Mixed Crop-livestock Systems Research Articles

Exante assessment of dual-purpose sweet potato in the crop–livestock system of western Kenya: A minimum-data approach

Mixed crop–livestock systems have a crucial role to play in meeting the agricultural production challenges of smallholder farmers in sub-Saharan Africa. Sweet potato is seen as a potential remedial crop for these farmers because of its high productivity and low input requirements, while its usefulness for both food and feed (dual-purpose) make it attractive in areas where land availability is declining. In this paper, we develop and apply a ‘minimum-data’ methodology to assess ex ante the economic viability of adopting dual-purpose sweet potato in Vihiga district, western Kenya. The methodology uses and integrates available socio-economic and bio-physical data on farmers’ land use allocation, production, and input and output use. Spatially heterogeneous characteristics of the current system regarding resources and productivity are analyzed to assess the profitability of substituting dual-purpose sweet potato for other crops currently grown for food and feed. Results indicate that a substantial number of farmers in the study area could benefit economically from adopting dual-purpose sweet potato. Depending on assumptions made, the adoption rate, expressed as the percentage of the total land under adopting farms, is between 55% and 80%. The analysis shows that the adoption rate is likely to vary positively with the average total yield of dual-purpose sweet potato, the harvest index (the ratio between tuber and fodder yields), the price of milk, and the nutritional value of available fodder. This study demonstrates the usefulness of the minimum-data methodology and provides evidence to support the hypothesis that dissemination of the dual-purpose sweet potato could help improve the livelihoods of smallholder farmers operating in mixed crop–livestock systems in east Africa.

A metapopulation model for the spread and persistence of contagious bovine pleuropneumonia (CBPP) in African sedentary mixed crop–livestock systems

Contagious bovine pleuropneumonia (CBPP) is endemic in several developing countries. Our objective is to evaluate the regional CBPP spread and persistence in a mixed crop–livestock system in Africa. A stochastic compartmental model in metapopulation is used, in which between-herd animal movements and the within-herd infection dynamics are explicitly represented. Hundred herds of varying size are modelled, each sending animals to n other herds (network degree). Animals are susceptible, latent, infectious, chronic carrier or resistant. The role of chronic carriers in CBPP spread being still debated, several chronic periods and infectiousness are tested. A sensitivity analysis is performed to evaluate the influence on model outputs of these parameters and of pathogen virulence, between-herd movement rate, network degree, and calves recruitment. Model outputs are the probability that individual- and group-level reproductive numbers R 0 and R * are above one, the metapopulation infection duration, the probability of CBPP endemicity (when CBPP persists over 5 years), and the epidemic size in infected herds and infected animals. The most influential parameters are related to chronic carriers (infectiousness and chronic period), pathogen virulence, and recruitment rate. When assuming no CBPP re-introduction in the region, endemicity is only probable if chronic carriers are assumed infectious for at least 1 year and to shed the pathogen in not too low an amount. It becomes highly probable when assuming high pathogen virulence and high recruitment rate.

Low-Cost Economic and Environmental Performance Assessment of Farm Households Systems: Application to Mixed Crop-Livestock Systems in the Ethiopian Highlands

ABSTRACT The farm household system (FHS) is one of the main entry points for interventions for rural development. To identify appropriate interventions, it is necessary to assess a priori potential impacts of these interventions on the livelihoods and environment of rural households. This study presents an analytical approach to assess concurrently the environmental and economic performance of FHSs. The approach combines qualitative resource flow diagrams for rapidly assessing the organization and resource flows of the FHS with quantitative economic and environmental performance indicators of the household. We apply the approach to three types of mixed crop-livestock FHSs in Northern Ethiopia, i.e., wealthy, medium, and poor FHS. The wealthier FHS diversifies production, recycles nutrients, and makes substantial use of common resources, with the risk of degrading them. Diversification leads to increased labor productivity at the expense of low land productivity. The livelihood strategy of the poor FHS is based on a combination of off- and on-farm activities. Although the medium FHS is fully engaged in farming, the household is not able to produce sufficient food on-farm, but is able to use cash generated from selling products to bridge the food deficit. The low-cost analytical approach uses existing databases and a limited set of indicators to evaluate economic and environmental performance of FHSs. The methodology can be used to assess and evaluate the current performance of different types of FHSs. This information can be used to identify FHS-specific interventions (recommendation domains) aimed at poverty reduction or improved resource use efficiency and to assess environmental effects of these interventions.

Systems dynamics and the spatial distribution of methane emissions from African domestic ruminants to 2030

Livestock production systems in Africa are experiencing rapid changes in structure and function due to increased demands for livestock products from a more prosperous and ever-increasing human population. Some of these changes could lead to increased emissions of greenhouse gases. This paper explores the magnitudes of changes in production systems as a function of increased population densities and climate change. This paper also quantifies the methane emissions from African cattle, goats and sheep from 2000 to 2030. The study integrates methodologies from different disciplines to derive spatially explicit distributions of methane emissions from domestic ruminants and their changes as livestock production systems evolve. A livestock systems classification framework was used to differentiate pastoral and crop–livestock systems using agro-ecological thresholds based on temperature and length of growing period (hyper-arid, arid, humid and temperate regions), the extent of irrigation and human population densities. Livestock numbers (tropical livestock units, TLU) were estimated from FAO data for each country and production system defined. Projections of livestock populations were derived from analysis of demand shifts in livestock products, and livestock systems changes estimated on the basis of potential climate change and population density change to 2030. For the estimation of diets for ruminants, Africa was split into regions (East, West, Southern, Central and North Africa, and The Horn of Africa) and diets for both the rainy and the dry seasons were estimated from literature reviews for each livestock species in each production system in each region. Feed intake, livestock production and the computation of methane emissions were obtained using a previously validated and widely used mechanistic model of digestion and metabolism in ruminants. Results suggest that (1) Africa produced around 7.8 million tonnes of methane/year in 2000. This figure is likely to increase to 11.1 million tonnes/year by 2030. (2) Methane emissions per tropical livestock unit (TLU, 250 kg bodyweight) can vary from 21 to 40 kg/(TLU year), depending on the production system and the region. (3) The highest emissions per animal come, and will continue to come, from ruminants in mixed crop–livestock systems. (4) The regions producing the highest concentrations of methane, now and in the future, are in general terms, The Horn of Africa, West and East Africa. (5) The average emission factors obtained in this study (31.1 kg/(methane (TLU year))) are in close agreement with the emission factors used by the International Panel on Climate Change (IPCC) for African ruminants (32 kg methane per animal per year). (6) The methodology employed in this study permits the disaggregation of methane emissions by country and production system, thus allows us to quantify changes in emissions as climate changes and production systems evolve. The results of the study are compared with those obtained in other studies around the world and its implications are discussed in relation to how systems are likely to evolve in Africa.

L’embouche ovine à base de fanes d’arachides et de son de mil dans le Sahel ouest africain

L’embouche ovine est économiquement importante dans les systèmes agriculture - élevage dans le Sahel ouest africain. Elle est particulièrement attrayante pour les paysans pauvres y compris les femmes en raison du faible investissement requis et de la rapidité de cycle. Un essai d’alimentation a été mené pendant 56 jours pour déterminer les niveaux optimums des fanes d’arachide et de son de mil pour un engraissement profitable des moutons. Quarante-huit béliers Peuls Oudah, achetés dans un marché de bétail, d’environ 12-15 mois d’âge et d’un poids initial moyen de 20,3 kg (écart-type = 1,7) ont été alloués aléatoirement, par groupes de six, à huit traitements définis par une combinaison factorielle de quatre niveaux de fanes d’arachide (0, 300, 600 et 900 g par animal par jour) et deux niveaux de son de mil (0 et 400 g par animal par jour). La paille de brousse a été offerte à volonté comme alimentation de base à 40 g/kg de poids vif. L’ingestion totale de matière sèche et l’ingestion de matière organique digestible ont été linéairement associées au niveau des fanes d’arachide et de son de mil offert. Les gains moyens quotidiens (gmq) de poids pour les moutons qui ont reçu 0, 300, 600 et 900 g/jour de fanes d’arachide sans son de mil ont été respectivement de -27,5, 10,4, 30,8 et 35,7 g/jour. Avec 400 g/jour de son de mil, les gmq ont été respectivement de 40,3, 59,5, 91,7 et 63,4 g/ jour pour les quatre niveaux de fanes d’arachides. La complémentation avec 600 g/jour de fanes d’arachide et de 400 g/ jour de son de mil a donné le bénéfice net le plus élevé.

The Syrian Jabali goat and its production system

The Jabali mountain goats inhabit the extremly unfriendly and harsh environment of western Syria, where they are kept by different ethnic groups, namely, the Alawits, Druses and Bedouins. The Jabali goat is a black goat, with dropping ears and a curved head; both sexes have horns. A survey was conducted in two different sites, namely, Al-Ghab in Hama district and in As-Sweida district. Forty-three household interviews were carried out to document the current production system. The system can be characterised as a low-input, mixed crop–livestock system. Goat keeping is only of minor importance to the household income compared to crop production or off-farm activities, but provide food in the form of milk, dairy products and meat for the family. Animals are kept on natural pasture most of the year; feed is only supplemented during winter. Farmers emphasise milk production. Milk products like ghee, Shinglish or Jameed are produced for home consumption and for sale. Major constraints mentioned by farmers are government policies for the conservation of forests, feed shortage and limited access to markets because of bad infrastructure and low market prices for their products. The fact that young people migrate to urban areas or work off-farm is seen as potential problem in the near future.

A mathematical model of contagious bovine pleuropneumonia (CBPP) within-herd outbreaks for economic evaluation of local control strategies: an illustration from a mixed crop-livestock system in Ethiopian highlands

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides small colony. CBPP is a major cause for concern in African countries (because of mortality, animal-production losses and cost of control). We present a simu- lation framework to compare economic efficiency of local (i.e., at the herd level) CBPP-control strat- egies (vaccination and antibiotic treatments). This framework was illustrated with data from an Ethiopian highlands cattle-smallholder system (Boji district, West Wellega Zone), where veterinary services recently reported CBPP cases and a research programme was set up to estimate the epide- miological parameters of infection spread. With the data considered (low CBPP virulence), antibi- otics were the most efficient strategy. A sensitivity analysis should be carried out taking into account all uncertain parameters regarding economic values of costs and benefits, expected effectiveness of animal health interventions, animal production yields and epidemiological patterns of the disease. Our framework can help for decision making in CBPP management and health policy design at herd level. Moreover, any threshold analyses (e.g., value of vaccine cost for a benefit being nil) could easily be implemented. contagious bovine pleuropneumonia / control strategies / economics / Markov model / Ethiopia

A mathematical model of the effects of chronic carriers on the within-herd spread of contagious bovine pleuropneumonia in an African mixed crop–livestock system

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease of cattle; CBPP is caused by Mycoplasma mycoides subsp. mycoides small colony. CBPP is a major cause for concern for African countries (because of mortality, animal-production losses and cost of control). The clinical form of the disease is the more infectious (contagion occurs essentially through coughing). However, chronic lung lesions with viable mycoplasmas can persist in recovering cattle. Animals presenting these lesions might have a time-delimitated infectious phase. Such carriers are suspected to generate field outbreaks (although this hypothesis remains debated). We investigated the potential quantitative effects of these chronic carriers on the within-herd CBPP spread. Data were collected during a longitudinal field herd survey in a mixed crop–livestock system in the Ethiopian highlands. Two stochastic Markov-chain models’ outputs (seroconversion dynamics, basic reproduction ratio R 0, cumulative clinical incidence and risk of herd infection) were compared given different hypotheses on the carrier infectiousness. The late seroconversions observed in the field data were fitted correctly only for the highest carrier infectiousness we considered (mean chronic duration of 1 year and carriers 50-times less infectious than clinical cases). Although sensitivities (in terms of disease impact in the herd) were in general negligible when the carrier infectiousness was low (e.g. when carriers were assumed to be 1000-times less infectious than clinical cases), they rapidly became important when the infectiousness increased.

Effect of intensification on feed management of dairy cows in the Central Highlands of Kenya

In sub-Saharan Africa mixed crop-livestock systems predominate in the semi-arid, sub-humid and cool highland zones. In these areas, systems intensify and crops and livestock become increasingly integrated as the human population increases and land becomes a more important constraint than labour (Boserup, 1965; McIntireet al., 1992). As intensification progresses, use of crop residues moves from open access to crop fields, following harvest, to labour intensive management of cereals as dual-purpose crops.

Importance of crop residues in crop–livestock systems in India and farmers’ perceptions of fodder quality in coarse cereals

The mixed crop–livestock systems of India are underpinned by the crop residues which contribute on an average 40–60% of the total dry matter intake per livestock unit. There is however considerable regional variation in the dominant type of crop residue: rice and wheat straws in irrigated regions compared to coarse cereal straws and hay from leguminous crops in the drier, semi-arid regions. This paper synthesizes a series of recent studies on the role and importance of crop residues and farmers’ perceptions of fodder quantity and quality in coarse cereal and groundnut based feeding systems. Crop improvement programs for sorghum, pearl millet and groundnut have traditionally focused on grain/pod yield improvement, pest and water stress tolerance. Only relatively recently have dual-purpose (grain and fodder) plant types been developed. While the nutritive value of fodder from dual-purpose crops can be determined through in vivo and in vitro analysis, such experimental procedures cannot necessarily capture the often-subjective quality attributes that farmers (and their animals) value. Results indicate that farmers perceive a range of quality traits, some of which could be screened for relatively easily, whereas others may be more difficult to assess. These findings highlight the importance of farmer participatory evaluation of fodder traits in the development of improved dual-purpose varieties. However the impact of these varieties on poor farm households will be contingent on the complementary improvement in the effectiveness of seed systems.

Management for sustainable use — forage production for rangelands

Rangeland animal farming requires a continual supply of adequate quality forage to a) sustain animal output targets, b) facilitate flexibility to vary reproductive cycle dates for continuity of offtake, c) avoid enforced sale dates and d) alleviate the need to overgraze. The integration of herbaceous and/or woody forage to supplement natural range grazing, particularly in dry season, continues to be a serious research challenge. The many environmental, physical, biological, economic and social issues involved require an interdisciplinary research approach and also that scientists must understand diverse farming systems to gain the confidence of potential users. In two main papers and 70 posters, Session B6 aims to evaluate progress and to chart future research and development strategies for improved resource use. It would be entirely naive to suggest that all of the issues raised could be captured in this truncated summary and it is hoped that it will serve to arouse interest and discussion which will in turn advance the understanding and future research outlook for the areas involved. One main paper examines various management options to overcome possible conflict between increasing demand to satisfy human requirements for food and other needs based on combining animal farming with the protective use of natural resources. Resource conservation is defined and the effects of climate and animal based factors are explored in relation to the main aim of achieving a good fit between animal food requirements and vegetative food supply over the whole year. The relative effects of dry and wet season grazing are closely examined for a range of climatic, soil and vegetation biotypes with emphasis on the effects of the scale at which they are assessed and the relative importance of the plant-climate and plant-animal components. The suggestion that the impact of grazing is related to the presence of key resource areas in dry season is questioned. The extension of the discussion to the development of whole grazing ecosystems with and without alternative food sources (intensive and non-intensive systems) represents an embodiment of the many management interventions outlined. Alternative improved grazing/resting managements are suggested to ensure continuity of forage supply and preservation of range condition. The paper provides a component checklist as a basis for future research planning. The role of improved forages and their integration to supplement natural range vegetation is discussed in the second main paper with particular emphasis on improving smallholder welfare and maintenance of landscape function. It is argued that the latter is not restricted to the maintenance of the original mix of plant species. Evidence of regeneration of degraded rangeland is quoted for which the use of compatible species mixtures is advocated. The historic high expectancy and disappointing rate of adoption are emphasised, citing some experiences of undesirable evolutionary dominance and possible loss of biodiversity caused by the use of exotic forages as one cause. However, over-utilisation is presently considered a much greater cause of rangeland degradation and loss of biodviersity. The comparative advantages and limitations for the development of indigenous as opposed to exotic germplasm are outlined. Three strategies for the integration of improved forages to improve the standard of living, especially of smallholders, are outlined, mindful of various farmer and farming conditions and associated community specific socioeconomic circumstances which tend to preclude their use. The specific values of a range of herbaceous and woody species are examined. It is suggested that improved forage species will have greatest impact in increasing livestock products in the more intensive mixed crop-livestock systems. Reference to success in related technology uptake in SE Asia provides hope for the future. About half of the posters examine aspects of yield and feed value of a wide range of plant species and also their use ranges in about 20 countries. Between 5% and 10% of the posters are concerned with each of supplementary forage, specific legume species, sylvopastoral systems and drought tolerance. Land tenure, irrigation, chemical fertilisation, rehabilitation of degraded rangeland, seed germination, gene banks, communal grazing, grazing selection and extension/development are other areas included to give a comprehensive cover of the present state of knowledge on forage production for rangelands. It is anticipated that discussion will further explore the many topics covered and clarify future research orientation. Property rights to germplasm before and after improvement or modification requires clarification as is this may have serious consequences related to collection and other related issues. Discussion of the relatively slow uptake of research results and why research tends to be organised on a commodity basis when the opposite is true for the majority of commercial users appears appropriate in the context that scientists must understand farming systems and be aware of the broader context into which the improved technology will be integrated so that potential users can identify with the results and have confidence in their adoption.

Harnessing the Potential of Livestock in Mixed Farming Systems in India

The most dominant form of livestock production in India relates to mixed crop livestock system. Pressure on agricultural land forces cultivators to maintain livestock for manure purposes, consume the meat or egg to meet the need for dietary protein and of course to ensure a little milk for the children and the aged. Smaller the farm size, greater is the need to keep a given fleet of livestock so that real income reaches a moderate figure. Productivity of farm livestock in regard to both meat and milk in India happens to be below the world average. Inadequate provision of fodder and lack of good grazing lands are the most important factors holding up productivity growth. Crop residues from cereals and pulses like rice bran or wheat bran serve as good cattle feed but they have more lucrative uses epitomized in bran scams. The paper argues in favour of technological change in fodder and introduction of cultivated grazing lands.

Policies for livestock development in the Ethiopian highlands.

Since 1991, there have been significant changes in utilization of feed resources in the Ethiopian highlands: while use of communal grazing lands and private pastures has declined, use of crop residues and purchased feed has increased. In addition, although use of animal health services and adoption of improved livestock breeds and modern management practices have increased, ownership of various types of livestock has declined. Rapid population growth has contributed most to the declining trends in grazing resources and ownership of livestock, showing the negative effects of increasing pressure on already degraded resources in the Ethiopian highlands. Land redistribution, increased participation in credit and extension programs targeting livestock, and improvement in access to markets, on the other hand, have had significant positive impacts on adoption of improved livestock technologies and ownership of livestock. Thus, reducing population growth and improving access to markets and credit and extension programs targeting livestock can enhance the role of livestock in improving food security and reducing poverty, especially in the mixed crop-livestock farming systems as exist in the East African highlands.

Traditional cattle-husbandry systems in Eritrea: cattle–man relationships

Through surveys and participatory rural appraisal methods, the study documents the traditional cattle-husbandry systems in both the mixed crop–livestock system in the highlands and the pastoral system in the lowlands in Eritrea. Herding, grazing, breeding strategies, heat detection, milking letdown, food habits, marketing, housing and traditional veterinary practices are described in each system. The pastoral system is based on large, mobile, predominantly female herds that go for long-range grazing and cattle are mainly kept for milk and milk products. In the highland farming communities, cattle are sedentary, relatively fewer, predominantly male and are mainly kept to provide energy for agricultural purposes.

CROP RESIDUES FOR MULCH AND FEED IN CROP–LIVESTOCK SYSTEMS: IMPACT ON MAIZE GRAIN YIELD AND SOIL PROPERTIES IN THE WEST AFRICAN HUMID FOREST AND SAVANNA ZONES

A study was conducted in the humid-forest, forest-savanna, and Guinea savanna zones of West Africa from 1993 to 1999 to examine the effect of managing crop residues from cereal–legume cropping systems for mulch and fodder for sheep. Increasing the proportion of total crop residues produced from a unit area of land and used as mulch increased maize grain yield, soil organic carbon, nitrogen and available phosphorus. The extra increases obtained when more than half the crop residues were applied as mulch were relatively small, however, suggesting that 25–50% of the crop residues could be removed as feed without any detrimental effect. When any crop residues rejected by sheep were mixed with livestock urine and faeces and returned to the respective fields from where the crop residues had been removed, subsequent grain yield and soil organic carbon, nitrogen, and available phosphorus increased. The study demonstrated the possibility of managing crop residues for increased productivity in smallholder mixed crop–livestock systems.

Habitat management strategies for the control of cereal stemborers and striga in maize in Kenya

Maize is the principal food and cash crop for millions of people in the predominantly mixed crop-livestock farming systems in Kenya. Stemborers and striga (Striga hermonthica) are major constraints to increased maize production in eastern Africa. An intercropping and trap crop system has been developed, using a ’push-pull’ strategy, for the control of stemborers in small scale maize farming systems. The ’push-pull’ strategy involves trapping stemborers on highly susceptible trap plants (pull) and driving them away from the crop using repellent intercrops (push). Napier grass (Pennisetum purpureum Schumach) and Sudan grass (Sorghum vulgare sudanense Stapf.) are used as trap plants, whereas molasses grass (Melinis minutiflora Beauv.) and two species of desmodium (Desmodium uncinatum Jacq. and Desmodium intortum Urb.) repel ovipositing stemborers. The integrated ’push-pull’ strategies were shown to increase parasitism of stemborers through attraction of parasitoids to one of the intercrops, molasses grass. The leguminous intercrop, silver leaf desmodium, drastically reduced damage to maize by the parasitic weed, striga. This aspect was further investigated and developed for integration **********w;th stemborer control. On-farm trials with farmers in Kenya have shown significant yield increases in maize farming.

Prevalence of antibodies to Brucella spp. in cattle, sheep, goats, horses and camels in the State of Eritrea; influence of husbandry systems

Samples from 2427 cattle, 661 goats, 104 sheep, 98 camels and 82 horses were screened for brucella infections by the Rose Bengal Test and positive reactors confirmed by the complement fixation test. In cattle, the highest individual seroprevalence was in dairy herds kept under the intensive husbandry system, with an individual prevalence of 8.2% and unit (herd) seroprevalence of 35.9%. This was followed by the pastoral husbandry system in the Western Lowlands with 5.0% individual but a higher unit (vaccination site) prevalence of 46.1%. The lowest was in the mixed crop-livestock system in the Southern Highlands with individual 0.3% and unit (village) prevalence of 2.4%. In sheep and goats, no positive animals were detected in the mixed crop-livestock areas. In the Eastern Lowlands individual prevalences of 3.8% (goats) and 1.4% (sheep) and unit prevalence of 33.3% (goats) and 16.7% were found, while 14.3% of individual goats and 56.3% of the units in the Western Lowlands were positive. No positive horses were found. The present study documents the first serological evidence of Brucella spp. infection in camels (3.1%) in Eritrea.

Stratification and synthesis of crop-livestock production system using GIS

Population increases, land-use changes and marketing opportunities are important factors affecting crop-livestock integration particularly with respect to their effect on soil fertility and feed supply for ruminant livestock. As the human population density rises, crop farmers and grazers are finding it profitable to establish contracts for paddocking, and they are reaching agreement on equitable ways to make use of crop residues and take care of livestocks. As the processes of intensification proceed, mixed crop-livestock systems are evolving as the viable and dominant farming system, allowing smallholder farmers to capitalize on the complementarity between crops and livestock. Strategies directed to raise the productivity of specific crop-livestock systems need to consider the stage of development of the target area in relation to intensification and the nature of crop-livestock interactions. Information related to crop and livestock systems in West Africa is currently available from various sources e.g., household surveys, aerial surveys, rural appraisal, experimental etc., and held by different agencies. The approach used in this study shows how such data (biophysical and socioeconomic) can be integrated within a GIS environment and synthesized to identify the evolution of systems across environments and also to identify constraints and potential of the systems. Potential for integrated crop-livestock systems remains untapped and/or knowledge of its existence is unknown for large parts of Nigeria. Using data from 36 case studies and georeferenced data on cropping intensities and livestock population for the entire country, it was possible to predict emerging crop-livestock systems using GIS. Indeed, depending on availability of data, it is now possible to extend a similar approach in other African countries. The potential contribution of this technology is largely unknown in West and Central Africa, where few operational programs use them. Major technological innovations and appropriate government policies have potential to shift the balance in regional developments, if targeted carefully at areas where the right conditions exist. Further research could then target specific areas thus ensuring efficient allocation of resources while policy makers can achieve development goals by directing policies and resources to domains that have the greatest potential.

Measuring the production efficiency of alternative land tenure contracts in a mixed crop-livestock system in Ethiopia

Abstract In this paper, we test the hypothesis that land held under varying configurations of property rights will be farmed at different levels of production efficiency. Production data were collected from 477 plots in a fairly productive, mixed farming system in the Ethiopian highlands. Interspatial measures of total factor productivity, based on the Divisia index, were used to measure the relative production efficiency of three informal and less secure land contracts (rented, share-cropped and borrowed) relative to lands held under formal contract with the Ethiopian government. Although the informally-contracted lands are farmed 10–16% less efficiently, the analysis indicates that farmers of such lands actually apply inputs more, rather than less, intensively (i.e., more inputs per unit of land). The gap in total factor productivity thus results from the inferior quality of inputs (or lack of skills in applying them) rather than a lack of incentive to allocate inputs to mixed crop-livestock farming. For this reason we find no empirical basis to support the hypothesis that land tenure is a constraint to agricultural productivity.

Nutrient balance patterns in African livestock systems

This paper presents an overview of the current status, problems and prospects for achieving a better nutrient balance to support varying levels of productivity from the three major livestock systems in Africa. In free range grazing systems, livestock nutrient deficiencies are mainly overcome by moving the animals to better grazing areas. This makes monitoring and managing of nutrients within a system very difficult. Nutrient recovery, cycling and synchronization of manure with other recycled or purchased sources are greater in mixed crop–livestock systems. In these systems, inclusion of nitrogen-fixing leguminous forage/tree crops as companions or rotation crops with cereals further improves the nutrient use efficiency and balance. With more favourable market and policies, commercialized dairy systems are developing around the urban areas of Africa. Such systems heavily depend on purchased feeds and nutrients, and have serious implications for the nutrient balance and sustainability of land use systems in the rural areas which supply the feeds, and for the urban areas because of the risk of pollution from the accumulating animal wastes.