP and CT<sub>d</sub> as no fuel is needed for tillage and just slightly more fuel for additional spraying of glyphosate. Anyhow, the energy efficiency parameters did not differ between tillage treatments, as theses parameters were mainly determined by energy output, which was considerably higher than the energy input. However, year effects on the energy efficiency were observed for both crops. Nitrogen fertilisation and diesel fuel consumption were identified as the most energy-intensive inputs. Consequently, the energy input for sugar beet was higher than that for soybean, which was identified as a low-input crop. But sugar beet attained a more than 4 times higher net-energy output, a 2.5 times higher energy use efficiency, and an energy intensity for yield production of less than 3 times those of soybean.  


Author(s):  
Nawal Khamis Al-Mezeini ◽  
Abdulrahim M. Al-Ismaili ◽  
Said M. Tabook

Sustainable agricultural production could be assessed through energy-use efficiency (EUE). Thus, this paper aims to evaluate the EUE for cucumber greenhouse production in Oman. Data were obtained by interviewing farmers (face-to-face). Result indicated that total energy inputs (e.g. electricity, water, fertilizers and agrochemicals) and total energy output (cucumber yield) were 1159726.0 MJ ha-1 and 89942.9 MJ ha-1, respectively. The highest energy consuming input in the greenhouse production was electricity, consuming 88% of total energy input. This indicates that electricity had again the highest impact in cucumber greenhouse production and 99% of electricity goes for cooling the greenhouse. When all energy inputs were classified into its forms; direct (D) and indirect (ID), and renewable (R) and non-renewable (NR), the highest portion of total energy forms in greenhouse cucumber production was for D and NR energy. The EUE and energy productivity (EP) were found to be 0.07 and 0.10 kg MJ-1, respectively. Energy use in greenhouse cucumber production was inefficient and solar energy need to be implemented to improve cucumber greenhouse sustainability production.


2021 ◽  
Vol 67 (No. 12) ◽  
pp. 739-746
Author(s):  
Gerhard Moitzi ◽  
Reinhard Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

The effect of crop sequences (CR – continuous winter rye; CropR – three-field crop rotation of winter rye-spring barley-bare fallow) and fertilisation systems (unfertilised control, mineral fertiliser (NPK), farmyard manure (FYM)) on crop yield, energy efficiency indicators and land demand were analysed in a long-term experiment under Pannonian climate conditions. Due to lower fuel consumption in the bare fallow, the total fuel consumption for CropR was 27% lower than in CR. It was for NPK and FYM fertilisation by 29% and 42% higher than in the control. Although the energy output was lower in CropR than CR, the energy use efficiency for grain production increased by 35% and for above-ground biomass production by 20%. Overall crop sequences, the NPK treatment had higher crop yields, energy outputs and net-energy output with a lower energy use efficiency than the unfertilised control. CropR increased the land demand just by 20% in comparison to CR, although one-third of the land was not used for crop production. The land demand could be decreased with fertilisation by 50% (NPK) or 48% (FYM). A bare fallow year in the crop rotation decreased the crop yield, energy input and increased the energy use efficiency and land demand.  


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 229
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

A goal in sustainable agriculture is to use fossil energy more efficiently in crop production. This 60-year-old experiment on a silt loam chernozem investigated effects of fertilization (unfertilized control, mineral fertilizer (NPK) and farmyard manure (FYM)) and rotation (continuous winter rye (CR), winter rye in rotation (RR), spring barley in rotation (SB) on diesel fuel consumption, total energy input (made of both direct and indirect inputs), crop yield, energy output, net-energy output, energy intensity, energy productivity and energy use efficiency. The input rates of fertilizer, herbicides and seeds were set constant during the experiment. Soil tillage was done with a moldboard plough with subsequent combined seedbed preparation and seeding. The mean calculated total energy input was highest in NPK with 11.28 GJ ha−1 and lowest in the unfertilized control with 5.00 GJ ha−1. Total energy input for FYM was intermediate with 6.30 GJ ha−1. With energetic consideration of NPK nutrients in FYM the total energy input increased to the level of NPK. The share of the fertilizer energy on the total energy input was 49% for NPK. Fertilization with FYM and NPK increased yield and energy output considerably, especially of CR and SB which attained about doubled values. Crop rotation also increased the yield and energy output, especially of unfertilized rye, which attained values increased by about 75%. Fertilization with FYM resulted in the highest energy efficiency as the net-energy output, the energy productivity and the energy use efficiency were higher but the energy intensity was lower compared to unfertilized controls and NPK. When the nutrients in FYM were also energetically considered, the energy efficiency parameters of FYM decreased to the level of the NPK treatment. Crop rotation increased the energy efficiency of winter rye compared to the monoculture.


2014 ◽  
Vol 1073-1076 ◽  
pp. 2468-2472
Author(s):  
Dong Tian ◽  
Jing Wang ◽  
Jian Ying Feng

This study examines energy consumption of inputs and output used in protected grape production, and aims at to find relationship between energy inputs and yield in the major protected grape producing regions in China. For this purpose, the data were collected from 516 questionnaires which included 304 effective ones by questionnaire survey method. The results indicated that total energy inputs were 57697.84 MJha-1where the Chemical with (32.4%) and Fertilizer with about (21.1%) were the major energy consumers. About 53.4% of the total energy inputs used in protected grape production was indirect while 46.6% was direct. The non-renewable shared about 78% whereas the renewable energy did 22%. Average yield and energy consumption are calculated as 25367.22Kgha-1and 299333.2MJha-1. Energy use efficiency, energy productivity, specific energy and net energy were 5.18, 0.44 kgMJ-1, 2.27 MJkg-1and241635.36 MJha-1, respectively.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1892 ◽  
Author(s):  
Xiaoyan Zheng ◽  
Almas Heshmati

This paper investigates energy use efficiency at the province level in China using the stochastic frontier panel data model approach. The stochastic frontier model is a parametric model which allows for the modeling of the relationship between energy use and its determinants using different control variables. The main control variables in this paper are energy policy and environmental and regulatory variables. This paper uses province level data from all provinces in China for the period 2010–2017. Three different models are estimated accounting for the panel nature of the data; province-specific heterogeneity and province-specific energy inefficiency effects are separated. The models differ because of their underlying assumptions, but they also complement each other. The paper also explains the degree of inefficiency in energy use by its possible determinants, including those related to the public energy policy and environmental regulations. This research supplements existing research from the perspective of energy policy and regional heterogeneity. The paper identifies potential areas for improving energy efficiency in the western and northeastern regions of China. Its findings provide new empirical evidence for estimating and evaluating China’s energy efficiency and a transition to cleaner energy sources and production.


2017 ◽  
Vol 4 (03) ◽  
Author(s):  
PARMEET SINGH ◽  
M. A. RATHE ◽  
R. H. KANTH ◽  
LAL SINGH ◽  
PURSHOTAM SINGH ◽  
...  

Energy being the critical aspect of agricultural production, the modern agricultural system takes into account all the agricultural operations in terms of energy input and the yield obtained as energy output. It is this energy balance equation which describes the viability of a system. Depending upon the variation in energy consumption among various agro–climatic and environmental conditions and the output therein, a wide variation exists in the viability of these systems. In the present study, the energy balance in Kala zeera management system was taken into consideration. Data and information were collected and different energy use efficiency indices were calculated. Amon the production practices in Kala zeera cultivation, consumed root tubers for sowing were the most energy consuming input (43.32%) followed by diesel fuel (20.28 %) and Nitrogen (18.30). the total energy input could be classified in Kala zeera fields as direct ( 10.80%), indirect (25.60%), renewable (43.3%) and non-renewable (20.27%). Overall in view of sustainability,it is recommended that major input consumptive processes shall be optimized to increase energy use efficiency


2019 ◽  
Vol 59 (5) ◽  
pp. 879 ◽  
Author(s):  
J. C. C. Chagas ◽  
M. A. Ferreira ◽  
M. M. Campos ◽  
F. S. Machado ◽  
L. C. Silva ◽  
...  

This experiment aimed to estimate the energy and protein requirements for Holstein × Gyr calves up to 60 days of age fed with milk replacer and amino acid supplement. Fifty male calves were used, of which seven were randomly allocated into the reference group and slaughtered at 8 days of age, seven were randomly allocated into the maintenance group slaughtered at 30 days of age, and the 36 remaining calves were included in the experiment at 8 days of age and randomly supplied with four dietary methionine+cysteine:lysine ratios (RMCL; 44%, 48%, 52%, and 56%) through amino acid supplement added as 1 kg/day of milk replacer reconstituted at 13.8% of dry matter. Different RMCL were tested for the models, and there were no significant effects on energy and protein requirements. The net energy requirement for maintenance was 75.2 kcal/empty bodyweight (EBW)0.75.day, with an energy use efficiency for maintenance of 67.38%. The prediction equation of net energy requirement for gain (Mcal/day) was energy retained = 0.0879 × EBW0.75 × empty bodyweight gain (EBWG)0.7580, with an energy use efficiency for gain of 47.57%. The estimated requirements for metabolisable protein for maintenance were 4.83 g/EBW0.75.day. The estimated equation for net protein requirements for gain (g/day) was NPg = EBWG × 246.73 × EBW–0.1204, with a protein use efficiency for gain of 71.55%. The estimated requirements for energy and proteins were greater than the values reported for calves fed with milk. Milk replacers are less efficiently used by calves up to 60 days of age when compared with whole milk.


2011 ◽  
Vol 34 (2) ◽  
pp. 113-123 ◽  
Author(s):  
R.P. Zentner ◽  
P. Basnyat ◽  
S.A. Brandt ◽  
A.G. Thomas ◽  
D. Ulrich ◽  
...  

Food Research ◽  
2020 ◽  
Vol 4 (S5) ◽  
pp. 34-39
Author(s):  
Liyana N.A. ◽  
D.E. Pebrian

Preservation of energy resources for crop production is a crucial act in an endeavour to make agriculture more sustainable. In response to that matter, this study aims to analyse and evaluate energy use pattern and its economic in rockmelon (Cucumis melo) production in Malaysian farms. Face-to-face interviews with the sampled farmers were employed to collect the data through a case study in Klang district, Selangor state of Malaysia. The collected data was then analysed using mathematical operations and spreadsheet software. The results indicated that the total energy inputs in rockmelon were 4475.62 MJ/ha. The highest portion, which accounted for 73.29% of the total energy inputs were consumed by fertilizers, while the lowest portion was used for seed (0.01%). The total energy inputs were formed from 85.12% indirect energy and 14.88% direct energy; and 85% non-renewable energy and 15% renewable energy. The net energy and energy productivity values were 11332.85 MJ/ha and 2.81 kg/MJ, respectively. The farmers gained 29.94% profit margin from their farms business. The ratio of energy output -inputs in rockmelon production was 5.34. As the ratio was much greater than 1, thus, conclusively, the energy inputs used by the farmers in the process of rockmelon production was highly efficient.


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