Semi-arid Agro-ecological Zones Research Articles

Restoring soil nutrient stocks using local inputs, tillage and sorghum-green gram intercropping strategies for drylands in Eastern Kenya

Soil macronutrient and micronutrient availability is particularly critical in semi-arid agro-ecological zones that are characterized by poor soil fertility and low rainfall regimes. An experiment was initiated in Siakago, Embu County to investigate the effects of tied-ridges, conventional tillage and input applications on soil nutrient fertility using a randomized complete block design with a split-split plot arrangement for 4 seasons (2018–2021). The treatments comprised of two main plot tillage systems, three cropping systems allocated to the sub-plots and four soil input management treatments assigned to sub-sub plots. ANOVA was used to test the effects of different treatments including tillage, crop system and soil fertility management using Genstat software. The data was also subjected to Principal Component Analysis procedures using R ("FactoMineR" and "factoextra") to examine the inter-relationship patterns between different soil fertility parameters and to reduce the data into independent soil fertility components. There were significant main effects due to crop system (Soil Mn), tillage and crop system interaction (SOC and TSN) and soil fertility management (TOC, TSN, Ca, Zn). Soil inputs significantly influenced soil carbon concentrations (p = 0.002), with the lowest values observed in the control (0.2 %), followed by sole fertilizer (0.35 %), manure + fertilizer (0.41 %) and the fully decomposed manure treatment (0.61 %). The soil-extracted manganese values recorded significant effects due to crop system, while soil-extracted Zn values were significant due to soil fertility management. Multivariate analysis results revealed the structure of soil nutrient distribution. Tied ridging can improve soil micronutrient availability through reduced soil erosion, conservation of soil organic matter, which can improve soil micronutrient availability. Soil conservation practices such as tied-ridging integrated with organic input applications can enhance multiple nutrient availability for improved crop performance and human nutrition in dryland farming systems where farmers lack soil moisture, technologies and resources to enhance crop nutrient availability.

Farmer Perception of Trees in a Semiarid Agroecological Zone

Trees in upland, semiarid agroecological zones typically require water efficiency due to low rainfall, cold and dry temperatures as in Niğde Province, Central Anatolia, Türkiye. This study quantitatively assessed farmer perception of ecosystem services and production advantage of trees in a semiarid zone. Forty-nine farmers in Niğde Province were surveyed. The survey evaluated two major factors: ecosystem services and production advantage using eleven indicators. The responses were grouped by age, gender, education, district class (rural and urban) and farm settlement (rural and urban) and were analysed by test of association (χ2) at P≤0.05. Most farmers had knowledge of trees in their environment and mainly supported the perspective that trees were important mainly for cultural and provisioning ecosystem services. However, they held the opinion that having trees on their farmer was a production disadvantage in a semiarid agroecological zone. Although there were no gender differences in their perspectives, there were significant difference by age, education, district class and farm settlement. Farmers in this semiarid agroecological zone seemed more interested in trees with evident ecosystem services and production advantage such as improved crop yield, water efficiency, weed and pest management, ease of harvesting as well as reduced overall production cost. By implication, trees with multiple benefits are required if further planting by farmers is to be encouraged for agroecosystem improvement. In addition, tree choice will be based on farmer perception of the benefits of trees for ecosystem services and production advantage and further research to identify and promote trees that benefits the widest range of agroecosystems.

Rainfall and Temperature Trends and Variability in Arid and Semi-arid Lands of Kitui County, Kenya

A study was carried out to analyse rainfall and temperature trends and variability in selected agro-ecological zones in Kitui County. Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) rainfall dataset was used while temperature data was obtained from the Climatic Research Unit gridded Time Series (CRU TS) dataset. The results indicated that there was a non-significant decreasing trend (p<0.05) in average annual rainfall in all the four agro-ecological zones (p<0.05) for a 30-years period (1988-2018) in the study area. A decreasing trend in March-April-May (MAM) seasonal rainfall trend was reported in the arid and semi-arid agro-ecological zones while an increasing trend was recorded in the transitional and semi-humid zones. For the October-November-December (OND) seasonal rainfall, a non-significant decreasing trend was reported in all the four agro-ecological zones. Additionally, a higher annual rainfall variability was recorded in the drier (arid) and wetter (semi-humid) zones compared to that in semi-arid and transitional zones. Moreover, the study established that there was a spatial variation in both MAM and OND seasonal rainfall variability and that rainfall variability was higher in the OND seasonal rainfall than that of the MAM seasonal rainfall in all the agro-ecological zones. With reference to temperature trends, a statistically significant increasing trend in annual and OND seasonal average maximum and minimum temperatures was reported in all the four agro-ecological zones. Further, the study noted a non-significant increasing trend in maximum and minimum temperatures for the MAM season in all the agro-ecological zones. In regard to temperature variability, the study deduced that there was low temperature variability compared to rainfall variability in all the four agro-ecological zones. The study recommends that location-specific rainfall and temperature analysis should guide planning and implementation of adaptation strategies for effective response to climate variability. Keywords: Agro-ecological Zones, Mann-Kendall Test, Coefficient of Variation, CHIRPS, CRU TS DOI: 10.7176/JEES/12-12-05 Publication date: December 31 st 2022

Regrowth Response and Nutritional Composition of Moringa oleifera to Cutting Back in Three Agro-Ecological Zones in South Africa

Moringa (Moringa oleifera Lam.) is a fast-growing tree that can reach a height of 3 m when left to grow naturally. Cutting-back management can enhance lateral branching, water use efficiency, regrowth, and leaf biomass production. Although M. oleifera can thrive in diverse ecological environments, including areas with high temperatures and drought where most crops cannot survive, the prevailing agro-ecological conditions can influence the tree’s response to cut-back and nutritional composition. An observation trial on the re-sprouting of M. oleifera after cutting back was conducted in three agro-ecological zones, including arid, semi-arid, and dry sub-humid regions. The soil analysis from the three agro-ecological zones showed variations, with the soil collected from the arid area recording the highest clay content (24.4%), nitrogen (8.14%), and phosphorus (168.2 mg/kg). The nutritional composition of the M. oleifera leaves in response to the cutting back was assessed. The trees planted in the arid region responded well to the cutting back by producing considerable new vegetative growth in the spring (13.4 sprouts averaging 21.50 cm in length) compared to semi-arid and dry sub-humid regions. The region’s climatic conditions favoured M. oleifera re-sprouting, and the stems did not die after cutting back. During the winter, the stems die back, sprout from the root collar area during more favourable weather conditions, and take longer to reach the harvestable stage. The leaves of M. oleifera harvested from the arid and dry sub-humid regions exhibited increased total fat, magnesium, sodium, phosphorus, potassium, and zinc content when compared to the semi-arid agro-ecological zone. In contrast, the calcium content of the leaves was higher in the semi-arid region than in the other agro-ecological zones. The influence of cutting back M. oleifera trees on biomass production and quality in varying agro-ecological zones requires further investigation to ensure that smallholder farmers use appropriate crop management practices in those regions for long-term, economically viable tree production.

Contributions of integrated soil fertility management (ISFM) to various sustainable intensification impact domains in Tanzania

CONTEXTThe implementation of integrated soil fertility management (ISFM) varies widely among farmers, from no ISFM to multiple computations of ISFM components (i.e., improved germplasm, organic resources, fertilizers, and local adaptations e.g., soil and water conservation (SWC)). There is no comprehensive report on farmers' use of ISFM components and their impact on sustainable intensification domains of productivity, economic, social, human condition, and environment and the associated variations across farmer fields and agro-ecological zones (AEZs). OBJECTIVEThis study 1) evaluated the current implementation status of ISFM by farmers in relation to the various ISFM components and 2) provided multi-dimensional multi-scale evidence of ISFM implications that can guide ISFM investments within SSA contexts, with a specific focus on Tanzania. METHODSWe used data collected from 1406 plots between 2013 and 2020 in semi-arid and sub-humid AEZs. The data are from farmer practices. The plots were grouped by the various combinations of ISFM components implemented and analysed using Tukey's test to examine the association of ISFM use with selected indicators within a domain. RESULTS AND CONCLUSIONSThe number of ISFM components used by farmers is higher in sub-humid (1 to 4) than in semi-arid AEZ (0 to 3). Except for SWC used by 40% of farmers in both AEZs, the proportion of farmers using improved seeds (95%) and manure (55%) in the sub-humid AEZ are more than double those using these ISFM components in the semi-arid AEZ. Productivity and economic benefits increase with the number of ISFM components at the expense of higher labour demand. Increasing plot-level ISFM benefits also translate to increased household-level whole-farm income but contributions to human nutrition are unclear. The contribution to SOC by increasing ISFM is insignificant, compounded by strong effects of slope position of the field. Differential access to resources, decision-making and control rights drive the number and choice of the specific ISFM components. SIGNIFICANCEUnderstanding of ISFM impacts across domains is essential to guide the scaling of ISFM in Tanzania and beyond and therefore recommended in future studies.

Abundance and distribution of plant-parasitic nematodes in tomatoes grown in a semi-arid agro-ecological zone in Tanzania

The abundance and distribution of plant-parasitic nematodes (PPN) on tomato plants grown in nine villages in the semi-arid zones of Singida and Dodoma in Tanzania were assessed in December 2020. Samples from soil and plant roots were evaluated for abundance, genera and distribution of PPN. Nematodes were extracted, counted and identified based on morphological descriptors. Ten genera of PPN were identified in both root and soil samples, with root-knot nematodes (RKN) being the most common PPN in all nine villages surveyed. The results showed that the abundance of RKN was significantly higher (p = 0.002) in soil than in tomato roots. Tutu and Chamkoroma villages had a significantly (p = 0.001) higher population density of RKN compared to other villages. In addition, RKN was associated with Penicillium and Aspergillus fungi, while the nematode genera Helicotylenchus, Aphelenchus, Scutellonema and Pratylenchus exhibited relationships with Alternaria and Fusarium fungi. The results also indicated that the abundance of RKN was significantly higher (p = 0.001) in sandy soil as compared to other types of soils. Inappropriate agronomical practices (e.g., no fallow, rotation of tomato plant with related crops) and poor phytosanitary measures were the major factors associated with high levels of abundance and distribution of RKN in soil.

Act of phosphorus on cell hydraulic state, K+ use efficiency and induction of positive correlations between yield and vegetative traits in chickpea

ABSTRACT Salinity is one of the most severe factors that can affect agricultural productivity worldwide particularly in the arid and semi-arid agro-ecological zones. Chickpea seedlings were grown in the field and subjected to different NaCl concentrations (0, 50 and 150 mM) and P application (90 kg ha–1). The experimental design was based on a completely randomised design with three replications. Salinity has disturbed the physiological and ionic state of cells by increasing stomatal resistance and significantly decreased growth and yield parameters (−66%). Under salinity, plant growth traits presented a negative correlation with yield components. P application had positive effect on growth parameters and physiological responses of the plants. Our results suggest that the tolerance of chickpea at (NaCl × P) combination is closely associated with ionic homeostasis and physiological activities of the plants. Phosphorus application allowed salinity tolerance by increasing leaf hydraulic statute, improvement of KUE and consequently enhanced grain yield of chickpea. (P × salinity) combination induced a positive correlation between vegetative traits and yield parameters like unstressed treatment. These results suggest that the use of suitable amounts of phosphorus fertiliser (i. e. 90 kg ha–1) to saline soil is a beneficial starter for plant development, yield components and rehabilitation of degraded soils.

Quantifying ecosystem service supply-demand relationship and its link with smallholder farmers’ well-being in contrasting agro-ecological zones of the East African Rift

Ecosystem service supply (ESS) has experienced a progressive decline due to degradation and increased ecosystem social demands (ESD). Quantitative studies assessing ecosystem services have mostly focused on ESS with limited attention to ESD and human well-being. To quantify, analyze and map the ESS, ESD, ESDR (Ecosystem Supply-Demand Ratio), weight-based smallholder farmers’ well-being (SWB), subjective satisfaction and change-driving factors, questionnaire surveys, semi-structured interviews and focus group discussions were used in contrasting agro-ecological zone (AEZ). The soil loss rate was estimated and mapped using the Revised Universal Soil Loss Equation (RUSLE) to evaluate the role of soil erosion control in regulating ESS. A five point Likert scale was employed to evaluate smallholder farmers’ well-being (SWB), subjective satisfaction, and the contribution of ESS to the components of well-being. A radar diagram was used to link ESS, ESD and SWB. The research was carried out between October 1, 2019 and March 30, 2020. The results showed a high supply of provisioning ESS observed in the humid AEZ, whereas low provisioning ESS was observed in the semi-arid AEZ. The observed ESS was not in accordance with ESD, and different change drivers affecting this balance were identified by smallholder farmers. Population pressure was identified as the main driver from smallholder farmers’ report and was confirmed by the multiple linear regression model. Due to the undulating topography, a high rate of soil loss was observed in the humid AEZ. Smallholder farmers in humid AEZ attached higher values for soil erosion control than those from the semi-arid AEZ. Of all indicators of SWB, income was assigned the highest weight while receiving low subjective well-being satisfaction levels in both humid and semi-arid AEZs. The overall relative contribution of ESS shows a medium relationship with all components of smallholder farmers’ well-being. Therefore, we suggest policies and strategies that would help to recuperate, and the continuous flow of ESS, control population growth, and improve well-being.

Oil yield from Euphorbia tirucalli as an alternative bioenergy source in Tanzania

Due to the worldwide increase in the demands for bioenergy sources to replace fossil fuels. Euphorbia tirucalli oil produced by stems and modified leaves (phylloclades) is a valuable liquid fuel as an alternative energy source for biofuel production. In this study, E. tirucalli oils were extracted from stem barks with varying stem girths (20cm–80cm) and fully grown apical phylloclades. Soxhlet apparatus was used in oil extraction according to Luque de Castro and García (2000). The percentage (%) oil yield was calculated by the weight of extracted oil to the total weight of the dried sample (20g). The study hypothesized that significantly higher oil yields would be obtained from larger stem girths than phylloclades of the same trees in different Agro-Ecological Zones (AEZs). Likewise, the difference in oil yields was higher in the Semi-arid AEZ than in the Southern highland and the Coast AEZs (p > 0.05). Results showed slightly higher oil yields from large stem girths [16.47% ± 0.34%/(20g) max ≡ 82.35% ± 0.34%/(100g) max] than phylloclades [15.7% ± 0.49%/(20g) max ≡ 78.5% ± 0.34%/(100gmax] in different AEZs. Oil yields from Semi-arid [82.35% ± 0.34%/(100g) max and 78.5% ± 0.49%/(100g) max] were slightly higher than Southern highland [79.0% ± 0.34%/(100g) max and 76.4% ± 0.49%/(100g) max] and the Coast [76.4% ± 0.34%/(100g) max and 70.25% ± 0.49%/(100g) max] AEZ. But the difference in oil yields was not significant (p > 0.05). Results exhibited increasing patterns in the percentage (%) oil yields from low (20cm) to larger (80cm) stem girths. High oil yields between stem girths (82.35%) and phylloclades (78.5%) suggest that E. tirucalli oil is suitable for liquid biofuel production as an energy source in Tanzania.

Spatial clustering of livestock Anthrax events associated with agro-ecological zones in Kenya, 1957\u20132017

BackgroundDeveloping disease risk maps for priority endemic and episodic diseases is becoming increasingly important for more effective disease management, particularly in resource limited countries. For endemic and easily diagnosed diseases such as anthrax, using historical data to identify hotspots and start to define ecological risk factors of its occurrence is a plausible approach. Using 666 livestock anthrax events reported in Kenya over 60 years (1957–2017), we determined the temporal and spatial patterns of the disease as a step towards identifying and characterizing anthrax hotspots in the region.MethodsData were initially aggregated by administrative unit and later analyzed by agro-ecological zones (AEZ) to reveal anthrax spatio-temporal trends and patterns. Variations in the occurrence of anthrax events were estimated by fitting Poisson generalized linear mixed-effects models to the data with AEZs and calendar months as fixed effects and sub-counties as random effects.ResultsThe country reported approximately 10 anthrax events annually, with the number increasing to as many as 50 annually by the year 2005. Spatial classification of the events in eight counties that reported the highest numbers revealed spatial clustering in certain administrative sub-counties, with 12% of the sub-counties responsible for over 30% of anthrax events, whereas 36% did not report any anthrax disease over the 60-year period. When segregated by AEZs, there was significantly greater risk of anthrax disease occurring in agro-alpine, high, and medium potential AEZs when compared to the agriculturally low potential arid and semi-arid AEZs of the country (p < 0.05). Interestingly, cattle were > 10 times more likely to be infected by B. anthracis than sheep, goats, or camels. There was lower risk of anthrax events in August (P = 0.034) and December (P = 0.061), months that follow long and short rain periods, respectively.ConclusionTaken together, these findings suggest existence of certain geographic, ecological, and demographic risk factors that promote B. anthracis persistence and trasmission in the disease hotspots.

Evaluation of Socio-Economic Drought Risk over Bundelkhand Region of India using Analytic Hierarchy Process (AHP) and Geo-Spatial Techniques

The Bundelkhand region situated in the central part of India has a long history of droughts. Although recurrent drought events in this region are controlled by the climatic variables, its unique soil, and physiography, the adversities associated with this devastating hazard largely depend upon the coping capacity of the local communities. Hence, estimating the socio-economic vulnerability of drought is necessary for adopting specific mitigation strategies to reduce the adverse impacts of drought. In this study, we explored the potentiality of geographical information system (GIS)-based analytic hierarchy process (AHP) for assessing drought risk in the Bundelkhand region from socio-economic perspective. The 10-day composite Satellite Pour l'Observation de la Terre Vegetation (SPOT-VGT) Normalized Difference Vegetation Index (NDVI) (1998–2013) dataset was used for computing the Vegetation Condition Index (VCI), a satellite-derived agricultural drought index for monitoring spatio-temporal dynamics of drought. NDVI maps of each year were assessed for mapping drought frequency. On the other hand, the socio-economic vulnerability of drought was estimated using five relevant parameters, viz. population density, marginalized population, cultivators, agricultural labours, and literacy rate, with employing AHP in a GIS platform. The pairwise comparison method was used for estimating the weights of each criterion. Most of the districts under hot semi-arid agro-climatic zone located in the Uttar Pradesh (UP) part of Bundelkhand are highly vulnerable to socio-economic drought, mainly due to high density of population and extensive agricultural activities. Out of the total area under highly vulnerable zone (27.8%), about 20% fall under semi-arid agro-ecological zone covering a large part of UP. The Madhya Pradesh (MP) part of Bundelkhand, located under the hot sub-humid agro-ecological zone, is comparatively less vulnerable to socio-economic drought. A substantial portion of this area is covered by forest, and the percentage of the total population involved in agricultural activities is relatively less. The study reveals that near about half of the total area is under threat to high (20.1%) and very high (29.1%) risk of socio-economic drought. Most of this drought risk zone falls under UP part of Bundelkhand. It is a matter of deep concern as this extensive fertile plain produces various cash crops, as well as cereals; therefore, high drought risk over this region needs a suitable strategy to mitigate the adversities of the hazard.

Euphorbia tirucalli stem bark and phylloclades’ oil quality variability and implication for energy use

Liquid biofuels have emerged as a worldwide alternative fuel with potential to replace fossil fuels. Due to their wide availability as derivatives of organic materials from plants, they have attracted much attention and investment in developing countries including Tanzania, as alternative sources of energy. This study examined effects of oil quality from stem barks and phylloclades of Euphorbia tirucalli trees of different girth sizes (viz., 20 cm, 30 cm, 40 cm, 50 cm, 60 cm, 70 cm, and 80 cm) from semi-arid, coastal, and southern highlands in Dodoma, Dar es Salaam, and Mbeya Southern highland, agro-ecological zones in Tanzania. Using Soxhlet extraction method, oils were extracted from E. tirucalli stem barks with different girth sizes while oils from phylloclades were extracted from matured apical phylloclades collected from shoots of E. tirucalli trees from which the stem bark samples had been collected. Oil yields were determined by measuring the weight of oil (g) by the total weight of sample extracts used (20 g), and the average oil yield on each sample was determined. Oil quality was evaluated as oxidative stability index (OSI), acid values (AVs), and percent free fatty acids (%FFAs). Their results were then compared with the European Union (EU) oil quality standard specifications prescribed in EN 14214 of 6 h, 0.5 mg KOH/g, max and 0.020 maximum wt% limits, respectively. Differences in the quality of E. tirucalli (stem bark and phylloclades) oil were analyzed statistically with paired-sample t test (two-tailed) using the SPSS 15.0 software package. Results showed that the difference in OSIs from stem barks were not significantly higher (3–5 h) than phylloclades (3–4 h) at the p > 0.5 level. Also, the difference in AVs and %FFAs from the stem barks (7.6–7.4 mg KOH and 3.8–3.6%) was not significantly lower than those from the phylloclades (8.4–8.1 mg KOH and 4.3–4.0%) respectively. The quality of oil from stem bark and phylloclades samples at different stem girth sizes semi-arid agro-ecological zone was not significantly higher than from southern highland and coastal agro-ecological zones, respectively. Thus, there were no significant differences in the quality of E. tirucalli oil (stem bark and phylloclades) among stem girth sizes in different agro-ecological zones. The AVs and %FFAs of oils from stem bark and phylloclades were higher than the recommended standards, while the OSIs were below the biofuel standard limit. High AVs and %FFAs reduced oil quality by producing considerably low OSIs values than recommended standards. Finally, the study concluded that E. tirucalli oil requires purification to reduce levels of AV and %FFA contents so that the oil becomes suitable for application as liquid biofuel for energy generations.

Seroprevalence of brucellosis in bovine herds using parallel diagnostic approach in the semi-arid agro-ecological zone in Pakistan

Seroprevalence of brucellosis in bovine herds using parallel diagnostic approach in the semi-arid agro-ecological zone in Pakistan

Effect of Cadmium Toxicity on Growth, Oxidative Damage, Antioxidant Defense System and Cadmium Accumulation in Two Sorghum Cultivars.

Heavy metal stress is a leading environmental issue reducing crop growth and productivity, particularly in arid and semi-arid agro-ecological zones. Cadmium (Cd), a non-redox heavy metal, can indirectly increase the production of reactive oxygen species (ROS), inducing cell death. A pot experiment was conducted to investigate the effects of different concentrations of Cd (0, 5, 25, 50, 100 µM) on physiological and biochemical parameters in two sorghum (Sorghum bicolor L.) cultivars: JS-2002 and Chakwal Sorghum. The results showed that various concentrations of Cd significantly increased the Cd uptake in both cultivars; however, the uptake was higher in JS-2002 compared to Chakwal Sorghum in leaf, stem and root. Regardless of the cultivars, there was a higher accumulation of the Cd in roots than in shoots. The Cd stress significantly reduced the growth and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2) concentration and malondialdehyde (MDA) content in both cultivars, but the Chakwal Sorghum showed more pronounced oxidative damage than the JS-2002, as reflected by higher H2O2, MDA and EL. Moreover, Cd stress, particularly 50 µM and 100 µM, decreased the activity of different antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). However, the JS-2002 exhibited higher SOD, POD and CAT activities than the Chakwal Sorghum under different Cd-levels. These findings revealed that JS-2002 had a stronger Cd enrichment capacity and also exhibited a better tolerance to Cd stress due to its efficient antioxidant defense system than Chakwal Sorghum. The present study provides the available information about Cd enrichment and tolerance in S. bicolor, which is used as an important agricultural crop for livestock feed in arid and semi-arid regions.

Seasonal profitability of soil and water conservation techniques in semi-arid agro-ecological zones of Makanya catchment, Tanzania

Soil and water conservation techniques are known to be profitable and widely promoted in sub-Saharan Africa. However, how their profitability vary across cropping seasons has not been fully explored. Thus, farmers are often faced with the dilemma of which agricultural technique(s) and/or combination(s) thereof to implement in which cropping seasons, and for which crops to maximize profits. In this paper, we investigated the profitability of two soil and water conservation techniques (terraces and borders) and compared them against the conventional flat cultivation in Makanya catchment Tanzania. Farmers in the area grow maize, beans, lablab and cowpeas over three cropping seasons (locally called masika, vuli and chamazi/kipupwe). Based on field survey of 382 farmers in 2019, it was found that aggregate yields were generally higher on fields with intercrop than those with monocrop with more than 0.5 ton/ha of total grain yields. Borders were generally more profitable (399 USD/ha) than terraces and flat cultivation during all three cropping seasons while flat cultivation was more lucrative during the masika than vuli season. Terraces was only lucrative for rainfed beans with Benefit Cost Ratio of 1.5 (208.7 USD/ha) and 1.2 (90.5 USD/ha) in masika and vuli respectively. Beans grown on borders during chamazi season had the highest profitability with Benefit Cost Ratio of 1.9 (399 USD/ha) compared to terraces and flat cultivation in all three cropping seasons. Whereas it was more profitable to grow maize, beans and lablab on borders, farmers could still realize appreciable profits by growing these crops as purely rainfed on flat cultivation especially during the masika season. It was concluded that in semi-arid zones, soil and water conservation techniques used in combination with other auxiliary practices such as irrigation, intercropping with legumes, mulching and manure application could greatly enhance profitability, but that depends on cropping season and market factors.

Legal and Policy Responses to Climate Change-induced Migration and Conflict: Insights from Nigeria

Nigeria has witnessed dramatic climate change impacts in recent years resulting in droughts and desertification in several northern states with fast receding grassland vegetation. This has induced migration especially by pastoral farmers from the semi-arid agro-ecological zones down south towards the Benue trough in search of lush green vegetation for their herds. The result is frequent strife and conflict between these nomadic groups and the sedentary farming communities in the rich Benue River Basin trough, resulting in loss of lives and properties. In recent years, the conflicts have assumed diverse political, religious and socio-cultural dimensions. Using an in-depth desk review of extant literature and policy documents, this paper appraises the policy and regulatory responses to these crises juxtaposing it with climate change mitigation and adaptation measures in Nigeria. We posit that the major causes of conflicts revolve around land ownership for settlement, grazing and farming; that the conflict has assumed ethno-religious colorations with great impact on the socio-economic wellbeing of the inhabitants and migrants. We realize that migration is a form of local level adaptation measure and conflict a directional reaction to these adaptation manifestations which need to be addressed holistically, and therefore propose a comprehensive, all-engaging approach to dealing with this problem by recognizing the cause and effect of this migration and conflict which is climate change. This will inform policy and strategic interventions to address the underlying causes (climate change), and not just the manifestations (migration and conflict). Keywords: Temperature changes, pastoralism, Farmers, Herdsmen, Desertification DOI: 10.7176/JLPG/99-01 Publication date: July 31 st 2020

Quantifying smallholder farmers’ managed land use/land cover dynamics and its drivers in contrasting agro-ecological zones of the East African Rift

Understanding the relationships between land use land cover (LULC) change and its drivers is essential for designing appropriate strategies for managing and conserving natural resources. This study examined the status, trends, and driving factors of smallholder farmers’ managed land use land cover (LULC) dynamics over the past 30 years (1988–2018) in two contrasting agro-ecological zones (AEZ) of highly-populated Southeastern escarpments of the Ethiopian Rift Valley. Changes in LULC were quantified by integrating field observation, remote-sensing data, and geographic information systems. Landsat images (1988, 2003, and 2018), household surveys (for drivers), and time-series data sources were used to generate the datasets. Results showed that: (1) the total area of 75,246.98 ha (33.79%) was non-linearly changed to various LULC classes. Cultivated land and agroforestry were dominant and increased in humid AEZ from 1988 to 2018. In the same period, waterbody, wetland/marshy, and grass/bushland were dominant and increased in semi-arid AEZ. Cultivated land increased remarkably at the expense of wetland/marshy, woodland, forestland, and grass/bushland in both humid and semi-arid AEZs, and, consequently, bare land was expanded by 1288% in the region. Agroforestry was highly persistent, while forestland was found to be highly susceptible to LULC change. (2) We observed that there was a spatial variation of drivers between humid and semi-arid AEZs. Population growth and landholding size (land fragmentation) were considered to be the main drivers of LULC changes in humid AEZ, while drought/rainfall variability and agricultural investment were the principal drivers in semi-arid AEZ. Ordinary least square (OLS) and binary logistic regression have also confirmed that population density and agricultural investment are the top drivers that significantly influence LULC classes. We conclude that unmanaged population growth, coupled with the continued expansion of cultivated land, have remarkably contributed to the expansion of bare land and decreases vegetation cover. Hence, improving farm-level participatory land-use management is required to recuperate the environment and smallholder farmers’ well-being.

English

This study assessed the impact of climate change and climate variability on food security in Kenya based on a sample size of 270 farmers randomly selected from semi-arid agro-ecological zones in Kenya. Both primary and secondary data were used in the present study. Data analysis was conducted using descriptive statistics and regression models. The results revealed that increase in temperature and reduction in rainfall had significant effect (p<0.01) on food security in Kenya. Increase in the amount of rainfall by 1 mm in the semi-arid areas enhanced food security by 0.01 kg while increase in maximum temperatures by 1°C reduced food security among households by 0.03 kg. Further, food security of Kenya is affected by increase in temperature and decline in rainfall. One unit increase in temperature would cause USD 3.9 million worth of value to become at risk as compared to USD 118,942 worth when rainfall decreased by 1 mm. Overall, the value at risk in the Kenyan economy is USD 112,351,112.46. Key words: Food security, climate change, temperature, rainfall, risk.

Water footprint and economic water productivity of sheep meat at farm scale in humid and semi-arid agro-ecological zones

Tunisia is prone to serious depletion of water resources that is threatening the sustainable agriculture development especially the livestock sector. The current study aimed to measure water footprint (WF) and economic water productivity (EWP) of sheep meat within twelve smallholder farms in two different agro-ecological zones in Tunisia; humid in northern and semi-arid in central Tunisia. A year-round monitoring of on-farm practices was performed using water meters and recording equipment’s installed in key locations in the target sheep farms. The water source green (rainwater) and blue (from irrigation) corresponds to (i) water used for feed production, (ii) sheep watering, (iii) cleaning and servicing water, (v) water used for crop and pasture yield production, and (iv) economic and production performance. Results show that farms in semi-arid region have the highest WF averaging 9.07 ± 0.48 m3/ kg sheep body weight (BW) of which 8.58 ± 0.46 m3/kg BW was green water and 0.49 ± 0.05 m3/kg BW was blue water. The lowest WF values were recorded in farms in humid region averaging 6.98 ± 0.3 m3/kg BW out of 6.79 ± 0.27 m3/kg BW was green water. Around 17.3% of the total WF of sheep meat was attributed to virtual water from off-farm feed production in farms in humid region. However, in farms in the semi-arid region, the proportion of off-farm feed exceeds 65% and they are imported from international markets or produced in northern region. Most of the total volume of water (99%) refers to the WF of feed production. Drinking water, service and cleaning water account only for less than 1%. The assessment of the EWP revealed that farms had an average gross margin per m3 of water of 0.49 ± 0.1 US $ and US$ 0.29 ± 0.04 in humid and semi-arid regions, respectively. The current results confirm that producing sheep meat in humid region is 20% more efficient in term of water use and create 60% more gross margin return per m3 of water than in semi-arid region. In addition, semi-arid region is more prone to the impact of climate change that humid region. Moreover, rangeland degradation coupled with the high density of sheep flocks in the semi-arid region, mean that farms in the humid region would profit more from sheep rearing.

Conservation Agriculture for Environmental Sustainability in A Semiarid Agroecological Zone under Climate Change Scenarios

Using the Mann&ndash;Kendall Test to analyze data from a survey of 400 farmers, this study compared the rate of adoption of conservation agriculture (CA) in two contrasting villages of Mnyakongo and Ugogoni locating in the Kongwa District, a semi-arid zone in central Tanzania. Results exhibited that the level of CA adoption was &lt;10% of the total households. The trend of CA adoption was determined at the coefficient of R2 = 0.95, 0.90, 0.68 and 0.57 for mulching, crop rotation, agroforestry and little tillage, respectively. Despite little tillage and crop rotation having high acreage under CA, the rate of mulching adoption was significantly higher than that of others. Furthermore, there were significant correlations between the CA adoption and crop yields or environmental sustainability (p &lt; 0.05). Maize, sorghum and millet yields were significantly greater under CA (1.7 t ha&minus;1) than no-CA (0.7 t ha&minus;1). Particularly, maize yields were increased from 1.3 to 2.3 t ha&minus;1 from 2000 to 2015 under CA when it was intercropped with legumes. The majority farmers (&gt;70%) asserted that CA had optimized their yields for both food and economic incentives. Thus, this study recommends the adoption of CA in the semi-arid agro-ecological zones.