scholarly journals Ancient WEF: Water–Energy–Food Nexus in the Distant Past

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 925
Author(s):  
Steven G. Pueppke

The concept of water–energy–food (WEF) nexus is gaining favor as a means to highlight the functions of the three individual nexus elements as interrelated components of a single complex system. In practice, the nexus approach projects forward from the present, seeking to maximize future WEF synergies and avoid undesirable tradeoffs. A complementary approach was employed here to gain insights into how the ancients dealt with WEF relationships, whether currently relevant nexus principles were practiced long ago, and how past WEF dynamics compare to those of today. Two examples, both dating to before the common era (BCE), are considered in detail. The qanats of ancient Persia brought groundwater to the surface and directed it to clusters of agricultural fields in arid areas where crop production was not otherwise feasible. In contrast, the Dujiangyan irrigation scheme of ancient China harnessed previously destructive surface water flows to stabilize food production across a vast agricultural plain. Designed and constructed under highly uncertain conditions and with a long-term perspective, both relied on local resources and expertise to exploit the tight coupling of water and the intrinsic energy from its flows to produce food. Ingenious infrastructure combined with sound governance allowed both to achieve remarkable synergies among the WEF components with minimal apparent tradeoffs. Although both are now challenged by climate change and the increasing complexity of modern WEF relationships, qanat systems and the Dujiangyan irrigation scheme have survived for millennia and still exist in recognizable form. This is due in large part to the persistence of governance systems that devolved significant decision-making authority to those who used water and energy for food production. Although it is not feasible to roll back technology to that of an earlier time, the successful attributes of earlier WEF governance systems warrant more attention in the future.

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1011
Author(s):  
Bartłomiej Bajan ◽  
Joanna Łukasiewicz ◽  
Agnieszka Poczta-Wajda ◽  
Walenty Poczta

The projected increase in the world’s population requires an increase in the production of edible energy that would meet the associated increased demand for food. However, food production is strongly dependent on the use of energy, mainly from fossil fuels, the extraction of which requires increasing input due to the depletion of the most easily accessible deposits. According to numerous estimations, the world’s energy production will be dependent on fossil fuels at least to 2050. Therefore, it is vital to increase the energy efficiency of production, including food production. One method to measure energy efficiency is the energy return on investment (EROI), which is the ratio of the amount of energy produced to the amount of energy consumed in the production process. The literature lacks comparable EROI calculations concerning global food production and the existing studies only include crop production. The aim of this study was to calculate the EROI of edible crop and animal production in the long term worldwide and to indicate the relationships resulting from its changes. The research takes into account edible crop and animal production in agriculture and the direct consumption of fossil fuels and electricity. The analysis showed that although the most underdeveloped regions have the highest EROI, the production of edible energy there is usually insufficient to meet the food needs of the population. On the other hand, the lowest EROI was observed in highly developed regions, where production ensures food self-sufficiency. However, the changes that have taken place in Europe since the 1990s indicate an opportunity to simultaneously reduce the direct use of energy in agriculture and increase the production of edible energy, thus improving the EROI.


2021 ◽  
Author(s):  
Lynette Morgan

Abstract Integrated crop management (ICM) is an all-inclusive, holistic approach to sustainable food production that focuses on conserving natural resources. One of the main objectives is to blend the use of modern technology with time proven methods of crop production, maintenance of soil fertility and care for the natural environment as part of an economically-viable horticultural business. Horticultural practices that avoid or minimise waste and pollution, incorporate energy efficiency, reduce external farm inputs such as fertilizers, pesticides and herbicides, and follow a long term strategy for conservation and management, are the basis of this system. Resource management is a key feature of integrated crop management to minimise the consumption of non-renewable resources, while at the same time safeguarding the environment and biodiversity of the land used for food production. Integrated crop management is often defined as a 'whole farm system' where the requirements for production of an economic product are balanced with the care of the land and environmental considerations. While integrated crop management seems a simple concept to understand, the implementation and approaches taken vary considerably depending on the site, production system, crops and many other factors. Being site specific means that individual producers must plan and develop their own individualised integrated crop management programme based on their local needs, crops, resources and areas for improvement.


2013 ◽  
Vol 38 (2) ◽  
pp. 257-269 ◽  
Author(s):  
M Shahe Alam ◽  
MA Islam

Despite high pressure of population on land and other natural resources, Bangladesh has made remarkable progress in food production over the last three and a half decades. The shrinking trend in land availability for crop production is another challenge ahead of the economy. The declining trend in cultivable land was quite sharp in the period of 1990 to 2005. Although the population has doubled, cereal food production has increased in the range of 100-125% during this period. The progress is the result of development and dissemination of modern high-yielding rice and wheat varieties supported by favourable public policies. There has been impressive technological advancement in the rice sector. Bangladesh Rice Research Institute (BRRI) made substantial contribution in the recent past and a total of 59 modern high yielding rice varieties (HYVs) suitable for different production ecologies have been released after independence in 1972. Although the progress in variety development was slower during the seventies and eightees, it was triggered up in the later decades and a quantum of achievement was made after 2000. The rate of varietal development was almost double in the last quarter of the decades compared to that made in the seventees. During the period of 1972 to 1980, the share of modern rice in total production was only 29%, but by the year 1985, it increased to 41% and jumped to nearly 90% by 2010 implying a highly impressive contribution of the diffusion of modern rice technologies in the overall supply of cereal foods in the country. Bangladesh J. Agril. Res. 38(2): 257-269, June 2013 DOI: http://dx.doi.org/10.3329/bjar.v38i2.15889


2010 ◽  
Vol 58 (Supplement 1) ◽  
pp. 1-5 ◽  
Author(s):  
M. Jolánkai ◽  
F. Nyárai ◽  
K. Kassai

Long-term trials have a twofold role in life sciences, acting as both live laboratories and public collections. Long-term trials are not simply scientific curios or the honoured relics of a museum, but highly valuable live ecological models that can never be replaced or restarted if once terminated or suspended. These trials provide valuable and dynamic databases for solving scientific problems. The present paper is intended to give a brief summary of the crop production aspects of long-term trials.


2014 ◽  
Vol 63 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Éva Lehoczky ◽  
M. Kamuti ◽  
N. Mazsu ◽  
J. Tamás ◽  
D. Sáringer-Kenyeres ◽  
...  

Plant nutrition is one of the most important intensification factors of crop production. The utilization of nutrients, however, may be modified by a number of production factors, including weed presence. Thus, the knowledge of occurring weed species, their abundance, nutrient and water uptake is extremely important to establish an appropriate basis for the evaluation of their risks or negative effects on crops. That is why investigations were carried out in a long-term fertilization experiment on the influence of different nutrient supplies (Ø, PK, NK, NPK) on weed flora in maize field.The weed surveys recorded similar diversity on the experimental area: the species of A. artemisiifolia, S. halepense and D. stramonium were dominant, but C. album and C. hybridum were also common. These species and H. annuus were the most abundant weeds.Based on the totalized and average data of all treatments, density followed the same tendency in the experimental years. It was the highest in the PK treated and untreated plots, and significantly exceeded the values of NK fertilized areas. Presumably the better N availability promoted the development of nitrophilic weeds, while the mortality of other small species increased.Winter wheat and maize forecrops had no visible influence on the diversity and the intensity of weediness. On the contrary, there were consistent differences in the density of certain weed species in accordance to the applied nutrients. A. artemisiifolia was present in the largest number in the untreated control and PK fertilized plots. The density of S. halepense and H. annuus was also significantly higher in the control areas. The number of their individuals was smaller in those plots where N containing fertilizers were used. Contrary to them, the density of D. stramonium, C. album and C. hybridum was the highest in the NPK treatments.


Author(s):  
N. S. Levgerova ◽  
Е. S. Salina ◽  
I. А. Sidorova

The results of the technological assessment of new apple, cherry, black currant, red currant and gooseberry cultivars of VNIISPK breeding for the suitability for the natural food production are given. As a result, the cultivars that are promising for cultivation in raw plantings have been selected. For the production of raw materials in the juice industry, apple cultivars with a high juice yield and content of soluble solids higher than 10.0% were selected: ‘Bolotovskoye’ (Vf), ‘Candil Orlovsky’ (Vf), ‘Osipovskoye’ (3x), ‘Rozhdestvenskoye’ ((Vf + 3x), ‘Zaryanka’ (Vm), ‘Priokskoye’ ((Vf + Co), etc. Based on the long-term study of cultivars for their suitability for compote, jam and jelly, the cultivars that are most suitable for these types of processing are identified. It has been found that taking into account the daily needs of vitamins C and P as the most important antioxidants, all processed products from black currant can serve as their sources, all processed products from cherries, as well as apple juice and gooseberry marmalade can serve as a source of P-active compounds. All columnar apple cultivars as well as ‘Bolotovskoye’, ‘Rozhdestvenskoye’, ‘Veteran’, ‘Imrus’, etc. show high suitability for the production of apple chips. Cherry cultivars ‘Rovesnitsa’, ‘Putinka’, ‘Podarok Uchitelyam’ and ‘Novella’ are suitable for dried fruit. Based on the long-term studies of the technological qualities of the VNIISPK gene pool, a new generation assortment has been formed that has an optimal combination of chemical and technological indicators of fruits that meet modern technological requirements and are suitable for cultivation in the raw plantations of Central Russia.


2012 ◽  
Vol 21 (05) ◽  
pp. 1250048
Author(s):  
L. IORIO

We analytically work out the long-term orbital perturbations induced by the leading order of perturbing potential arising from the local modification of the Newton's inverse square law due to a topology ℝ2 × 𝕊1 with a compactified dimension of radius R recently proposed by Floratos and Leontaris. We neither restrict to any specific spatial direction [Formula: see text] for the asymmetry axis nor to particular orbital configurations of the test particle. Thus, our results are quite general. Nonvanishing long-term variations occur for all the usual osculating Keplerian orbital elements, apart from the semimajor axis which is left unaffected. By using recent improvements in the determination of the orbital motion of Saturn from Cassini data, we preliminarily inferred R ≳ 4-6 kau . As a complementary approach, the putative topological effects should be explicitly modeled and solved-for with a modified version of the ephemerides dynamical models with which the same data sets should be reprocessed.


2005 ◽  
Vol 85 (1) ◽  
pp. 81-93 ◽  
Author(s):  
C. A. Campbell ◽  
R. P. Zentner ◽  
F. Selles ◽  
P. G. Jefferson ◽  
B. G. McConkey ◽  
...  

Assessment of the long-term impact of fertilizers and other management factors on crop production and environmental sustainability of cropping systems in the semi-arid Canadian prairies is needed. This paper discusses the long-term influence of N and P fertilizers on crop production, N uptake and water use of hard red spring wheat (Triticum aestivum L.), and the effect of the preceding crop type [flax (Linum usitatissimum L.) and fall rye (Secale cereale L.)] on wheat grown on a medium-textured, Orthic Brown Chernozem at Swift Current, Saskatchewan. We analysed 36 yr of results (1967–2002) from eight crop rotation-fertility treatments: viz., fallow-wheat receiving N and P (F-W, N + P), three F-W-W treatments fertilized with (i) N + P, (ii) P only, and (iii) N only; two other 3-yr mixed rotations with N + P (i) F-flax-W (F-Flx-W) and (ii) F-fall rye-W (F-Rye-W); and two continuous wheat rotations (Cont W), one receiving N + P and the other only P. Growing season weather conditions during the 36-yr period were near the long-term mean, but the first 22 yr were generally drier than normal while the last 14 yr (1989–2002) had average to above-average growing conditions. This was partly responsible for grain and N yield being greater in the latter period than in the first 22 yr. The 36-yr average response of wheat grown on fallow to P fertilizer was 339 kg ha-1, while the response to N fertilizer over this period was only 123 kg ha-1. The 36-yr average response of wheat grown on stubble to N was 344 kg ha-1 for F-W-(W) and 393 kg ha-1 for Cont W. Neither flax nor fall rye influenced the yield response of the following wheat crops. Annualized grain production for F-W (N + P), F-W-W (+ N) and F-W-W (+ P) rotations were similar (1130 kg ha-1 yr-1); this was about 15% lower than for F-W-W (N + P), 40% lower than for Cont W (N + P), and 5% lower than for Cont W (+ P). Annualized aboveground N yield for Cont W (N + P) was 57% higher than for Cont W (+ P). Regressions were developed relating straw to grain yields for wheat, flax and fall rye. The amount of NO3-N left in the soil was directly related to amount of N applied and inversely to N removed in the crop. Thus, F-(W)-W (+ N) left about 28% more NO3-N in the rooting zone than F-(W)-W (N + P), while F-W-(W) (N + P) left 20% more than F-W-(W) (+ P), and Cont W (N + P) left 39% more than Cont W (+ P). F-Rye-W (N + P) left much less NO3-N in the soil than any other fallow-containing system and similar amounts to Cont W (N + P). Key words: Yields, grain protein, N and P fertilizer, straw/grain regressions, water use, soil nitrate


2021 ◽  
Author(s):  
Lynette Morgan

Abstract Crop production in many regions has been reliant on irrigation for almost as long as man has been cultivating plant life. For 6000 years, irrigation has ranked among the most powerful tools of human advancement (Postel, 1999), and by the start of the 21st century no less than 75% of the world's fresh water was in use for agricultural production (Levy and Coleman, 2014). In 2012, twenty percent of total cultivated land was under irrigation, contributing forty percent of the total food production worldwide, this represented 275 million hectares under actual irrigation with a total of 324 million hectares equipped for irrigation (FAO, 2016). Irrigation, which can be defined as 'the artificial application of water to land, soil or other growing medium for the purposes of crop growth', has become a global issue in more recent times as the increasing demand for fresh water has seen problems develop with water scarcity, quality issues and conflict over usage.


2011 ◽  
Vol 47 (2) ◽  
pp. 267-291 ◽  
Author(s):  
K. P. C. RAO ◽  
W. G. NDEGWA ◽  
K. KIZITO ◽  
A. OYOO

SUMMARYThis study examines farmers’ perceptions of short- and long-term variability in climate, their ability to discern trends in climate and how the perceived trends converge with actual weather observations in five districts of Eastern Province in Kenya where the climate is semi-arid with high intra- and inter-annual variability in rainfall. Field surveys to elicit farmers’ perceptions about climate variability and change were conducted in Machakos, Makueni, Kitui, Mwingi and Mutomo districts. Long-term rainfall records from five meteorological stations within a 10 km radius from the survey locations were obtained from the Kenya Meteorological Department and were analysed to compare with farmers’ observations. Farmers’ responses indicate that they are well aware of the general climate in their location, its variability, the probabilistic nature of the variability and the impacts of this variability on crop production. However, their ability to synthesize the knowledge they have gained from their observations and discern long-term trends in the probabilistic distribution of seasonal conditions is more subjective, mainly due to the compounding interactions between climate and other factors such as soil fertility, soil water and land use change that determine the climate's overall influence on crop productivity. There is a general tendency among the farmers to give greater weight to negative impacts leading to higher risk perception. In relation to long-term changes in the climate, farmer observations in our study that rainfall patterns are changing corroborated well with reported perceptions from other places across the African continent but were not supported by the observed trends in rainfall data from the five study locations. The main implication of our findings is the need to be aware of and account for the risk during the development and promotion of technologies involving significant investments by smallholder farmers and exercise caution in interpreting farmers’ perceptions about long-term climate variability and change.


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