Simulation of production alternatives in ranching systems in Togo

A simulation model developed by CIAT, Columbia, was used to analyse the economics of large-scale beef production alternatives, comprising different breeds, types of pasture and levels of technical efficiency, for the West African savanna belt based on price-cost relationships in Togo, 1976. With intensive ranching systems an acceptable financial return is only achieved when high productivity levels of the herds are obtained while using low-cost production techniques. These systems have large finance requirements and, thus, involve a high managerial risk. Extensive systems (similar to nomadic systems) with minimum investments in fencing and artificial pastures, seem to be the most profitable alternatives. Available stock numbers are the most binding constraint for livestock development at a regional level, hindering the full exploitation of the main natural resource. Further analysis should be undertaken to see whether sheep and goats, with their higher rates of reproduction, could not significantly accelerate the utilisation of understocked land resources.     

The potential for systems and modelling research in pasture science in South Africa

The availability of computers has made it possible to process large volumes of complex data. This development has enabled scientists to enter the field of systems research which both analyses and synthesises complex multivariate agricultural production systems. By building models which represent real systems and by simulating the internal processes of each component of the system, systems research can be used in prediction, decision-making, developing new production methods and teaching. The potential use of modelling in the field of pasture science in South Africa deserves careful evaluation, in view of the complexity, expense and long-term nature of traditional grazing experiments. There is a place for modelling by inter-disciplinary teams in local research, in spite of the present shortcomings of this recently-developed approach.     

Simulation of production systems in East Africa by use of interfaced forage and cattle models

A forage model and a cattle production model were interfaced and adapted for tropical production conditions in East Africa. The objectives of the modelling were to structure and conceptualise a complex system for better comprehension, thereby determining constraints on a traditional African grazing system. The model was designed to simulate the physical linkages between the scarce resource of forage and the outputs of cattle, meat and milk. The effects of improved management practices were examined for a traditional village livestock grazing system. Verification and validation for the baseline village herd were carried out using several different sources of data. A combination of a restricted breeding season, supplemental feeding during the dry season and a seasonal sales policy resulted in a 40% increase in net revenue to village producers above the baseline for a ten-year period.     

Assessing rangeland drought in South Africa

The meteorological and agricultural assessment techniques that have been developed in South Africa are discussed, with reference to their strengths and weaknesses, application and suggested future developments. Future challenges in drought assessment as influenced by democratization are also considered. We conclude that meteorological methods have several inherent deficiencies which render them risky for the optimum allocation of drought relief. Agricultural drought assessment is suggested to be more preferable. Current agricultural drought models should nevertheless be improved to deal more successfully with the dynamic nature of rangeland. Evidence indicates that no absolute objective biophysical criteria for the quantification of the onset and the end of a drought have been identified and that all current criteria have an inherent subjectivity. Choosing appropriate interpolation techniques for mapping drought extent is a cause for concern, and there is scope for future research. Remote sensing techniques, integrated with crop modelling techniques, are options to pusue further. We finally suggest that in a democratic South Africa, more attention should be given to a multi-disciplinary approach where impacts, other than meteorological and agricultural, on previously disadvantaged black farmers are also assessed.     

Developing environmental principles, criteria, indicators and norms for potato production in South Africa through field surveys and modelling

The sustainability of agricultural production is linked to the environment from which it draws its resources. Potato production in the Sandveld in the South African Western Cape occurs in the Cape Floral Kingdom: a vulnerable and globally significant biodiversity hotspot. A scientific approach defining and monitoring sustainability criteria and indicators is required to improve the sustainability of potato production in such a sensitive area. In this paper we propose principles related to the ecological impact of potato production (nature preservation, water preservation and the minimization of chemical and carbon-dioxide emissions) and their derived criteria related to land clearing, irrigation, emissions, and others. Next we defined calculable and measurable indicators of the efficiency with which resources are used, such as proportion of land cleared, water use by the crop, amount of biocides used, the embodied energy of biocides, and the energy needed for farming operations versus the potato yields obtained. In-depth interviews were held with 14 farmers representing 20% of the total potato production area to obtain the current values of these indicators. These were compared to model outcomes of two main sustainability indicators: land and water use efficiency. The land use efficiency varied least between growers, from (36 to 58 Mg (tonnes) ha⁻¹), water use efficiency returned values between 3 and 9 g potato l⁻¹ water, while chemical fertilizer phosphorus use efficiency varied most at 98 and 995 g potato g⁻¹ P applied. Model outcomes confirmed some of the trends revealed by the survey, e.g. growing potatoes in winter and growing them with less than optimal water offers possibilities to double water use efficiency. Ways to derive indicator threshold norms are proposed based on the knowledge of physical and biological processes determining resource availability, the observed variation among farmers and the model outcomes. Knowing indicator values, their range and the means to improve resource use efficiency will aid in establishing sustainability norms by providing a quantitative approach to any environmental certification scheme that wishes to licence the delivery of potatoes from the Sandveld.     

Australian wattle species in the Drakensberg region of South Africa – An invasive alien or a natural resource?

An investigation into the spread of two alien wattle species (Acacia mearnsii and Acacia dealbata) in rural parts of the Drakensberg region of South Africa and the importance of the trees to the livelihoods of the local communities was carried out. With the aid of aerial photography two plots near the village were selected. Wattle aerial cover increased from 7% and 20% in the two plots, respectively, in 1953, over 21% and 33% in 1975, to 48% and 58% in 2000. In 1995, a government-sponsored national programme, “Working for Water” was established, with the expressed purpose of employing people described as being from the poorest and disadvantaged rural communities to clear areas of invasive alien species from river catchments and water courses. Whilst the programme provides an income to thousands of families in rural areas, it may also be jeopardising the livelihoods of the same communities.The wattle is an important resource for village households; virtually all households used it as their primary heat source and for building materials. Other uses included medicine extraction and 20% of the interviewed households gained income from selling firewood.From the rural communities’ perception, the greatest concern regarding the alien species is its high water consumption (although this did not affect them directly), and the fact that it provides cover to thieves and criminals. Consequently, most villagers wanted either a reduction of the wattle stands (58% and 86% in the 2001 and 2003 study, respectively), or that they remained as at present (42% and 10%, respectively).Leaves from woody legumes have demonstrated large potential as green manures and fodder providers in many agroecosystems. The abundance of the wattle in the study area suggested an exploration of alternative beneficial uses in the low input farming systems practiced. The wattle’s potential as green manure was evaluated in a decomposition trial. In all treatments, the wattle litter immobilised nitrogen from soil, in spite of a high N content of the litter. Plant available P increased in soil after 4–5 months of incubation.We argue that the current practice of externally funded wattle control is not sustainable in the long term. We discuss alternative approaches with a higher level of community participation and ownership, and conclude that the current underutilization of land may, ironically, be one of the largest constraints for a viable solution to the spread of wattle.     

Exploring options for farm-level strategic and tactical decision-making in fruit production systems of South Patagonia,Argentina

In South Patagonia, Argentina, sweet cherry is the main fruit-tree crop grown for export, resulting in a highly seasonal labour demand. Managers of deciduous perennial fruit orchards must consider both biological and economic relationships in selecting crop species and orchard design. This makes decisions at the farm-level extremely complex, as especially in such perennial crops, strategic (‘what to plant’, ‘with which technology’ and ‘how much area of each activity’, i.e. the final design) and tactical (‘when, what and how to plant in time’, the pathway to the planned farm) decisions have a long-term effect. The objective of this study was to explore the consequences of different strategic and tactical decisions at farm scale in fruit production systems of South Patagonia, considering the variation in interests and aims of different stakeholders, and using a sensitivity analysis to evaluate the consequences of possible changes in external conditions. A dynamic farm-scale optimization model called OPTIFROP was developed to generate alternative farm development plans, by allocating, in the course of the time horizon of the run, production activities to different land units, while optimising different objective functions, subject to several constraints. Although time-dependent, dynamic, mathematical programming models for analysing farming systems have been described in literature, the dynamic aspects of long-term decision-making in orchard design and their impact on the sequential (annual) nature of orchards in different growth phases (i.e. medium-term decision-making), need a higher time-staged dynamic approach with a staircase matrix structure. The model includes two objective functions at farm level: (1) maximization of the present value of cumulative financial result, which is the main objective for growers, and (2) maximization of cumulative farm labour, which is an objective often mentioned by policy makers. The inter-months deviation for labour demand (during the period of high labour demand, November–April) was included as an upper-bound. Input and output coefficients for the land use options considered in OPTIFROP were quantified using the Technical Coefficient Generator FRUPAT. Model results indicated that the present value of cumulative financial result and the cumulative farm labour are conflicting to a very limited extent. Timing and feasibility of implementing certain combinations of production technologies are affected by resource endowments and initial conditions, but these factors do not influence land use selection in the long term. Land use selection is driven by the objectives of the stakeholders. OPTIFROP showed that, through introduction of alternative crops, substantial reductions in labour peaks in the period November–April could be achieved with a relatively small reduction in farm income. The sensitivity of the model solution to the cherry price suggests that the fruit production sector of South Patagonia should pay more attention to the robustness of their land use plans and take preventive measures to avoid being caught by a possible crisis due to changes in the context.     

Water productivity in smallholder irrigation schemes in South Africa

This study investigates the productivity and value of water in two smallholder irrigation schemes (Zanyokwe and Thabina) in South Africa. We apply the residual valuation method (RVM), willingness to pay (WTP) and cost-based approaches (CBA) (i.e. accounting costs of operation and maintenance) to evaluate water productivity and values per crop, per farm, and by scheme. In both schemes, water value estimated by the RVM for vegetables (cabbage, tomatoes and butternuts) is greater than water value for dry maize. At the farm and scheme levels, a comparison was made between gross margin per m³ of water, WTP per m³ and accounting cost per m³ to estimate the relative value of water productivity. The active farmers in the Zanyokwe scheme have lower WTP per m³ (R0.03) than the gross margin of output (R0.69). Also, the accounting cost (R0.084) per m³ of water is less than the gross margin. In the Thabina scheme, active farmers are willing to pay (R0.19) per m³ of water. Hence farmers in Thabina are ready to pay as much as three times the proposed costs of O&M (R0.062) per m³ of water used. Both the accounting cost and willingness to pay are less than the gross margin per m³ of water in the Zanyokwe scheme. Our findings indicate that extension and training may be required to improve the productive use of water for those farmers whose returns are insufficient to cover the cost of supply.     

Evolution of drought policy and related science in Australia and South Africa

Australia and South Africa are dominated by extensive agriculture, both countries being predominantly arid and exposed to a highly variable climate. Limiting land degradation, maintaining the financial viability of farms and improving the risk-management skills of farmers are common problems which government and industry in both countries are attempting to address. Both countries are currently refining their approaches to drought management, and have been making substantial use of science in improving the monitoring and assessment of drought, and the management of the land. Unlike the situation in Australia, however, South Africa's approach is being reviewed against the backdrop of a fundamental reorientation of broader agricultural policies in the context of that country's transition to a fully fledged democracy. The changing approach to drought policy in South Africa can therefore only be fully understood in the context of this broader process of change. This paper compares the climate and agriculture of Australia and South Africa, and how their different drought policies have evolved. Observations are made on the role of scientists in providing advice to political decision makers, and ways in which the process of decision making with respect to drought may be improved.     

Yield and seasonal water productivity of sunflower as affected by tillage and cropping systems under dryland conditions in the Limpopo Province of South Africa

Sustainable food production in semi-arid tropical countries can be achieved through efficient utilization of rainwater. A field experiment to assess the grain yield, seasonal water use (WU), water use efficiency (WUE) and precipitation use efficiency (PUE) of sunflower (Helianthus annuus L.) intercropped with cowpea (Vigna unguiculata L.) on two tillage systems was conducted during the 2007/2008 and 2008/2009 cropping seasons at the University of Venda (22°58′ S, 30°26′ E at 596 m above sea level). The experiment was configured as a 2 × 2 × 2 factorial design with three replications. The tillage treatments were conventional tillage (CT) (control) and in-field rainwater harvesting (IRWH) system. The IRWH is a special crop production technique that promotes runoff on 2.0-m wide no-till strip between crop rows and collects the runoff water in basins where it infiltrates into the soil profile. The treatments in the cropping system (CS) consisted of a sole crop (sunflower or cowpea) and an intercrop (sunflower × cowpea). Results of the experiment revealed that IRWH led to a significant (P < 0.05) increase in sunflower grain yield in the second season but cowpea grain yield was not influenced by tillage systems. IRWH resulted in significantly higher WU, WUE and PUE of both crops compared to CT system in the second season. The CS had significant effects on sunflower grain yield in both seasons but none on the cowpea grain yield. WU was significantly higher in intercrops than in sole cowpea and sole sunflower in the first and second season, respectively. WUE and PUE were significantly greater in sole sunflower than in the intercrops but less in the sole cowpea than in the intercrops.     

The evaluation of preliminary farming systems technologies: Zero-tillage systems in West Africa

The appropriate form of evaluation of new farming systems depends on the stage of development of the technology. At each state of technology development new systems are screened and the most promising ones selected for further research. Linear programming is a cost-effective tool for the evaluation of preliminary technologies as it allows interaction between the production parameters, quantifies the impact of limiting factors by shadow prices and can also be used for simulation. The screening of potential zero-tillage systems for West Africa is a concrete example.     

Water requirement for irrigated rice in a semi-arid region in West Africa

The purpose of this study was to determine the water requirement of rice (Oryza sativa L.) in the areas of the Office du Niger (Niono, Republic du Mali, West Africa). Average annual rainfall is 600 mm and evapotranspiration exceeds precipitation in every month except August. Alluvial soils vary in texture from heavy clay to sandy loam and have very low infiltration rates. The water use of rice was measured by establishing the water balance of four irrigation units varying in size from 12 to 26 ha. Evapotranspiration was evaluated with ‘non-weighing’ lysimeters and varied in 1980 from 5.3 mm/day shortly after flooding and 7.1 mm/day during heading to 4.1 mm/day at ripening. The crop coefficients found in this study do not always correspond to those presented by Doorenbos and Pruitt (1977). The crop coefficient depended strongly on the soil cover and was 1.0 for 10–70% soil cover and increased linearly to 1.25 for 100% soil cover. This relationship between soil cover and crop coefficient can be used to improve the estimates of rice evapotranspiration from large irrigation units with incomplete soil cover. The peak evapotranspiration may be as high as 7.8 mm/day during a 10-day period under full soil cover. The peak water requirement during the period of dry land preparation does not exceed 6 mm/day on level fields. The amount of water needed to saturate the soil profile after the dry season varied from 122 to 302 mm. A significant difference was measured between the pre-irrigation gift on a level field (175 mm) and on a non-level field (255 mm), which indicates the importance of levelling.     

Wastewater production, treatment, and irrigation in Middle East and North Africa

The Middle East and North Africa (MENA) region is the driest region of the world with only 1% of the world’s freshwater resources. The increasing competition for good-quality water has cut into agriculture’s water share but since the use of freshwater for domestic, industrial and municipal activities generates wastewater, the volume of wastewater used in agriculture has increased. About 43% of wastewater generated in the MENA region is treated; a relatively high percentage compared to other developing-country dominated regions. This is because of the perceived importance of wastewater as a water resource and several oil-rich countries with the resources to treat wastewater. The MENA region has an opportunity for beneficial reuse of wastewater but few countries in the region have been able to implement substantial wastewater treatment and reuse programs. The major constraints leading to seemingly slow and uneven reuse of wastewater are: inadequate information on the status of reuse or disposal of wastewater and associated environmental and health impacts; incomplete economic analysis of the wastewater treatment and reuse options, usually restricted to financial feasibility analysis; high costs and low returns of developing wastewater collection networks and wastewater treatment plants; lack of wastewater treatment and reuse cost-recovery mechanisms and lack of commitment to support comprehensive wastewater treatment programs; mismatch between water pricing and regional water scarcity; preference for freshwater over wastewater; and inefficient irrigation and water management schemes undermining the potential of wastewater reuse. However, some countries such as Tunisia, Jordan, and Israel have policies in place that address wastewater treatment through a range of instruments. Policymakers in these countries consider use of treated wastewater to be an essential aspect of strategic water and wastewater planning and management. With flexible policy frameworks addressing rapid demographic changes and increasing water scarcity in the MENA region, water reuse has great potential if integrated with resource planning, environmental management and financing arrangements.     

Exploring changes in world ruminant production systems

In the past 30 years world production of ruminant meat and milk has increased by about 40%, while the global area of grassland has increased by only 4%. This is because most of the increase in ruminant meat and milk production has been achieved by increasing the production in mixed and landless production systems and much less so in pastoral systems. Pastoral systems depend almost exclusively on grazing, while mixed and landless systems rely on a mix of concentrates (food crops) and roughage, consisting of grass, fodder crops, crop residues, and other sources of feedstuffs. A model was developed to describe these two aggregated production systems for different world regions, each having typical production characteristics, such as milk production per animal for dairy cattle, and off-take rates and carcass weights for non-dairy cattle, sheep and goats. The energy needed by the animals for the production of meat and milk is calculated on the basis of requirements for maintenance, grazing and labour, pregnancy, and lactation. We implemented the FAO Agriculture Towards 2030 projection for crop and livestock production and assumed that the past trend in the area of grassland will continue in the coming three decades. This assumption implies a rapid intensification of grassland management with a 33% increase in global grass consumption, which will only be possible with increasing fertilizer inputs, use of grass-clover mixtures and improved grassland management.     

Returns from small ruminant production in South West Nigeria

Dwarf goats and sheep are ubiquitous in the humid zone of West Africa, although only as a supplement to cash and food crop production. This paper presents estimates of the returns obtained from these small ruminants under traditional production systems. Returns are, on average, high, but variable, especially in view of disease risks. Apart from disease control measures to reduce mortality, improved nutrition is needed for intensifying production. At current levels of management neither pasture production nor housing and hand-feeding are likely to yield increased returns. Alley farming, a system of intercropping with shrub species and the feeding of shrub trimmings to small ruminants, seems a promising alternative.     

Shifting from extensive to intensive agricultural systems: a case study in the Sudan

The development of the mechanized vertisols of Sudan has been very successful in achieving rapid expansion of crop area. Unfortunately, there has been minimal use of purchased inputs. Hence, crop yields have been low and declining over time with increasing variability of output. Now the frontier is disappearing and past land and credit subsidies have been eliminated. With modeling, we show that in the absence of the area-expansion option, even risk-averse farmers shift to the more intensive technologies involving improved cultivars and fertilization. We explore several options involving further research or policy changes that would induce intensification even before the passing of the frontier.     

Water buffalo and cattle ranching in the Lower Amazon Basin: Comparisons and conflicts

From 1975 to 2000, the water buffalo population in the Brazilian Amazon increased at nearly 13% per year, making it one of the fastest growing herds in the world. On the floodplains of the Amazon River buffalo are managed in a similar manner to cattle, but often earn superior production figures. This production advantage, however, is tempered by the role buffalo play in conflicts between landowners; buffalo are prone to altering the floodplain environment and interfering with production activities such as fishing and farming. In this research, we show that buffalo are kept on the floodplains 24% longer than cattle throughout the year, and 37% longer than cattle during periods when landowner conflicts are most likely to occur. We also show that buffalo productivity is greater than cattle in this system, which gives an opportunity to design management regimes for buffalo that may increase production costs, but that will lower the environmental and social problems that involve buffalo. Specifically, when the waters begin to rise, buffalo should be removed from the floodplains at the same time as cattle. Although this will not lessen the damage done while the buffalo is on the floodplain, it will place buffalo on the floodplain during the dry season when the erosion potential is at its lowest, and reduce the time that buffalo may interfere with other production activities such as fishing. The additional production costs incurred by early removal will not dissipate the production advantage over cattle. Without specific management that addresses the socio-economic and environmental problems caused by buffalo, the continued high growth rate for the buffalo population on the Amazon floodplains may not be sustainable and conflicts will become commonplace.     

An innovation systems perspective on strengthening agricultural education and training in sub-Saharan Africa

This paper examines the role of postsecondary agricultural education and training (AET) in sub-Saharan Africa in the context of the region’s agricultural innovation systems. Specifically, the paper looks at how AET in sub-Saharan Africa can contribute to agricultural development by strengthening innovative capacity, or the ability of individuals and organisations to introduce new products and processes that are socially or economically relevant, particularly with respect to smallholder farmers who represent the largest group of agricultural producers in the region. The paper argues that while AET is conventionally viewed in terms of its role in building human and scientific capital, its also has a vital role to play in building the capacity of organisations and individuals to transmit and adapt new applications of existing information, new products and processes, and new organisational cultures and behaviours. The paper emphasizes the importance of improving AET systems by strengthening the innovative capabilities of AET organisations and professionals; changing organisational cultures, behaviours, and incentives; and building innovation networks and linkages. Specific recommendations in support of this include aligning the mandates of AET organisations with national development aspirations by promoting new educational programs that are more strategically attuned to the different needs of society; inducing change in the cultures of AET organisations through the introduction of educational programs and linkages beyond the formal AET system; and strengthening individual and organisational capacity by improving the incentives to forge stronger linkages between AET and diverse user communities, knowledge sources, and private industry.     

Farmers’ management strategies and land use in an agropastoral landscape: roquefort cheese production rules as a driver of change

Cultural landscapes in Europe provide a wide range of food products and fulfil social and environmental functions. In order to maintain agricultural practices that contribute to maintaining the biological and cultural value of semi-natural landscapes, agri-environmental schemes are being implemented in many western European countries. In the mountains of southern Europe a major issue is the encroachment of shrubs and trees through natural forest succession following agro-pastoral extensification.In this paper we analyse trends in land use strategies of sheep breeders in response to milk pricing and in relation to various within-farm mechanisms. We show that changes in production rules within the Roquefort cheese protected geographical indication have caused farmers to develop an alternative land use strategy. In this alternative model, farmers now consider rangelands as a valuable resource. By increasing the use of rangelands for sheep grazing and alimentation, this new strategy provides a more effective control of shrub and tree encroachment.We suggest that this involuntary consequence of production and market decisions has been at least as important as agri-environmental schemes in leading ewes’ milk producers to make changes in their land use strategy.