Climate and the efficiency of crop production in Britain

The efficiency of crop production is defined in thermodynamic terms as the ratio of energy output (carbohydrate) to energy input (solar radiation). Temperature and water supply are the main climatic constraints on efficiency. Over most of Britain, the radiation and thermal climates are uniform and rainfall is the main discriminant of yield between regions. Total production of dry matter by barley, potatoes, sugar beet, and apples is strongly correlated with intercepted radiation and these crops form carbohydrate at about 1.4 g per MJ solar energy, equivalent to 2.4% efficiency. Crop growth in Britain may therefore be analysed in terms of ( a ) the amount of light intercepted during the growing season and ( b ) the efficiency with which intercepted light is used. The amount intercepted depends on the seasonal distribution of leaf area which, in turn, depends on temperature and soil water supply. These variables are discussed in terms of the rate and duration of development phases. A factorial analysis of efficiency shows that the major arable crops in Britain intercept only about 40 % of annual solar radiation and their efficiency for supplying energy through economic yield is only about 0.3%. Some of the factors responsible for this figure are well understood and some are immutable. More work is needed to identify the factors responsible for the large differences between average commercial and record yields.

2020 ◽  
Author(s):  
António Canatário Duarte ◽  
Abel Veloso ◽  
António Ramos ◽  
Dora Ferreira ◽  
Maria Paula Simões

The irrigation patterns in two peach orchards, located in the central eastern region of Portugal, called “Beira Interior”, and the effect of different amounts of irrigation on the total production and fruit quality were evaluated. The experiment was conducted in 2016, in two different orchards, and included three treatments correspondent to three different flow rates per tree: 8, 12 and 16 l/hour. The water balance, which included the water supplied by rain and irrigation and the crop evapotranspiration, was developed. At harvest, crop production, pulp firmness and percentage of the total soluble solids were evaluated. There were no significant differences between treatments in the average production per tree. However, in one of the orchards production increased with the volume of irrigation. In the same orchard, fruit firmness decreased with the increasing water supply. Total soluble solids had decreased with the increasing water supply in both orchards, probably as a consequence of the dilution effect due, directly, to the water incorporated in the fruits, or, indirectly, to the larger fruits produced by the trees that were irrigated more. In general, the treatments used in this study as well as in the farmers’ practices, the supplied water was in deficit, but the farmers tend empirically to follow closely the evolution of evapotranspiration. Keywords: Deficit irrigation, Peach tree, Production, Total soluble solids, Fruit firmness


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1152
Author(s):  
Rebekah Waller ◽  
Murat Kacira ◽  
Esther Magadley ◽  
Meir Teitel ◽  
Ibrahim Yehia

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semi-transparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S. The wavelength-selective OPV arrays were installed in a contiguous area on a section of the greenhouse roof, decreasing the transmittance of all solar radiation wavelengths and photosynthetically active radiation (PAR) wavelengths (400–700 nm) to the OPV-shaded area by approximately 40% and 37%, respectively. Microclimate conditions and tomato crop growth and yield parameters were measured in both the OPV-shaded (‘OPV’) and non-OPV-shaded (‘Control’) sections of the greenhouse. The OPV shade stabilized the canopy temperature during midday periods with the highest solar radiation intensities, performing the function of a conventional shading method. Although delayed fruit development and ripening in the OPV section resulted in lower total yields compared to the Control section (24.6 kg m−2 and 27.7 kg m−2, respectively), after the fourth (of 10 total) harvests, the average weekly yield, fruit number, and fruit mass were not significantly different between the treatment (OPV-shaded) and control group. Light use efficiency (LUE), defined as the ratio of total fruit yield to accumulated PAR received by the plant canopy, was nearly twice as high as the Control section, with 21.4 g of fruit per mole of PAR for plants in the OPV-covered section compared to 10.1 g in the Control section. Overall, this study demonstrated that the use of semi-transparent OPVs as a seasonal shade element for greenhouse production in a high-light region is feasible. However, a higher transmission of PAR and greater OPV device efficiency and durability could make OPV shades more economically viable, providing a desirable solution for co-located greenhouse crop production and renewable energy generation in hot and high-light intensity regions.


Agromet ◽  
2017 ◽  
Vol 31 (1) ◽  
pp. 43
Author(s):  
Pono Ngatui ◽  
. Handoko ◽  
Bregas Budianto ◽  
Marliana Tri Widyastuti

<p>Solar radiation greatly affects the development of plant biomass. The process of plant development is complex. Here, we simplified this complexity through modeling experiment by integrating climate variables. This study aims to determine the dynamics of canopy intercepted solar radiation under soybean (<em>Glycine Max (L.) Merrill</em>). We employed the shierary-rice model to calculate plant biomass. The results showed that intercepted radiation continuosly increased during vegetative phase, whereas the radiation remains constant during generative phase. Our observation confirmed that the pattern of intercepted radiation followed the angular pattern of sunlight. The intercepted radiation was optimum at 10:00 to 14:00 pm, and it was used to form the plant dry matter. We found that the intercepted radiation contributed until 12%. Based on this contribution, we built our crop model of soybean biomass. Our model performed well in simulating dry biomass with high R<sup>2</sup> (0.9), and as indicated by the plot 1:1 between dry matter of model and field observations. Further, the result of t test between model and observed data confirm this strong corelation (<em>p-value</em> 0.07).</p>


2021 ◽  
Vol 67 (No. 5) ◽  
pp. 45-52
Author(s):  
Gerhard Moitzi ◽  
Reinhard W. Neugschwandtner ◽  
Hans-Peter Kaul ◽  
Helmut Wagentristl

Sustainable crop production requires an efficient usage of fossil energy. This six-year study on a silt loam soil (chernozem) analysed the energy efficiency of four tillage systems (mouldboard plough 25–30 cm, deep conservation tillage 35 cm, shallow conservation tillage 8–10 cm, no-tillage). Fuel consumption, total energy input (made up of both direct and indirect input), grain of maize yield, energy output, net-energy output, energy intensity and energy use efficiency were considered. The input rates of fertiliser, herbicides and seeds were set constant; measured values of fuel consumption were used for all tillage operations. Total fuel consumption for maize (Zea mays L.) production was 81.6, 81.5, 69.5 and 53.2 L/ha for the four tillage systems. Between 60% and 64% of the total energy input (17.0–17.4 GJ/ha) was indirect energy (seeds, fertiliser, herbicides, machinery). The share of fertiliser energy of the total energy input was 36% on average across all tillage treatments. Grain drying was the second highest energy consumer with about 22%. Grain yield and energy output were mainly determined by the year. The tillage effect on yield and energy efficiency was smaller than the growing year effect. Over all six years, maize produced in the no-tillage system reached the highest energy efficiency.  


10.5772/34796 ◽  
2012 ◽  
Author(s):  
Carlos Campillo ◽  
Rafael Fortes ◽  
Maria del Henar Prieto

2016 ◽  
Vol 39 (1) ◽  
Author(s):  
Nitin Gudadhe ◽  
M. B. Dhonde ◽  
N. A. Hirwe ◽  
N. M. Thete

This study was conducted during the year 2006-07 and 2007-08 to determine how energy balances of crop production are affected by cotton-chickpea cropping sequence and different sources of organic and inorganic fertilizer under the semi-arid conditions of western Maharashtra. The energy input and output, energy balance per unit input ratio and the energy output/ input ratio were varied significantly individually to cotton and chickpea during both the years. However on pooled mean basis to cotton-chickpea cropping sequence, the energy input, output and energy balance were significantly higher by application of (RDF) Recommended Dose of Fertilizer according to Soil Test Crop Response (STCR) equation to cotton and 100% RDF to chickpea. Significantly higher energy balance per unit input and energy output per input ratio (6.46 MJ/ ha and 7.46) were recorded by 100% RDF + 10 FYM/ha to cotton and it was 5.72 MJ/ha and 6.72 by 100% RDF to chickpea. Application of RDF according to STCR equation (₹ 64960 and 3.07) to cotton and 100% RDF (₹ 46744 and 2.23) application to chickpea registered higher net monetary returns and benefit cost ratio respectively.


Author(s):  
Hemchandra Saikia ◽  
B. C. Bhowmick ◽  
R. A. Halim

Energy is a very key component in every sphere of our life, be it a crop production or any other field. Again seasonality is a very common phenomenon in crop production and due to this there exist slacks and peak season of various sources of energy use and production. Present study was conducted in Golaghat district of Assam to highlight the month-wise energy use and also to know the energy output-input and benefit-cost ratio. Sampling method used for the study was Three Stage Sampling method. Result from the study revealed that the cropping intensity of the study area was 119.57 per cent. The most dominant energy consuming months were July, August, November, and December using 30.64, 18.90, 13.12 and 7.65 per cent of the total energy used in crop production in per hectare of gross cropped area. The energy output-input and benefit –cost ratio of the study area were 10.84 and 1.64 respectively. From the study it was found that there is vast scope to boost the production, productivity and profitability of crop production in study area by providing all the necessary infrastructures in due space and time in adequate amount and proper quality.


1997 ◽  
Vol 12 (3) ◽  
pp. 130-132 ◽  
Author(s):  
M. Sefik Yesilsoy ◽  
Sabit Ersahin

AbstractTurkey is experiencing pressure to increase crop production per unit area to achieve self-reliance in food supply. The main production concern before 1970 was to increase crop yields to meet the national consumption of an ever-increasing population. During this time the country's capability to produce wheat was insufficient to meet the national demand. After the initiation of the National Wheat Research and Extension Project in 1969 the objectives of wheat production methods were changed to achieve not only higher but more economical yields per unit area. As a result the total area sown to wheat increased by only 9% between 1969 and 1990, whereas yields and total production increased 75 and 90%, respectively. This was due to developing or importing high-yielding varieties adapted to dry areas, increasing use of fertilizers and plant protection chemicals, and timely use of proper tillage made possible with modem equipment. Transferring research results to farmers and exchanging information with international scientists led Turkish scientists to establish the new goal of developing ecologically sound farming systems that could achieve higher, more economical yields per unit area. The key to this approach is to maintain or increase soil organic matter.


Author(s):  
Evangelia STEFANOPOULOU ◽  
Ioannis ROUSSIS ◽  
Konstantinos TSIMPOUKAS ◽  
Stella KARIDOGIANNI ◽  
Ioanna KAKABOUKI ◽  
...  

Nigella sativa L. is considered to be an alternative crop offering innovative and high-quality products. A case study was implemented on an existing farm to determine the prospects of N. sativa production in Greece and to assess the economic outcomes of the cultivation of this crop under organic and conventional cropping systems. The total production cost of organic N. sativa seeds was 6.09 €/kg, while the cost of conventional seeds was 4.77 €/kg. The organic and conventional N. sativa seed selling prices were 17.04 and 12.01 €/kg, respectively. Moreover, the financial performance of farm is better after the introduction of N. sativa crop under organic cropping system, where the net profit increased by 63.8% compared to the initial profit of the farm, while the increase in the conventional was less at 49.2%. N


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