Crop Yield Changes Research Articles

Analyzing the Impact of Climate Change on Cotton Yield Using Spatial Analysis and Statistical Modeling in the Indus River Basin, Pakistan

Cotton is an excessive growing fiber crop in the world. In Pakistan, climate warming is hurting the cotton crop. To identify countermeasures of climate change impacts on crop production, it is needed to explore the changes in crop yield and their relationship to climate change. This study, we conducted spatial analysis of cotton yield and climate data in the Indus River basin in Pakistan from 1989- 2018. We analyzed the trend in cotton production indices and climate variables using the Mann-Kendal nonparametric test, and the impact of climate change on cotton yield through Pearson’s correlation and best-subset multivariate linear regression model. Sunshine hours positively impacted on cotton yield, but an increasing trend in average temperature, minimum temperature and air relative humidity in main crop areas had a negative impact on the cotton crop. Our results illustrate the relationship between the cotton yield and climate change variables on regional basis in the Indus River basin, Pakistan. This research could provide a reference for understanding the intolerance of cotton in the Indus River basin, Pakistan to climate change.

Modeling optimal windbreak design in maize fields in cool humid climates: Balancing between positive and negative effects on yield

The net change in crop yield imparted by tree windbreaks is the difference between the gain in the sheltered zone and loss in the competition zone. Previous modeling studies have simulated either positive or negative windbreak effects on crop yield. However, both effects should be considered to determine the optimal windbreak structure. We developed a simple process-based model for estimating the effects of windbreak structure on maize yield in cool humid climates. In this model, both yield gain due to growth rate promotion resulting from increased soil temperature, and yield loss due to shading were considered. The model was validated with maize field measurements in Hokkaido, northern Japan. The average maize whole plant and grain yield for four years were 4% and 5% greater in the sheltered zone (3–5 H; H = windbreak height) and 22% and 30% lower in the competition zone (0.5–1 H), respectively, than 10–11 H. The positive and negative windbreak effects on yield could be adequately estimated using our model. Compared to an open field, the net benefit throughout the field was estimated to be 2–3% and 6–11% for whole plant and grain, respectively. The windbreak design that maximized the wind speed reduction did not necessarily maximize the windbreak benefit on maize yield. The proposed optimal total area density differed depending on the windbreak orientation, even under the same meteorological conditions. For windbreaks taller than 5–15 m, those oriented on the west and southwest sides had lower optimal total area density than windbreaks on the south side due to greater shading effects. These results indicate that windbreak height and porosity should be optimized for each field considering the balance between positive and negative effects. Our model provides a framework for determining the windbreak design best suited for each field.

Trichoderma asperellum alters fungal community composition in saline–alkaline soil maize rhizospheres

AbstractThe Songnen Plain is an important agricultural region in China with an abundance of saline–alkaline soil that significantly restricts maize growth. Trichoderma spp., free‐living fungi, are commonly used biofertilizers. The effects of Trichoderma asperellum on the fungal community in saline–alkaline soils remain unclear; hence, in this study, three T. asperellum conidium suspension concentrations were used: 0 g (control), 0.7 g (low dose), and 1.4 g (high dose) over three consecutive years, following which high‐throughput sequencing was conducted to analyze the effect of T. asperellum on fungal diversity in the rhizosphere soil. Changes in crop yield, soil salt ion content, and pH were also monitored. T. asperellum treatment effectively regulated the soil salt ion balance, lowered the pH, and improved the crop yield by 4.88–20.26%. Additionally, the T. asperellum treatment significantly increased the relative abundance of T. asperellum and Ceratobasidium sp and inhibited that of the pathogenic fungi Neonectria and Fusarium. Changes in the soil fungal community composition were closely associated with soil properties and yield. Our findings suggest that long‐term T. asperellum exposure can alleviate saline–alkaline stress for maize growth by decreasing soil pH and salt ion content and regulating the fungal microbial community, thereby increasing crop yield.

Economic impacts of climate-induced crop yield changes: evidence from agri-food industries in six countries

The potential impact of climate change on agriculture has been one of the most discussed topics in the literature on climate change. Although the possible impacts of climate change on crop yields have been widely studied, there remains little quantitative understanding of the heterogeneous economic responses to climate-induced crop yield changes in different economies, particularly at higher levels of warming. This study assesses the economic impacts of eight scenarios of warming, from 1.5 to 4 °C, on rice and wheat yields in China, India, Brazil, Egypt, Ghana and Ethiopia. The role of both natural and social factors in crop production is considered by coupling a statistical crop model (ClimaCrop) and a global economic model (GTAP). Changes in economic outputs, consumer and producer prices and national economic welfare are presented. The study shows marginal benefits of crop yield changes on GDP and welfare in China up to 3.5 and 3.0 °C, respectively. This is due to projected increases in rice yields which lower domestic consumer rice prices. Although at higher warming levels these trends begin to reverse. The other countries are negatively impacted due to declining crop yields, with increasing consumer prices of domestic and imported rice and wheat. GDP and welfare declines, with more severe reductions associated with the higher warming levels, particularly in India and Ethiopia. The method is beneficial as the economic outputs reflect a more in-depth picture of the response of global markets and ultimately regional consequences of agricultural impacts that will be of importance to decision makers.

Does actual cropland water consumption change with evaporation potential in the Lower Yellow River?

The North China Plain (NCP) is one of the most important regions for food production in China; however, the typical winter wheat–summer maize cropping system has created a continuous decline in groundwater levels, triggering serious ecological problems. Additionally, changes in the evaporation potential in the NCP have altered from decreasing to sharply increasing. Therefore, it is critical to understand the actual cropland water consumption (i.e., the actual evapotranspiration, AET) and crop water use efficiency (WUE) under this new trend. This understanding is significant for agricultural water management in the NCP. This study investigated the historical AET and WUE trends for the winter wheat–summer maize cropping system during 1992–2014. This investigation was based on a long-term AET dataset obtained using a large lysimeter from 1992 to 2014 at the Yucheng Comprehensive Experiment Station of the Chinese Academy of Sciences near the Lower Yellow River. The results showed that annual AET decreased pre-2008 and rebounded post-2008. The rebound rate of annual AET from 2008 to 2014 was more than three times the annual decrease rate of AET from 1992 to 2008. The significant increase in summer maize AET mainly contributed to the rebound of the annual AET after 2008. Following the changes in AET and crop yield, the annual WUE had evidently increased for 1992–2008 and sharply decreased from 2008 to 2014. The significant decrease in winter wheat WUE mainly contributed to the annual decrease in WUE post-2008. Climate change, agricultural management, and crop yields were observed to regulate the changes in AET and WUE. In the context of accelerating climate change and the increased frequency of extreme climatic events, strategies to improve WUE by the Lower Yellow River have been proposed, which may also be helpful in the NCP and similar regions worldwide.

Effects of Semiarid Wheat Agriculture Management Practices on Soil Microbial Properties: A Review

Agricultural management decisions on factors such as tillage, fertilization, and cropping system determine the fate of much of the world’s soils, and soil microbes both mediate and respond to these changes. However, relationships between management practices and soil microbial properties are poorly understood, especially in semiarid regions. To address this knowledge gap, we reviewed research papers published between 2000 and 2020 that analyzed soil microorganisms in semiarid wheat fields. We aimed to determine if and how soil microbial properties reliably respond to management, and how these properties indicate long-term changes in soil health, carbon (C) sequestration, and crop yield. We found that reducing tillage increases microbial activity as much as 50% in upper soil layers and stratifies both bacteria and fungi by depth. Higher cropping intensity (reduced fallow) increases C storage, microbial activity, and biomass, and particularly fungal biomass, which can be three times greater under continuous wheat than wheat-fallow. Chemical and organic fertilizers both increase bacterial biomass, though only organic inputs provide lasting benefits by promoting C storage and increasing fungal as well as bacterial biomass. We found microbial properties to be sensitive indicators of long-term changes in soil health and productivity, and formed recommendations on appropriate sampling, analysis, and interpretation of microbial data depending on the system studied.

Enhancement of sustainable agricultural production system by integrated natural resources management framework under climatic and operational uncertainty

Constant decline of freshwater reserve poses a major challenge for coastal agricultural systems. The present study focuses on the integrated land and water resources management framework under operational and climatic uncertainties to achieve sustainable agricultural production in a tropical coastal river basin. To capture the operational and climatic uncertainties, Grey Linear Programming (GLP) and Acceptability Constrained Linear Programming (ACLP) optimization models were developed. GLP can consider both climatic and operational uncertainties. However, ACLP can accommodate operational uncertainty only. Groundwater model was coupled within the optimization models (GLP and ACLP) by a grey response matrix. The SWAT estimated recharge rates were utilized in the MODFLOW model as the groundwater flux. The calibrated (R2 = 0.80) and validated (R2 = 0.84) groundwater flow simulation model was utilized to generate the grey response matrix. The eight plausible scenarios were tested for GLP (Scenarios I, II, III, IV, V, VI, VII, VIII) and ACLP (Scenarios Ia, IIa, IIIa, Iva, Va, VIa, VIIa, VIIIa) with groundwater table fluctuation (GWTF) method and grey response matrix as drawdown constraint. A reduction in net annual return was observed in Scenarios III and IV (with grey response matrix) in comparison to Scenarios I and II (with groundwater table fluctuation) under any change in crop yield. Decrease was more prominent for Rabi (winter) season compared to Kharif (monsoon) season. Futuristic Scenarios (V, VI, VII, VIII) considering crop yield reduction showed a possible change required in cropping pattern (specifically rice area reduction in Kharif Season). ACLP model results showed similar trends. Results suggest that the GWTF method overestimates the groundwater availability compared to the physically based simulation model. Obtained land and water resources management plans were cross-validated for the safe yield limit using MODFLOW simulation model.

Mechanical and biological chiseling impacts on soil organic C stocks, root growth, and crop yield in a long-term no-till system

Soils under no-till (NT) in Brazil have been aimlessly chiseled mainly due to compaction symptoms. The impacts on soil organic carbon (SOC) of these operations as well as the effects of more sustainable alternatives are still highly unknown. We hypothesized that the use of plants with deep root systems in the crop rotation could be a suitable alternative to mechanical chiseling for no-till fields. Thus, our objective in this study was to evaluate changes in SOC stocks, root development, and crop yield over time caused by mechanical and biological chiseling in a long-term no-till system (i.e., 18 years). The experiment was laid out as randomized blocks with four replicates and the treatments were as follows: 1) No-till system without any mechanical disturbance, cultivated with black oats + vetch in winter, here called “No-till cover crop (NT-CC)”. 2) No-till system with one mechanical disturbance through chiseling, also cultivated with black oats + vetch in winter, here called “No-till Mechanical Chiseling (NT-MC)”. 3) No-till without any mechanical disturbance cultivated with black oats + forage radish (Raphanus Sativus L.) instead of vetch, here called “No-till Biological Chiseling”. Compared to NT-CC, the use of NT-MC depleted the SOC stocks by -0.41 Mg ha−1 year−1. NT-MC also highly depleted proxies for microbial-related C pools such as hot-water and permanganate extractable C. It demonstrates the deleterious effects of the mechanical chiseling operations on the surface depths (0−30 cm depth) of our long-term no-till system and raises concerns about the use of these operations in highly weathered areas. On the other hand, the NT-BC promoted significantly higher sequestration rates of 1.29 Mg ha−1 year−1 (LSD test, p < 0.05). The NT-BC has also promoted significantly higher sequestration rates of proxies of microbial-related organic matter, and soybean and wheat root development (length and mass) than the other managements. For cumulative crop yield and biomass input, both NT-BC and NT-CC promoted significantly higher values than NT-MC during the four years of assessment. The root development of wheat and soybean significantly contributed to the increase of SOC stocks, observed by positive correlations (p < 0.01). The results demonstrated that the use of radish as an intercrop for alleviating soil compaction was a good alternative to replace mechanical chiseling in compacted NT fields due to its superior performance in increasing SOC stocks, promoting higher root development, and crop yield.

Evaluating the Potential Contribution of Non-timber Forest Products (NTFPs) to Smallholder Farmers in Semi-arid and Arid Regions: A case of Chivi, Zimbabwe

Food insecurity in most dry regions in Zimbabwe has taught many people a lesson of using non timber forest products (NTFPs) to reduce food insecurity and improve livelihoods as well as poverty alleviation. The aim of the study was to evaluate the potential contribution of non-timber forest products to smallholder farmers in arid and semi-arid regions. The research was carried out as a survey and data was collected using interviews, questionnaires and focus group discussion. Data was analysed for descriptive statistics using IBM SPSS version 25. Results indicated that 64 % were females and 36 % were males with the majority of participants being married (57.6 %) with only 8.8 % being widowed. Results show that all respondents (100%) indicated that they obtain fruits from the forests as a major source of food during winter and rain season. Vegetables (84.2 %), thatching grass (80.8%) and edible worms (62.5 %) were also major non-timber forest products obtained from the forests by participants. All participants (100%) indicated that income generation, firewood and source of heat for brick moulding were major benefits they obtain from forest with vegetables (74.2 %), brooms (91.7 %) and improved nutrition (85.0 %) being regarded as other important benefits enjoyed by local people from forests. Afforestation and reforestation were regarded as major sustainable forest management practices by all (100%) participants with agroforestry being indicated by only 12.5 % since people had no knowledge about it. NTFPs has capacity of improving food security, human livelihoods and alleviate poverty. People are encouraged to harvest NTFPs sustainably to allow future use. Use of agroforestry can be a best way for managing forests sustainably, improve food security, crop yield, poverty alleviation and climate change mitigation.

Crop straw retention influenced crop yield and greenhouse gas emissions under various external conditions.

Crop straw retention is a strongly recommended practice for sustainable agricultural production in China. However, a comprehensive analysis of straw retention effects on crop yield, N2O and CH4 emissions, net greenhouse gas (NGHG), and net greenhouse gas intensity (NGHGI) and their response to various external influence factors, including location/climatic conditions, soil properties, and field management practices, in a national scale were easily ignored. Based on the collected published literatures, we found that straw retention improved crop yield and N2O and CH4 emissions by 4.7% (-4.6 to 25.8%), 18.3% (-26.6 to 57.6%), and 21.0% (-49.0 to 214.5%) in contrast with no-straw retention. For different external conditions, crop yield was increased by 15.9% in temperate zone and 10.7% in upland soils with straw retention. N2O emissions which correspond to the above conditions were enhanced by 42.2% and 18.8%, while CH4 emissions were restrained by 49.0% in temperate zone. Negligible changes in crop yield and N2O emissions were observed for subtropical zone or paddy soils, but with increase in CH4 emissions. Additionally, straw retention enhanced NGHG and NGHGI by 20.7% and 15.4% on average regardless of various external conditions, respectively. However, NGHG was reduced under conditions of straw retention in temperature or mulching to field. Straw retention under appropriate site-specially conditions simultaneously safeguard food security and slightly increase environmental effects.

Impacts of climate change and increasing carbon dioxide levels on yield changes of major crops in suitable planting areas in China by the 2050s

Maize, rice, and wheat are the major staple food crops in China and are crucial components of national food security and economic development. The cultivation and production of these crops are expected to be affected by climate change and elevated atmospheric carbon dioxide (CO2) concentration, and have drawn considerable public attention. The objective of this experiment was to understand the impact of future climate change (including increased temperature and changed precipitation patterns) and elevated CO2 concentration on variations of crop yields in their suitable planting areas. We conducted a spatial grid-based analysis of maize, rice, and wheat yields using projections of future climate generated by a multi-model ensemble of global climate models for three representative concentration pathway scenarios (RCP2.6, RCP4.5, and RCP8.5) in suitable planting areas in China for the 2030s (2021–2040) and the 2050s (2041–2060). Suitable areas for the planting of maize, rice, and wheat under the high-emission scenarios migrated slightly northward over time. Yield of all three crops would be expected to remain stable or to slightly increase across China in the future. A possible reason for this result may be because the positive effects of increased precipitation and CO2 offset the negative effect of increased temperature on crop yields, resulting in a much more appropriate growth environment and increased biomass accumulation and crop yield. In addition, this study also indicated that changes in crop yields were mainly driven by temperature and CO2 factors. The potential effects of climate change and elevated CO2 concentration on migration of planting areas and yield fluctuations for crops should be given greater attention in the future.

Analysis of temperature variability and extremes with respect to crop threshold temperature for Maharashtra, India

Temperature is one of the prime factors affecting crop yield and thereby, in changing climate, it is imperative to investigate the co-variability of crop yield and temperature change. Temperature change can manifest itself in multiple factors such as deviation from long-period average, daily scale variability and frequency/intensity of extreme temperature events. To add to the complexity, each of these factors can affect the crop yield differently which necessitates understanding their effect on crop yield individually as well as collectively. Concerning this, we evaluated their distinct and combined impact with respect to threshold temperature of three major crops, i.e. sorghum, sugarcane and millet sown across the Maharashtra State of India. Further, the temperature parameters were conflated using confirmatory factor analysis to formulate a temperature variability index (TVI) that helped in identifying the collective impact of these multiple factors on each crop. Results show that the TVI and sugarcane yield for Nagpur and Bhandara districts of the Vidarbha region exhibited negative co-variability (− 0.30/year), implying the negative impact of temperature change on sugarcane. For sorghum, Wardha and Bhandara of Vidarbha region, Solapur of Pune region and Ratnagiri of Konkan region exhibited negative co-variability with TVI (~− 0.2 to − 0.4/year). Contrary to sugarcane and sorghum, for millets, Akola, Amravati and Chandarpur districts in Vidarbha region; Hingoli, Parbhani, Nanded and Osmanabad in Marathwada region; Satara and Sangli in Pune region; Jalgaon in Nashik region and Ratnagiri; and Sindhudurg in Konkan region exhibited positive co-variability (0.50/year), signifying the favourable temperature conditions for sowing millet. Overall, due to the high exposure of districts to temperature change in Vidarbha and Pune regions, farmers in these districts are advised to refrain from sowing sorghum and sugarcane; instead, farmers can moderate the adverse effects of climate change by sowing millet due to the existence of conducive temperature for millet in Maharashtra. Further, analysis was used to suggest the region and climate-specific cropping pattern for other districts of Maharashtra that can be used by the policy makers to improve the situation of agriculture, farmers and economy of India.

Monitoring of Spring Wheat Cultivation Under the Climatic Conditions of Kursk Region

With the help of generalization and mathematical processing of statistical data, the author found that in Kursk Region, the yield of spring wheat from 1995 to 2018 increased more than 2.5 times (from 1.58 metric tons / ha in 1995 to 3.97 metric tons / ha in 2018), although in Russia there were no significant changes in crop yield. While conducting a correlation analysis of the associated data of spring wheat yield in Kursk Region for the period studied, a close relationship was established with the application of basic nutrients (0.84) and with the prevailing weather conditions of a particular year of cultivation (0.86). It was found out that spring wheat grew under optimal weather conditions in 50% of cases. Adverse and favorable weather conditions are formed equally in 25 % of cases of years. Under optimal weather conditions, a high direct linear relationship between yield and the sum of active temperatures is recorded, which is significant at 99% level. Crop shortage in unfavorable years was associated with high air temperature during the entire growing season of the crop and a lack of humidity from seedlings to grain ripeness and an increase in humidity during the harvest of the crop. A linear regression relationship between yield and moisture coefficient was revealed. Thus, the moisture coefficient is the limiting agro-climatic resource of spring wheat yield under the conditions of Kursk Region.

How Does the Waterlogging Regime Affect Crop Yield? A Global Meta-Analysis.

Waterlogging, an abiotic stress, severely restricts crop yield in various parts of the world. Thus, we conducted a meta-analysis of 2,419 comparisons from 115 studies to comprehensively evaluate the overall change in crop yield induced by waterlogging in the global region. The results suggested that waterlogging obviously decreased crop yield by 32.9% on average, compared with no waterlogging, which was a result of a reduced 1,000-grain weight (13.67%), biomass (28.89%), plant height (10.68%), net photosynthetic rate (Pn, 39.04%), and leaf area index (LAI, 22.89%). The overall effect of a waterlogging regime on crop yield is related to the crop type; the crop yield reduction varied between wheat (25.53%) and cotton (59.95%), with an overall average value of 36.81% under field conditions. In addition, we also found that compared with no waterlogging, waterlogging in the reproductive growth stage (41.90%) caused a greater yield reduction than in the vegetative growth stage (34.75%). Furthermore, decreases in crop yield were observed with an extension in the waterlogging duration; the greatest decreases in crop yield occurred at 15 < D ≤ 28 (53.19 and 55.96%) under field and potted conditions, respectively. Overall, the results of this meta-analysis showed that waterlogging can decrease crop yield and was mainly affected by crop type, growth stage, and experimental duration.

Effects of long-term tillage systems on soil physical quality and crop yield in a Brazilian Ferralsol

Long-term soil tillage trials can provide important knowledge about sustainable changes in soil physical quality and crop yield. This study evaluated soil physical quality indicators under different long-term tillage systems and examined the relationships between quality indicators and crop yield. The study was carried out on a Rhodic Ferralsol with three tillage systems established in 1989: conventional tillage (CT), strategic tillage (ST), and no-tillage (NT). All treatments had long-term crop rotation. The soil parameters evaluated were total organic carbon (TOC), bulk density (ρs), macro and microporosity (Mac and Mic), relative gas diffusivity (D/D0), pore tortuosity (τ), relative field capacity (RFC), structural stability index (SSI), least-limiting water range (LLWR), and degree of compactness (DC, taking as reference the soil bulk density in which LLWR = 0). Soybean and maize yields in two consecutive summer seasons were measured. Conventional and strategic tillage provided higher ρs in the 0.15–0.30 m layer depth, leading to higher DC in CT. Using soil bulk density at LLWR = 0 as reference proved useful to assess soil DC and plant response. No-tillage provided lower DC in the 0–0.15 m (86 %) and 0.15–0.30 m (78 %) layers than CT (91 % and 94 %, respectively). The maize yield had a negative linear relationship to DC, with the lower values at DC > 87 %. All tillage systems affected D/D0, even at similar porosity values. The better soil physical quality under NT provided 1211 kg ha−1 higher maize yield compared with CT. The differences in soybean yield between treatments were not significant, but NT provided 381 kg ha−1 more than CT. These findings indicate that NT is the best system studied. Our results strongly suggest that ST does not improve physical properties of soils under NT with crop rotation, and that a diversified crop rotation in NT was efficient to avoid soil physical degradation.

Assessment of environmental sustainability in renal healthcare.

The health effects of climate change are becoming increasingly important; there are direct effects from heatwaves and floods, and indirect effects from the altered distribution of infectious diseases and changes in crop yield. Ironically, the healthcare system itself carries an environmental burden, contributing to environmental health impacts. Life cycle assessment is a widely accepted and well-established method that quantitatively evaluates environmental impact. Given that monetary evaluations have the potential to motivate private companies and societies to reduce greenhouse gas emissions using market mechanisms, instead of assessing the carbon footprint alone, we previously developed a life cycle impact assessment method based on an endpoint that integrates comprehensive environmental burdens into a single index—the monetary cost. Previous investigations estimated that therapy for chronic kidney disease had a significant carbon footprint in the healthcare sector. We have been aiming to investigate on the environmental impact of chronic kidney disease based on field surveys from the renal department in a hospital and several health clinics in Japan. To live sustainably, it is necessary to establish cultures, practices, and research that aims to conserve resources to provide environmentally friendly healthcare in Japan.

Global economic impacts of climate shocks, climate policy and changes in climate risk assessment

This study assesses the global economic consequences of climate-related risk in three broad areas: (1) the macroeconomic impacts of physical climate risk due to chronic climate change associated with global temperature increases and climate-related extreme shocks; (2) the macroeconomic effects of climate policies designed to transition to net zero emissions by 2050 (transition risk); and (3) the potential macroeconomic consequences of changes in risk premia in financial markets associated with increasing concern over climate events. We consider four widely used climate scenarios (Representative Concentration Pathways, or RCP), and identify the physical damage functions due to chronic climate risks. The chronic climate risks include sea-level rise, crop yield changes, heat-induced impacts on labor, and increased incidence of diseases. We also estimate the future incidence of climate-related extreme events, including droughts, floods, heat waves, cold waves, storms and wildfires, based on climate variable projections under the climate scenarios. After translating physical climate shocks into economic shocks to labor force and sectoral productivity, we investigate the macroeconomic consequences under the climate scenarios using the G-Cubed model. The results demonstrate that physical climate risk is likely to cause large economic losses in all RCP scenarios, both through chronic climate change and extreme climate shocks. We then explore the impact of country-specific economy-wide carbon taxes as a representative policy action to drive the global economy to achieve net-zero emissions by mid-century. Transition risks vary according to the ambition and the design of policies to reduce emissions. The results demonstrate that there can be potentially significant costs associated with policies to reduce emissions, and the costs differ across sectors and across countries. We also address whether changes in climate risk perceptions can significantly impact the real economy through changes in risk premia in financial markets. We calculate shocks to financial risk premia based on relationships between historical climate shocks and changes in financial market risk premia. We apply these shocks to risk premia under the RCP scenarios and find that the cost of rising risk premia can be of a magnitude consistent with historical experience. The cost appears to be smaller than the economic costs of changes in physical climate risk and transition risk.

An efficient crop yield prediction using Bootstrap Aggregative MapReduce Rocchio Classification

Climatic changes in environmental condition affect crop growth and crop yield. Therefore, the impact of climate change on crop production is a significant problem to be solved. Though a handful of research works are present to predict the crop yield, the prediction accuracy of crop productivity is not sufficient. Besides, the time duration needed to identify the crop production using big agriculture dataset was higher. To avoid such limitations, the Bootstrap Aggregative MapReduce Rocchio Classification (BAMRC) technique is proposed. The BAMRC technique contains two key processes i.e., feature selection and classification. The experimental evaluation of BAMRC technique is conducted on metrics such as prediction accuracy, prediction time and false positive rate relating to numerous test instances collected at varied time period. The experimental results depict that the BAMRC technique is able to improve the prediction accuracy and also minimise the prediction time of crop yields from soybean large dataset when compared to state-of-the-art works.

An efficient crop yield prediction using Bootstrap Aggregative MapReduce Rocchio Classification

Climatic changes in environmental condition affect crop growth and crop yield. Therefore, the impact of climate change on crop production is a significant problem to be solved. Though a handful of research works are present to predict the crop yield, the prediction accuracy of crop productivity is not sufficient. Besides, the time duration needed to identify the crop production using big agriculture dataset was higher. To avoid such limitations, the Bootstrap Aggregative MapReduce Rocchio Classification (BAMRC) technique is proposed. The BAMRC technique contains two key processes i.e., feature selection and classification. The experimental evaluation of BAMRC technique is conducted on metrics such as prediction accuracy, prediction time and false positive rate relating to numerous test instances collected at varied time period. The experimental results depict that the BAMRC technique is able to improve the prediction accuracy and also minimise the prediction time of crop yields from soybean large dataset when compared to state-of-the-art works.

Drought assessment on barley and millet production in Karnali Province, Nepal

Spatio-temporal characteristics of agricultural drought and its impact on the yield of winter barley and summer millet crops in Karnali Province of Nepal were evaluated. For this purpose, precipitation data from 1988 to 2018 of 18 stations and agricultural data from 2003 to 2018 were used for the analysis. Standardized Precipitation Indices (SPI-3 and SPI-4) were used for measuring drought intensity. Based on drought intensity, SPI&lt;-1 was considered for drought occurrence. Similarly, Standardized Residual Yield Series (SYRS) was also calculated for crop yield change, eliminating other factors responsible for crop yield. The result shows that Salyan, Surkhet, and Jumla districts have more occurrence of summer and winter drought in comparison to other districts. Similarly, 1999, 2002, 2004-05, 2008-09, 2012, and 2015 were considered as drought years in most stations. Moreover, the province experienced more winter drought events than summer and winter droughts are increasing after 2015. Concerning the impact of drought occurrence on cereal yield loss, barley seems to be more affected. SPI-3 and SYRS (barley) are significantly correlated in Jumla, Humla, Mugu, Jajarkot, Dailekh, Surkhet, and Salyan districts at 95% confidence. With the exception, drought occurrence has a larger impact on barley yield loss than drought severity in the study area. However, millet yield loss doesn't seem to be affected due to drought occurrence and intensity in all districts except Rukum, as millet is a drought-tolerant crop. Therefore, for sustainable agriculture practices, drought-tolerant crops like millet could be suitable in Karnali Province, where drought frequency is very high.