Top PDF Effects of climate variability on maize yield in the arid and semi arid lands of lower eastern Kenya

Effects of climate variability on maize yield in the arid and semi arid lands of lower eastern Kenya

Effects of climate variability on maize yield in the arid and semi arid lands of lower eastern Kenya

These findings appear to corroborate the views of Adejuwon [13] that variability in climate has wide im- pacts on maize yields in southern part of Nigeria. The work revealed that the more the climate variability, the greater the Z-scores and the less reliable the maize yields in Southern Nigeria. These findings are also explained by Thornton et al. [10] on a study on spatial variation of crop yield responses to climate in East Africa region. This may call for major reversals in the way adaptation strategies are being pursued in Kenyan dry land farming. The declining trend of maize yield in the four counties is mainly due to variable onset and seasonal rainfall, in- creased warming, and high potential evaporation (“Effects of climate on maize yields”). Generally increased warming has a tendency to accelerate the loss of water from soil thereby affecting maize growth from germination to vege- tative growth and later grain filling. This effect can also interact with the heat stress if maize crop varieties grown are approaching their thermal maxima. It is therefore rea- sonable to consider the results collected in the present work that indicate that climate variability is significant in maize production in lower eastern Kenya. Declining yields and drought episodes would be one of the primary reasons why smallholder farmers in ASALs do not appear to be adopting improved farming practices as observed by Nyandiko et al., (unpublished). A more reliable new Table 5 Summary of maize yield trend statistics by district in
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Effects of Climate Variability on Maize Yield in Matungulu West, Machakos County Kenya

Effects of Climate Variability on Maize Yield in Matungulu West, Machakos County Kenya

The mean annual temperature is on a rise according to the fifth assessment report of the IPCC Working Group (2007). It is dangerously increasing and unless the trend is curtailed then the 21st century is posed to experience an increase by at least 2°C. This will be more disastrous to Africa due to its vast land receiving rainfall below 700mm per year. It is also projected that Africa will continue to have a faster rise in temperature. According to Kang (2013) a rise in temperature is likely to affect water supply and its availability will become a problem because the water resources will decrease in the semi- arid areas. Kenya practices rain-fed agriculture thus crop production will be adversely affected. Hulme et al. (2001) and Faramarzi et al. (2013) projects a wetter climate for whole of East Africa in general. But due to regional differences the prediction for Matungulu West is still a temperature rise of 3°C. It is also projected that rainfall will decrease by 10-24% (Faramarzi et al., 2013).
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Trends of Extreme Temperature and Rainfall Indices for Arid and Semi Arid Lands of South Eastern Kenya

Trends of Extreme Temperature and Rainfall Indices for Arid and Semi Arid Lands of South Eastern Kenya

The Kenya Vision 2030 [2] identifies agriculture as one of the six sectors of the eco- nomic pillar to address the country’s economic growth since it contributes about 24% of gross domestic product (GDP). Rain-fed agricultural production provides a strong backbone to the overall economy by employing over 85% of the population. However, about 80% of Kenya’s land is classified as ASALs with very erratic and unreliable rain- fall. Further, the frequency and intensity of climate risks (droughts and flash floods) and associated effects on the fragile ASALs environment are anticipated to increase in future due to climate variability and climate change. Use of low and traditional farm inputs, diversity of cultivated crops, poor yield and very limited application of im- proved soil water management are common features of subsistence economy of small holder farmers in ASALs. A subsistence economy is one that provides sufficient food to last only from one harvest to the next. Therefore, a failure of one harvest means starva- tion for the ensuing year and shortage of seed for the next cropping season.
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Does it matter if people think climate change is human caused?

Does it matter if people think climate change is human caused?

Applied to eastern Oregon where declining forest health and rising wildfire risk could, in the near future, attain the salience of sea level rise in vulnerable coastal regions, an adaptive communication strategy might employ both cultural and consensus elements. Respected local leadership, participatory meetings, and identification of practical mi- tigation and adaptation steps are likely prerequisites for constructive change. At the same time, basic science communication could be im- proved, especially at the local level. For example, response to our survey question on past warming (Fig. 6B) suggests that many people have not encountered data on the observed regional climate (e.g., Fig. 3). Communication about such data, and what scientists make of it, could be more e ff ectively accomplished by sources with local credibility and connections (e.g., extension). This process has been initiated by at least one local group, the Umatilla County Climate Change Focus Group, which is comprised of federal, state, tribal and private forest and rangeland owners (Plaven, 2016).
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Effects of antecedent soil moisture on runoff modeling in small semiarid watersheds of southeastern Arizona

Effects of antecedent soil moisture on runoff modeling in small semiarid watersheds of southeastern Arizona

Soil water content in the upper soil layer prior to a rain event can be an important factor affecting the relationship between rainfall and runoff (Yair and Klein, 1973; Abra- hams et al., 1988; Karnieli and Ben-Asher, 1993; Martinez- Mena et al., 1998; Castillo et al., 2003; Zehe et al., 2005; James and Roulet, 2009; Brocca et al., 2009a, b; Penna et al., 2011; Tramblay et al., 2010; Kampf, 2011). Western et al. (1998) analyzed relationships between watershed aver- age soil moisture derived from point measurements and daily runoff coefficient for days with rainfall greater than 5 mm for the 10.5 ha semi-humid Tarrawarra watershed characterized by a silt loam soil type. Their results showed that the sur- face runoff was strongly controlled by soil moisture, with a threshold value of the volumetric water content varying from 41 to 46 %, below which no runoff occurred. Similarly, an- other study conducted by Brocca et al. (2004, 2005) on a semi-humid watershed (12.9 km 2 ) with sandy loam soils in central Italy indicated that only when antecedent volumetric soil moisture content was above approximately 36 % were the runoff coefficients generally greater than zero.
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A comparative study of GRACE with continental evapotranspiration estimates in Australian semi-arid and arid basins: sensitivity to climate variability and extremes

A comparative study of GRACE with continental evapotranspiration estimates in Australian semi-arid and arid basins: sensitivity to climate variability and extremes

In arid and semiarid environments, soil evaporation often makes up the majority of the total ET due to low vegetation coverage. This means that ET models should be able to reflect the relation with soil moisture conditions. Land surface models like AWRA partition precipitation to soil moisture and groundwater systems (other LSMs may not), and thus put a soil moisture constraint onto ET. However, the soil water constraint of energy-based ET products, such as PM-Mu and PT-CMRS, tends to be weak; most models tend to determine ET fluxes by energy factor, in particular based on net radiation estimation rather than by water constraint. Long et al. [16] mentioned that such RS-based ET models only make soil moisture implicitly linked to VIs and atmospheric variables. PM-Mu has soil moisture information indirectly linked to the LAI/NDVI and vapor pressure deficit (VDP); so does PT-CMRS, replaced by EVI and GVMI. These models implicitly assume that vegetation develops in agreement with water availability, which may be true over a long term or “standard” climatic period, but can fail in conditions when drought or rainfall present situations far from average. These models also rely on parameters (e.g., describing stomatal response) that are difficult to assess at large scale, as well as on the accuracy of land use maps. In semi-arid and arid regions, such as MDB and LEB, rain may fall and evaporate directly from bare soil, hence without major influence on vegetation indices and derived ET estimates. That is a potential explanation as to why satellite ET datasets like PT-CMRS and PM-Mu are less sensitive to rainfall/soil moisture and cannot balance well the water budget in these arid and semi-arid environments. Other RS-based ET models rely on the use of thermal infrared data that provide a strong link to water stress and moisture availability and which may improve significantly energy balance estimates. However, today there are no available operational ET products based on thermal infrared, in particular because such models are difficult to implement over large areas such as a continent or even a country. They either rely on a highly accurate characterization of spatial variation of climatic variables (in particular air temperature) or require a very homogeneous climatic zone for implementation.
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Protected Areas in the Brazilian Semi-Arid and the Management and Conservation of Ecosystems

Protected Areas in the Brazilian Semi-Arid and the Management and Conservation of Ecosystems

Abstract— The use of biodiversity has not been done sustainably on the planet, especially in South America, which has caused irreversible environmental impacts. Geodiversity is an important component of the existing natural heritage, but it lack s studies that mainly exploit the characteristics of the landscape and its forms of conservation. In this way, the aim is to discuss the relevance of the sustainable use of natural resources of protected areas of the Brazilian semi-arid, especially of the paleodunate areas, as well as to present a proposal for the management and conservation of these areas in accordance with the realities investigated, based on renowned theorists, in the existing legislations and above all, based on the practical investigations ca rried out. Therefore, it is crucial to understand the relevance of the adequate management of Brazil's protected areas, especially those that have environmental indicators from other geological eras and that, once destroyed, will never be recomposed, since it is a dynamic complex, thus requiring greater attention and a coherent management for its actual conservation.
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Ecological Restoration of Forest Soils Case of the Forest “Aioun Branise” Saida Algeria

Ecological Restoration of Forest Soils Case of the Forest “Aioun Branise” Saida Algeria

According to Pfefer (1996), the mud is an element that holds lots of water and doesn’t lose that very slowly, to the soil remains wet for a long time. The variability of the effectiveness of waste sludge depends on the type of soil on which it is epandee (Darwish et al., 1995). The effect of sludge will be more pronounced in soils with unstable structure as the soil silty but lesser in soils where other agents of stabilization of the aggregates are present such as clays.

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Enabling Conditions for Improved Use of Seasonal Climate Forecast in Arid and Semi Arid Baringo County—Kenya

Enabling Conditions for Improved Use of Seasonal Climate Forecast in Arid and Semi Arid Baringo County—Kenya

Studies indicates that seasonal climate forecasts if accessed at the right time and used well, are a potential tool that can assist pastoralists in coping and adapting to variable climate conditions [1] [2] [3]. Effective climate information services for the pastoralist communities involve improving information products, infor- mation services and delivery of those products. According to [4], pastoralists can best use climate forecast information when: it is interpreted at a local scale and includes information about timing beyond seasonal climate means; expressed accurately in transparent and probabilistic terms; and can be interpreted in terms of impacts and management implications. Effective use of climate infor- mation requires that raw climate information be translated into quantitative in- formation (water status, pest or disease risk, vegetation and yields) with uncer- tainties expressed in probabilistic terms [4]. Useful seasonal forecasts are those produced and disseminated with the user in mind as they aim at benefiting pro- duction if continuously and effectively used [1]. The forecasts should be com- municated in a manner that is comprehensible to the end users, and addressing the local needs of pastoralists for whom the seasonal rains have critical impor- tance [5] [6] [7].
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Impact of climate change on arid lands agriculture

Impact of climate change on arid lands agriculture

Adaptation tools to confront climate change impact Application of biotechnology for dryland agriculture Water stress caused by drought and salinity is the most important abiotic factor limiting plant growth and crop productivity in arid lands. Therefore, enhancing osmotic stress tolerance in crops grown under such conditions could provide a solution to this problem [22]. High genetic diversity exists for the components of abiotic stress response in genetic resources collected from the dry areas. This resource has to be properly evaluated and documented for future use. In addition to field evaluation in stressed environments, where the individual stress effect cannot usually be separated from the multiple- stress response, germplasm characterization in controlled conditions using morphophysiological criteria may reveal new evidence on different components of the abiotic stress response. Moreover, advances in molecular biology open new opportunities for understanding the physiolo- gical and genetic mechanisms involved in plant response to different stresses and provide tools for molecular screening and genetic engineering applications in crop improvement for increased abiotic stress tolerance. A thorough evaluation and exploration of genetic diversity existing in the crops’ wild relatives, primitive forms and landrace collections may be a strategic first step in germ- plasm development in the extensive arid drylands.
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Performance of canola (Brassica napus l.) genotypes under drought stress

Performance of canola (Brassica napus l.) genotypes under drought stress

No. of days from sowing to 50% flowering, plant height, number of branches, silica and seed/plant, oil and protein percentage, seed, oil protein yield/ha in both 2014/2015 and 2015/2016 seasons. Physiological growth indices were reduced under drought stress. This condition can be the most important environmental factor for the increase of total dry matter of control of irrigation [17]. A long term drought stress effects on plant metabolic reactions associates with, plant growth stage, water storage capacity of the soil and physiological aspects of plant. Canola is one of the most important oil crops in the world[1].The agricultural use of water in the world is more than 85% of total water use, moderate to severe intermittent or terminal drought is a common occurrence, and dry most crops cannot be grown without supplemental irrigation [2].Regularly, water deficit stress has detrimental effects on many processes in plants, which include reducing photosynthesis, accumulation of dry matter, stomatal exchanges, and protein synthesis that affects their growth stages[18,19].Grain yield showed high sensitivity to water deficit, proving that irrigation can definitely benefit crop grain yield [20]. Generally, plants respond to water deficit stress through developmental, biochemical and physiological changes and the type of the observed response depends on several factors such as stress intensity (SI), stress duration and genotype [21]. The stresses imposed at a later stage of development, reduce sink size, shorten the duration of seed filling and decrease the opportunity of crop to recover. Irrigation had more influence on seeds per pod than other yield components and water deficit influenced flowering to maturity stages more than other growth stages [5]. Water stressed conditions, those of rapeseed cultivars which were able to maintain their relative water content at high levels had a higher seed yield. Since water stress during seed development did effect on the sink size (seeds per plant), decreased source capacity led to reduction of seed weight [22].A similar result was reported by[3,4,5,6,23].
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Variability of Rainfall in the Semi-Arid Region of Brazil

Variability of Rainfall in the Semi-Arid Region of Brazil

The present analysis uses three techniques for characterization of the variability of the time series of rainfall in one location in the semi-arid region of Brazil: (a) Mann-Kendall test (MK), which has been widely used to detect trends in time series (Silva et al., 2015; Brito Neto et al., 2016), (b) Sen slope estimator, which calculates the rate of change if a significant trend is found (Silva et al., 2015), and (c) wavelet analysis, which can detect different frequencies of occurrence of events within a time series (Torrence & Compo, 1998; Santos et al., 2001; Santos & Morais, 2013).
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Has Ever Brahmaea Ledereri Rogenhofer, 1873 Inhabited the Colchis Refugium

Has Ever Brahmaea Ledereri Rogenhofer, 1873 Inhabited the Colchis Refugium

It should be stressed that among the relict fauna of Colchis, stenopaleoendemic B. ledereriis very problematic species for this region till today. A controversial information of its occurrence in perhumidhabitats of Colchis lowland and foothills arises chiefly from very old, questionable and with a large probability incorrect records. It seems to be doubtful the presence of this species along the eastern and southern Black Sea coast supposedly as a result of wrongly given locality in scientific literature [27]. Lepidopterologist Dr. E. Didmanidze in her’s monograph ‘The butterflies of Georgia’ [28] wrote: ‘In collections of the museum (Georgian National Museum – A.G.) only one specimen of B. ledereri is preserved, label of which is ‘1875’ (Romanoff’s collection)’. In another unpublished paper Didmanidze and Goginashvili [30] underline: ‘The first summarized information on Brahmin moths of South Caucasus is summarized by N. Romanoff (1885) [65] in which is indicated Brahmaealedereri from “Batumi province”.
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Storm wise sediment yield prediction using hillslope erosion model in semi arid abundant lands

Storm wise sediment yield prediction using hillslope erosion model in semi arid abundant lands

ment response simulation model (ANSWERS), to simple models requiring only a few key param- eters, the universal soil loss equation (USLE) and the revised universal soil loss equation (RUSLE) to predict runoff and soil loss. Soil erosion and sediment yield models therefore play a critical role in addressing problems associated with land management and conservation, particularly in selecting appropriate conservation measures for a given field or watershed (Wilson et al. 2001; Sadeghi et al. 2008). Thus, when evaluating the application of models in an area, it is very impor- tant to ascertain how reasonable the predictions are and how sound the assessment is. Soil ero- sion and sediment yield models can assist in the development of suitable policies and regulations for agricultural, rangeland and forestry practices. Some models, in spite of their strong theoretical base, may not be very suitable in the context of developing country situations such as those in Iran, where the detailed rainfall, topographic and other input data are not often available or are difficult to collect due to resource constraints (Sadeghi et al. 2008; Noor et al. 2010, 2012).
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Food security and human security in semi-arid regions: the impact of climate change on drylands, with a focus on West Africa

Food security and human security in semi-arid regions: the impact of climate change on drylands, with a focus on West Africa

– At local levels (and in the sub-humid zones in particular – Northern Ghana was studied in depth) only very minor, and sometimes even opposite correlations between rainfall and crop yields (and for all regions a lot of doubts about the reliability of both rainfall and crop-yield data, and about the usefulness of the ‘agro-climatological drought risk indicator’ that was devel- oped for this research).

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The potential role of sorghum in enhancing food security in semi-arid eastern Kenya: A review

The potential role of sorghum in enhancing food security in semi-arid eastern Kenya: A review

5794 Government policies: The arid and semi-arid lands of the world make up to over 40 % of the earth’s surface on which over one billion people depend for their livelihood (GoK, 2004). The arid and semi-arid lands in Kenya, which account for approximately 84 % of Kenya’s land mass, are characterized by low and erratic rainfall thus leading to massive crop failures when non-drought tolerant crops are grown (FAO, 2007; GoK, 2010). Acknowledging that 60 % of the ASALs inhabitants live below the poverty line (GoK, 2004), MoA (2009) called for the urgent need to diversify livelihoods by adopting traditional crops that are known to do well in the areas. Kenya’s agricultural sector is guided by the Agricultural Sector Development Strategy (ASDS), 2010-2020, which aims to increase agricultural productivity, commercialization and competitiveness of the sectors’ commodities and enterprises to achieve national food security, increase exports for foreign exchange earnings and create employment opportunities (Kilambya and Witwer, 2013). The ASDS classifies sorghum as one of Kenya’s main food crops, along with maize, rice, wheat, potatoes, cassava, vegetables and beans and puts forth several broad based strategies for increasing productivity and marketability of these crops. Before ASDS was developed, agricultural policy focussed on cash crops rather than staple food crops and even among food crops, more attention was paid to maize than other cereals.
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Modelling sustainability performance to achieve absolute reductions in socio-ecological systems

Modelling sustainability performance to achieve absolute reductions in socio-ecological systems

22 The system first experiences an excessive waste of resources led by overconsumption of products from the Jester’s and Noble’s baskets when resources are abundant (only 788 out of 1,300 resource units are consumed – 62%). This leads essentiality to a lower level than the pre-assigned minimum in year 19 (see Figure 9), so an intervention (e.g. market forces, government policy) of reducing the absolute consumption of these products is implemented, bringing the essentiality level back to 0.41 in year 20. Subsequently, as the ratio between impact and resources increases, a new intervention is needed to maintain the surplus within the 30% target (e.g. increased efficiency). Coincidently, this happens when the system’s essentiality level is below 0.4 (year 24). Consequently, the system forces a 10% reduction in both Noble’s and Jester’s baskets in year 25, alongside an additional reduction of the overall consumption of all baskets in the following order: Noble’s by 10%; Knight’s by 5%; Jester’s by 4%; Peasant’s by 1%. However, this happens after the baskets’ natural growth has occurred. Thereby, the only basket that grows the following year is the Peasant’s. The model shows that sometimes reducing Knight’s and Noble’s baskets (both containing high-impact products) only is sufficient to achieve Sueland’s targets for relative surplus and essentiality. Nevertheless, later, the system experiences the pressure of overall consumption from the Peasant’s and Jester’s baskets despite previous interventions. Although the products from both baskets have low individual impact, their overall absolute impact (consumption of resources) becomes collectively significant (Figure 10). Then, a new intervention is needed to control the consumption of all baskets simultaneously. Without this control and self-organisation based on both essentiality and impact, Sueland becomes unstable and approaches collapse. The overall results in Sueland with evolution of all baskets of consumption are presented in Table 2.
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The Effects of Capital Assets on Livelihood-Based Outcomes from Livestock Production among Youth in the Semi-Arid Lands of Kenya

The Effects of Capital Assets on Livelihood-Based Outcomes from Livestock Production among Youth in the Semi-Arid Lands of Kenya

In comparison to this study, Perret et al. (2005) found factors determining livelihoods in households in two communities in South Africa to comprise of gender, number of adult household members, skills, age and income. Apart from gender, the independent variables could represent natural/human capital, education, age, and economic/financial capital in this study. Iiyama (2006) estimated the effects of particular livestock livelihood patterns and household characteristics (capital assets) on livestock livelihood among a census of households in Keiyo District in Kenya. The study found a positive association between the dependent variable (livestock livelihood) and age, years of education of household head, years of participation in farmer groups (social networking), and household adult equivalent (human capital). The above variables are self-explanatory in comparison to the variables in this particular research. Years of participation in farmer groups in the above study could represent social capital. However, there was a negative relationship between livelihood outcome and specialization in off-farm activities. The study also found either positive or negative relationships among acreage of some crops, years of education of household head and distance to service centres on the one hand and specific types of livelihoods ranging from mainly staple crop farming to specialization in mainly traditional livestock keeping. Finally, Morse et al. (2009) found that a village with better credit (financial capital) endowment in Southern Nigeria had better livelihoods in agriculture including livestock production than did a village with a poor endowment for credit. The researchers concluded that credit, which is a form of financial, like in this study, can determine agricultural livelihoods subject to context.
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A Preliminary Study on Phytoplankton in Fresh Water-Lake of Gogi, Yadgir District, Karnataka

A Preliminary Study on Phytoplankton in Fresh Water-Lake of Gogi, Yadgir District, Karnataka

ABSTRACT: The present study was conducted in a semi arid region of Karnataka. The study discusses the phytoplankton diversity of the Gogi lake ecosystem. A standard methodology was followed in conducting to complete this study and samples were collected at different points from the lake ecosystem located at the core area of the proposed uranium mining site. Through a field survey, twenty one species of phytoplankton were recorded coming under four classes viz., Bacillariophyceae(8), Chlorophyceae(7),Cyanophyceae (5) Charophyceae (1) and twelve families and Fragilariaceae (4), Bacillariaceae (3), Zygnemataceae(3), Desmidiaceae (2), Oscillatoriaceae (2), Melosiraceae (1), Cladophoraceae (1), Scenedesmaceae (1), Microcystaceae (1), Nostocaceae (1), Phormidiaceae (1), Characeae (1). The data were collected over two seasons- March to May and September to November -2012. A total of 21 species were recorded from the study region of which 10 species were recorded during March to May, while 02 species from September to November, nine species were recorded.
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The effect of sugarcane stillage on the yield of butternut squash (Cucurbita moschata) grown at Tambankulu Estates, a semi-arid region in the north eastern Lowveld of Eswatini.

The effect of sugarcane stillage on the yield of butternut squash (Cucurbita moschata) grown at Tambankulu Estates, a semi-arid region in the north eastern Lowveld of Eswatini.

Abstract— An experiment was conducted to compare the effect of sugarcane distillery waste (stillage) and chemical fertilizer (N:P:K; 2:3:2 (22)) on the yield of butternut squash (Cucurbita moschata) grown under rain - fed conditions at Tambank ulu Estates in the north eastern Lowveld of Eswatini. The experiment was run for a period of two years. Three levels of fertilizer, 43 k g, 86 k g and 129 k g and three levels of stillage 296 liters, 585 liters and 876 liters were applied to plots each measuring 450 m 2 .Yield (fruit weight) and fruit size (fruit length and diameter) characteristics were measured at harvest. Data was subjected to the analysis of variance as per the design of the experiment. Yield and fruit length showed highly significant differences between the factors and levels whereas there were no significant differences in diameter. The highest yield of 960 g /fruit was recorded for stillage when applied at 585 liters followed by the highest concentration of 876 liters that yielded 950 g/fruit. The lowest level of fertilizer yielded the lowest yield of 721 g /fruit, with the two higher levels of fertilizer yielding the same 810 g/fruit. The control treatments with no fertilizer or stillage yielded the same lowest yield on average 550 g. The results of the experiment show that distillery waste (stillage) can be effectively used in the production of butternut squash in place of 2:3:2 (22) fertilizer.
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