As demonstrated by [12–16], crop productivity is highly dependent on climate and weather under rain-fed agriculture. Additionally, works carried out on crop- climate relationship around the globe have revealed that there is a considerable relationship between weather and climate on crop yields [9, 10, 16, 17]. In Nigeria, inter- annual rainfall variability has shown to be a major cause of stress to farming and crop production . In Argentina, Podesta, et al.  demonstrated that climate variability is strongly correlated with yields of maize, sorghum, and soy beans in the Pambas, Southern Argentina, as a result of El Nino Southern Oscillation (ENSO). The interaction be- tween increase in temperature and precipitation as a result of climate change is likely result in the loss of arable land due to decreased soil moisture, increased aridity, increased salinity, and ground water depletion . Overall, crop yields in Africa are projected to fall by 10–20 % to 2050 because of warming and drying, but there are places where yield losses may be much more severe, as well as areas where crop yields may increase . There is a need to determine how changing climate parameters plays a critical role in yields of maize in lower eastern Kenya’s ASALs to guide agricultural planning and enhance adap- tive capacity of small holder farmers.
In both short rains 2014 and long rains 2015, treatment combinations where 20kgN/ha was applied registered increased vegetative growth. This could be due to the fact that, application of nitrogen fertilizer to crops facilitates development of leaf area and lateral stem as a result of increased physiological indices. When nitrogen is applied to crops, it improves plant growth by increasing plant height and stem diameter at the end of the vegetative growth. In addition, nitrogen promotes plant growth, enhances leaf expansion and development (Okpara, 2000). The increased leaf area in treatment combinations with addition of nitrogen fertilizer agrees with the findings of Adeleke and Haruna (2012) who reported significant response of maize leaf as a result of nitrogen application. The increased leaf area shows the important role played by nitrogen in promoting vegetative growth because nitrogen enhances cell division and is required in protein synthesis. The rate of growth, development processes and final leaf size are negatively affected by higher temperatures as well as inadequate rainfall (Birch et al., 2003) hence, the differences in leaf area during short rains 2014 and long rains 2015. In addition, Asim et al., (2012) observed differences due to season, plant population and N fertilizer application on leaf area of plants.
The magnitude and trend of temperature and rainfall extremes as indicators of climate variability and change were investigated in the Arid and Semi-AridLands (ASALs) of Kenya using in-situ measurements and gridded climate proxy datasets, and analysed using the Gaussian-Kernel analysis and the Mann-Kendall statistics. The results show that the maximum and minimum temperatures have been increasing, with warmer temperatures being experi- enced mostly at night time. The average change in the mean maximum and minimum seasonal surface air temperature for the region were 0.74˚C and 0.60˚C, respectively between the 1961-1990 and 1991-2013 periods. Decreasing but statistically insignificant trends in the seasonal rainfall were noted in the area, but with mixed patterns in variability. The March-April-May rainfall season indicated the highest decrease in the seasonal rainfall amounts. The southern parts of the region had a decreasing trend in rainfall that was greater than that of the northern areas. The results of this study are expected to sup- port sustainable pastoralism system prevalent with the local communities in the ASALs.
Drought is a phenomenon that affects people’s economy and livelihood its effects can be countered through application of tools such as indigenous knowledge strategies and convectional strategies. Drought has been studied in Southern Africa for over a hundred years (Chenje and Johnson, 1996) and is recorded in text and in oral history dating back many generations. As noted by Springer (2004), drought is a recurrent phenomenon in dry land Africa. It has been observed that droughts are not always the same. Oba (2001) acknowledges that a drought does not always have the same impacts: some are localised while others are widespread; some affect grass production while others affect crops and these impacts are their countered through use of indigenous knowledge strategies or techno-science strategies. International relief is the first techno-science strategies that the government employ when drought strikes; however in addition, traditional knowledge systems (consumption of wild fruits, hunters and gatherers, storage of carcass from animals, storage of green leaves, eating wild root tubers, excavating salt from soils, migrating to central Kenya (barter trade), feeding on cattle hides and resources were incorporated in order to alleviate some of the adverse impacts of the drought (Kemp, 1990; Derman et al, 2007).
Woody vegetation in farmland acts as a carbon sink and provides ecosystem services for local peo- ple, but no macro-scale assessments of the impact of management and climate on woody cover ex- ists for drylands. Here we make use of very high spatial resolution satellite imagery to derive wall- to-wall woody cover patterns in tropical West African drylands. In arid and semi-arid Sahel, areas of more people are associated with more trees: mean woody cover is greater in farmlands (12%) than in savannas (6%), and likewise it is higher close to villages than further away. In sub-humid savan- nas of West Africa, woody cover is generally above 20% and decreases with increasing population density, but remains around 15% in farmlands, independent of rainfall. In the region as a whole, rainfall, terrain and soil are the most important (80%) determinants of woody cover, while man- agement factors play a smaller (20%) role. We conclude that agricultural expansion cannot general- ly be claimed to cause woody cover losses, and that observations in Sahel contradict simplistic ideas of a high negative correlation between population density and woody cover.
ABSTRACT: The present study was conducted in a semiarid 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.
this study suggested that these vegetation indices (NDVI and SAVI) and bare soil index (BSI) are helpful to detect the spatial distribution of SOM concentra- tions. In addition the statistical analysis results were useful to analyse measured values in the field and to understand the relationships that helped to estimated SOM concentrations by remote sensing data, although the pixel size (30 m × 30 m) used in the study area was relatively large with this area, which reflected the variation in SOM concentrations. The results of this study support the approach that the remote sensing data are useful to detect and investigate the environ- mental changes. This approach was used through mapping and determines the spatial distribution of SOM concentrations using spectral indices processed re- mote sensing data; techniques could be effective to monitor and manage soil.
T=8.868) seasonal variation. The EC values depend on the amount of dissolved materials in water . Higher electrical conductivity is noted in wet season than in dry due to leaching/infiltration of salts and nutrients. High chloride, phosphate and nitrate contents associated with agriculture increase electrical conductivity [27,28]. Variations in conductivity are due to slow flow rate, dissolved solids from agricultural farms, dilution by rainfall, ion exchange between sediments, water and submerged organic matter (Table 1) .
Although bricoleurs participate in shaping institutional arrangements through conscious and unconscious actions, previous sections indicate that bricolage remains an authoritative process that is shaped by historical patterns of access and accumulation and by corresponding power relationships among bricoleurs in present-day Kenya. Working visibly and invisibly through taken-for-granted social orders (Lukes 2005), power ‘shapes processes of bricolage through public decision-making, in everyday social interactions, and through broader social-structural factors’ (Cleaver et al. 2013: 175). For example, a widespread lack of familiarity with the economic principles of conservation among pastoralists means that people are inherently disadvantaged in public decision- making processes that impact their lives in community conservancies – even though NRT prioritises the design of democratic and transparent institutions that are said to protect the autonomy and ownership pastoralist communities have over communal lands and natural resources. For the sake of illustration, a member of Il Ng’wesi leadership described how the Board of Directors failed to adequately inform the community about the implications of value deprecation during one AGM, when trying to achieve a consensus on the fate of the conservancy’s Land Cruisers: ‘We tried to explain the idea
substrates. To clarify such significant issues, we have carried out researches to study the species composition of habitat plants, peculiarities of food specialization and alimentary behavior of termites of genus Anacanthotermes. For this purpose, we have observed certain peculiarities of food foraging by termite workers and studied the plant residue composition in alimentary cells in their natural habitats (desert and semi zone) adjoining with antropocenozis habitats, as well as pockets in termite-damaged buildings. In such a case, in addition to the species composition, we also investigated the quantitative content of the particular plant in alimentary cells.
The Brazilian semi-arid area is a tropical drought-prone region subject to a high inter-annual variability of its seasonal rainfall. Most of the region presents rainfall concentrated in only 2–4 months of the year. Annual average ranges from about 400 to 800 mm, with high coefficient of variation. The mechanisms of rainfall generation in the region have been well described, but climate change detection and projection are still challenging climatologists for decades (Markham, 1974; Oliveira et al., 2017; Marengo et al., 2017). Drought in Northeast Brazil—past, present, and future, Theoretical and Applied Climatology, 129, 1189–1200). The work reported in this paper uses a combination of techniques to characterize a long rainfall time series in the region towards detection of change in the pattern of variability.
associated with some theoretical considerations (theo- retical lognormal distribution law in general, all the space in the arid and semi-arid, allowed development of a cal- culation model of flood flow rates for ungauged streams in these areas). Operation requires only knowledge of the watershed area S. The value of the latter is determined by planimetry of the contour of the basin on a topographic map. The established method provided satisfactory re- sults and considered reliable for hydrological study in the absence of measurement data.
Successive droughts in Kenya compounded with other socio-economic constraints have led to persistently unstable and declining agricultural productivity in semi-arideasternKenya. This has given rise to the need to find coping strategies that would include growing alternative crops that are drought tolerant and thus suitable for the areas. Research in Kenya and elsewhere has shown that sorghum (Sorghum bicolor L. Moench) has the potential to end severe food insecurity in ASALs due to its tolerance to drought and ability to thrive under a wide range of soils. However, research and government policy in Kenya have shown a continual inclination to maize production in these areas though the crop is regarded a high risk option due to poor adaptation especially to the low rainfall. This paper reviews the potential of sorghum for improving food security in ASALs of Kenya with specific focus on semi-arideasternKenya. This will contribute to the ongoing debate to inform private and public sector policy and investments for increasing production of sorghum and other drought tolerant crops in the ASALs as a way of alleviating food insecurity and poverty.
cator present in most SQIs, relating its important role and limiting nature in biotic activity of terrestrial ecosystems. Other macronu- trients such as S and P are SQI indicators that could provide insight into the likelihood of successful reclamation efforts. For this study, indicators such as N and P were scored as “more is better” functions, but in more humid systems where runoff and aquatic eutrophica- tion are of greater concern, could be scored as optimum functions to penalize excessive amounts (Andrews and Carroll, 2001). Even in arid and semi-arid environments, excess N can lead to undesir- able changes in plant species composition (e.g., invasion by weedy species) or inhibit successional development. Somewhat surpris- ingly, the bioavailable (DTPA) form of micronutrients/metals such as Cu, Zn, Mn did not always correlate higher than total metals, but as mentioned previously, preference for other metals by that extractant may be interfering.
Arid and Semi-arid areas in central Tanzania are risky environments for those communities whose livelihood depends on natural resources. For example, due to insufficient and unreliable rainfall, agricultural production is characterized by frequent crop failures. Under situations of unpredictable rainfall timely access to key production resources is of critical importance, and one of such resources is farm labor. Focus group discussions and in-depth interviews in Mtumba, Makoja and Sejeli villages reveal that agro-pastoral communities in semi-arid Tanzania are socially bound and help each other in various aspects including sharing of grain and labor. Sharing of labor, for example, takes the form of work parties through which labor-deficit and vulnerable households are offered such assistance. These work parties operate under a system locally known as kulalika where able-bodied persons in the village are invited to provide labor support to the needy households. In this way, the food-insecure households are able to benefit from others simply by virtue of their membership to the community. These societal obligations have been playing an important role in cushioning the poorer households from sinking into deeper poverty.
area is in the lower part of the basin and has a south-easterly aspect. The valley comprises a catena of soil and vegetation, where Stipa tenacissima L. tussocks dominate the upper slopes, alluvial fans in the midslopes are populated mainly by Anthyllis cytisoides L. shrubs and the lower alluvial fans and drainage channels are dominated by Retama sphaerocarpa. L. Boiss. The soils have poorly developed pedogenic horizons and have been classified as Eutric Fluvisols and Eutric Regosols on the lower part of the fans and Eutric Leptosols on the upper fans and hillslopes (Puigdefábregas et al., 1996). An intensive field study of the Rambla Honda site (Puigdefábregas et al., 1996) found that these two soil groups have values of pH ranging from pH 6.5 to pH 8 and low values of electrical conductivity, cation exchange capacity and water holding capacity. From geographic and topographic interpretation of 30 years’ data from 166 meteorological stations installed in the Almería province, Lazaro and Rey (1991) estimated mean annual rainfall to be 300–350 mm and mean air temperature to be 15.5–16.5ºC. Rainfall occurs mainly in the autumn and winter between September and February and, normally, spring rainfall precedes a pronounced dry season from May to September. Rainfall has a high temporal and spatial variation.
sidered as the most rainfall-dependent of all human ac- tivities [6,7]. This vulnerability is enhanced for the less economically developed countries in the tropics that, in many cases, are exposed to high climate variability at different spatial-temporal scales. Of particular impor- tance and relevance to Kenya is the El Niño Southern Oscillation (ENSO) phenomenon that has been linked to climate variability in many parts of Sub-Saharan Africa where unique and persistent anomaly patterns have been detected in the rainfall over parts of southern Africa, eastern Africa, the Sahel region during periods of strong and persistent ENSO events [8-12]. The Sub-Saharan Africa is the only region world-wide where food produc- tion per capita has decreased over the last twenty years . Staple crop production occupies an important place in government policies, and one of the top priorities has become the stabilization of crop yields  in the con- text of the long-term drought of the last decades  and the uncertainties of the global climate change . With increased capability to forecast ENSO events well in advance [17-19], there has emerged a growing convic- tion and interest in using climatic information in deci- sion-making process, especially during crop production [20,21]. The assumption we explore here is that the
The study was carried out in Machakos Agricultural Training Centre (Machakos ATC) in Machakos County, during the 2011 short and 2012 long rain seasons. Machakos ATC is located at 1°54'S; 37°24'E and at 1,614 meters above sea level (Appendix 1). It is about 66 km South East of Nairobi. Machakos ATC lies in agro-ecological zone (AEZ) IV, with a bimodal pattern of rainfall, with a mean annual rainfall of 655 mm. The long rains fall between the months of March and May, with the peak in the month of April with an average of 273 mm while the short rains fall between the months of October and December with the peak in November with an average of 382 mm. The mean maximum temperature is 24.7°C while the mean minimum temperature is 13.7°C. The main type of soil is luvisols .