Academic literature on the topic 'Yield decline'
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Journal articles on the topic "Yield decline"
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Ahmad, Mirza Junaid, Kyung-Sook Choi, Gun-Ho Cho, and Sang-Hyun Kim. "Future Wheat Yield Variabilities and Water Footprints Based on the Yield Sensitivity to Past Climate Conditions." Agronomy 9, no. 11 (November 11, 2019): 744. http://dx.doi.org/10.3390/agronomy9110744.
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This article analyzed the wheat yield variabilities and water footprints under projected future climate based on wheat yield sensitivity to past (1980–2017) trends of maximum temperature (Tmax), minimum temperature (Tmin), solar radiation (Rn) and rainfall (P) for the semi-arid condition of Punjab, Pakistan. The past and projected future trends of the climate variables were identical featuring prominent Tmin rise than Tmax accompanied by Rn and P declines. Based on the past influences and the projected future trends of the climate variables, Tmin was the principal driver of wheat yield decline followed by the Tmax, P and Rn. Wheat evapotranspiration and net irrigation water requirement declined due to the influence of both decrease of growing season length and Rn for the first half of 21st-century, and this trend reversed during the second half of 21st-century. These phenomena were caused by different degree of climate warming between the two-time slices. Due to future wheat yield decline and a gradual rise in green water scarcity the blue and grey water footprints rise consistently particularly during 2nd-time slices. CO2 enrichment showed limited mitigation potential of nullifying the warming-induced threats on future wheat yield and water footprints.
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Jefferson, P. G., and F. Selles. "The decline in hay yields: A Saskatchewan perspective." Canadian Journal of Plant Science 87, no. 5 (December 1, 2007): 1075–82. http://dx.doi.org/10.4141/cjps07128.
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Yield data collected by Statistics Canada show that annual hay yields have been declining in several Canadian provinces including Saskatchewan for the past 31 yr. Data from Saskatchewan provincial statistics on Beef Cow number, Area Harvested for Hay, Value of Land and Buildings, and Fertilizer Price Index were used to examine the relationships between hay yield and these variables. Weather from 16 sites across Saskatchewan’s agricultural region for the April, May, and June (AMJ) period was also examined from 1973 to 2003. Precipitation during AMJ was positively correlated to hay yield, but the difference between maximum and minimum temperatures (Δtemperature) was negatively correlated. Fertilizer Price Index was negatively correlated to hay yield, suggesting that producers are reducing fertilizer input to this crop resulting in lower yields. Step-wise regression analysis suggested that fertilizer cost was the most important variable, which explained 38% of the variation in hay yield. When fertilizer price was combined with Δtemperature, the Value of Land and Buildings and AMJ precipitation, 65% of the variation in Saskatchewan hay yield could be explained. Examination of census data on tame forage and tame pasture acres by district did not support the hypothes is that more hay has been seeded in lower yield regions of the Province. We speculate that climate change is negatively affecting Saskatchewan’s ability to produce hay, particularly since low inputs of fertilizer and infrequent stand rejuvenation are commonly practiced on forage crops. This problem needs more in-depth analysis to confirm the cause(s) of this decline and avoid a future scenario where low hay yields make ruminant livestock production economically unsustainable in Western Canada. Key words: Forage yield, precipitation, temperature, fertilizer
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Lamb, M. C., J. I. Davidson, and C. L. Butts. "Peanut Yield Decline in the Southeast and Economically Feasible Solutions." Peanut Science 20, no. 1 (January 1, 1993): 36–40. http://dx.doi.org/10.3146/i0095-3679-20-1-10.
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Abstract Peanut (Arachis hypogaea L.) yields in the Southeast declined 368 kg/ha during the 1980's and 596 kg/ha in the late 1980's when compared to the 1974-1979 period. The peanut yield decline was correlated with significant meteorological and policy changes in the Southeast during each time period. Meteorological changes were statistically estimated to decrease peanut yield by 137 kg/ha and 194 kg/ha in the 1980's and late 1980's, respectively. The effect on peanut yields from changes in agricultural policy and management decisions was estimated at -166 kg/ha and -225 kg/ha during the respective time periods. Field data gathered during crop years 1987-1990 reflected the meteorological and policy changes during the late 1980's in both non-irrigated and irrigated peanut fields. EXNUT, an expert systems model for peanut irrigation and pest management, was evaluated in 1987, 1988, 1989, and 1990 against expert farmers in the Southeast and increased peanut yields by 204 kg/ha. Evaluation of EXNUT demonstrated one example of how expert system technology can offer economically feasible solutions to the peanut yield decline in the Southeast.
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Magarey, RC. "Microbiological aspects of sugarcane yield decline." Australian Journal of Agricultural Research 47, no. 3 (1996): 307. http://dx.doi.org/10.1071/ar9960307.
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Sugarcane is an important Australian crop earning over $1.8 billion in export revenue annually. The crop is grown as a monoculture, and much of the production area has been continually cropped for over 60 years. Increasing production trends plateaued in the 1970s and soil based constraints now reduce industry income by $200~1 annually. The condition, termed sugarcane yield decline (YD), is similar to replant diseases in other crops. Large growth responses to soil fumigation, soil solarisation, and the application of fungicides, suggest that soil microbiology is intimately involved. Research has identified a previously unclassified oomycete, Pachymetra chaunorhiza, as a new sugarcane root pathogen. Additional root pathogens identified include Pythium arrhenomanes and various nematode species. Other organisms which appear to be involved in YD, are discussed.
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Sandhu, Harpinder, Benjamin Waterhouse, Stephane Boyer, and Steve Wratten. "Scarcity of ecosystem services: an experimental manipulation of declining pollination rates and its economic consequences for agriculture." PeerJ 4 (July 5, 2016): e2099. http://dx.doi.org/10.7717/peerj.2099.
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Ecosystem services (ES) such as pollination are vital for the continuous supply of food to a growing human population, but the decline in populations of insect pollinators worldwide poses a threat to food and nutritional security. Using a pollinator (honeybee) exclusion approach, we evaluated the impact of pollinator scarcity on production in four brassica fields, two producing hybrid seeds and two producing open-pollinated ones. There was a clear reduction in seed yield as pollination rates declined. Open-pollinated crops produced significantly higher yields than did the hybrid ones at all pollination rates. The hybrid crops required at least 0.50 of background pollination rates to achieve maximum yield, whereas in open-pollinated crops, 0.25 pollination rates were necessary for maximum yield. The total estimated economic value of pollination services provided by honeybees to the agricultural industry in New Zealand is NZD $1.96 billion annually. This study indicates that loss of pollination services can result in significant declines in production and have serious implications for the market economy in New Zealand. Depending on the extent of honeybee population decline, and assuming that results in declining pollination services, the estimated economic loss to New Zealand agriculture could be in the range of NZD $295–728 million annually.
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Zandstra, Bernard H., Sylvia Morse, Rodney V. Tocco, and Jarrod J. Morrice. "Response of Asparagus to Repeated Application of Residual Herbicides." HortTechnology 23, no. 1 (February 2013): 109–13. http://dx.doi.org/10.21273/horttech.23.1.109.
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Asparagus (Asparagus officinalis) is a perennial crop that has a 12- to 20-year production life in the field. Herbicides are applied in the spring each year and again after final harvest in early summer. Asparagus yield declines with age, and herbicides may contribute to yield decline. An experiment was established in 2004 and maintained for seven years with the same herbicide treatments applied each spring to determine herbicide effects on marketable spear yield. Spring-applied diuron, metribuzin, terbacil, sulfentrazone, halosulfuron, mesotrione, and clomazone had no adverse effect on yield or quality over the seven years of the experiment. Flumioxazin reduced yearly average marketable yield compared with standard treatments, and some spears developed lesions early in the season after rainfall. Asparagus yield from most treatments declined more than 50% from 2004 to 2010.
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Jefferson, Paul G., and Kathy Larson. "The relationship between Saskatchewan hay yield and changing cropping practices." Canadian Journal of Plant Science 94, no. 7 (September 2014): 1157–60. http://dx.doi.org/10.4141/cjps-2014-024.
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Jefferson, P. G. and Larson, K. 2014. The relationship between Saskatchewan hay yield and changing cropping practices. Can. J. Plant Sci. 94: 1157–1160. A previously reported decline in Saskatchewan hay yield statistics was re-examined with additional data. The decline in hay yield was confirmed in the new analysis, but the rate of decline was lower than previously reported. Several agronomic and economic variables were examined for their relationship to hay yield and precipitation use efficiency. Precipitation use efficiency for hay yield was correlated to summerfallow area, which has declined by 75% in Saskatchewan during the study period. Perennial hay crops are deep-rooted and therefore able to exploit soil water and nutrients at depth in previously summerfallowed land that was unavailable to grain and oilseed crops. We suggest that declining hay yield is due to less summerfallow land in modern Saskatchewan crop rotations.
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Bi, J., J. A. Blanco, B. Seely, J. P. Kimmins, Y. Ding, and C. Welham. "Yield decline in Chinese-fir plantations: a simulation investigation with implications for model complexity." Canadian Journal of Forest Research 37, no. 9 (September 2007): 1615–30. http://dx.doi.org/10.1139/x07-018.
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A variety of competing hypotheses have been described to explain yield decline in Chinese-fir ( Cunninghamia lanceolata (Lamb.) Hook.) plantations. The difficulty in implementing field experiments suggests ecosystem modeling as a viable option for examining alternative hypotheses. We present a conceptual model of Chinese-fir yield decline and explore its merits using the ecosystem-based FORECAST model. Model results suggest that yield decline is caused primarily by a decline in soil fertility, largely as a consequence of slash burning in conjunction with short rotations. However, as tree leaf area declines, there is a transition (over subsequent rotations) from seed rain based competition to bud bank based competition, increasing the competitive impact of minor vegetation on tree growth. Short rotations increase understory survival between rotations and may cause a gradual shift from tree dominance to shrub/herb dominance over subsequent rotations. These effects are most evident on nutrient-poor sites, but understory competition poses a significant yield decline risk on good sites as well. We conclude that sustainable production in Chinese-fir plantations requires the avoidance of activities that compromise soil fertility and increase understory competition. The risk and severity of yield decline would be reduced by increasing rotation lengths and avoiding plantations on infertile sites.
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Clements, Jeff C., Josefin Sundin, Timothy D. Clark, and Fredrik Jutfelt. "Extreme original data yield extreme decline effects." PLOS Biology 21, no. 2 (February 6, 2023): e3001996. http://dx.doi.org/10.1371/journal.pbio.3001996.
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Arumugam, Surendran, Ashok K.R., Suren N. Kulshreshtha., Isaac Vellangany, and Ramu Govindasamy. "Yield variability in rainfed crops as influenced by climate variables." International Journal of Climate Change Strategies and Management 7, no. 4 (November 16, 2015): 442–59. http://dx.doi.org/10.1108/ijccsm-08-2013-0096.
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Purpose – This paper aims to explore the impact of climate change on yields and yield variances in major rainfed crops and measure possible changes in yields under projected climate changes in different agro-climatic zones of Tamil Nadu, India. Although many empirical studies report the influence of climate change on crop yield, only few address the effect on yield variances. Even in such cases, the reported yield variances were obtained through simulation studies rather than from actual observations. In this context, the present study analyzes the impact of climate change on crops yield and yield variance using the observed yields. Design/methodology/approach – The Just-Pope yield function (1978) is used to analyze the impact of climate change on mean yield and variance. The estimated coefficient from Just-Pope yield function and the projected climatic data for the year 2030 are incorporated to capture the projected changes in crop yield and variances. Findings – By the year 2030, the yield of pulses is estimated to decline in all the zones (Northeast, Northwest, Western, Cauvery delta, South and Southern zones), with significant declines in the Northeast zone (6.07 per cent), Cauvery delta zone (3.55 per cent) and South zone (3.54 per cent). Sorghum yield may suffer more in Western zone (2.63 per cent), Southern zone (1.92 per cent) and Northeast zone (1.62 per cent). Moreover, the yield of spiked millet is more likely to decrease in the Southern zone (1.39 per cent), Northeast zone (1.21 per cent) and Cauvery delta zone (0.24 per cent), and the yield of cotton may also decline in the Northeast zone (12.99 per cent), Northwest zone (8.05 per cent) and Western zone (2.10 per cent) of Tamil Nadu, India. Originality/value – The study recommends introducing appropriate crop insurance policies to address possible financial losses to the farmers. Prioritizing area-specific stress-tolerant crop varieties without complementing yield would sustain crops cultivation further.
Dissertations / Theses on the topic "Yield decline"
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Madamombe, Godwil Mirirai. "Yield and quality decline in vegetatively propagated cultivar tea (Camellia sinensis (l) O. Kuntze) under continuous mechanical harvesting." Thesis, University of Pretoria, 2016. http://hdl.handle.net/2263/60825.
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Manual plucking is highly labour intensive, occupying almost 70% of the total labour force on tea estates and accounting for approximately 40 - 45% of cost of production. The high labour costs and shortages and the cost of production has resulted in tea (Camellia sinensis (L) O. Kuntze) industries in central and southern Africa becoming unprofitable. The solution to this problem has been the full mechanization of shoot harvesting, however, a reduction in yield and quality has been observed with mechanical harvesting. The overall aim of the study was to determine the causes of yield and quality decline in mechanically harvested tea and if higher nitrogen application rates could mitigate against the yield and quality decline. In order to achieve these aims, field experiments were carried out at Tingamira Estate, Chipinge, Zimbabwe and consisted of seven treatments laid out in a 2 x 3 factorial plus added control experiment, in a randomized complete block design replicated three times. Three harvesting methods (hand plucking performed every 10/11 days, hand-held and ride-on machines performed every 14 days) were tested against three fertilizer application rates (265, 300 and 400 kg N ha-1 yr-1), with hand plucking (265 kg N ha-1 yr-1) being the standard.
The study showed that highest yields were produced under hand plucking (HP) across all seasons (43 945 kg green leaf ha-1 yr-1) as compared to hand-held (HHM; 35 114 kg green leaf ha-1 yr-1) and ride-on machines (ROM; 36 268 kg green leaf ha-1 yr-1 (p < 0.05). Continuous mechanical harvesting therefore reduced yield, with yield declining between 17% and 19% compared to hand plucking over the three year pruning cycle. This reduction in yield was associated with a decrease in both the number and mass of desirable shoots in each season. This was largely due to the indiscriminate removal of foliage by the machines, which resulted in the proliferation of immature shoots, with an associated increase in sink strength and competition for available photo-assimilates. In addition, the maintenance layer was depleted in mechanically harvested bushes. This was indicated by reduced fractional interception of photosynthetically active radiation in the top 10 cm in these bushes and reduced photosynthetic rates in these bushes. This suggests that these bushes were also source limited, as compared to hand plucked bushes. Therefore the changes in tea bush architecture, as a result of mechanical harvesting, resulted in changes in sink/source dynamics, which led to a proliferation of immature shoots which competed for limited photo-assimilates.
The decline in yield in mechanically harvested tea has also been associated with a decline in tea quality. In this study hand plucking resulted in a higher % of good leaf quality compared to machine harvesting treatments in the first two seasons, irrespective of N application rate. However, in the third season there were no differences in % good leaf between treatments. Tea tasters' assessments in the third season also showed that there were no significant differences in liquor colour and strength, briskness, brightness and total tea tasters' valuation between hand plucking and mechanical harvesting. However, seasonal differences were observed with higher scores and valuation being observed in the off - season (May 2013), as compared to the main growing period (February 2013). High N-rates tended to reduce made tea density and % fibre content under machine harvesting, but there were no significant differences between treatments. Based on organoleptic evaluation scores and taking hand plucking as a standard for good quality, the harvesting techniques did not show any differences in quality. An analysis of biochemical compounds, important for black tea quality, in tea from February 2013 and May 2013 showed no difference between harvesting techniques and N-application rates. However the dimers and trimers of smaller catechins produced during harvesting initiating field fermentation increased in mechanically harvested bushes and with higher N-application rates, as compared to hand plucking. This could possibly have improved quality in mechanically harvested teas. Based on these results mechanical harvesting can be used as an alternative to hand plucking, as it does not adversely affect black tea quality as previous believed.Thesis (PhD)--University of Pretoria, 2016.
Plant Production and Soil Science
PhD
Unrestricted
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Heelan, Lisa A. "Development and application of DNA-based technologies for identification and analysis of soilborne oomycetes associated with yield decline in sugarcane /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16728.pdf.
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Flohr, Bonnie Maree. "Stabilising the flowering time of wheat in response to autumn rainfall decline in southern Australia." Phd thesis, 2018. http://hdl.handle.net/1885/148888.
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Wheat (Triticum aestivum) production is important to global food
security and the livelihoods of those who cultivate it. Increases
in water-limited potential yield (PYw) and farm yield (FY) are
necessary to keep pace with global demand, and in order for
Australian growers to remain competitive in a changing climate
and with declining terms of trade. In drought prone environments
such as south-eastern Australia, alignment of the key
developmental stage of flowering to the period that is optimal
for the local climate is a critical determinant of yield. The
optimal flowering period (OFP) begins when the risk of frost
decreases, and ends to avoid increasing temperature, heat and
water stress during grain fill. Flowering time is a function of
the interaction between the speed of plant development (genetic,
G), establishment date (management, M) and prevailing seasonal
conditions (environment, E). Autumn rainfall decline, extreme
spring weather and increasing farm size challenge traditional G x
M combinations which are currently used to achieve the OFP in
south-eastern Australia i.e. predominately fast developing spring
wheats sown in late-April to early May.
The objective of this study was to identify novel G x M
combinations that stabilise flowering and maximise yield under
changing rainfall patterns and recent changes to farming systems.
This study used crop simulation and conducted field experiments
in Temora, New South Wales (NSW); Berriwillock, Victoria;
Minnipa, South Australia and Cunderdin, Western Australia.
Firstly, OFPs were quantified in south-eastern Australia, the
area most affected by autumn rainfall decline to align novel G x
M strategies accordingly. Simulation demonstrated that the
predicted timing and duration of OFPs varied with site and
season. The relative importance of seasonal water supply and
demand and extremes of temperature in defining the window also
varied.
To identify the physiological changes associated with breeding,
the PYw and other parameters were quantified and compared at
common sowing or flowering dates with a historic set of NSW
cultivars released between 1901 and 2014. Genetic improvement
through this period, increased grain yield at a rate of 26 kg
ha-1 pa-1 regardless of sowing or flowering dates. The slow
development and stable flowering observed in historic cultivars
and superior partitioning to grain of modern cultivars were
independent, and could potentially be combined in new cultivars
to achieve future yield gains. Yield results for a novel
fast-winter genotype (FW, with photoperiod insensitivity and
requiring vernalisation) grown in a diverse set of environments,
supported this hypothesis. The FW development pattern extended
sowing windows while achieving 10-20% higher yields than current
spring cultivars. The flowering stability index (1 minus the
ratio of range in thermal time for flowering for each cultivar,
to the range in thermal time of sowing dates) of the FW genotype
was improved for the sowing dates currently used by farmers.
Finally, novel agronomic packages to capture the higher yield
potential of FW cultivars was investigated using simulation.
Reliance on irregular rainfall to establish FW wheat could be
reduced, and early establishment opportunities increased by
sowing genotypes with long coleoptiles into stored sub-soil
moisture accumulated during fallow. Combining the G x M flowering
date stabilising factors; winter wheat, long coleoptile, early
sowing and fallow reduced the reliance on autumn rainfall for
timely crop establishment to provide a further buffer against
seasonal climate variability. Consequently, simulated whole farm
yield was increased as a greater area of wheat flowered during
the optimal period.
To achieve the productivity increases demonstrated here requires
continued collaboration between agronomists and breeders. This
includes the development of winter wheat cultivars with long
coleoptiles that are adapted to different growing season lengths
and OFPs, such that crops can be established earlier and emerge
from a greater depth than current cultivars.
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Harris, Robert H. "Identifying the cause of cereal yield decline in lucerne companion cropping systems; and the role of agronomy for mitigating cereal productivity losses." Thesis, 2011. http://hdl.handle.net/2440/70193.
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Integrating perennial plants like lucerne into farming systems has been widely recommended to mimic pre-agricultural native vegetation, to improve year round transpiration and reduce the off-site impacts of agriculture on the surrounding environment. Despite perennial plants providing greater hydrological benefits compared to traditional annual plant based farming systems; integration of lucerne into farming systems remains a challenge. One approach that may enhance the integration is companion cropping, where annual crops are sown directly into an existing lucerne stand. However, past research has shown that this practice can be harmful to the productivity of annual crops, due to competition with lucerne for environmental resources. Yet beyond quantifying the effect on annual crop production, little is understood about what causes the loss of yield. Under-standing the underlying mechanisms dictating the performance of annual crops growing with lucerne could help design agronomic strategies that mitigate competition, and improve annual crop productivity; in turn potentially improving industry acceptance and adoption of both lucerne and companion cropping. In this study, two field experiments showed that competition was apparent early in the growing season prior to cereal stem elongation; when cereal biomass in the presence of lucerne was significantly lower than that of cereal grown in monoculture. Although there were no differences in cereal establishment, companion cereals produced significantly (P<0.05) less tillers, spikes, cereal biomass, and consequently grain yield compared with cereals grown in monoculture. Both field experiments showed that fertiliser N could potentially increase companion cereal productivity, and that in-crop lucerne suppression could improve cereal grain quality by reducing lucerne pod contamination. Apart from quantifying the temporal effects of competition between the companion cereal and lucerne and assessing the role of agronomic strategies for mitigating competition, field experiments did not give much insight into what was causing the loss of companion cereal productivity. Simulation modelling using APSIM (Agricultural Production Systems Simulator) explored competition between the companion cereal and lucerne, and each component’s response to resource supply and agronomic intervention over longer periods. APSIM was found to satisfactorily simulate both simultaneous and stand alone wheat and lucerne growth, after comparison with field observed data. Although APSIM tended to deplete soil mineral N more rapidly under lucerne than field observations indicated, necessitating soil mineral N to be constrained within previously measured values in long-term simulations. Simulations showed that companion cereals were frequently sown into drier soil profiles, due to soil water extraction by lucerne over the preceding summer/autumn period, compared with monoculture cereals sown after the summer/autumn fallow. Competition for soil water appeared the major contributing factor to companion cereal performance, and simulated data predicted that companion cereals had to rely solely on in-crop rainfall. Therefore companion cropping in low rainfall environments where growing season rainfall (April to October) is less than 350 mm, or in environments where crops rely heavily on stored soil water at sowing for subsequent production, would be unsuitable for reliable grain production from companion cropping.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2011
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(12804776), Stephen Barry Johnson. "Nitrogen fixation by potential ley pasture legumes for Central Queensland." Thesis, 1997. https://figshare.com/articles/thesis/Nitrogen_fixation_by_potential_ley_pasture_legumes_for_Central_Queensland/20010641.
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Yield decline following continuous cropping cycles in Central Queensland has been attributed to the declining soil nitrogen status. In this study an assessment of the level of nitrogen fixation was made to assist in the selection of potential ley pasture legumes for use in rotational systems to achieve sustainable cropping yields.
Twenty one winter and summer growing legumes were evaluated for nitrogen fixation in glasshouse trials in two seasons. Nitrogen fixation was determined using the hydrogen evolution technique (an instantaneous measure of fixation rate) in an artificial media trial and the 15N natural abundance technique (an integral measure of fixation) in a soil based trial.
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Maas, Bea. "Birds, bats and arthropods in tropical agroforestry landscapes: Functional diversity, multitrophic interactions and crop yield." Doctoral thesis, 2013. http://hdl.handle.net/11858/00-1735-0000-0022-5E77-5.
Full textBooks on the topic "Yield decline"
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Committee, India Ministry of Agriculture Fact Finding. Decline in crop productivity in Haryana and Punjab: Myth or reality? : report of the Fact Finding Committee, May 1998. New Delhi: Indian Council of Agricultural Research, 1998.
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Sumit, Guha, ed. Growth, stagnation, or decline? agricultural productivity in British India. Delhi: Oxford University Press, 1992.
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Harvey. Strategies to Manage Soil-Borne Fungi and Mitigate Sugarcane Yield Decline. Sugar Research Australia, 2018.
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Capussela, Andrea Lorenzo. Conclusions. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198796992.003.0010.
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The main conclusions of the book are four. Without the credible prospect of an equilibrium shift even well-designed reforms of Italy’s political or economic institutions are likely to yield limited results, because they shall be undermined by the constraints posed by the extant equilibrium. The country’s political and economic elites are unlikely to be either willing or able to promote an equilibrium shift, however, by reason of those same constraints. Two consequences follow. First, absent an external shock the country is likely to remain on the extant equilibrium for as long as its material and moral consequences shall be tolerable. Second, a strategy to reverse Italy’s decline should focus on the variable that is freer from the grip of that equilibrium, namely ideas.
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Collini, Stefan. Scrutinizing the Present Phase of Human History. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198800170.003.0003.
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This chapter examines the range of F. R. Leavis’s historical thinking, from the early work of his Ph.D. through to his post-1945 dealings with the nineteenth century. The chapter argues that, rather than being largely derived from Eliot’s work, Leavis’s thinking drew on older and more conventional strains of historical writing whose framework he never entirely shook off. It emphasizes the extent to which Leavis believed that a proper cultural history would yield an evaluative assessment of the quality of human living in various periods and hence an overall judgement about progress or decline. It shows that the two key periods in Leavis’s scheme were the seventeenth century, understood as the beginnings of the modern world, and the nineteenth century, seen as the triumph of a broadly mechanical and economistic world view that he tended to equate with ‘Utilitarianism’.
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Sager, Jalel. National Energy Signatures. Edited by Debra J. Davidson and Matthias Gross. Oxford University Press, 2018. http://dx.doi.org/10.1093/oxfordhb/9780190633851.013.4.
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Fossil fuels and their high yield of available energy regulate the global economy and structure its hierarchy of nations. When a “pulse” of energy—over months, years, decades, or centuries—enters the global industrial system, overshoot dynamics are often observed. The system enters a new mode of production, with new technical combinations. Once it does, it is extremely difficult to return to the old infrastructure, even though the energy resource that provided the pulse likely will yield less over the years (the US and its highway system provide one example of an infrastructural system conceived in a higher-yielding environment, the US oil boom of the early twentieth century). As the energy surplus, or marginal resource return, begins to diminish, output declines, slowing the rise of powerful nations, and transferring growth elsewhere. The effects of declining returns often show up in the monetary system.
Book chapters on the topic "Yield decline"
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Verdejo-Lucas, Soledad. "Pre-planting solutions for the slow decline of citrus caused by Tylenchulus semipenetrans." In Integrated nematode management: state-of-the-art and visions for the future, 174–81. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789247541.0025.
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Abstract The citrus nematode, Tylenchulus semipenetrans, is the causal agent of the slow decline of citrus. The nematode is well adapted to reproduce on citrus and very high densities are required to damage the trees and reduce yield. This chapter discusses the economic importance, geographical distribution, host range, damage symptoms, biology and life cycle, interactions with other pathogens, recommended integrated management, and management optimization of T. semipenetrans. Future research requirements and future developments are also mentioned.
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Ghimire, Rajan, Prakriti Bista, and Stephen Machado. "Crop Yield Limitation by Soil Organic Matter Decline: A Case Study from the US Pacific Northwest." In Advances in Understanding Soil Degradation, 609–21. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-85682-3_27.
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van Zonneveld, Maarten, Gayle M. Volk, M. Ehsan Dulloo, Roeland Kindt, Sean Mayes, Marcela Quintero, Dhrupad Choudhury, Enoch G. Achigan-Dako, and Luigi Guarino. "Safeguarding and Using Fruit and Vegetable Biodiversity." In Science and Innovations for Food Systems Transformation, 553–67. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15703-5_30.
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AbstractFruit and vegetable species and varieties, their wild relatives, and pollinators and other associated organisms underpin diverse food production systems and contribute to worldwide health and nutrition. This biodiversity, however, is threatened, remains poorly conserved, and is largely undocumented. Its loss leads to a narrowing of new food options, reduced variation for breeding, and yield gaps due to pollinator decline. This constrains the supply of climate-resilient and nutritious foods to the global human population and limits long-term progress towards the 2030 Sustainable Development Goals and any future goals set thereafter. It will require that awareness be raised globally to safeguard and sustainably use fruit and vegetable biodiversity and that a global rescue plan for reducing and reversing the decline in this biodiversity be devised. Success will depend on a global partnership of custodians and users of fruit and vegetable biodiversity and requires an investment of at least 250 million USD over ten years.
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Matsuura, Eri, and Nobuo Sakagami. "Climate Change and Crop Management in Indonesia." In Interlocal Adaptations to Climate Change in East and Southeast Asia, 145–47. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-81207-2_15.
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AbstractRice is a daily staple for the most of Indonesian people, and rice consumption has increased every year as the population has increased (Suryani et al. 2016). Climate change has severely affected rice production by increasing minimum temperatures and changing rainfall patterns. The decline in rice yield due climate change could threaten national food security over the long term. To maintain the food self-supporting rate and support farmers, new technologies for adapting to climate change in farming systems are needed. Asia-Pacific Climate Change Adaptation Information Platform (AP-PLAT) (2020) reported that the Indonesian government published the National Action Plan for Climate Change Adaptation (Rencana Aksi Nasional Adaptasi Perubahan Iklim or RAN-API) in 2014, and the Ministry of the Environment of Japan (MOEJ) and the Ministry of National Development Planning, Indonesia (BAPPENAS) are cooperating to assess the impact of climate change for local adaptation planning in the Republic of Indonesia.
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Sako, Dramane, Mamary Traoré, Folocoum Doumbia, Fodé Diallo, Moussa Fané, and Issoufou Kapran. "Kolokani Groundnut Innovation Platform Activities and Achievements Through TL III Project in Mali." In Enhancing Smallholder Farmers' Access to Seed of Improved Legume Varieties Through Multi-stakeholder Platforms, 51–64. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-8014-7_4.
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AbstractGroundnut productions have been declining in Mali in spite of several new improved varieties being released, the key problem being inadequacy of the seed supply system. To solve this problem, Kolokani MSP was established in 2012 and reorganized with support from TL III in 2015 to include more stakeholders in the groundnut value chain—farmers particularly women, farmer associations, cooperative societies, seed producers, agro-dealers, grain traders, processors, research and extension. Four new varieties Fleur11, ICGV 86124, ICGV 86015, and ICGV 86024 were supplied to the platform for FPVS and among them two, Fleur 11 and ICGV 86124 were preferred for their high yields and large grain size under farmer conditions. Through training of trainers, the different members of the platform reached 1246 farmers among them 928 women with improved groundnut seed production, aflatoxin management, seed business plans, and small-scale mechanization. A total 47 FPVS, 50 Demonstrations, and three multi-locational variety trials were conducted annually from 2016 to 2018. Kolokani platform have played an important role in groundnut value chain by producing and marketing 85 tons groundnut certified seed of these varieties annually for farmers. This is expected to stop the national productivity decline while improving platform members’ livelihoods and nutrition status.
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Meddi, Mohamed, and Saeid Eslamian. "Uncertainties in Rainfall and Water Resources in Maghreb Countries Under Climate Change." In African Handbook of Climate Change Adaptation, 1–37. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-42091-8_114-1.
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AbstractThe vulnerability of the climate change in the South of the Mediterranean’s south regions varies depending on the part of their climate which is sensitive to the economy. In Tunisia, agriculture represents 16% of the workforce and 12% of GDP in 2006. In Algeria, agriculture represents 20% of the workforce and 8% of GDP in 2009. In Morocco, agriculture accounts for 40% of the workforce and 17.7% of GDP in 2006. The agriculture is directly related to the availability of water which in turn is directly related to rainfall. The drought has affected all countries of the Maghreb. It is considered the most severe in the history of these countries. The drought has forced the agricultural sector in Morocco to the limitation of annual crops which are not needed, the prohibition of any new tree planting and the ban on vegetable crops in dry years. During the years 1987, 1988, and 1989, Tunisia has experienced the most critical drought. It led to a water deficit of around 30%. For Morocco the rainfall shows a negative trend at national and regional scales, and spring rainfall has declined by over 40% since the 1960s. For Algeria, the western region has recorded a considerable reduction in rainfall. The winter rains have decreased between 40% and 70%. Contributions to dams have decreased between 30% and 50%. These changes had a negative influence on the water resource and crop yield. Many programs have been initiated since then to meet the growing demand.
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Meddi, Mohamed, and Saeid Eslamian. "Uncertainties in Rainfall and Water Resources in Maghreb Countries Under Climate Change." In African Handbook of Climate Change Adaptation, 1967–2003. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_114.
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AbstractThe vulnerability of the climate change in the South of the Mediterranean’s south regions varies depending on the part of their climate which is sensitive to the economy. In Tunisia, agriculture represents 16% of the workforce and 12% of GDP in 2006. In Algeria, agriculture represents 20% of the workforce and 8% of GDP in 2009. In Morocco, agriculture accounts for 40% of the workforce and 17.7% of GDP in 2006. The agriculture is directly related to the availability of water which in turn is directly related to rainfall. The drought has affected all countries of the Maghreb. It is considered the most severe in the history of these countries. The drought has forced the agricultural sector in Morocco to the limitation of annual crops which are not needed, the prohibition of any new tree planting and the ban on vegetable crops in dry years. During the years 1987, 1988, and 1989, Tunisia has experienced the most critical drought. It led to a water deficit of around 30%. For Morocco the rainfall shows a negative trend at national and regional scales, and spring rainfall has declined by over 40% since the 1960s. For Algeria, the western region has recorded a considerable reduction in rainfall. The winter rains have decreased between 40% and 70%. Contributions to dams have decreased between 30% and 50%. These changes had a negative influence on the water resource and crop yield. Many programs have been initiated since then to meet the growing demand.
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de Jong Cleyndert, Georgia, Rebecca Newman, Cecile Brugere, Aida Cuni-Sanchez, and Robert Marchant. "Adaptation of Seaweed Farmers in Zanzibar to the Impacts of Climate Change." In African Handbook of Climate Change Adaptation, 3–28. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_54.
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AbstractSeaweed farming is an important alternative livelihood activity that has been heralded as a development success story. It has advanced women’s empowerment and economic liberation in coastal communities in Zanzibar, despite recent declines in its production. Using data from 36 semistructured interviews, we explore the impacts of climate change on seaweed farming in Zanzibar and the coping and adaptation strategies available to farmers. Interviews reveal that climatic changes observed in Zanzibar are characterized by increased temperatures, increased winds, and irregular rainfall, and these changes have negatively affected coastal seaweed farming yields and quality. Combined with economic challenges, these environmental stressors are threatening the sustainability of seaweed farming and the wider development impacts that have been gained over the past decades. Establishing seaweed farms in deeper water, using new technologies, could be an adaptation method to overcome rising temperatures; however, there are significant socioeconomic barriers for this to happen. For example, women lack access to boats and the ability to swim. Adaptation options to the increasing impacts of climate change will be possible only with institutional support, significant investment, and through the empowerment of women and the participation local communities.
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Zazu, Cryton, and Anri Manderson. "Agroecology and Climate Change Adaptation: Farmers’ Experiences in the South African Lowveld." In African Handbook of Climate Change Adaptation, 363–78. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-45106-6_181.
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AbstractMotivated by interest to increase the resilience of smallholder farmers to adapt to climate change through uptake of agroecology, two community development organizations commissioned a project evaluation upon which this book chapter is written. The chapter discusses how smallholder farmers were experiencing implementing agroecology, trying to understand the reasons for adopting such an approach to farming. The chapter also explores and problematizes the relationship between trends in adoption of agroecology and the smallholder farmers’ awareness of climate change and adaptation. The chapter confirms that agronomic and income generation are the key reasons for adoption of agroecology. Most of the farmers reminisced about how their crop yields had declined and soils no longer producing enough to feed the family. Other motivating factors for uptake of agroecology included lack of employment, limited income sources, access to health organic foods, and medicinal value of herbs grown. The chapter further concluded that the correlation between adoption of agroecology and farmers’ awareness of it as a climate change adaptation measure is generally weak. Smallholder farmers adopted agroecology more for responding to issues of food security, than any conscious desire to adapt to climate change. Implications of this observation is that practitioners working with smallholder farmers need to rethink their approaches and design of interventions to integrate climate change education and learning, so that strong connections between the agroecological practices promoted and adaptation to climate change are made. Such an approach has potential to improve the sustainability and value of the agroecological practices adopted.
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Zazu, Cryton, and Anri Manderson. "Agroecology and Climate Change Adaptation: Farmers’ Experiences in the South African Lowveld." In African Handbook of Climate Change Adaptation, 1–16. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-42091-8_181-1.
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AbstractMotivated by interest to increase the resilience of smallholder farmers to adapt to climate change through uptake of agroecology, two community development organizations commissioned a project evaluation upon which this book chapter is written. The chapter discusses how smallholder farmers were experiencing implementing agroecology, trying to understand the reasons for adopting such an approach to farming. The chapter also explores and problematizes the relationship between trends in adoption of agroecology and the smallholder farmers’ awareness of climate change and adaptation. The chapter confirms that agronomic and income generation are the key reasons for adoption of agroecology. Most of the farmers reminisced about how their crop yields had declined and soils no longer producing enough to feed the family. Other motivating factors for uptake of agroecology included lack of employment, limited income sources, access to health organic foods, and medicinal value of herbs grown. The chapter further concluded that the correlation between adoption of agroecology and farmers’ awareness of it as a climate change adaptation measure is generally weak. Smallholder farmers adopted agroecology more for responding to issues of food security, than any conscious desire to adapt to climate change. Implications of this observation is that practitioners working with smallholder farmers need to rethink their approaches and design of interventions to integrate climate change education and learning, so that strong connections between the agroecological practices promoted and adaptation to climate change are made. Such an approach has potential to improve the sustainability and value of the agroecological practices adopted.
Conference papers on the topic "Yield decline"
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DA SILVA SIQUEIRA, THIAGO, Luiz Henrique Antunes Rodrigues, FELIPE FERREIRA BOCCA, and Monique Pires Gravina de Oliveira. "Decision trees for knowledge discovery on the yield decline of sugarcane ratoons." In XXV Congresso de Iniciação Cientifica da Unicamp. Campinas - SP, Brazil: Galoa, 2017. http://dx.doi.org/10.19146/pibic-2017-78279.
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Akkus, Ozan, Fran Adar, and Mitchell B. Schaffler. "Increased Collagen Mineralization Affects the Yield Stress But Not the Yield Strain in Cortical Bone of Rats: Implications for Age-Related Tissue Embrittlement." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-32599.
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It has been well documented that the fracture susceptibility of cortical bone increases significantly with age [1]. Although the age-related decline in the fracture resistance of the cortical bone is attributed to reduced bone quantity; a substantial overlap in the bone mass of normal subjects and those sustaining fractures suggests that bone mass alone does not identify the fracture risk on an individual basis [2]. Therefore, the conceptual framework should be improved to include bone quality measures in addition to bone quantity to refine fracture risk assessment. In this study, Raman microspectroscopy was used to assess two key variables of bone tissue quality in aging rat cortical bone: the relative amount of mineral with respect to the amount of collagen (i.e. collagen mineralization) and the mineral crystallinity (i.e. size and stoichiometric perfection of mineral crystals). In this regard the first aim of this study was to investigate age-related changes in the extent of mineralization of collagen fibers and to test its relationship to elastic deformability of cortical bone tissue. The second aim of the study was to investigate age-related changes in the mineral crystallinity and to test its relationship to elastic deformability of cortical bone tissue. The first hypothesis of this study is that both collagen mineralization and mineral crystallinity will increase with age. The second hypothesis of this study was that age-related changes in compositional properties will compromise the elastic deformation capacity of cortical bone tissue.
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Molina, Oscar, Laura Santos, Francisco Herrero, Agustin Monaco, and Darren Schultz. "Is Decline Curve Analysis the Right Tool for Production Forecasting in Unconventional Reservoirs?" In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206152-ms.
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Abstract This study presents a novel metaheuristic algorithm that uses a physics-based model for multi-fractured horizontal wells (MFHW) to accurately predict the estimated ultimate recovery (EUR) for unconventional reservoirs. The metaheuristic algorithm creates a sizeable number of stochastic simulations and keeps the simulation results from those random models that closely reproduce observed production data. Unlike other optimization methods, the proposed algorithm does not aim at finding the exact solution to the problem but a group of sufficiently accurate solutions that help to construct the partial solution to the optimization problem as a function of production history. Results from this work provide sufficient evidence as to why traditional decline curve analysis (DCA) is not a suitable solution for production forecasting in unconventional reservoirs. Two case studies are discussed in this work where results from both modeling strategies are compared. Evolutionary prediction of EUR over time using DCA behaves erratically, regardless of the amount of historical production data available to the regression model. Such erratic behavior can, in turn, yield an erroneous estimation of key economic performance indicators of an asset. In contrast, the proposed metaheuristic algorithm delivers precise and accurate results consistently, achieving a significant reduction of uncertainties as more production data becomes available. In conclusion, the proposed partial optimization approach enables the accurate calculation of important metrics for unconventional reservoirs, including production forecasting and expected productive life of an asset.
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Kawphoy, Rampueng, and Phanat Thatmali. "Integration of Multiple Data to Improve Condensate Yield Prediction in Pailin and Moragot Field, Pattani Basin, Gulf of Thailand." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21777-ms.
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Abstract The objective of this study was to improve the accuracy of condensate gas ratio (CGR) prediction in the Pailin and Moragot areas. Conventional method to predict liquid component reserves used only long-life condensate gas ratio (long-life CGR) from near-by production platform(s). The long-life CGR data are available in the mature production platforms which commonly takes 1-2 years to observe the decline trend so that there is no available data in the new drilled area and non-production area. This might cause inaccurate prediction of liquid reserves in the future platform especially in the platform locates far away from the mature production area. Multiple data which are basin modeling, geochemical data, drill-stem test, and batch-level production were analyzed and integrated to improve the accuracy of CGR prediction and understand geological reasons of high or low liquid production platform. These data can improve the confident level for CGR estimation in the non-production area and help identify potentially high liquid production platforms. The results show that the high liquid production in Pailin and Moragot fields related with the differentiation of source rock and migration process. There are three (3) separated trends in Pailin field and two (2) trends in Moragot field using geochemical data and basin modeling data. The local DST data has been integrated to confirm the extent of potentially high liquid production in several future platforms which locates in non-production area. Also, the updated production data has been re-visited to estimate the new CGR for the project located near-by production platform.
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Shao, Shanshan, Guodong Jia, Luowei Cao, and Chenyang Du. "Experimental Investigation of Post-Fire Mechanical Properties of Q345R Steel." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45330.
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The degeneration of mechanical properties is one of the main concerns in assessment of fire damaged pressure vessels. This study investigates the influence of fire exposure on mechanical properties of Q345R steel which is widely used for pressure vessels in China. Heat treatment with different temperatures and holding times was conducted to simulate various heat exposure conditions in fire event. Hardness testing, metallographic analysis and tensile tests were carried out to investigate the effects of fire exposure temperature and duration. The experimental results indicate that the inflection temperature for mechanical property degeneration of Q345R steel is 700 °C. The decline of hardness, yield and tensile strengths due to spheroidization become more obvious with increasing heat exposure duration. A linear correlation is indicated by fitting the tensile strength and hardness. For the assessment of fire damaged component, the mechanical properties of Q345R steel at room temperature can be determined combining on-situ field metallographic examination and hardness testing with.
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Wilbur, Jessica, Ozzie Abaye, Bo Zhang, and Carol Willki. "Introducing Mung Bean as an Alternative or Rotation Crop to Tobacco in Virginia." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/vsph2015.
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Mung bean [Vigna radiata] is an important grain legume crop in Asia, particularly in India. Mungbean is consumed in the United States by a niche market in Asian cuisines, mostly as bean sprout, but is on the rise for use as an alternative plant protein as it is very high in micronutrients such as zinc, iron, and folic acid while also being low in fat and high in protein. Currently, more than two-thirds of mungbeans consumed in the United States are imported and nearly all domestically farmed mungbeans are produced in Oklahoma. This project explores the viability for mungbean to be produced by Virginia tobacco farmers as an alternative specialty or rotation crop since the demand for tobacco is on the decline. Two cultivars commercially available in the United States, Berken and OK2000, were planted in two locations in southern piedmont Virginia with an early and late planting date to determine the optimal time to plant mungbean and if it is a feasible crop in Virginia. Location played the most determining factor in overall seed size (g/100 seeds) for both cultivars--which is an indicator of quality--but the overall yield was not affected by location or planting date for either cultivar. Berken yielded an average of 771.03 lbs/ ac and OK2000 yielded an average of 728.81 lbs/ac as compared to 1000 lbs/ acre being considered “good yield.” This study suggests that an early versus late planting date has minimal effect on overall yield of mungbean, and with proper management techniques, there is potential for production in Virginia. This project is important to the AOCS community because it looks into the potential for mungbean to be grown in greater acreage within the USA as an alternative plant protein crop.
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Kozlova, Zoya, Lyubov' Matais, and Ol'ga Glushkova. "Influence of sainfoin on soil fertility and agro-economic indicators of fodder crop rotations under conditions of East Siberia." In Multifunctional adaptive fodder production23 (71). ru: Federal Williams Research Center of Forage Production and Agroecology, 2020. http://dx.doi.org/10.33814/mak-2020-23-71-67-72.
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Under conditions of East Siberia, the positive effect of sainfoin on the fertility of gray forest soil and the introduction of this crop into fodder five-course rotations have been studied. In Siberia the Hungarian sainfoin (Onobrychis arenaria) is well-spread. As a control variant the crop rotation without perennial legume crops (sainfoin-free) was taken. Our research on the introduction of a new legume crop — sainfoin has shown that the content of mobile phosphorus, on the average in crop rotations, varies from 15.3 to 17.1 mg per 100 g of soil, the value of the nitrate nitrogen indicator — from 21.5 to 25.3 mg/kg. The intake of organic matter into the soil, due to a green manure — sainfoin — increases the humus content to 4.8–4.9 %. The rise in the yield of cultivated grain-forage crops after perennial legumes has been proved. Thus, the yield of pea-oats amounted 2.0–2.4 t/ha feed units. Among the crops harvested for green mass corn was more productive. It provided 1.8–2.2 t/ha of feed units. Pea-oats gave less productivity — from 1.5 t/ha of feed units in a control variant to 1.8 t/ha of feed units in the variants with sainfoin. The yielding capacity of sainfoin was 2.1–2.2 t/ha of feed units. The average yield for crop rotations with sainfoin was higher than the control by 16.6 %. Taking the obtained data into account, it may be concluded that all three five-course crop rotations are productive, the best, according to all criteria, is the variant with two fields of sainfoin providing the decline in cost price up to 3529.9 rub. one feed unit, the high level of pure income 11848 rub./ha and the biggest coefficient of energy efficiency — 3.0
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ZINKEVIČIENĖ, Danutė, Remigijus ZINKEVIČIUS, and Sigitas PETKEVIČIUS. "ECONOMIC EVALUATION OF CONVENTIONAL INTENSIVE AND PRECISION FARMING TECHNOLOGIES." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.081.
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In Lithuania, besides the usual farming technologies, starting precision agriculture (PA). The basic principle of the PA is to focus technological operations on the conditions located in separate field locations. When there in separate fields is a significant difference in the amount of nutrients in the soil, the distribution of weeds or diseases, then the crop fertilization and maintenance operations must be precisely adapted to these differences. Most importantly, these differences in soil and crops can be captured and converted into correspondingly differentiated instructions for agricultural machinery. This ensures the timely use of appropriate material resources, helps to optimize yields at the lowest cost, reduce environmental pollution and increase economic returns. The purpose of this study is to perform a comparative analysis of economic indicators for spring wheat cultivation by using a usual intensive and PA technologies, and to determine the financial effect. Novelty of this study are the new approach and new method for financial effect calculations in Lithuania, they can lead to future deeper analysis of money return related with PA technologies. The tests for a year 2014-2015 was carried out on A. Bardauskas farm in Raseiniai district, and in year 2016 on ASU testing station in Kaunas district. Economic indicators of spring wheat cultivation by using conventional intensive and precision farming (PA) technologies was determined, i.e. additional cost-benefit effect was calculated and the financial effect generated. Underlying research shows that better economic indicators are obtained through the using of PA technology. It was determined that the cost of mineral fertilizers during spring wheat cultivation in accordance with the PA technology was lower in the two analyzed years and slightly higher in one year than the conventional intensive agricultural technology. The decline in fertilizer costs also led to a decrease in yield, which resulted in less incomes for one year from precision farming than the use of conventional intensive agricultural technology, and received a negative financial effect. In the other two years of analysis, additional revenues from spring wheat cultivation with PA technology exceeded the additional costs related with this technology and received a positive financial effect. Due to the reduced yield, the incomes for precision farming in 2014 were 41.6 Eur/ha less, and in 2015 and 2016, respectively, 12.8 Eur/ha and 30.58 Eur/ha higher than for the conventional intensive farming technology
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Javadi, A., M. Soltanieh, S. Sahebdelfar, D. Bastani, and K. Javadi. "Estimation of Temperature and Residence Time of Carbon Black Oil Furnace Industrial Reactors." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15671.
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In the absence of powerful rigorous models, in this research a simple but practical method for calculating the temperature and residence time and carbon black yield in oil-furnace reactors is proposed. For this purpose an empirical formula of the form CxHy is assumed for the carbon black feedstock based on typical feedstock used in this industry. Based on the prevailing reactor conditions, thermodynamic considerations and available outlet tail gas from the reactor, a few representative reactions are considered to describe the entire reaction network. These include complete combustion for the fuel and, incomplete combustion and pyrolysis for the feedstock. Carbon black yield can be estimated from a mass balance. From the combined mass and heat balance, the reactor temperature as well as the residence time is predicted. The reactions can also be used to obtain the composition of the tail gas. Despite the simplicity of the model, in all cases studied, relatively good agreements were observed between the calculated values and the available industrial data as well as those obtained from computational fluid dynamics (CFD) simulation. An exception was the effects of the air/oil ratio on the reactor mean residence time in the CFD approach. The influences of air/oil ratio and inlet air temperature on reactor mean-temperature were studied. In both cases one observes good agreement between our results and CFD simulation data. They both show an increase in reactor mean-temperature as expected. The effects of process air flow rate on reactor residence time also were studied and a good agreement was observed. However, comparison the effects of the air/oil ratio on reactor residence time showed quite different trends. While the results of CFD simulation predicts insignificant change in reactor residence time versus air/oil ratio, our results show a decline in the residence time in this case. To explain this, prediction of carbon black particle size was considered. Utilizing our predicted residence time results for prediction of particle size showed a good agreement with industrial data, while in contrast the CFD simulation data show opposite trend with the industrial data and our work. Therefore, it can be said that one of the most important reasons caused poor prediction in referred CFD simulation in some cases could be considerable error in prediction of the residence time.
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Dizon, Lisa Stephanie, Robert S. Bertrand, Mark Zappi, Rafael Hernandez, William Holmes, Dhan Lord Fortela, and Emmanuel Revellame. "Effects of Growth Conditions on the Bacterial Conversion of Methane to Lipids." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/kevn4864.
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The huge decline in natural gas prices led to an increase in flaring which embodies wasted product, lost energy, lost revenues, and major greenhouse gas emission (GHG). Methane is a major component of natural gas that could be diverted as microbial substrate for the production of valuable products. Methanotrophs are gaining interests due to their ability to utilize CH4 as its sole carbon and energy source to produce a wide variety of bio-products such as lipids, carbohydrates, fuels and power, biomolecules, proteins and renewable chemicals. The lipids derived from the intracellular membrane of methanotrophs are vital precursors for the production of biodiesel and human health supplements. This study aimed to establish the growth conditions of methanotrophs that maximize methane consumption and lipid production. Growth parameters were varied to study the effects of media (nitrate mineral salts (NMS) and synthetic wastewater (SW)), pH (4.0 and 6.8) and CH4 to air ratio (1:1 and 1:4) on the bacterial conversion of methane to lipids. A multi-level categoric design of experiment was employed to verify the most suitable conditions for CH4 consumption and lipid production. Methane consumption was monitored via gas chromatography analysis of the headspace gases. Full length 16S rRNA gene diversity analysis was done to identify the species present in the consortium and to determine the changes in their relative abundance. After 18 days of incubation, results show that the highest CH4 consumption was 6.62% with a lipid yield of 6.93% that can be achieved using SW medium, at pH=6.8, and CH4 to air ratio of 1:1. Thus, this research provides new insights on the potential of natural microbial consortium to convert CH4 into lipids that could address concerns on greenhouse gas emission reduction as well as for value-added resources recovery.
Reports on the topic "Yield decline"
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Sarmiento, Miguel. Sudden Yield Reversals and Financial Intermediation in Emerging Markets. Banco de la República, October 2022. http://dx.doi.org/10.32468/be.1210.
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Banks in emerging market economies rely on cross-border interbank lending to financing firms in the real sector. By matching cross-border bank-to-bank loan level data with domestic bank-to-firm loan level data, and firm-level data, this paper shows that sudden yield reversal observed during the 2013 Fed taper tantrum resulted in a substantial contraction of cross-border interbank lending in emerging markets that significantly reduced the supply of domestic corporate credit and increased the corporate loan rates. Results show that firms with an ex-ante high concentration of credit granted by exposed banks in the cross-border interbank market exhibited low bank credit and substantial real effects, including a decline in imports and exports. The results further indicate that cross-border intra-group lending and domestic unsecured interbank funding contribute to smoothing the effects of sudden yield reversals on the financial intermediation. Overall, the results are consistent with the notion that banks’ exposition in international credit markets contributes to global financial conditions’ transmission to the economy.
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Cohen, Roni, Kevin Crosby, Menahem Edelstein, John Jifon, Beny Aloni, Nurit Katzir, Haim Nerson, and Daniel Leskovar. Grafting as a strategy for disease and stress management in muskmelon production. United States Department of Agriculture, January 2004. http://dx.doi.org/10.32747/2004.7613874.bard.
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The overall objective of this research was to elucidate the horticultural, pathological, physiological and molecular factors impacting melon varieties (scion) grafted onto M. cannonballus resistant melon and squash rootstocks. Specific objectives were- to compare the performance of resistant melon germplasm (grafted and non-grafted) when exposed to M. cannoballus in the Lower Rio Grande valley and the Wintergarden, Texas, and in the Arava valley, Israel; to address inter-species relationships between a Monosporascus resistant melon rootstock and susceptible melon scions in terms of fruit-set, fruit quality and yield; to study the factors which determine the compatibility between the rootstock and the scion in melon; to compare the responses of graft unions of differing compatibilities under disease stress, high temperatures, deficit irrigation, and salinity stress; and to investigate the effect of rootstock on stress related gene expression in the scion. Some revisions were- to include watermelon in the Texas investigations since it is much more economically important to the state, and also to evaluate additional vine decline pathogens Didymella bryoniae and Macrophomina phaseolina. Current strategies for managing vine decline rely heavily on soil fumigation with methyl bromide, but restrictions on its use have increased the need for alternative management strategies. Grafting of commercial melon varieties onto resistant rootstocks with vigorous root systems is an alternative to methyl bromide for Monosporascus root rot/vine decline (MRR/VD) management in melon production. Extensive selection and breeding has already produced potential melon rootstock lines with vigorous root systems and disease resistance. Melons can also be grafted onto Cucurbita spp., providing nonspecific but efficient protection from a wide range of soil-borne diseases and against some abiotic stresses, but compatibility between the scion and the rootstock can be problematic. During the first year experiments to evaluate resistance to the vine decline pathogens Monosporascus cannonballus, Didymella bryoniae, and Macrophomina phaseolina in melon and squash rootstocks proved the efficacy of these grafted plants in improving yield and quality. Sugars and fruit size were better in grafted versus non-grafted plants in both Texas and Israel. Two melons (1207 and 124104) and one pumpkin, Tetsukabuto, were identified as the best candidate rootstocks in Texas field trials, while in Israel, the pumpkin rootstock RS59 performed best. Additionally, three hybrid melon rootstocks demonstrated excellent resistance to both M. cannonballus and D. bryoniae in inoculated tests, suggesting that further screening for fruit quality and yield should be conducted. Experiments with ABA in Uvalde demonstrated a significant increase in drought stress tolerance and concurrent reduction in transplant shock due to reduced transpiration for ‘Caravelle’ plants. In Israel, auxin was implicated in reducing root development and contributing to increased hydrogen peroxide, which may explain incompatibility reactions with some squash rootstocks. However, trellised plants responded favorably to auxin (NAA) application at the time of fruit development. Gene expression analyses in Israel identified several cDNAs which may code for phloem related proteins, cyclins or other factors which impact the graft compatibility. Manipulation of these genes by transformation or traditional breeding may lead to improved rootstock cultivars. Commercial applications of the new melon rootstocks as well as the ABA and TIBA growth regulators have potential to improve the success of grafted melons in both Israel and Texas. The disease resistance, fruit quality and yield data generated by the field trials will help producers in both locations to decide what rootstock/scion combinations will be best.
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Katan, Jaacov, and Michael E. Stanghellini. Clinical (Major) and Subclinical (Minor) Root-Infecting Pathogens in Plant Growth Substrates, and Integrated Strategies for their Control. United States Department of Agriculture, October 1993. http://dx.doi.org/10.32747/1993.7568089.bard.
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In intensive agriculture, harmful soilborne biotic agents, cause severe damage. These include both typical soilborne (clinical) major pathogens which destroy plants (e.g. Fusarium and Phytophthora pathogens), and subclinical ("minor") pathogens (e.g. Olpidium and Pythium). The latter cause growth retardation and yield decline. The objectives of this study were: (1) To study the behavior of clinical (major) and subclinical (minor) pathogens in plant growth substrate, with emphasis on zoosporic fungi, such as Pythium, Olipidium and Polymyxa. (2) To study the interaction between subclinical pathogens and plants, and those aspects of Pythium biology which are relevant to these systems. (3) To adopt a holistic-integrated approach for control that includes both eradicative and protective measures, based on a knowledge of the pathogens' biology. Zoospores were demonstrated as the primary, if not the sole propagule, responsible for pathogen spread in a recirculating hydroponic cultural system, as verified with P. aphanidermatum and Phytophthora capsici. P. aphanidermatum, in contrast to Phytophthora capsici, can also spread by hyphae from plant-to-plant. Synthetic surfactants, when added to the recirculating nutrient solutions provided 100% control of root rot of peppers by these fungi without any detrimental effects on plant growth or yield. A bacterium which produced a biosurfactant was proved as efficacious as synthetic surfactants in the control of zoosporic plant pathogens in the recirculating hydroponic cultural system. The biosurfactant was identified as a rhamnolipid. Olpidium and Polymyxa are widespread and were determined as subclinical pathogens since they cause growth retardation but no plant mortality. Pythium can induce both phenomena and is an occasional subclinical pathogen. Physiological and ultrastructural studies of the interaction between Olpidium and melon plants showed that this pathogen is not destructive but affects root hairs, respiration and plant nutrition. The infected roots constitute an amplified sink competing with the shoots and eventually leading to growth retardation. Space solarization, by solar heating of the greenhouse, is effective in the sanitation of the greenhouse from residual inoculum and should be used as a component in disease management, along with other strategies.
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Amanor, Kojo, Joseph Yaro, and Joseph Teye. Long-Term Change, Commercialisation of Cocoa Farming, and Agroecosystems and Forest Rehabilitation in Ghana. Institute of Development Studies (IDS), February 2022. http://dx.doi.org/10.19088/apra.2022.002.
Full textAbstract:
Cocoa production has a long history in Ghana, originating in the late nineteenth century. Since then, cocoa production has seen significant changes. Originally, cocoa was cultivated in newly cleared forests in which many forest trees were preserved as shade trees. Cocoa is ideally suited to these conditions and produces high yields with minimum investment in labour and inputs. However, over time, as the forest conditions change, the cost of cultivating cocoa has increased and yields have declined. As long as new forest frontiers exist, farmers have continued to move into these areas, which have displaced older areas of cultivation, since the costs of production are significantly lower in the new frontiers. In recent years, however, new forest frontiers have declined and most cocoa farmers have been forced to rehabilitate and replant cocoa in open land. This study examines the rational of frontier development; changes in land relations, labour relations and use of technology; and the impact of these factors on different categories of farmers, including women and youth. This is developed through two comparative case studies drawn from the older cocoa frontier of the Eastern Region, and the more recent frontier of Western North Region.
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Kirby, Stefan M., J. Lucy Jordan, Janae Wallace, Nathan Payne, and Christian Hardwick. Hydrogeology and Water Budget for Goshen Valley, Utah County, Utah. Utah Geological Survey, November 2022. http://dx.doi.org/10.34191/ss-171.
Full textAbstract:
Goshen Valley contains extensive areas of agriculture, significant wetlands, and several small municipalities, all of which rely on both groundwater and surface water. The objective of this study is to characterize the hydrogeology and groundwater conditions in Goshen Valley and calculate a water budget for the groundwater system. Based on the geologic and hydrologic data presented in this paper, we delineate three conceptual groundwater zones. Zones are delineated based on areas of shared hydrogeologic, geochemical, and potentiometric characteristics within the larger Goshen Valley. Groundwater in Goshen Valley resides primarily in the upper basin fill aquifer unit (UBFAU) and lower carbonate aquifer unit (LCAU) hydrostratigraphic units. Most wells in Goshen Valley are completed in the UBFAU, which covers much of the valley floor. The UBFAU is the upper part of the basin fill, which is generally less than 1500 feet thick in Goshen Valley. Important spring discharge at Goshen Warm Springs issues from the LCAU. Relatively impermeable volcanic rocks (VU) occur along much of the upland parts of the southern part of Goshen Valley. Large sections of the southwest part of the Goshen Valley basin boundary have limited potential for interbasin flow. Interbasin groundwater flow is likely at several locations including the Mosida Hills and northern parts of Long Ridge and Goshen Gap in areas underlain by LCAU. Depth to groundwater in Goshen Valley ranges from at or just below the land surface to greater than 400 feet. Groundwater is within 30 feet of the land surface near and north of Goshen, in areas of irrigated pastures and wetlands that extend east toward Long Ridge and Goshen Warm Springs, and to the north towards Genola. Groundwater movement is from upland parts of the study area toward the valley floor and Utah Lake. Long-term water-level change is evident across much of Goshen Valley, with the most significant decline present in conceptual zone 2 and the southern part of conceptual zone 1. The area of maximum groundwater-level decline—over 50 feet—is centered a few miles south of Elberta in conceptual zone 2. Groundwater in Goshen Valley spans a range of chemistries that include locally high total dissolved solids and elevated nitrate and arsenic concentrations and varies from calcium-bicarbonate to sodium-chloride-type waters. Overlap in chemistry exists in surface water samples from Currant Creek, the Highline Canal, and groundwater. Stable isotopes indicate that groundwater recharges from various locations that may include local recharge, from the East Tintic Mountains, or far-traveled groundwater recharged either in Cedar Valley or east of the study area along the Wasatch Range. Dissolved gas recharge temperatures support localized recharge outside of Goshen. Most groundwater samples in Goshen Valley are old, with limited evidence of recent groundwater recharge. An annual water budget based on components of recharge and discharge yields total recharge of 32,805 acre-ft/yr and total discharge of 35,750 acre-ft/yr. Most recharge is likely from interbasin flow and lesser amounts from precipitation and infiltration of surface water. Most discharge is from well water withdrawal with minor spring discharge and groundwater evapotranspiration. Water-budget components show discharge is greater than recharge by less than 3000 acreft/yr. This deficit or change in storage is manifested as longterm water-level decline in conceptual zone 2, and to a lesser degree, in conceptual zone 1. The primary driver of discharge in conceptual zone 2 is well withdrawal. Conceptual zone 3 is broadly in balance across the various sources of recharge and discharge, and up to 1830 acre-ft/yr of water may discharge from conceptual zone 3 into Utah Lake. Minimal groundwater likely flows to Utah Lake from zones 1 or 2.
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Financial Stability Report - September 2015. Banco de la República, August 2021. http://dx.doi.org/10.32468/rept-estab-fin.sem2.eng-2015.
Full textAbstract:
From this edition, the Financial Stability Report will have fewer pages with some changes in its structure. The purpose of this change is to present the most relevant facts of the financial system and their implications on the financial stability. This allows displaying the analysis more concisely and clearly, as it will focus on describing the evolution of the variables that have the greatest impact on the performance of the financial system, for estimating then the effect of a possible materialization of these risks on the financial health of the institutions. The changing dynamics of the risks faced by the financial system implies that the content of the Report adopts this new structure; therefore, some analyses and series that were regularly included will not necessarily be in each issue. However, the statistical annex that accompanies the publication of the Report will continue to present the series that were traditionally included, regardless of whether or not they are part of the content of the Report. In this way we expect to contribute in a more comprehensive way to the study and analysis of the stability of the Colombian financial system. Executive Summary During the first half of 2015, the main advanced economies showed a slow recovery on their growth, while emerging economies continued with their slowdown trend. Domestic demand in the United States allowed for stabilization on its average growth for the first half of the year, while other developed economies such as the United Kingdom, the euro zone, and Japan showed a more gradual recovery. On the other hand, the Chinese economy exhibited the lowest growth rate in five years, which has resulted in lower global dynamism. This has led to a fall in prices of the main export goods of some Latin American economies, especially oil, whose price has also responded to a larger global supply. The decrease in the terms of trade of the Latin American economies has had an impact on national income, domestic demand, and growth. This scenario has been reflected in increases in sovereign risk spreads, devaluations of stock indices, and depreciation of the exchange rates of most countries in the region. For Colombia, the fall in oil prices has also led to a decline in the terms of trade, resulting in pressure on the dynamics of national income. Additionally, the lower demand for exports helped to widen the current account deficit. This affected the prospects and economic growth of the country during the first half of 2015. This economic context could have an impact on the payment capacity of debtors and on the valuation of investments, affecting the soundness of the financial system. However, the results of the analysis featured in this edition of the Report show that, facing an adverse scenario, the vulnerability of the financial system in terms of solvency and liquidity is low. The analysis of the current situation of credit institutions (CI) shows that growth of the gross loan portfolio remained relatively stable, as well as the loan portfolio quality indicators, except for microcredit, which showed a decrease in these indicators. Regarding liabilities, traditional sources of funding have lost market share versus non-traditional ones (bonds, money market operations and in the interbank market), but still represent more than 70%. Moreover, the solvency indicator remained relatively stable. As for non-banking financial institutions (NBFI), the slowdown observed during the first six months of 2015 in the real annual growth of the assets total, both in the proprietary and third party position, stands out. The analysis of the main debtors of the financial system shows that indebtedness of the private corporate sector has increased in the last year, mostly driven by an increase in the debt balance with domestic and foreign financial institutions. However, the increase in this latter source of funding has been influenced by the depreciation of the Colombian peso vis-à-vis the US dollar since mid-2014. The financial indicators reflected a favorable behavior with respect to the historical average, except for the profitability indicators; although they were below the average, they have shown improvement in the last year. By economic sector, it is noted that the firms focused on farming, mining and transportation activities recorded the highest levels of risk perception by credit institutions, and the largest increases in default levels with respect to those observed in December 2014. Meanwhile, households have shown an increase in the financial burden, mainly due to growth in the consumer loan portfolio, in which the modalities of credit card, payroll deductible loan, revolving and vehicle loan are those that have reported greater increases in risk indicators. On the side of investments that could be affected by the devaluation in the portfolio of credit institutions and non-banking financial institutions (NBFI), the largest share of public debt securities, variable-yield securities and domestic private debt securities is highlighted. The value of these portfolios fell between February and August 2015, driven by the devaluation in the market of these investments throughout the year. Furthermore, the analysis of the liquidity risk indicator (LRI) shows that all intermediaries showed adequate levels and exhibit a stable behavior. Likewise, the fragility analysis of the financial system associated with the increase in the use of non-traditional funding sources does not evidence a greater exposure to liquidity risk. Stress tests assess the impact of the possible joint materialization of credit and market risks, and reveal that neither the aggregate solvency indicator, nor the liquidity risk indicator (LRI) of the system would be below the established legal limits. The entities that result more individually affected have a low share in the total assets of the credit institutions; therefore, a risk to the financial system as a whole is not observed. José Darío Uribe Governor