Category: hydroponic growing

Furthermore, the study tried to indicate which vegetables accumulated the most nutrients. results demonstrate that organically grown vegetables generally contain a significantly higher level of macro elements compared to the ones grown in a conventional way. It is commonly known that fertilizers, whether the mineral or organic ones importantly affect the content of elements in the soil as well as in plant tissues. Other very important factors are the physicochemical characteristics of the soil and the climate conditions.The content of Ca in the soil depends primarily on the type of bedrock from which it originated and on the degree of weathering processes. In Poland, the content of Ca in the top layers of the mineral soil ranges from 1000 to 34,300mg∙kg−1 . Our results revealed a much lower concentration of Ca in the soil cultivated in a conventional way, compared to the organic one. This might be due to the regular compost application.

Stępień and A damiak in their 5-year field study investigated the influence of the different type of fertilizers on the chemical properties of the soil. Their results clearly demonstrated that long-term compost application increases the content of Ca compared to another type of fertilizers. Plants usually contain quite a high amount of Ca, on average 5000 – 30,000 mg∙kg−1. The main reason for the high content of this element in the plant tissues is the elevated concentration of Ca in the soil solution. However, the uptake of Ca by the plant is usually slower than the uptake of other elements . The biological factors affecting the Ca intake are primarily the species and variety of the plant, root and rhizosphere structure,plant transpiration, my corrhiza activity, and the effect of phytohormones .In our study, a significantly higher concentration of Ca was found in organic celery, potato, and parsley root. This is in agreement with the results of the meta-analysis conducted by Williams. In 21 out of 47 studies, it was found that a higher content of Ca was reported in the organically grown vegetables; in20, the amount was similar between the two growing systems; in 6 only, a higher content was recorded in conventional plants.

Similarly, Warman and Havard in their 3-year study found an increased amount of Ca in organic carrot compared to conventional one.The average concentration of Mg in arable soils of Poland is 770 mg∙kg−1.However, this value is much higher in western Poland were both farms are located and it reaches up to 980 mg∙kg−1 . Soils of both organic and conventional farms evaluated in this study revealed Mg concentrations below average,which is 503 mg∙kg−1 and 668 mg∙kg−1, respectively. Generally, the lighter the soil, the less Mg it contains. That could explain lower concentration of this element in the organic soil compared to the conventional one. On the other hand, the soil of the conventional farm was represented mainly by podsols made of clay loam.Therefore, the soil physicochemical characteristics might be one of the reasons.Mg is very mobile; therefore, the majority of this element is often moved to deeper parts of the soil profile, particularly in the case of light sandy soils .

Considering the importance of this element in the plant growth it can be suspected that a significant dose of fertilizers containing Mg was applied in the conventional farm which would contribute to higher levels of it. The concentration of Mg in plant tissues varies between 3000 and 10,000 mg∙kg−1 and it depends on the plant species, its age, organ and plant demand for Mg. Generally,higher concentrations of this element are observed in the aboveground parts of the plant compared to the roots . It agrees with our results where the Mgcon centration in parsley leaves was found to be higher than in the root and generally the highest among all analyzed plants. Although the concentration of Mg was higher in the conventionally cultivated soil, plant tissue analysis demonstrated a higher Mg content in all organically grown vegetables compared to conventional ones.

It is consistent with several other studies where a superior concentration of Mg in organically grown vegetables was reported.Stępień and Adamiak  reported that on average N concentration in the soils cultivated in different ways vary between 800 and 1000 mg∙kg−1. The same authors demonstrated that among different types of fertilizers, organic ones increased the content of N in the most significant way. In our study, the organically cultivated soil was characterized by an increased concentration of N and it was over two times higher than in conventionally treated soil . We hypothesize that the main reason for high N content is the frequent application of compost and cow manure in the organically managed farm. Nitrogen is considered to be one of the most important nutrients for the plant growth and development, primarily because it is essential in protein synthesis and it builds nucleic acids.

The study identifies the best practices not only in economic terms but also from a climate change perspective. However, organic rice farming is found to be more respectful of the environment, albeit at the expense of lower yields in the short term. Nevertheless, these practices ensure higher financial profits, even in the short term.It seems that decision-making based exclusively on traditional accounting information,and/or on data on the environmental performance of the specific agricultural productive stage tends to hide environmental degradation. Therefore,further research is needed, along with practical improvements in sustainability accounting, to provide essential guidelines for the better administration of natural resources.The remainder of this article is organised as follows. Section 2 discusses the advances made in the accounting of the environmental impact of farming. Section3 explains the methodology adopted. Section 4 presents the results and a discussion of these findings and, finally, section 5 offers some concluding remarks,while identifying some of the limitations of the study and avenues for further research.

Over recent decades, input-intensive agricultural technologies have brought about significant changes in agricultural production, especially, for cereal crops.The increasing use of genetically modified seeds, irrigation, chemical fertilisers,pesticides and mechanisation have, in some cases, resulted in higher yields. However, they have also resulted in undesirable anthropogenic causes of climate change with increased greenhouse gas emissions due to a growing dependence on scarce fossil fuels . Studies of the industrialisation of farming have provided evidence that certain practices mean the misuse of common resources. Agriculture’s vast energy consumption is today estimated at an annual 11 exajoules , and this amount is set to rise with expanding populations and the mechanisation of farming .Additionally, modern agricultural practices are having other environmental impacts, including, the degradation of soil and water quality, and the loss of biodiversity,wildlife habitats and landscapes . The heavy dependence of farming on chemical pesticides and fertilisers has increased in recent years and today they pose a serious threat to human health and the environment. However, despite the investment in pesticides, pests are calculated to destroy 50% of treated crops worldwide. Yet, at the same time, millions of humans suffer the effects of pesticide poisonings each year.

The overuse of chemical pesticides,combined with mono cropping, is also the cause of the loss of biodiversity ,while the overuse of fertilisers is one of the main causes of water pollutant runoff and leaching .In conventional farming, the increase in required inputs results not only in unwanted environmental degradation but also in an undesired rise in operating costs. Thus, the average net income per farm has declined and the average debt per farm has increased in the long term . As a result, a call has been made to shift the goal from maximising productivity to optimising agricultural production while upholding environmental and social justice .The need to reduce the GHG emissions from agriculture has highlighted the urgency of shifting to non-fossil fuels. Here, each new scenario requires a specific accounting measure and a method for predicting natural resource usemaximization. Accounting for natural resources in this way should provide an efficient system for monitoring, controlling and mitigating irresponsible be haviour, thus making it possible to achieve the aforementioned goals of maximization. The environmental and social elements involved in economic activities can be addressed through sustainability accounting, a school of practice that provides tools for performance measurement and reporting when considering such matters as carbon reduction and water shortages or surpluses attributable to climate change .

Research carried out to date monitoring the impact of agriculture on climate change has, in some instances, compared the productivity and environmental impact of different styles of farming, but it does not quantify differences in economic performance  . Thus, various studies specifically analyse the differences in productivity of conventional and organic farming   and although they take into account the environmental dimension, their focus is very much on technical efficiency. Clearly, the limitation is that technical efficiency is ultimately measured in terms of the yields, inputs and prices explicitly recorded in a farm’s accounts, and as such needs to be economic-centred. The research conducted to date tends merely to consider the minimisation of current expenses but it fails to take externalities into account.The solution proposed from within the academic world for revealing and “internalizing”farming externalities is that of placing a monetary value on them  .This paper contributes to the analysis of how climate change externalities might be accounted for by presenting a microeconomic perspective for rice production and the measurement of the environmental impact of farming practices conventional and organic. The economic performance indicators used here include yields per hectare in kilograms, sales revenues, and income both before and after wages. These indicators have previously been considered as being representative of economic performance.

Precision farming in crop production is the application of exact farming technologies to manage spatial and temporal variability for the purpose of improving crop performance and environmental quality . Precision farming has become established due to advances in technology which enable accurate geo-referencing, real-time data acquisition, sensing, telemetric and variable rate application of inputs. Precision farming in crop production uses extensive data from a farmer’s field and the surrounding region to help predict weather conditions and optimize operations . For effective collection and analysis of relevant crop cultivation information, precision farming in crop production employs the services of agro-based remote/sensory technologies.Remote sensing technology  refers to the science of wirelessly observing and obtaining information on crop and soil characteristics using devices attached to aircraft, satellite, and agricultural equipment such as tractor .

The sensors are made up of electronic probes and optical scanners that detect changes in the soil and surrounding environment. Remote sensors vary in the type of platform they are mounted, based on light source,spatial and spectral resolution. Remote sensors are classified as passive or active depending on the light source.Passive sensors rely on sunlight,thereby limiting recording to the time when the cloud cover is minimal and the sun is illuminating the target area. These restrictions often limit data collection around noon to maximize available sunlight. Passive sensors are mounted on satellites or airplanes. In contrast to passive sensor, active sensors use their own modulated light at defined or fixed wavelengths. The sensor illuminates the object and uses photodiodes to measure the portion of light that is reflected . A primary advantage of active sensor over passive is its ability to obtain measurements at any period, regardless of the time of the day or season in addition to eliminating the effects of sun angle and cloud cover. Active sensors are mounted on satellites  or ground vehicles .

RST can provide useful information for many crop management decisions, including detection of nutrient or water deficiencies and excesses in the soil, damages caused by insects, weeds, or diseases in various portions of the cultivated fields. RST obtains information about an object without directly contacting it. Data collected can range from a simple colour photograph to the crop’s emission of electromagnetic energy . Sensordata can provide farmers real-time information regarding their crop condition, allowing them to respond and make corrective or other management decisions to maximize production. Using a combination of sensors such as temperature, light and humidity, helps the farmer detect risks of frost/drought, possible plant pests/diseases and establish watering requirements based on soil dampness . With the RST, data can be collected for an entire field as compared to traditional scouting methods which only provides single point or partial field coverage while data collected over multiple dates during the season allows farmers to monitor trends in crop progression and manage cultivation of crop in addition to monitoring the exact conditions in which the plants are growing from the comfort of homes.The objectives of smart  agriculture among others is to help control conditions and closely monitor performance of crops, where the smallest amount of change in climate can affect the final outcome, and to determine the best conditions for each crop, by comparing the data obtained during the best harvests.

Remote-sensory technology has a variety of applications, including environmental monitoring,site-specific agronomic management,land cover classification, climate- and land-use-change detection, and drought monitoring . The ability of a remote sensor to detect subtle differences in vegetation makes it a useful tool for quantifying within-field variability, evaluating crop growth, and managing fields based on current conditions that may be overlooked using typical ground-based visual scouting methods during crop cultivation. While collecting real-time data on weather, soil, health of crops and air quality is important, it is also necessary to apply precision in crop harvesting to reduce damage and loss. To help cope with the trending resultant events of climate change and to generate enough food to meet the ever-growing demands of a growing global population for food, crop production needs to embrace smarter farming methods through the use of technologies such as agriculturally applicable sensor technology.Using RST in PF will revolutionize the data collection in agricultural field, support the highly sought after automated agriculture system  which requires intensive sensing of environmental conditions at the ground level and rapid communication of the raw data to a local or remote server where there is the availability of computational and storage power, the identification of pests in the crops, drought or increased moisture, decision making, while the control of farm equipment is done in real time using automated actuation devices.

The yield increments with biochar amendments following AWDI could be due to the maximum productive tillers/hill and higher nutrients availability to rice grain compared to other treatments. Sanjit et al.  reported that rice grain yield was a bit higher in conventional irrigation compared to the AWDI treated field plot yield  during the dry boro season in Bangladesh.Ali et al.  also reported that the AWDI treatment showed superiority for the rice yield performance and seasonal CH4 emission reduction, water savings, and maximum water productivity index under the dry seasonal conditions in Bangladesh. It was also reported that moderate wetting and drying increased rice yield, decreased water use and CH4 emissions . In this study, biochar applications 20 – 30 t/ha under alternate wetting and drying  irrigation resulted least cumulative CH4 emissions and GWPs, while highest water productivity and moderate yield performance were found in the rainfed wet season and dry boro season.

The lower CH4 emission under AWDI treated field plots may be due to increased aeration, stabilization of soil organic carbon, improved soil redox potential status and accumulation of free iron oxides, sulfate ions which acted as electron acceptors, thereby,reduced methanogens’activity. On the contrary, Ali et al.  reported that biochar amendments in paddy soils increased cumulative CH4 emissions. This contrasting result may be due to the variation in the composition of biochar as well as different agro-ecological zones. Zhang et al.  reported that the soil amendment with biochar was found effective for mitigating CH4 emission, which also increased rice yield by 25% – 26% compared to inorganic fertilizers. Ali et al. also reported that intermittent irrigations significantly reduced total seasonal CH4 emissions by 27% compared to conventional  irrigated rice paddy field. In this study, biochar amendments improved the soil redox status and soil porosity, mostly observed under the AWDI treated field plots.Consequently, total seasonal CH4 emission significantly decreased in AWDI plot compared to the conventional irrigated rice field. Hiya et al.  found that total GWP of CH4 significantly decreased with AWDI treatments as compared to continuous flooded plots.

This result also showed that AWD irrigation system is better than conventional irrigation in terms of water productivity index and water savings. Higher productivity index was found in biochar amended field plots under the AWDI method compared to conventional irrigation. Singh et al. reported that combined application of rice husk biochar and FYM with reduced chemical fertilizer under less water inputs was effective to sustain wheat crop yield in the highly vulnerable dry tropical agro-ecosystem of India. Hossainet al.  reported that water productivity increased from 0.35 kg·m−3 to 0.65kg·m−3 following better research management over the farmers’ practice, environment friendly technology for reducing groundwater use in the irrigated ecosystem.Xiao et al.  reported that rice straw biochar amendments at 20 t/ha and 40 t/ha significantly decreased CH4 emissions by 29.7% and 15.6%, respectively,while rice yield was increased by 24% and 33% and irrigation water productivity was increased by 36% and 42%, respectively, over the control. In this study, biochar amendments 20 – 30 t/ha showed the maximum free iron oxide contents under both AWDI and conventional irrigated  field soils, which was supported by Ali et al. .

This study showed that there were negative correlations between total seasonal CH4 fluxes with grain yield, water productivity index, soil pH, soil Eh, soil porosity, soil organic carbon, total N, available P and S , while positive correlations were recorded with plant productive tillers and above ground biomass.Hiya et al.  stated that total seasonal CH4 flux was negatively correlated with grain yield, water productivity index, soil Eh, organic matter, total N,available P and S, soil porosity and soil pH under continuous irrigated treatment.The increased water productivity of rice and water saving aspects will make farmers and other stakeholders to adopt AWDI technique. Therefore, biochar applications @ 15 – 20 t/ha with half of the recommended chemical fertilizers and adopting alternate wetting drying irrigations may be a feasible technique for reducing yield scaled CH4 emission as well as GWPs and sustaining rice productivity through improving soil properties and rice rhizosphere environmental conditions. The alteration or modification in an organism’s genome using modern DNA technology is called genetic engineering or genetic modification. Since it involves the introduction of foreign DNA or synthetic genes into the organism of interest the resulting artifact is often referred as transgenic and or genetically modified . The ability to introduce alien genes from distant species or life forms into plants has made available an entirely new and novel gene resource pool to breeders in their pursuit to improve crops for survival, productivity, and products.

Examination of 31 documented cases of African and Latin American farmers adopting “resource conserving agriculture” found that yield improved in19 of the 25 cases that reported on it, food security improved in seven of eight cases, and net income improved in 19 of 23 cases  and observed that successful “resource conserving agriculture” initiatives did not occurs pontaneously rather required a variety of skills from smallholders and their allies which included adaptive farm management, effective producer organizations, entrepreneurship, capacity to innovate, value addition and boundary spanning, these being noted in the case of traditional farming in Ethiopia .Unfortunately, the struggling Ethiopian small farmers and pastoralists have already been hit hard by climate variability, losing harvests and livestock to drought, floods and struggling to survive amid changing rainfall patterns.

Sub-Saharan Africa is considered one of the most vulnerable regions to climate change, because of the high exposure and the low adaptive capacity of agriculture which is the most important livelihood .Mean annual temperature of Ethiopia has already increased by 1.3˚C between 1960 and 2006, also daily temperature data indicate significantly increasing trends in the frequency of hot days, and much larger increasing trends in the frequency of hot nights . Continued changing patterns and intensities of rainfall with increasing temperatures expected to have dire consequences for all Ethiopians, but especially more than 70 million poor rural people whose survival depended on rainfed agriculture,in 2005, 39% of Ethiopia’s population lay below the national poverty line.As the impacts of climate hazards and change occur alongside other trends, for example, population growth, land degradation, poor infrastructure, and low opportunities for markets, indicating the compounded nature of the problems faced by the rural community; the efforts to tackle climate hazards, variability and change in Ethiopia must be aligned with the overall development plans .

Despite the Government of Ethiopia and other development actors giving widespread recognition of this by planning for climate change, most attempts are isolated and suffer from under-investment.There is an important need of in depth research and closer scrutiny of how the local climate is changing, what the local communities are thinking about this change, what the small farmers can do in the long term as adaptations,and possible interventions/future investments needed to deliver sustainable results. As indicated above, till now, the Ethiopian agriculture has remained rather “traditional and ecological”—little change being experienced like “agricultural intensification” but to cater the need of the increased population, the traditional system has proved insufficient, has to be improved especially to cope with the climate change instabilities. For such a need the necessity for “ecological intensification” under unfavorable conditions was advocated which depends on reducing the reliance on subsistence cereal production and integration with livestock enterprises, greater crop diversification and agroforestry practices that may ensure higher economic value and soil conservation . So, to understand the nexus of climate change and sustainable development, what needed is an in-depth field survey to find out the local community’s ideas and perceptions and how they are responding to climate irregularities.

As in most vulnerable communities, there is a symbiotic relation between lives, livelihoods and the biophysical environment. It is hypothesized that in response to the climate change the small farmers, in the way of the process of adaptation to all changes and survival strategy,may have modified and/or replaced many practices which have become unsustainable and adopt new ones can be demonstrated in the present study in the Highlands of Ethiopia. This understanding is also important for understanding the level of success of the process of constant adjustment to change be considered as an indicative of the adaptive capacity and knowledge of the rural farmers as has been stressed for attaining sustainable development. A focus group of elderly men and women  who have been living for long in the area were selected from the community to discuss about climate and farming .The discussion was facilitated in local language , as these community members lived for long periods in the area had good understanding of conditions and changes in their surrounding and also about the “normal climate conditions”. Discussion was started by posing questions such as what are the “good”seasons and what were the “bad” seasons, how did they understand and describe climate and climate change at the local levels. The participants described “good season” as that give enough rain with regular distribution that can support crops, trees and animals in sufficient amount, there would be no fear of starvation and insecurity to the family; whereas they described “bad” season associated with low and irregular rains, heat, hails and storms bringing crop damage and the fear to face food shortage, starvation and insecurity to the family. The participants were solicited to identify and list the bad and good points of the earlier as well as during recent years in a chart and filter tip pen, the main memorable indicators of climate situation in the area from past were identified by the participants as rain fall, heat, hail and coolness.

Successful implementation of these strategies will improve production and favour the farmer and the farming families. The farmers are complaining of sweeping changes they could not comprehend as their previous knowledge could not serve them competently. It is thus necessary to determine the extent to which climate change has impacted on the farmers and their families in the region and as well important to testthe suggested adaptation strategies for conformity in the locality. Niger Delta like most coastal low lying regions of the world is constantly faced with flooding of various degrees.However, due to increased and varying extent of precipitation attributable to climate change, the occurrence of flooding has increased with rivers and oceans easily overflowing their banks. This was observed in the 2012flooding that impacted negatively on agriculture in the region.

The flood ravaged farmlands, storage buildings and farmers houses. Climate change seems to have impacted to a low extent on water availability for irrigation as well as drying up of ponds and streams. This finding is true to the region as artificial irrigation is seldom practiced and increased precipitation has ensured constant supply of water to ponds and streams. As stated, wet regions will receive more rain while dry regions will become even drier. Increase in mortality rate tied directly to climate change in the region was not indicated by the respondents. This finding disagrees with who stated that there will be increased death rate due to factors favoured by climate change.Climate change has impacted negatively but moderately on most farming families though with some farmers reporting that the extent of impact is slightly high on cost of production as well as on net profit from farming thus impacting on poverty level of farmers in the region. This finding is in agreement with that of that stated that difficulty on farm operations and cost of agricultural production will increase with decreasing returns to the farmer.Findings of the study revealed that significant difference does not exist between the mean responses of the farmers and the extension workers on the perceived impacts of climate change on farmers and the farming families in the region, as indicated by t-test. Any observed difference is not a statistical difference, but a mere chance which could have resulted from sampling error. The farmers and the extension workers strongly agreed to construction of foot bridges with wood, stones and sand bags as a coping strategy mainly due to its affordability and suitability and not waiting for government and foreign aid. This strategy is really in use in the region to divert flood water and create walk ways.The respondents disagreed with planting deeper than the usual planting depth as a coping strategy likely due to the specified planting depth for various crops. If the depth is increased beyond the required, the plants may not germinate well or results to scanty germination as some of the seedlings may not successfully pass through the increased depth to germinate. Sand filling water logged area to reclaim lost land seems to be an expensive and tedious practice as a coping strategy for an indigent farmer. Trips of sand to fill the vast water logged area could cost the farmer a fortune he may not be able to afford. This is the explanation given by majority of the respondents as to why they disagreed with this option as a coping strategy. For changing profession entirely, most farmers interviewed revealed that “farming is all they know and for the elderly, it is already late to change profession”.The farmers disagreed to changing from production of agriculture to marketing due to the vital role of local farmers as producers. On further inquiry using the interview, the farmers simply reply “if everyone switches to marketing, who will do the production for supplies to be marketed?” For artificial irrigation as an alleviating strategy, most farmers in the region are too poor to own boreholes in their farms. The region being a coastal one does record high occasion of rainfall in a planting cycle. This was explained as the reason why most crop farmers in the region practice rain-fed agriculture. This view is supported by who stated that the abundant rainfall in the region favours rain-fed agriculture.The farmers and the extension workers agreed to most of the suggested coping strategies. These findings are favoured by the views of many authors such as  – who suggested the adaptive measures against climate change as contained in their respective works.The opinion of the farmers and the extension workers is at variance with each other, may be due to varying degree of education, awareness and experience in farming as well as their geographical location. Smallholder dairy farming systems in the highlands of Ethiopia and elsewhere in East Africa  are classified as rural, peri-urban and urban systems. The major classification criterion is demographic; the peri-urbanand urban systems are located around and in towns and cities.

Plants are most economical and feasible production systems for vaccines or recombinant products. Replacement of fermenters and bioreactors with contained plant growth rooms or greenhouses with appropriate biological containment reduces manufacturing cost.Production costs of a recombinant protein in transgenic plants are 10 – 50-fold lower than that by E. coli fermentation. Plant vaccines can also be delivered orally, overcoming the cost and inconvenience of purification and injections. Use of plants as source of therapeutic proteins has a major advantage that productionin large quantities is possible. Feasibility for scaling up and high expression level of recombinant genes/proteins are also high in plant systems. Also,large scale cultivation is possible, and this can be adopted in less developed or resource-poor nations which lack sophisticated facilities or infrastructure for production of life-saving drugs.

Designing a recombinant vector, introduction and integration into plant system for production of antibodies, or other proteins of therapeutic value is relatively easy. The edible vaccines are easy to handle as well. When a new microbe or its antigen is evolved posing a threat to human health, it is easy to modify the synthesis of plant-based vaccines than animal-based ones. Edible vaccines are easy to deliver through oral administration and can be directly consumed without need for any injection. Edible vaccine is a needle-less vaccination method or a substitute of painful immunization procedures that require sophistication or trained manpower. It is also inexpensive, attractive to children, can be stored nearby the place of usage, harmless, and offers systemic and mucosal immunity. Edible vaccines are safe oral-delivery vehicles wherein specific plant tissues such as grains, fruits, or leaves can be used as formulation of vaccines, without extensive purification and processing. Post-translational modifications such as glycosylation, folding and assembly are significant for a protein to be biologically active and function as a vaccine.

Plants have machinery for expression, folding, assembly, and glycosylation, necessary for preservation of immunogenic activity of vaccines. In plants, the foreign or recombinant proteins of therapeutic value are glycosylated, accurately folded and the multimeric proteins assembled properly, to have structural integrity and biological activity for functioning as a vaccine.Protein synthesis as well as post-translational modifications of proteins in plants is similar to that of animal cells, making it possible to use plants as bioreactors for animal proteins/pharmaceuticals. The plantibodies or plant vaccines produced using plant-based systems are mostly safe and devoid of any toxic components.Plants do not host animal or human pathogens such as viruses or prions, as in the mammalian cell culture systems or transgenic animals, and hence do not transmit these. Chances of contamination with the pathogens during fermentation and extraction processes,is less in plant systems, Plant-based vaccines and therapeutics also have nobiosafety and environmental issues as with other animal or microbial systems of production of vaccines, except that of transgene containment.

The plant products can be stored safely for long duration at room temperature,unlike the need for refrigeration in case of other animal-based vaccines. Edibleor plant-based vaccines can also be easily produced by a freeze-dried process,leading to formulations with high stability under a cold chain-free distribution. Proteins produced in plants such as seeds remain stable for years at ambient temperatures, without loss of activity. Plant expression system has several advantages for human as well as veterinary vaccine production, however, only few of vaccine candidates are under clinical trials. Commercial human vaccines are not available due to low level of expression,relatively weak efficacy, and comparatively shallow knowledge on the characteristics of plant-made antigen and production system.Some of the challenges or constraints in the plant-based vaccines are discussed. Immunogenic response depends on nature of the vaccine, route of administration and the delivery system. Many antigens are poor immunogens, recognized poorly by the immune system and are prone to degradation in the harsh environment of the digestive tract. Plant cells protect vaccine antigen and prevent degradation as it passes through the gut.

Immunogen such as Cholera toxin Bsubunit, which can modify the cellular environment to present the antigen,can act as an efficient transmucosal carrier molecule and delivery system for plant-derived subunit vaccines and can overcome this problem. It is difficult to measure the effective dose for a mucosally delivered vaccine as it is exposed to the complex environment of the gastrointestinal tract. Further, or alvaccines may require co-administration with specific adjuvants to reach sufficient immunogenic activity. An insufficient amount of antigen would not produce the immune response needed for protection against disease and in appropriate dosage could lead to tolerance to vaccine and ineffectiveness of vaccine.

Though the seeds do not require nutrient application for germination initially,they require nutrients for proper growth and development. Thus, it is essential to grow plants under different concentration of nutrient solution with a control to determine the optimum concentration for maximum growth which can be derived through growth curve.In an experiment conducted on Brassica microgreens to study the impact of light intensity and quality of sole source LED on their growth, morphology and nutrient content, 25% Hoagland’s no. 1 nutrient solution was applied to the microgreens after 5 days of sowing to provide essential nutrients such as nitrogen,phosphorus, potassium, calcium, magnesium, iron, manganese, zinc, copper,boron and molybdenum.There are many different liquid fertilisers commercially available in the market for microgreens.

In an experiment conducted to compare the nutrient content on cabbage and lettuce microgreens grown on vermin compost and hydroponic growing pads, used 0.4% solution of General Hydroponics “FloraGro” Advanced Nutrient System 2-1-6 on the 7th day of growth of microgreens. However,there are not many experiments conducted on the application of commercial liquid fertilisers on microgreens. Thus, the application of commercial liquid fertilizer containing all such essential nutrients for enhanced growth of microgreens shall be considered for microgreens. From the literatures, it is found that the microgreens are commonly grown in plastic trays or vessels and the trays are not covered with lids. This implies that the microgreens are grown exposed to the climatic conditions until the harvest period and once they are harvested, the microgreens require separate packaging material for marketing which would increase the cost of production. Containerised vertical farming technology can be suggested to grown microgreens in a closed container which provides suitable microclimate by considering the capacity of the container, head space for gaseous exchange, availability, cost, light penetrance and ease in handling and marketing.

There might be risks of microbial contamination due to the development of high humidity within the closed containers which can be overcome by sterilising the containers under ultraviolet light for 15 minutes. There might also be a problem of gaseous exchange in closed containers which can be overcome by making tiny holes in the lid. Man has evolved in his continuous journey of “struggle for survival” on the earth. Microbial diseases not only had adverse effects on human health and life due to the fatality rate, but also had dwindled the economies of nations world-wide. Pandemics caused by known as well as newly evolved pathogens,which are more frequent during recent times, have sent alarm signals to mankind,to prepare against more deadly pandemics in future and promote development of vaccine platforms for handling the worst outbreaks. The ongoing global catastrophe of massive scale, the COVID-19 is wreaking havoc, killing people en masse without any discrimination of region or race.

The world is on the war to vanquish the virus, where all ways and means to control the virus are being tested and implemented. A virus is not considered as a living organism,but is an assembly of biomolecules, an obligate parasite requiring a living host for its multiplication. Also, there is a growing concern globally of the increasing antibiotic resistance among many pathogenic bacteria. Some bacteria and fungi are as well obligate and life-threatening.Drugs which can cure, and vaccines for prevention and treatment of fatal microbial diseases, are the prime mode of tackling a disease. When an epidemic or pandemic outbreak occurs through spread of deadly pathogen at a fast pace, as with the COVID-19, a solution or cure or treatment of the disease is desired on an emergency basis, than understanding the problem per se of the disease and the pathogen, through detailed scientific investigation or research. The convention alsystem of treatment relies on curative drugs and vaccines, which forms the first line of defense or treatment against the contagion.

A vaccine may be attenuated form of the live virus or microbial pathogen, or a subunit of the virus,which can elicit immunity response with production of antibodies, that act against the viral antigens. The body’s response to pathogen attack through production of antibodies constitutes active immunity. In passive immunity, the antibodies which can react or bind with the pathogen-derived antigens are administered to induce immunity. Vaccination greatly reduces disease, disability, death and inequity worldwide. Diseases like smallpox have been eradicated and diseases such polio, tetanus, measles etc. are restricted by vaccination. The rapid spread of severe contagious infections such as HIV, SARS, Ebola, and Zikain recent years has emphasised on the significance of global preparedness for pandemics, which necessitates extremely rapid development and comprehensive distribution of vaccines against potentially deadly, novel pathogens.

Some data between 1983 and1987 were unavailable and so were not used for the analyses. Rainfall data over the last five years as well as temperature data from 1983 to 2014were analysed in determining current rainfall trends in the study area. Maize production data was also obtained from the assembly of the Municipality for analysis. The study relied on survey, qualitative interviews and focus group discussions to obtain essential field data from the selected farming communities. The survey was administered among some selected maize farming communities in the Municipality of which purposive and accidental sampling techniques were used to enhance diversity of the respondents. The purposive technique was used to obtain the farming communities, percentage of male and female farmers as respondents, and selection of key informants. The key informants were made up of the aged, chiefs, a meteorologist and an agricultural officer. Any farmer chanced upon was also given the opportunity to answer the questionnaire .

The survey questions included close-ended as well as a few open-ended questions,most of which sought information on respondents’ perception on climate change and variability, farm size, variety of maize cultivated, farming system,application of fertiliser and other coping strategies meant to reduce the effects of low yields. The survey was conducted face-to-face with the respondents in different locations and in different communities. The questions were read and translated into Akan for the respondents to answer.In all, 12 key informants were interviewed to gain information about their views on climate change and variability impacts on maize farming in the Municipality.Seven of the respondents were maize farmers; three were elders from the chief’s palace whose ages were between 65 and 73 years and the rest were farmers. At least, one respondent came from each of the five farming communities in the study area. Apart from these key informants, one of the Municipal Agricultural Officers was also interviewed. Lastly, a staff of Ghana Meteorological Agency was interviewed. The questions in these qualitative interviews were unstructured, but were administered with the help of an interview guide. The themes covered were similar to those in the questionnaire survey, but were more interactive and probing, seeking information on climate change and variability of the study area, adaptation of the farmers,etc. with ample opportunity for the informants to provide extensive personal narratives.

The interviews were done in the participants’ homes or residences and were tape-recorded with their permission and later transcribed.Two FGDs were organised at the end of the data collection in two communities.Averagely the two FGDs were made up of three females and seven male farmers. The focus groups dealt with the changing climate and variability in the area, its impacts both positive and negative on their livelihoods, their adaptive capabilities to alleviate the challenges posed by the changing climate and economic/financial assistance they received elsewhere to support themselves.All the deliberations were videoed with the permission of the discussants and later transcribed. The selection was made based on how well they answered questions during the survey . Twenty-nine percent of the respondents had not received any formal education with only 5.5% of the respondents having attained tertiary level education.Most of the respondents were Junior High School /Middle School graduates,representing 40.9% of the respondents. Data from the survey indicated that males were better educated than females. About 34.8% of the female farmers had not received formal education, whereas 26.6% of the males had no formal education. A study in Pakistan revealed that if producers are educated,it enhances the application of best farming practices in tomato production.

According to 39.1% of the respondents, the major challenge which confronted the farmers in the transitional zone was rainfall. This challenge had to do with the late onset of the major and minor rainy seasons and the early cessation of the minor season. Challenges with regard to climate affecting farming might not necessarily be increasing temperatures since the monthly annual air temperatures for the study area from GMet was between 29.5˚C -34.3˚C which is within the optimal range for lowland maize in the tropics according to . It was rather the erratic rainfall pattern characteristic of both seasons that had affected crop yields as it was also reported by .Apart from rainfall irregularity, another challenge militating against farming was capital/money according to 30.0% of the respondents. Financial institutions feared the risk of farmers not being able to repay their loans due to erratic or failure of rainfall and thus were not prepared to finance the farmers. For financial support from the banks, farmers needed to provide two guarantors who were on government pay roll but these government workers were also not sure about whether the farmers would be able to pay back the loans due to the uncertainty of rainfall .Another challenge facing farmers in the field was pest and disease infestation according to 15.0% of the respondents.

The main objectives of this manuscript are to report, for a southern African study region, on agricultural impacts assessment under climate variability and change scenarios for rainfed systems to illustrate the regional challenges of climate change and variability in southern Africa. The research uses a selected study area, known as the Pandamatenga Plains, which is located in northern Botswana, and it considers cropping of maize, sorghumand sunflower under rainfed conditions.The specific objectives are: 1) to show real world climate change through the scientific understanding of downscaled climate scenarios; 2) to integrate downscaled climate scenarios with a crop model and adaptation option models, and with agricultural production information; 3) to assess the impact of climate change on crop yield, soil moisture stress, excess runoff etc. in rainfed agricultural systems; 4) to determine the potential for excess moisture enhancement and water harvesting through a modeling study; and finally 5) to recommend adaptation strategies based on modeling evidences.

The southern African region is vulnerable to climate change that causes multiple biophysical, political, and socioeconomic stresses. The stresses remain a major threat to the region’s susceptibility to vulnerability; they restrain the region’s populace adaptive capacity to climate changes and variability. Besides increases in temperature, climate change in sub-Saharan Africa is expected to cause, increases in the incidence of extreme events such as droughts and floods, changes in rainfall intensity,increases in desertification and increased in drought frequencies .Present research confirms that while crops would respond positively to elevated CO2 , the associated impacts of elevated temperatures, altered patterns of precipitation and possibly increased frequency of extreme events, droughts and floods. Taken all else as equal, these events will probably combine to depress crop yields and increase production risks.Expected impacts include shortened or disrupted growing seasons, reductions in the area suitable for agriculture, and declines in agricultural yields in many regions of sub-Saharan Africa . Several studies have already revealed that a combination of increased rainfall variability and increasing ambient air temperatures will cause a significant decline in yields of major staple crops, particularly for maize. In a recent work, Lobel et al. used a data set of more than 20,000 historical maize trials in combination with daily weather data.

It showed that for each degree day spent above 30˚C maize yield was reduced by 1 percent under optimal rain-fed conditions, and by 1.7 percent under drought conditions. In a similar study, maize yield projections in Malawi found a decline of up to 20 percent in the next 50 years. A similar study projected a decline of 10 to 57 percent by 2080 in Zimbabwe, which is mainly due to increased rainfall variability.It is noted that many other factors contribute, but these projections allow to showcase the framework and if business as usual would prevail.Climate change is emphasized as one of the major sources of challenge for food security, and livelihoods making the southern African region vulnerable to a variety of stresses. It is estimated that the livelihoods of nearly 70% of the region which depends on rain-fed agriculture, an activity that is characterized by small-scale,subsistence farms is affected . Due to its largely adverse effects on African agriculture and livelihoods,climate change is expected to have a negative impact on food security. In a recent study, most farmers in Zambia are unable to afford certain alternatives, such as those of agro-forestry or conservation; they face difficulties in accessing markets due to poor road infrastructure, fluctuating market prices, high costs and late deliveries of farming in puts.

Coupled with the low presence of systematic early warning systems in place against natural hazards and disasters, it shows the adaptation capacity of farmers remains limited.Most of the research on climate change impacts related to food in Africa, as evident in IPCC assessments, focuses on changes in crop yields and food production  reported climate change impacts on the yield of maize by considering regional model across southern Africa. These authors experimented on several climate change scenarios and examined the sensitivity of maximized yields to shifting of sowing dates as a means of developing adaptation decisions by keeping yields as high as possible.It is reported that with current climate change mitigation policies and related sustainable development practices,global GHG emissions will continue to grow over the next few decades .The various future storylines of GHGemission scenarios are expressed in terms of SRES scenarios. The SRES scenarios, provided in , are grouped into four scenario families that represent alternative development pathways, covering a wide range of demographic, economic and technological driving forces and resulting GHG emissions.The emissions projections are widely used in the assessments of future climate change, as inputs to many recent climate change vulnerability and impact assessments.