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About this book

This 32-chapter volume represents the core of several oral and poster presentations made at the conference. In addition to Introduction and Conclusion sections, the book is thematically divided into 7 sections, namely, 1) Land Use and Farming Systems, 2) Effects of Climate Change on Crop Yield, 3) Soil Nutrient and Water Management for Carbon Sequestration, 4) Rehabilitation of Degraded Lands through Forestry and Agroforestry, 5) Management of Animal Production for Greenhouse Gas Emissions, 6) Smallholder Adaptation to Climate Change, and 7) Economic, Social and Policy Issues. It addresses these themes in the context of sustainable intensification (SI). It implies increasing agronomic production from the existing land while improving/restoring its quality and decreasing the C or environmental footprint. Simply put, SI means producing more from less.

Table of Contents

Frontmatter

Introduction

Frontmatter

Chapter 1. Sustainable Intensification for Adaptation and Mitigation of Climate Change and Advancement of Food Security in Africa

Africa is endowed with diverse eco-regions, climates, soils, landscapes and water resources. There were three regions of crop domestication in Africa. In addition to the Fertile Crescent in Mesopotamia, crop domestication also occurred in West Africa for yam and cassava, and in the Horn of Africa for teff, coffee, and the cucumber tree. With a land area of 30.2 million km

2

and population approaching one billion, Africa has a vast potential for agricultural and economic development. Africa’s population has been increasing rapidly since the beginning of the twentieth century. The population (million) was 120 in 1900, 221 in 1950, 796 in 2000, 867 in 2010, and is projected to be 1,081 in 2020, 1,804 in 2050 and 2,255 in 2100. Thus, food security has been a major concern since 1970s, and the Green Revolution by-passed the resource-poor and small landholders of the continent. There were 240 million food-insecure people in Africa (approximately 1 in 4) in 2012, 223 million in Sub-Sarahan Africa (SSA) in 2013, and the number is projected to increase by an additional 17 million (+6 %) by 2020. The problem is likely to be exacerbated by the changing and uncertain climate, because SSA is a vulnerable region, subject to the vagaries of projected climate change. Some project that as much as 65 % of the global total increase in climate-related hunger would occur in SSA. Climate change vulnerability in SSA is exacerbated by severe soil degradation, depletion of soil organic matter (SOM) and the negative soil nutrient balance of N, P, K at 40–50 kg/ha/year on continental scale. Soil degradation is the result of many factors, including wide spread use of extractive farming practices, poor structural stability and high erosion potential associated with harsh climates. Soils are highly prone to accelerated erosion by water and wind, crusting and hard setting, acidification and salinization. The rate of fertilizer input is low (~8 kg/ha) and less than 5 % of the potentially irrigable land is equipped for irrigation. Thus drought is a perpetual problem in SSA. A large yield gap exists between attainable and national average yield of most crops grown in the region. Recommended management practices (RMPs) for soils include conservation tillage, mulch farming, cover cropping, using integrated nutrient management and manuring, growing nitrogen fixing legumes and trees, and applying bio-solids to enhance SOM reserves. Important among water management techniques are water harvesting and recycling, micro irrigation, recycling city water and grey water. The strategy is to create positive C and nutrient budgets and improve soil quality and its rhizospheric processes. A wide spread adoption of RMPs can improve soil quality, enhance input use efficiency, increase climate change resilience, narrow the yield gap and sustain agronomic production. Sequestration of C in soils and vegetation (trees) can also mitigate climate change by reducing net anthropogenic emissions. Payments to land managers for provision of ecosystem services, such as C sequestration, water quality improvement, and bio diversity enhancement, can create additional income streams and promote the adoption of RMPs. Sequestration of C in agro-ecosystems is a win-win situation. It will enhance agronomic production and sustain the use of soil and water resources while improving the capacity of smallholder agriculture to adapt to climate change and off set anthropogenic emissions.

Rattan Lal

Land Use and Farming System

Frontmatter

Chapter 2. Geopedological and Landscape Dynamic Controls on Productivity Potentials and Constraints in Selected Spatial Entities in Sub-Saharan Africa

Soil-landscape relations play an important role in the agricultural production systems of Sub-Saharan Africa. As the demands on elevated agricultural productivity grows in the face of increasing demographic pressure and the adverse impacts of global environmental change, we must identify socio-ecological production landscapes that are resilient to environmental changes. This paper analyses a spectrum of spatial and non-spatial datasets covering soil, terrain, land use, and geology in a GIS environment to derive spatial entities that inform the production potentials and constraints of East Africa. Landscape analysis, premised on the geopedological and elevation constructs, culminated in a spatial coverage of lowlands (40 %), plateaux (46 %), highlands (11 %) and mountains (3 %) across the East African region. Regional-level analysis reveals spatially variable soil typologies dominated by Cambisols (24 %) and Ferralsols (13 %). In these geomorphic landscapes and soil types, there are two outstanding anthropogenic threats to productivity: soil erosion and land use/cover conversions and transformations. These must be delicately tackled with site-specific tailored interventions that not only recognize geopedological landscape sensitivity, but also the inherent social systems.

Yazidhi Bamutaze

Chapter 3. Land Degradation and Soil Carbon Pool in Different Land Uses and Their Implication for Food Security in Southern Ethiopia

This paper provides an overview of land degradation and a summary of carbon and nitrogen pooling under different land uses in Southern Ethiopia. The conversion of pristine vegetation to cultivated lands depletes soil organic matter (SOM). In this paper, we: (i) explore the extent of the land degradation in Ethiopia; (ii) assess changes in the stocks of soil organic carbon (SOC) and nitrogen (N) in soils under the chronosequences of 12–50 years of traditional agroforestry (AF) and crop fields (F); (iii) discover the effect of plantations on the state of SOC and N; (iv) consider the litter production and in situ decomposition rate under plantations; and (v) evaluate the effect of plantations on soil quality in Gambo District. The rates of soil erosion in Ethiopia hover around 16–300 Mg ha

−1

year

−1

. The SOM loss was estimated to be 1.17–78 Tg year

−1

from 78 M ha of cultivated and grazing lands. The SOC stock under the chronosequence of 12–50 years of AF and F land uses varied from 28.2 to 98.9 Mg ha

−1

, or 12–43 % of the stock, under the NF. The plantations accrued from 133.62 to 213.73 Mg ha

−1

, or 59.1–94.5 % SOC of that under the NF. Litter fall was higher under broad-leaved compared with the coniferous plantations. The soil quality index was high for NF and

Juniperous procera

. Plantations may represent the best option for mitigation of the increasing atmospheric CO

2

and sustenance of land productivity. Nevertheless, NF should be protected from further conversion to other land uses to maintain healthy ecosystem functions.

Ambachew Demessie, Bal Ram Singh, Rattan Lal

Chapter 4. Land Use Impact on Soil Organic Carbon and Total Nitrogen Storage in a Typical Dry Land District in Tigray, Northern Ethiopia

Soil serves to store and cycle soil organic carbon (SOC) and total nitrogen (TN), which are essential for functioning terrestrial ecosystems. We measured soil organic carbon (SOC) and total nitrogen (TN) concentrations and stocks in three soil depths (0–15, 15–30, and 30–50 cm) for four different land uses, namely, rainfed cultivation (RF), agroforestry (AF), open pasture (OP), and silvopasture (SP), with five replications within a watershed in Ethiopia. OP land use showed higher SOC concentration in the 0–15 cm layer. The highest SOC concentration (12.6 g kg

−1

) in 0–15 cm depth was found in OP land use system. Except for SP (8.6 g kg

−1

), it was significantly higher (p < 0.001) than those in other land use systems. The concentration of TN across land uses in different depths followed a trend similar to that of SOC. Thus, the highest TN concentration in 0–15 cm layer in OP (1.1 g kg

−1

) was significantly higher (p < 0.01) than that in RF land use. OP also had significantly higher (P < 0.05) SOC and TN stocks in the 0–50 cm depth than those in RF. The results of this study suggest that conversion of RF into grass and tree-based land uses has large technical potential for SOC and TN sequestration.

Aweke M. Gelaw, Bal Ram Singh, Rattan Lal

Chapter 5. Climate Risk Management Through Sustainable Land Management in Sub-Saharan Africa

Empirical evidence has shown that farmers can adapt to climate change by using sustainable land and water management (SLWM) practices that provide local mitigation benefits, reducing or offsetting the negative effects of climate change at the level of the plot, the farm, or even the landscape. However, adaptation to climate change using SLWM practices in sub-Saharan Africa (SSA) remains low. This study was conducted to examine the impact of government policies on adaptation to climate change.

Kenya and Uganda in East Africa and Niger and Nigeria in West Africa were used as case studies. The selection ensured that the transboundary sites had comparable biophysical and livelihood characteristics and that the major difference between the sites across adjacent countries was the policies in each country. The study used a variety of data sources, including satellite imagery data, focus group discussions, and household- and plot-level survey data to determine how land users have responded to climate change and the effects of their responses on agricultural productivity, climate-related risks, and carbon stock.

Each of the four case study countries offers success stories that enhance adaptation strategies. While Kenya’s policies have strongly supported agricultural research and development as well as an agricultural market environment that has offered incentives to farmers to adopt SLWM, neighboring Uganda has implemented government decentralization and a new land tenure policy, both of which have contributed to the rise of stronger local institutions that offer opportunities for improved community resource management. In West Africa, Nigeria has long supported irrigation development and recently focused on small-scale irrigation that has increased agricultural production and reduced production risks in the drier northern states. Even though such irrigation programs were not implemented as part of an adaptation to climate change, they have helped farmers to adapt well to climate change. Niger also offers a good example of tree planting and protection, which was successful due to a relaxation of the forest code and the passing of the Rural Code, which gave land users more rights to trees on their farms and thereby contributed to the regreening of the Sahel. Hence, in all the countries, we see the influence of policies that have influenced the adoption of SLWM and the response to climate change in general, policies that show promise for scaling up.

Scaling up these success stories requires public investment to raise awareness and provide the technological support required for these often knowledge-intensive practices. The relative success of Kenya in promoting soil conservation and fertility measures suggests that large-scale extension programs can be effective but require long-term commitment, something that is absent in the common practice of project funding. The long-term extension project in Kenya was also supported by a large number of nongovernmental organizations (NGOs) active in land management. These organizations not only complement an extension program but also inject a degree of innovation that can lead to the generation of improved SLWM practices. Facilitating the linkages among all development organizations and with research organizations would serve to enhance the scaling-up process.

Some SLWM practices may require special attention. Specifically, irrigation is touted as an essential ingredient for increased productivity and for climate change adaptation in Africa by numerous organizations, including the New Partnership for Africa’s Development (NEPAD). Irrigation faces many of the same challenges as other SLWM practices but given that irrigation development in SSA is the lowest in the world, there is greater need for capital investment (in water storage or distribution) to enhance more effective adaptation to climate change.

Ephraim Nkonya, Frank Place, Edward Kato, Majaliwa Mwanjololo

Chapter 6. Effects of Land Cover Changes on Soil Organic Carbon and Total Nitrogen Stocks in the Eastern Mau Forest Reserve, Kenya

This study analysed the variations of soil organic carbon (SOC) and total nitrogen (TN) stocks under natural forests (NF), plantation forests (PF), bamboo forests (BF), and croplands that had been converted from such forests (i.e., NF2C, PF2C, and BF2C) in the Eastern Mau Forest Reserve using field, laboratory, spatial, and statistical techniques. The results displayed significant differences in SOC and TN stocks between NF and NF2C (

p <

 0.0001), and between PF and PF2C (

p <

 0.0001). For instance, the surface soils (0–15 cm) of NF had the highest SOC and TN stocks (71.6 and 7.1 Mg ha

−1

, respectively), while NF2C had the lowest (35.4 and 3.5 Mg ha

−1

). Similarly, the subsurface soils (15–30 cm) of NF had the highest stocks (55.7 and 5.6 Mg ha

−1

), while NF2C had the lowest (32.5 and 3.2 Mg ha

−1

). This reflects a decline in both SOC and TN stocks by about 51 % in the surface and about 42 % in the subsurface soils after NF conversion. There were also significant differences in SOC and TN stocks (

p <

 0.05) between the surface and subsurface soils of different land cover types. The stocks decreased as soil depth increased. This trend suggests that (i) forest-to-cropland conversions are undermining the ecosystem’s capacity for carbon sequestration, and (ii) subsurface soils have potential for carbon sequestration. SOC and TN losses in the croplands may be mitigated by adopting best management practices (BMPs), especially agro-forestry. These findings are useful for designing sustainable land management (SLM) and carbon sequestration projects.

Kennedy O. Were, Bal Ram Singh, Øystein B. Dick

Effects of Climate Change and Crop Yield

Frontmatter

Chapter 7. Soil Erosion Hazard Under the Current and Potential Climate Change Induced Loss of Soil Organic Matter in the Upper Blue Nile (Abay) River Basin, Ethiopia

This chapter assesses soil erosion hazard in the Upper Blue Nile (Abay) River Basin of Ethiopia, where the Grand Renaissance Dam is under construction, under the existing land resource use practices and climatic conditions as well as a scenario of future potential change in soil organic matter (SOM) concentration by the projected climate change. The Revised Universal Soil Loss Equation (RUSLE) model was used to estimate the soil loss rate. To capture potential effects of SOM loss by climate change on soil erodibility, specifically due to increase in temperatures, arbitrary scenarios of 20 % and 50 % reduction in SOM concentration were considered. The use of dekadal rainfall from 1,634 points representing a 10 × 10 km spatial resolution is the key element of this study. Estimates show that the antecedent mean annual soil loss for the Basin was 16 Mg ha

−1

year

−1

. Scenario analysis of SOM reduction by 20 % and 50 % resulted in mean annual soil erosion rates of 17 Mg ha

−1

year

−1

and 19 Mg ha

−1

year

−1

, respectively. The mean annual soil loss for the 50 % SOM reduction scenario exceeds the estimated maximum soil loss tolerance level of the country (18 Mg ha

−1

year

−1

). Total soil loss from the Basin was estimated at 280 Tg year

−1

, (Tg = teragram = 10

12

g = 1 million Mg), compared with 300 Tg year

−1

and 332 Tg year

−1

for the 20 % and 50 % SOM reduction, respectively. The northeastern, eastern and southern parts of the Basin (~25 % of the total area) are prone to very severe soil erosion risks (>30 Mg ha

−1

year

−1

). The lowest soil erosion rate (<10 Mg ha

−1

year

−1

) was observed in the southwestern, western and northwestern parts of the Basin. The sediment delivery ratio of the Basin was estimated at ~50 %. The sediments transported from the Basin are already affecting reservoirs and irrigation canals in the downstream countries of Sudan and Egypt, and will also adversely affect the Grand Ethiopian Renaissance Dam. Using the estimated soil erosion rates, the Basin was divided into priority categories for conservation intervention. Sub-basins prone to severe soil erosion risks are Beshilo, Welaka, North Gojjam, Jemma and Muger, and these need immediate attention for soil conservation and watershed management planning.

Daniel Mengistu, Woldeamlak Bewket, Rattan Lal

Chapter 8. Climate Change and Crop Yield in Sub-Saharan Africa

Recent scientific evidence shows that crop yields in many Sub Saharan Africa (SSA) countries are likely to be severely affected by climate change. Reliance on rainfall in this region increases the vulnerability of cereal systems to climate change and variability. In large parts of SSA, maize (

Zea mays

L.) is the principal staple crop, covering a total of nearly 27 M ha, and yet maize yields remain the lowest in the world, stagnated at less than 2 Mg ha

−1

. Calculated and simulated analyses for SSA show that crop yields will decline by more than 10 % by 2055. The effect of climate change on crop yields is mainly attributed to: increased frequency of extreme events; effects of elevated CO

2

(where studies project crop yield increases of 5–20 % at 550 ppm CO

2

); interactions of elevated CO

2

with temperature and rainfall as well as with soil nutrients; and increased vulnerability to weed competition, insect pests, and diseases. However, several studies show that rainfall and water availability limit agricultural production more than temperature in SSA. The projected rainfall would increase by 2–4 % in Eastern Africa, but decrease by 5 % in Southern Africa during the main crop growing seasons. Temperatures are likely to increase throughout SSA by 2050, but the combination of increasing temperatures and low seasonal rainfall in Southern Africa suggest this region will be particularly vulnerable. Some of the crop models used for predicting the effect of climate change on yields are limited by their ability to predict effects of climatic events that lie outside the range of present-day variability. In addition, comparisons between models for the same setting have sometimes given differing results. This review paper shows that, for most of the SSA countries, the data required for assessing long-term effect of climate change on crop yield are lacking, that most of the models do not cater to assessment at the household level, and that no single approach can be considered as adequate. Therefore, a clear need exists for collaboration among different scientific disciplines for the development of agriculture in SSA in a changing climate.

Charles K. K. Gachene, Anne N. Karuma, Mary W. Baaru

Chapter 9. Factors in Smallholder Farmers’ Vulnerability to Climate Change Impacts in the Uluguru Mountains, Morogoro, Tanzania

This study assessed factors in smallholder farmers’ vulnerability to climate change impacts in the Uluguru Mountains in the Morogoro Region, Tanzania. To this end, the study first determined the smallholder farmers’ awareness and perception of climate change and identified adaptation options preferred by the farmers. A combination of methods, including focus group discussions, key informants interviews, participant observations, and household surveys, were used for data collection. The results indicate that smallholder farmers had a poor understanding of climate change issues, but their knowledge was enhanced by a project that was implemented collaboratively by Sokoine University of Agriculture (SUA) and Professionals for Fair Development (GRET), a French non-governmental organization (NGO). The adaptation strategies preferred by smallholder farmers included terracing, planting fruit trees, the rehabilitation of micro-irrigation canals, and fish farming. However, a noticeable disparity in preference between men and women was observed. The results further revealed that smallholder farmers were vulnerable to climate change and variation due to their limited knowledge of climate change risks, low level of literacy, limited access to climate information, and absence of farmer-based organizations to facilitate better access to credit and market services. The study concludes that crucial factors for smallholder farmers’ vulnerability to climate change in the Uluguru Mountains are access to information and resources, road and market infrastructure, and smallholder farmers’ organization.

Amon Z. Mattee, K. R. Mussa, Dismas L. Mwaseba, C. P. Mahonge, J. V. Nsenga

Chapter 10. Using Climate and Crop Simulation Models for Assessing Climate Change Impacts on Agronomic Practices and Productivity

Due to heavy dependence on rain-fed agriculture, most developing countries, particularly Sub-Saharan Africa including Tanzania, are likely to suffer negatively to the impacts of climate change. Future climate projections predict a 2–4 °C rise in temperature by 2100, and rainfall is expected to decrease especially in the interior regions. As a result, grain production is predicted to decrease, and particularly maize, which is the main cereal crop, will experience up to 33 % decrease in yield. To capture the impacts of climate change relevant to agronomic productivity, site-specific assessments are needed to inform adaptation options. This study investigated the impacts of climate change on maize production using outputs of Global Circulation Models (GCMs) and crop simulation models. Current conventional and recommended agronomic practices in Same District, Kilimanjaro region, Tanzania were simulated by Agricultural Production Systems sIMulator (APSIM) model using long-term and projected future climates. Four maize cultivars commonly used in the study area

Situka

,

Kito

,

Sc401

, and

TMV1

were used. Results show a yield decline of 13 % for cultivar

Situka

, and an increase of 10 % and 15 % for cultivars

Sc401 and TMV1

, respectively, in the long rainy season (March-May) under the conventional practices. A yield increase of 10 % is projected for

Sc401

and

TMV1

and a decrease of 10 % for

Situka

and 45 % for

Kito

cultivars under recommended practices. The short rainy season (October–December) is projected to register yield increases of between 75 and 146 % for all cultivars under both conventional and recommended agronomic practices. Generally, the study has revealed that the yield of only some maize varieties are expected to decrease due to a 2 °C rise in temperature and only during the long rainy season. Therefore, there is a need for more site-specific climate change studies that evaluate several crop varieties grown in the area.

Winfred B. Mbungu, Henry F. Mahoo, Siza D. Tumbo, Frederick C. Kahimba, Filbert B. Rwehumbiza, Boniface P. Mbilinyi

Soil Nutrient and Water Management for Carbon Sequestration

Frontmatter

Chapter 11. Microdosing of Mineral Fertilizer and Conservation Agriculture for Sustainable Agricultural Intensification in Sub-Saharan Africa

Microdosing of mineral fertilizer and conservation agriculture (CA) have been identified as promising approaches for sustainable agricultural intensification. Microdosing has been found to give a very good economic return for a small investment in fertilizer. Microdosing has created a demand for fertilizer in rural areas of Mali, and the local business community has responded by providing fertilizer in their shops. The agro-ecological advantages of microdosing are connected to adaption to climate change, highly efficient use of water, inhibition of the parasitic weed

Striga hermonthica

and earlier harvest. The possible problem that microdosing can lead to nutrient mining is exaggerated. The effect of CA on yield and soil properties is dependent on how it is practiced. Mulching has been identified as the key ecological component of CA, as it reduces soil surface temperature, improves water infiltration and helps control weeds. The major problem associated with mulching is the free roaming of animals in the dry season, which removes all the crop residues left on the soil surface. Grazing management must therefore go hand in hand with development of CA. It is concluded that microdosing and CA can be combined. Microdosing can give short-term benefits in terms of yield increase, while CA will build soil quality, which is of vital importance for the long-term sustainability of agricultural systems.

Jens B. Aune, Adama Coulibaly

Chapter 12. Approaches to Reinforce Crop Productivity Under Rain-fed Conditions in Sub-humid Environments in Sub-Saharan Africa

Smallholder farming in much of Sub-Saharan Africa is rain-fed and thus exposed to rainfall variability. Among the climate variables, rainfall is projected to decline and have an overriding effect on crop productivity. With little opportunity for supplementary irrigation for the majority of farmers, a plausible strategy to maintain crop production under water-limited conditions includes balanced nutrient management for enhancing efficiency of use of limited soil water. Co-application of judicious rates of organic and mineral nutrient resources, particularly including the use of phosphorus (P) on P-limited soils, will facilitate development of an extensive crop rooting system for efficient exploration and capture of soil water, especially at a depth >0.8 m. This chapter explores case studies across Eastern and Southern Africa where various soil water conservation and nutrient management approaches have been used to gain ‘extra miles’ with limited available soil water. Firstly, an approach is described that varies nitrogen (N) fertilizer application across growing seasons, by adjusting N application rates to match current season rainfall trends. The approach offers opportunities for farmers to increase crop productivity to >6 t ha

−1

in high agro-potential areas, compared to a ceiling of 4.5 t ha

−1

for the fixed fertilization model, while minimizing economic losses due to investments in N fertilizer during drought years. Secondly, we deal with the subject of fertilization across nutrient gradients, where a poor agronomic N use efficiency of <18 kg grain kg

−1

of applied N is demonstrated for soils with <0.4 % organic carbon, compared with >35 kg grain kg

−1

of N applied when soil organic carbon >0.5 %. Thirdly, the conservation agriculture (CA)-nutrient management nexus is examined, where maize yields in farmers’ fields with CA alone were barely 0.5 t ha

−1

compared to an average of 2.5 t ha

−1

for CA combined with fertilizers. Fourthly, a novel system that involves intercropping two legumes with contrasting phenology for enhanced cropping system functioning is described. Finally, an approach that can be used for co-learning with farmers on soil fertility management principles for risk management is presented. The data lead to the conclusion that the ‘doubled-up’ legumes system results in reduced fertilizer requirements for cereal crops grown in sequence, which benefits yield stability over time. Variable use of N fertilizer according to season quality and more tailored targeting of nutrients are vital for profitable investments in fertilizers in Africa. The Africa RISING project in Eastern and Southern Africa is currently harnessing some of these principles as vehicles for intensification of smallholder farming systems.

Regis Chikowo, Shamie Zingore, Justice Nyamangara, Mateete Bekunda, Joseph Messina, Sieglinde Snapp

Chapter 13. Effect of In Situ Soil Water Harvesting Techniques and Local Plant Nutrient Sources on Grain Yield of Drought-Resistant Sorghum Varieties in Semi-arid Zone, Tanzania

Aridity is becoming a key threat to more than 500 million people who depend on agriculture for their livelihood in semi-arid areas worldwide. Climate change represents a significant threat to current agricultural production, and consequently to farmers’ livelihoods in sub-Saharan Africa. The compounded effects of climate change, population pressure and change in dietary demands will further threaten fragile natural resources and accelerate land degradation processes. Poverty and hunger are still characteristics of sub-Saharan African countries in specific areas frequently hit by drought including the central zone of Tanzania. Typical characteristics of these areas are periodic to frequent dry spells that lead to crop failure, food shortage and lasting poverty. In Tanzania, the central regions of Dodoma and Singida are frequently threatened by drought that causes crop failure. In Dodoma, Singida and Tabora, 45–55 % of the households are food insecure. The purpose of this work was to investigate the effect of combining selected soil water harvesting techniques and locally available plant nutrient sources (FYM and urea-treated local phosphate rock,

Minjingu Mazao

) on the grain yield of early maturing and drought-resistant sorghum varieties (

Wahi

and

Hakika

). The trials were conducted at Mbande village, Kongwa District and Ikhanoda village, Singida Rural District in Tanzania. A split-split plot design setup was used in this study. The main plots were tillage methods, which were infiltration pit (PI), tied-ridging (TR) and flat cultivation (FC). The sub-plots were the fertilizers, which were farmyard manure and

Minjingu Mazao

, and the sub-sub plots were the two sorghum (

Sorghum bicolor

L. Moench) varieties:

Wahi

and

Hakika

. Data were subjected to one-way analysis of variance. Treatment differences were separated using least significant differences (LSD) at p < 0.05, p < 0.01 and p < 0.001. At the Ikhanoda study site, when

Minjingu Mazao

was applied, the

Wahi

grain yield was significantly (p < 0.05) higher in PI (2,414 kg ha

−1

) and FC (1,126 kg ha

−1

) than in TR treatment (648 kg ha

−1

). In contrast, with

Hakika

, TR significantly (p < 0.05) outperformed other water harvesting methods with the highest grain yield (3,199 kg ha

−1

). The PI treatment recorded the highest grain yield (2,789 kg ha

−1

under

Wahi

and 3,223 kg ha

−1

under

Hakika

) when FYM was applied at 5 t ha

−1

. The grain yield of both varieties under FYM and all water harvesting techniques, including FC, did not differ significantly (p > 0.05). However,

Hakika

under PI had the best yield (3,223 kg ha

−1

) while

Wahi

under FC registered the lowest yield (2,573 kg ha

−1

). In the absence of FYM or

Minjingu Mazao

, the grain yield showed the following trend: FC (1,660 kg ha

−1

, 1,863 kg ha

−1

) > PI (1,234 kg ha

−1

, 1,387 kg ha

−1

) > TR (875 kg ha

−1

, 930 kg ha

−1

) for

Wahi

and

Hakika

, respectively. At the Mbande site, the

Wahi

variety had a significantly higher grain yield (p < 0.05) in the FC treatment (1058.6 kg ha

−1

) than TR (543 kg ha

−1

) and PI (320.3 kg ha

−1

) when FYM was applied. With the application of 5 tons ha

−1

FYM, the

Wahi

variety gave a significantly (p < 0.05) higher grain yield (1320.2 kg ha

−1

) in the TR treatment but the lowest in the FC treatment (476.6 kg ha

−1

). With the

Hakika

variety, the grain yield was higher (1773.4 kg ha

−1

) in TR and FC than in PI (890.6 kg ha

−1

). The superiority of the FC treatment in the absence of external nutrient input is attributed to topsoil that is slightly richer in nutrients compared to the rest of the treatments in which the poorer subsoil is part of the root zone. External nutrient input might have compensated for nutrient deficiencies and thus attenuated the treatment differences. This study demonstrated that in the absence of external sources of plant nutrients such as FYM and

Minjingu Mazao

, FC performed better than PI and TR. With external nutrient input, the grain yield varied due to water harvesting practice and site. At Ikhanoda, PI was superior to the other treatments while at Mbande, TR outperformed the other treatments. The outcome of the use of rainwater harvesting technologies ought to be applied in well-characterized fields in terms of physical and bio-chemical soil characteristics for better results.

Method Kilasara, M. E. Boa, E. Y. Swai, K. P. Sibuga, Boniface H. J. Massawe, E. Kisetu

Rehabilitation of Degraded Land Through Forestry and Agro-Forestry

Frontmatter

Chapter 14. Restoration of Degraded Lands Affected by Salinization Process Under Climate Change Conditions: Impacts on Food Security in the Senegal River Valley

With the progressive degradation of agricultural lands due to climate change, there is a need to document how land responds to management practices and their resilience to salinization processes. Salinization is a problem associated with agriculture and it constitutes a constraint which results in inappropriate practices. In addition, agriculture intensification and changes in temperature and precipitation patterns expected from climate change are likely to affect the salt-water balance of fragile ecosystems. Information on the relationship between climate change and salt-affected land salinization processes is scattered. Little has been done to highlight the most affected or vulnerable areas or to promote practices that can be used to adapt agricultural production in fragile areas to climate change. This study will contribute to food security and reducing the stress on ecosystems. This study relates land management practices to lands degraded and salinized due to climate change. Several land management practices have been used to evaluate the level of restoration of degraded lands. Changes in temperature, relative humidity, evaporation, solar radiation, and soil temperature combined with agricultural management practices driven by different cropping systems were used to evaluate the best and most adapted management practices for degraded lands that are dedicated to agriculture. Results suggest that regular seasonal cropping under irrigation might be recommended for degraded lands to assure sustainable food security.

Mateugue Diack, T. Diop, R. Ndiaye

Chapter 15. Tree Integration in Banana-Based Cropping Systems: A Case Study of Jinja, Uganda

Bananas are a major staple crop and a source of livelihood for over seven million people in Uganda. However, productivity in many parts of the country has been declining over the past few years owing to low soil fertility as a result of nutrient mining among other causes. This has a negative effect on both household income and food security. Actual yields range from 10 to 25 Mg/ha/year compared to a potential yield of 70 Mg/ha. A study was conducted to assess the benefits and limitations of integrating trees in banana-based (

Musa

spp.) cropping systems in Uganda; 53 % of the farmers attributed the low yields to soil fertility decline, 25 % high fertilizer prices, and 49 % low availability of fertilizers.

The incorporation of coffee and

Ficus

trees in banana plantations was found to have several beneficial effects. The N content under the tree canopy (1,624 kg/ha) was significantly higher than outside the canopy (877 kg/ha) in the top soil. Similarly, the organic matter levels were found to be higher when trees were incorporated in the cropping systems. This was attributed to the high organic C levels under the tree crown (23.2 g/kg) compared to 16.2 g/kg outside the crown.

Ficus

was found to have other beneficial effects. According to 85 % of respondents, these included its use as fodder. The shading effects of the trees helped to modify soil temperatures, which were found to be beneficial in the dry season.

Ficus

trees also provided shade for coffee trees hence modifying the microclimate. However, optimal spacing between the trees and the bananas needs to be determined in order to avoid unnecessary competition for nutrients and water.

This paper also discusses other shortcomings of the current land development strategies and identifies potential research needs. The active participation of the farmer in banana-based research is also highlighted for the sustainable use of the land resource.

Lukman Nagaya Mulumba

Chapter 16. Management Practices/Techniques Commonly Used in Niger Republic, West Africa

Niger republic, a Sahelian country with about 75 % of its area covered by the Sahara desert, continues to face high land degradation due to human activities and climate change. This land degradation, which is mainly manifested in the forms of soil crusts, gullies, sand dunes, siltation of water bodies such as River Niger, Lake Chad, and many other inland lakes, has many consequences including loss of productivity and biodiversity that lead to desertification and poverty. To reverse the trend of land degradation, Niger Republic, with the support of its partners, has undertaken many actions on land restoration. These have helped to rehabilitate more than 250,000 ha of degraded land and develop local knowledge and skills that can be used worldwide. Sustainable land management practices and agroforestry techniques used in Niger to rehabilitate these degraded lands include tree planting (shelter belt, living fence, urban planting) and construction of anti-erosive infrastructures using soil and water conservation techniques such as: rock dikes, half-moon, stabilization of gullies and river banks, sand dunes stabilization, and protection and promotion of natural regeneration. Benefits derived from these techniques include reduction of wind and water erosion, production of fuel wood and fodder, increased soil fertility, food security and carbon sequestration, recovery of wild species, improvement of local population revenues and livelihood, and local knowledge and skills in land restoration.

Mohamadou Habibou Gabou, Abdou Maisharou

Chapter 17. Soil Organic Carbon Stocks of the Kitonga Catchment Forest Reserve, Tanzania: Variation with Elevation

The carbon stored in forest soils has significant implications in global climate change processes. Few studies on soil organic carbon (SOC) have been reported from the Miombo woodlands. This study was conducted to assess SOC at different elevations in selected sites of the Miombo woodlands of the Kitonga Catchment Forest Reserve (KFR). Ten sampling points located at different elevations were selected and georeferenced. At each point, three randomly selected mini-soil pits were excavated for the collection of soil samples. The soil samples from different soil depths, up to 60 cm, were collected and composited from the mini-pits in three replicates. The SOC was analyzed using the wet oxidation method. The mean SOC stock increased from 15.2 to 26.7 Mg ha

−1

at 928 and 1,548 masl, respectively, for the Fluvisols, and from 11.3 to 44.9 Mg ha

−1

at 1,258 and 1,598 masl, respectively, in Cambisols. Conversely, SOC stocks decreased with elevation in Leptosols, and the trends were 28.9–12.5 Mg ha

−1

at 831 and 1,083 masl, respectively. The mean topsoil (0–15 cm) SOC stock was 26.3 ± 5.0 Mg ha

−1

in Fluvisols, 20.6 ± 7.0 Mg ha

−1

in Leptosols, and 19.4 ± 7.0 Mg ha

−1

in Cambisols. The SOC stocks in the 15–30 cm soil depth decreased by 57 %, 41 %, and 31 % compared to those of the top soils (0–15 cm) in Leptosols, Fluvisols, and Cambisols, respectively. The relatively higher amount of SOC stocks in the surface horizons justifies the need for conservation of the intact vegetation of the Miombo woodlands in the KFR.

H. B. Shelukindo, E. Semu, B. M. Msanya, Bal Ram Singh, P. K. T. Munishi

Management of Animal Production for Greenhouse Gas Emissions

Frontmatter

Chapter 18. Alternative Goat Kid-Rearing Systems for Improved Performance and Milk Sharing Between Humans and Offspring in Climate Change Mitigation

Intensification of livestock production reduces the amount of land required to sustain a livestock unit and frees up the land necessary for carbon sequestration. Transforming the goat sector from meat only to a dual-purpose system with both milk and meat is reported to increase food production per unit of land. Dairy goats have been widely adopted among smallholders in Tanzania and are now gaining popularity in Malawi. High mortalities due to poor feeding of goat-kids have been identified as a major challenge and therefore kid rearing systems of different milking systems for dairy goats and use of different creep feeds and alternate rearing systems for meat goat on Likoma Island were evaluated.

In study I, the methods used were (a) suckling one teat twice daily and milking the other teat; (b) suckling in daytime only and morning-milking of dams, and (c) early weaning and bottle-rearing using goat’s milk. In study II, three different types of locally available creep feed supplements were evaluated for animals grazed on unimproved rangeland. The third study qualitative differences in kid rearing systems for local goats, with or without milking, were evaluated on Likoma Island in Malawi using a semi-structured questionnaire. In study I, kid growth rates, ranging from 62 to 76 g/day did not significantly differ; one teat milking provided the most milk for human consumption and artificial rearing was found to be the most labor intensive and therefore not recommended under small-holder conditions. Goat farmers on Likoma Island preferred faster kid growth to more milk for human consumption. It is concluded that successful kid rearing systems should address farmer milk utilization and kid growth and evaluate locally available feeds for creep feeding and dam feeding.

Fanny C. Chigwa, Lars Olav Eik, G. C. Kifaro, V. C. M. Muhikambele, Daniel E. Mushi

Chapter 19. Reducing GHG Emissions from Traditional Livestock Systems to Mitigate Changing Climate and Biodiversity

Climate change (CC) directly impacts the economy, ecosystems, water resources, weather events, health issues, desertification, sea level rise, and even political and social stability. The effects of CC affect different groups of societies differently. In Tanzania, the effects of CC have even acquired a gender dimension, whereby women are viewed as more vulnerable than men because of socioeconomic and historic barriers. CC is largely caused by anthropogenic activities, including those that increase the concentrations of greenhouse gases (GHGs) in the atmosphere. Recent findings indicate that the livestock sector is responsible for 18 % of GHG emissions measured in the CO

2

equivalent. Moreover, some gases emitted by livestock have higher potential to warm the atmosphere than CO

2

and have a very long atmospheric lifetime. Methane (CH

4

) has 23 times the global warming potential (GWP) of CO

2

, whereas nitrous oxide (N

2

O) has 296 times the GWP of CO

2

. It is now estimated that the atmospheric concentrations of CH

4

and N

2

O are increasing at a rate of approximately 0.6 % and 0.25 % per year, respectively. Cattle may emit CH

4

from enteric fermentation equivalent to 2–12 % of the ingested energy, whereas produced manure can emit N

2

O up to 1.25 % of its weight. The estimated total CH

4

and N

2

O emissions from Tanzanian ruminants stand at 26.17 Gg and 0.57 Gg, respectively. In this paper, we first very briefly review emissions of GHGs from different livestock production systems in Tanzania with the view of identifying the main hot spots. Then, we concentrate on the available adaptation options and the limitations on the adoption of such adaptation options in Tanzania. Emission of these GHGs per unit product varies with the level of intensification, the types of livestock kept, and manure management. Intensification of livestock production reduces the size of the land required to sustain a livestock unit and frees up the land necessary for carbon sequestration. In Tanzania, such intensification could take the form of the early harvesting and storing forage for dry-season feeding. The advantage of this intervention is twofold: young harvests have higher digestibility and emit less CH

4

when fed to ruminants than mature lignified forage; use of stored roughage in the dry season will reduce the desertification of rangeland and deforestation that occur when livestock search for pastureland. Dry-season supplementation of ruminants with energy and protein-rich diets will reduce CH

4

emission. The chemical treatment of crops byproducts will increase the crops’ digestibility and reduce CH

4

emission from ruminants. Crossbreds of indigenous and exotic breeds are more efficient converters of feed into products like meat and milk, with less GHG emitted per unit product. The use of manure for biogas production will reduce the emission of both CH

4

and N

2

O into the atmosphere. Shifting from liquid to solid manure management has the potential to reduce CH

4

emissions. Most of these interventions, however, are not cost neutral – enhancing awareness alone will not lead to their widespread adoption. In the absence of subsidies, the adoption of these interventions will depend on the relative cost of other options. Although some traditional livestock systems in Tanzania are already coping with the impact of CC, such efforts are handicapped by inadequate resources, poor coordination, and implementation of competing measures.

Daniel E. Mushi, Lars Olav Eik, A. Bernués, R. Ripoll-Bosch, F. Sundstøl, M. Mo

Chapter 20. Feeding Strategies for Improved Beef Productivity and Reduced GHG Emission in Tanzania: Effect of Type of Finish-Feeding on Carcass Yield and Meat Quality of Zebu Steers

The study was conducted to elucidate the effects of grazing on natural pastures alone versus total stall feeding on growth performance, carcass characteristics, and meat quality of Tanzania Zebu steers. In this experiment, 27 steers were distributed into 2 dietary groups; stall feeding (SF) and natural pasture feeding (NP). Animals in SF were totally confined in the feedlot with free access to wheat straw as a basal diet and supplemented with concentrate mixture, while those in NP were freely grazed on natural pasture. Animals in SF displayed 500 g higher average daily gain (ADG) and four units higher dressing percentage than those in NP. The marbling scores, hind leg length (HL), and hind leg circumference (Circ.) was also statistically higher among animals in SF than among those in NP (P ≤ 0.05). Moreover, postmortem temperature was observed to decline more rapidly among animals in NP than in SF. However, postmortem carcass pH, meat tenderness, meat color, meat chemical composition (moisture content, dry matter (DM), ash, Ether Extract (EE), and Crude Protein (CP)) were independent of concentrate supplementation (P > 0.05). The high performance of the SF group in terms of ADG, dressing percentage, and intramuscular fat deposition was associated with utilization of high energy rich concentrate and improved utilization of wheat straw following concentrate supplementation. It was concluded that, in addition to the manipulation of the animals’ body through nutrition, other factors such as reducing pre-slaughter stress and appropriate ageing of meat should be manipulated to improve the meat quality of indigenous Zebu cattle.

Ismail Saidi Selemani, Lars Olav Eik, Øystein Holand, Tormod Ådnøy, Ephraim J. Mtengeti, Daniel E. Mushi, Sørheim Oddvin

Smallholder Adaptation to Climate Change

Frontmatter

Chapter 21. Enhancing Resilience of Food Production Systems Under Changing Climate and Soil Degradation in Semi-arid and Highlands of Tanzania

Soil resources play a central role in food security as agriculture continues to depend on soil to feed the growing population. The objective of this paper is to review the status of food security, extent of soil degradation, and management options under changing climate to ensure food security in the semi-arid and highlands areas of Tanzania. Increased food production was realized over a 10-year period in the country, attributed to the increase in cultivated land at the rate of 0.38 million ha/year. Food productivity decreased at the rate of 0.04 t/ha/year despite higher average food production after (18.00 t) than before (13.75 t) introduction of fertilizer subsidy. Soil degradation due to soil loss of 9.2 Mg/ha/season accounted for 24 % yield reduction in semi-arid areas, and soil loss was 32–163 kg/ha/year in highlands. Poor residue and tillage practices contribute to low productivity even when inputs are used. Nutrient mining is widespread with 88 % of soils deficient in nitrogen, 71 % with low phosphorus, 29 % are low in potassium, and 67 % are deficient in Zn in semi-arid areas. In highlands, 92 % of soils are deficient in phosphorus while 24 % are deficient in zinc. Almost all soils in semi-arid and 58 % of soils from highlands had low soil organic carbon. Salinity increased in almost all irrigated areas in semi-arid regions without salinity management. Thus, climate smart agriculture to simultaneously conserve soil, harvest and conserve rainwater, and integrate nutrient management should be used to increase productivity and enhance agriculture resilience to changing climate.

Nyambilila A. Amuri

Chapter 22. A Risk-Based Strategy for Climate Change Adaptation in Dryland Systems Based on an Understanding of Potential Production, Soil Resistance and Resilience, and Social Stability

Climate change is expected to increase the intensity and temporal variability of storm events in many areas while reducing their frequency, resulting in increased runoff, and drought frequency and severity. Soil degradation can exacerbate these impacts by reducing both infiltration and plant-available water holding capacity. Therefore, an understanding of soil resistance and resilience to degradation is necessary to target climate change adaptation investments where they will have the largest impact. This paper (1) reviews key concepts necessary to understand the dynamic relationships between climate change adaptation, soil resistance and resilience, and social stability, and (2) provides a strategy for maximizing return on climate change adaptation investments in drylands based on an understanding of soil and ecosystem resilience. The strategy includes seven steps, which are completed for each landscape unit in the context of the surrounding landscape: (1) Determine current potential productivity based on soils, topography, and existing climate conditions. (2) Determine future potential productivity based on soil, topography, and climate change scenarios. (3) Rank landscape units based on predicted change in potential productivity. (4) Determine risk of land use change. (5) Determine degradation risk with and without land use change. (6) Rank each landscape unit based on degradation risk with and without land use change. (7) Determine priorities for climate change and soil conservation investments. The strategy described here can be applied on multiple scales to address a wide variety of objectives. We conclude by suggesting that climate change adaptation resources allocation decisions include consideration of soil resistance and resilience.

Jeffrey E. Herrick, Adam Beh

Chapter 23. Use of Conservation Tillage and Cropping Systems to Sustain Crop Yields Under Drought Conditions in Zambia

The adverse effects of climate change on agricultural productivity have been evident for several years. Factoring climate change risks into critical decision-making is crucial for ensuring food security. Zambia has adopted conservation agriculture in response to two real threats to food security: loss of animal draught power due to livestock disease, and poor yield and occasional total crop failure due to frequent drought. The main threats from climate change arise from the stresses and shocks caused by high temperature and erratic rainfall, such as shorter growing seasons and water deficit in the soil profile. Under these conditions, conventional tillage practices and a few of the current cropping systems have proved inappropriate and inadequate for sustaining high crop yields. For instance, the national long-term average yield of maize under conventional agricultural practices has declined by 40 %. In this paper, I discuss conservation tillage (CT), soil quality management, and crop and cultivar options for adapting to and mitigating the adverse effects of climate change with the aim of ensuring stable yields. In drought years, employing CT involving deep ripping (15–30 cm), leaving crop residues on the soil surface, and using an appropriate maturity cultivar have consistently resulted in yield increases of 30–70 % (with maize showing the highest yield increase) compared with conventional practices. Early planting is an important factor, and 45 % of the yield increment could be attributed to it. Both physical (plow pans) and chemical (subsoil acidity) impediments to soil depth can greatly restrict root growth into the subsoil and severely restrict the volume of soil exploited and, in turn, the quantities of nutrients and water available to the crop. This investigation shows that adopting a technology package of appropriate culture practices, and seed and crop management can potentially reduce the negative effects of drought and stabilize crop yields.

Obed I. Lungu

Chapter 24. Sustainable Intensification of Maize and Rice in Smallholder Farming Systems Under Climate Change in Tanzania

Maize and rice are major staple food crops in Tanzania and constitute 31 % and 13 %, respectively, of total food production. The current productivity of the two crops (1.6 t/ha and 2.3 t/ha, respectively) will not match with the increasing demand for food created by population growth unless there is an expansion of cultivated land or intensification measures are imparted to smallholder farmers, who produce nearly 90 % of each crop in the country. Expansion of cropped areas is limited by increased land-use pressure. Under smallholder farming the same land is continuously cultivated without proper input to replenish the removal of nutrients with crop harvesting, which leads to a decline in the subsequent crop yield. The situation is exacerbated by the effects of climate change. The smallholder farmers lack agro-inputs, information and extension services, and are faced with erratic rainfall. Therefore, a public-private partnership comprising two public universities and two multinational companies dealing with fertilizer and crop protection was initiated in December 2010, aiming at demonstrating sustainable intensification of maize and rice production in smallholder farmers’ fields. Five farms for maize and four for rice crops in different villages and districts were selected, and their soils were sampled for physical and chemical analysis. Two treatments were imposed on each farm. The treatments were farmers’ practice (control) and improved practice, which includes the proper use of fertilizer, crop protection inputs and recommended crop seed variety. Generally, the soils of most farms were acidic with low phosphorus, potassium, magnesium, sulphur, copper and zinc values. On average, maize and rice grain yield 14 % moisture content ranged from 2.5 to 5.4 t/ha in farmers’ practice and 6.6–8.5 t/ha in improved practice. Maize and rice stover/straw biomass ranged from 5.33 to 15.4 t/ha for improved practice and 2.11–9.13 t/ha for farmers’ practice. It can be concluded that improved agricultural practices, including plant nutrition, plant protection, improved seeds and conservation agriculture measures (e.g., crop residue recycling), enable sustainable intensification of smallholder crop production. Crop yields are improved, soil fertility is maintained, and family income is increased all at the same time. Therefore, public-private partnerships are needed to put this concept into practice and to make knowledge and technology available to smallholder farmers.

Ephraim J. Mtengeti, Frank Brentrup, Eva Mtengeti, Lars Olav Eik, Ramadhani Chambuya

Chapter 25. Smallholder Adaptation to Climate Change in Semi-arid Areas of Tanzania: Experiences from Iramba and Meatu Districts

A study of the impact over the past 30 years of climate variability and change on smallholders’ farming systems and adaptation strategies was conducted in three villages of Iramba and Meatu Districts, Tanzania. Both districts involved in the study lie within a semi-arid zone. Crop failure and food insecurity are common characteristics to all three villages in the study. Personal descriptions of climate change and meteorological data confirmed that rainfall patterns have become increasingly inconsistent and unpredictable and that the length of dry spells has increased. Crop growing seasons have been shortened by 1 month or more. The availability of ground water, particularly from rivers, has increasingly become seasonal, compared to the situation in the 1970s and 1980s. These results have all impacted negatively on rain-fed agriculture and livestock production systems and increased the vulnerability of smallholder livelihoods, because of their high dependency on natural resources. Almost 80 % of the households in both study areas were characterized as poor. Households are becoming increasingly vulnerable to multiple factors including drought, price fluctuations, increased population pressure, loss of soil fertility and decreased productivity, scarcity of farm and grazing land, water and fuel wood shortages, loss of ‘ngitiri’, increased conflicts over pastures, crop and livestock diseases, male out-migration, and increased labor burdens on women. Responses to climate change impacts varied by the socioeconomic condition of households and gender. Coping and adaptation mechanisms to which farmers have resorted include selling labor, land leasing, shifts in crop and livestock systems, use of early maturing, drought and disease resistant varieties, small scale irrigation systems, gardening, increased use of crop residues as animal feed, diversification to off farm activities, and petty trade.

Gry Synnevåg, Samwel J. Kabote, Carolyne I. Nombo, Delphina Mamiro, Amon Z. Mattee

Economic, Social and Policy Issues

Frontmatter

Chapter 26. Exploring the Meso-level of Agricultural Carbon Finance Projects

Agricultural carbon schemes are intended to mitigate climate change and provide carbon revenues while facilitating sustainable development. This is accomplished through practices which simultaneously increase yields, improve resilience, and store carbon, such as agroforestry, reduced tillage, and grasslands management. Proper monitoring, reporting, and verification of these activities enable the generation and sale of carbon credits. However, this requires linking smallholder farmers at the micro-level with carbon credit buyers operating at the macro-level. These vastly distinct scales are bridged by intermediaries operating at the meso-level, which influence, incentivize, monitor, and aggregate production decisions made by smallholders. Multiple levels of intermediaries may be involved, often including external initiating agencies, such as non-governmental organizations, as well as local-level units, such as farmer groups or local governance associations. Here, we frame evaluation of agricultural carbon schemes with this three-tiered approach, and describe parameters for appraising participation and power, as well as assessing financial feasibility, verifications and market linkages. This is applied to two case studies: The Kenya Agricultural Carbon Project and The Sofala Community Carbon Project.

Corinna Clements, Keith M. Moore

Chapter 27. Community, Climate Change, and Sustainable Intensification: Why Gender Is Important

Adaptation to climate change is greatly enhanced when it occurs across a landscape. Agricultural and herding communities are important loci of adaptation. Women’s knowledge and practices can help in determining new community livelihood strategies. Community adaptation is hindered when land grabs limit access to land for crops and animals. New forms of public-private partnerships that are often designated as foreign direct investment further complicate adaptation. Using the community capitals framework, community-based adaptation strategies that take gender into account are identified.

Cornelia Butler Flora

Chapter 28. Designing Environmental Instruments to Finance Agricultural Intensification Through the Clean Development Mechanism: Direct Cost Subsidy Versus Tax Cut Under Asymmetric Information

Various agreements addressing climate change plead for the adoption of innovative green technologies to reduce production of greenhouse gases responsible for global warming. Yet, the most successful instrument so far, the Clean Development Mechanism (CDM) is at pains to succeed in small, developing countries facing sustainable development problems like food security. Worse, while the CDM succeeded in financing agricultural projects, few are funded in small, developing countries.

A tax cut is one innovative financial scheme that many countries enact in their investment code to promote environmentally sound technologies. Tax cuts return a portion of investment costs to firms that implement green innovations, which ultimately reduces investment costs and so adds to their net benefits. We compare this scheme to a direct cost subsidy designed to offer firms access to capital at a lower interest, for their capacities to boost the use of CDM in agriculture. This paper shows that the narrow scope of tax cuts compared to direct cost subsidies make corporate tax relief inadequate for the needs of developing countries. We also show that while both schemes are equally efficient under perfect conditions and asymmetric information, the direct cost subsidy is more appropriate to further environmental and sustainability goals like food security in developing countries where informational problems are pervasive. Empirical results support these results (

JEL:

D61, D82, G21, O13, Q01, Q54, Q55.)

Albert N. Honlonkou, Rashid M. Hassan

Chapter 29. Farming Systems in Tanzania: Empirical Evidence of Changes in Livelihood Patterns and Poverty Among Smallholder Farmers

In this paper, the major farming systems in Tanzania are described and evidence regarding the recent changes in livelihood patterns across the farming systems and their effect on poverty among smallholder farmers is provided. Evidence from the literature shows that the six major farming systems in Tanzania are characterized by diverse livelihood activities, with agriculture-based livelihood activities being dominant across all of the systems. The contribution of agriculture-based livelihood activities to total household income varies from 53 % in the coffee/banana/horticulture system to 65 % in the wet rice/sugarcane system. These activities have been affected by changes in both climate- and non-climate-related factors; however, climate-related factors significantly influence these changes. Furthermore, the evidence shows that the magnitude of the effect of changes in livelihood patterns on poverty among smallholder farmers varies across the farming systems – smallholder farmers in farming systems with more diverse sources of livelihood are less affected than those with limited sources of livelihood. The proportion of households that were categorized as being poor varies from 46 % in the coffee/banana/horticulture system to 72 % in the cassava/cashew/coconut system. Given differences in resources, livelihood patterns, and constraints among the farming systems, farming system-specific rather than countrywide policy interventions will be required to improve agricultural productivity, enhance livelihoods, and reduce poverty levels in rural Tanzania. The differential impact of climate- and non-climate-related factors on the farming systems implies that coping strategies should take into account the differences in these systems’ vulnerabilities to such changes.

Ntengua S. Y. Mdoe, Gilead I. Mlay, Michael L. Kadigi

Chapter 30. Carbon Market Impacts on Farm Management Practices on Mount Kilimanjaro

Soil carbon sequestration projects have been promoted as a win-win strategy for agriculture in Africa to curb the global emission of greenhouse gases (GHG). Agriculture accounts for an estimated 10–14 % of total GHG emissions, so it has the potential of playing an important role in mitigating global warming. The large gap between soil maximum carbon sink capacity and current carbon stock levels could allow carbon sequestration projects to sequester more carbon while rapidly improving agricultural productivity and food security. This paper approximates the marginal cost of soil carbon sequestration and analyzes its implications for food security using the case of Mt. Kilimanjaro in Tanzania. We develop and calibrate a dynamic optimization model that maximizes the Net Present Value (NPV) of farm profit by allowing the farmer to choose optimal farm management practices subject to crop yield, soil carbon stock, and carbon price. The model is then simulated using various carbon prices to measure their impact on farm management choices. The results show farmer responsiveness to carbon prices but the resulting change in farm productivity is relatively modest.

Francis Mulangu, David Kraybill

Chapter 31. Adaptation to Climate Change: Changing Gender Relations in the Meatu and Iramba Districts in Tanzania

Neither the impacts of climate change on people nor the ways in which people respond to climate change are gender neutral. Important gender differences exist regarding the implications of climate change for the lives of females and males of all ages. Gender inequalities and gender roles play a key role in determining the choice of adaptation strategies of both men and women. They may ultimately lead to changing gender relations. The amount of research and documentation on existing coping and adaptation strategies has increased, but rarely are these findings differentiated along gender lines, and they frequently fail to describe how adaptive strategies cause changes in gender relations. Using qualitative data from the Meatu and Iramba Districts in Tanzania, this study examined changes in gender relations in response to climate change. Findings show that men and women react differently to climate change, leading to changes in gender roles and relations to accommodate the impact of the phenomenon. The impacts of climate change are changing gender relations, which can be to the advantage or disadvantage of either gender category. However, it was found that changes in gender relations had more disadvantages for women than for men. Adaptation strategies utilized by both men and women have positive and negative outcomes, which either challenge or reinforce existing gender inequality.

C. I. Nombo, S. J. Kabote, D. P. Mamiro, G. Synnevåg, A. Z. Mattee, J. K. Urassa, L. Matata

Conclusion

Frontmatter

Chapter 32. Forgotten Facts: Research and Development Priorities

Some high priority issues for research and development, and those which were not discussed included the followings: (1) Realizing the difference between climate and weather so that the confusion in short-term changes rather than the long-term trends can be minimized, and any opportunities emerging from changing climate are harnessed, (2) Evaluating water resources in terms of green vis-à-vis blue and grey water with the objective to enhancing the green water supply by conservation of blue water in the root zone and recycling of the grey water, along with the judicious use of virtual water through international trade, (3) Understanding sequestration of carbon in soils as secondary carbonates along with that as humus in the soil and the biomass-C in trees and other biota, (4) Assessing additional requirements of water and nutrients (N, P, S) for plantation and trees, and conversion of biomass-C(with low N, P, S) into humus, (5) Alleviating constraints(biophysical and socioeconomic) to adoption of recommended management practices by smallholder and resource-poor farmers, (6) Differentiating between genuine investments by overseas companies and the land grabs, (7) Developing nutrition-sensitive agriculture on the basis of the principle that healthy soils are essential to healthy plants, animals and people, (8) Making payments to farmers for provisioning of numerous ecosystem services for promoting adoption of best management practices, and creating another income stream towards alleviating poverty, (9) Addressing gender and other issues which affect agronomic productivity and wellbeing of under-privileged and minorities, and (10) Realizing the importance of interconnectivity and the nexus-approach to harness the benefits of a holistic approach to sustainable management of natural resources and for realizing the goals to sustainable intensification for advancing food security and developing climate-resilient agro ecosystems.

Rattan Lal, B. R. Singh, Dismas L. Mwaseba, David Kraybill, David O. Hansen, Lars Olav Eik

Backmatter

Additional information