Smallholder Areas Research Articles

Monitoring commercial and smallholder production inequalities during South Africa's lockdown using remotely sensed data

AbstractSouth Africa's dualistic agricultural sector consists of many smallholders that operate adjacent to dominant commercial producers. While the smallholder sector contributes to food security, households depend primarily on market food consumption. Poverty reduction is constrained when smallholders have limited access to markets, technology, or cheap capital. We collate remotely sensed data from the South African National Land Cover map and moderate‐resolution imaging spectroradiometer to monitor land use changes as the country entered the coronavirus disease (COVID‐19) lockdown. Production growth sustained aggregate food security, but hunger rose in the poorest households. This inequality in food security is also reflected in growing inequalities in production. Commercially cultivated land areas grew significantly, with more modest gains in smallholder areas. Commercial farmers were better positioned to expand capital in a low interest rate environment during the COVID‐19 crisis. Without using technology and capital to adapt, smallholders can fall further behind during future crises and growth episodes.

A Sub-Seasonal Crop Information Identification Framework for Crop Rotation Mapping in Smallholder Farming Areas with Time Series Sentinel-2 Imagery

Accurate crop rotation information is essential for understanding food supply, cropland management, and resource allocation, especially in the context of China’s basic situation of “small farmers in a big country”. However, crop rotation mapping for smallholder agriculture systems remains challenging due to the diversity of crop types, complex cropping practices, and fragmented cropland. This research established a sub-seasonal crop information identification framework for crop rotation mapping based on time series Sentinel-2 imagery. The framework designed separate identification models based on the different growth seasons of crops to reduce interclass similarity caused by the same crops in a certain growing season. Features were selected separately according to crops characteristics, and finally explored rotations between them to generate the crop rotation map. This framework was evaluated in the study area of Shandong Province, China, a mix of single-cropping and double-cropping smallholder area. The accuracy assessment showed that the two crop maps achieved an overall accuracy of 0.93 and 0.85 with a Kappa coefficient of 0.86 and 0.80, respectively. The results showed that crop rotation practice mainly occurred in the plains of Shandong, and the predominant crop rotation pattern was wheat and maize. In addition, Land Surface Water Index (LSWI), Soil-Adjusted Vegetation Index (SAVI), Green Chlorophyll Vegetation Index (GCVI), red-edge, and other spectral bands during the peak growing season enabled better performance in crop mapping. This research demonstrated the capability of the framework to identify crop rotation patterns and the potential of the multi-temporal Sentinel-2 for crop rotation mapping under smallholder agriculture system.

Influencing the Success of Precision Farming Technology Adoption—A Model-Based Investigation of Economic Success Factors in Small-Scale Agriculture

Even more than 30 years after the introduction of precision farming technologies and studies of their benefits in terms of productivity gains and environmental improvements, adoption rates, especially for variable-rate technologies, are very low. In particular, in smallholder areas, farm managers are reluctant to adopt these technologies. Therefore, this study identifies factors that hinder or facilitate adoption from an economic perspective. Using a model-based sensitivity analysis with three farms of different sizes (11 ha, 57 ha and 303 ha), it is shown that larger farms have higher resilience to external factors due to economies of scale. In addition, it is clarified that the certainty of obtaining additional benefits with GPS guidance systems can explain the higher adoption rates in farming practice, although the additional benefits (per hectare and year) are much lower for this technology than for variable-rate technologies. Small farms (>30 ha) are by no means excluded from the use of digital technologies, as it is shown that the influence of learning costs on profitability is very low, low subsidies can lead to a drastic reduction in the minimum farm size and the presence of low-cost technologies is an efficient solution which allows small farms to participate in the digital transformation of agriculture.

Clay content prediction using spectra data collected from the ground to space platforms in a smallholder tropical area

Proximal and remote sensors are emerging as powerful sources of soil spectral information at an array of temporal and spatial resolutions. This study investigated clay content prediction at three spectral acquisition levels: laboratory, airborne, and spaceborne. Two approaches were tested, the use of prediction models developed with local and regional spectral libraries (52 samples for local scale and 950, 200 e 224 samples for regional scale), termed internal and external models respectively. Local soil samples (52), were collected in a smallholder area, 83 ha, located in southeastern Brazil. Spectral data in the visible (Vis), near-infrared (NIR), and shortwave infrared (SWIR) regions were acquired in the laboratory using FieldSpec 3 sensor, and the clay content was determined by sedimentation technique. Afterward, bare soil images from AISA-FENIX, Planetscope, Sentinel-2 MultiSpectral Instrument (MSI) and Landsat-8 Operational Land Imager (OLI) were obtained. The clay content determined in the laboratory was related to the soil spectra acquired by each of the sensors and was predicted using the Cubist regression tree algorithm. The results obtained from local spectral libraries showed good predictions using FieldSpec 3 and AISA-FENIX sensors. Landsat-8 OLI and Sentinel-2 MSI provided satisfactory results, while PlanetScope gave poor results. For the prediction using regional spectral libraries, only lab-based FieldSpec 3 sensor provided a fair prediction, while other sensors gave poor results. This study demonstrated that soil sensing is possible at any level taking into account its advantages and limitations. This approach paves the way for acquiring soil spectra for smallholder farms.

The Delineation and Grading of Actual Crop Production Units in Modern Smallholder Areas Using RS Data and Mask R-CNN

The extraction and evaluation of crop production units are important foundations for agricultural production and management in modern smallholder regions, which are very significant to the regulation and sustainable development of agriculture. Crop areas have been recognized efficiently and accurately via remote sensing (RS) and machine learning (ML), especially deep learning (DL), which are too rough for modern smallholder production. In this paper, a delimitation-grading method for actual crop production units (ACPUs) based on RS images was explored using a combination of a mask region-based convolutional neural network (Mask R-CNN), spatial analysis, comprehensive index evaluation, and cluster analysis. Da’an City, Jilin province, China, was chosen as the study region to satisfy the agro-production demands in modern smallholder areas. Firstly, the ACPUs were interpreted from perspectives such as production mode, spatial form, and actual productivity. Secondly, cultivated land plots (C-plots) were extracted by Mask R-CNN with high-resolution RS images, which were used to delineate contiguous cultivated land plots (CC-plots) on the basis of auxiliary data correction. Then, the refined delimitation-grading results of the ACPUs were obtained through comprehensive evaluation of spatial characteristics and real productivity clustering. For the conclusion, the effectiveness of the Mask R-CNN model in C-plot recognition (loss = 0.16, mean average precision (mAP) = 82.29%) and a reasonable distance threshold (20 m) for CC-plot delimiting were verified. The spatial features were evaluated with the scale-shape dimensions of nine specific indicators. Real productivities were clustered by the incorporation of two-step cluster and K-Means cluster. Furthermore, most of the ACPUs in the study area were of a reasonable scale and an appropriate shape, holding real productivities at a medium level or above. The proposed method in this paper can be adjusted according to the changes of the study area with flexibility to assist agro-supervision in many modern smallholder regions.

Effect of Nitrogen Fertiliser Application on Maize Yield Across Agro-Ecological Regions and Soil Types in Zimbabwe: A Meta-analysis Approach

Accurate nitrogen (N) fertilisation increases crop yields and minimises environmental pollution in maize based production systems. In this study we report on a meta-analysis of the effects of N fertilisation on maize yield using observations from 53 studies conducted in Zimbabwe since the 1950s for possible refinement of fertiliser recommendations. We assessed the response of maize to: 100 kgN ha−1 compared to the control using the weighted mean yield difference approach. Application of N fertiliser significantly (p 100 kgN ha−1 (> 1.5 fold of recommended blanket rate) in mineral form in loam soils under good management in areas that receive 600–1000 mm year−1 rainfall whilst rates of < 30 kgN ha−1 (< 50% of recommended rate) can be relied upon for positive yield response in small holder areas that receive < 600 mm rainfall year−1.

UNDERSTANDING OF FIRE DISTRIBUTION IN THE SOUTH SUMATRA PEAT AREA DURING THE LAST TWO DECADES

Peat fire is an annual catastrophic event in Indonesia, particularly in South Sumatra region during the dry season. Several previous studies have suggested that anthropogenic forces (land cover) contribute to peat fires. Analysis of the hotspots distribution on land cover types is needed to address peat fires in the futures. This study is aimed to evaluate the distribution of hotspots on the land cover type of the South Sumatra peat area during the last two decades (1997-2016). Remote sensing technique with visual image interpretation method using multitemporal satellite images is used to identify the variations of land cover in the study area. The results showed that the peat area of South Sumatra in 2013 dominated by ferns/ shrub (58%) and only about 10% covered by peat swamp forest (PSF). The largest hotspot distribution during the observation periods was spread in land cover types of Ferns/ shrub (34.808 hotspots) and Industrial Plantation (7.223 hotspots). Note that the densest hotspot located in the industrial plantation with an average of 37 hotspots/ 100 km2 / year. Meanwhile, only a small percentage of the hotspots located in PSF and occurred consistently over the last five years of observation periods. Based on results, the South Sumatra peatland is very vulnerable to burn during the dry season in the future. The government as policy maker must protect the existence of PSF and keep the ferns/ shrub from the fires and subsequent land cover changes (Industrial plantation or small holder area).

AS TRANSFORMAÇÕES OCORRIDAS NO ESPAÇO AGRÁRIO DO MUNICÍPIO DE PINHAL GRANDE/RS - 1993-2017: OS REFLEXOS NA AGRICULTURA FAMILIAR

Com o processo de modernização da agricultura brasileira ocorrida após a década de 1960, o espaço agrário vem passando por significativas transformações estruturais e socioeconômicas. No entanto, a organização das atividades no interior da agricultura familiar vem sendo diretamente alterada, sendo necessário uma nova reorganização desta categoria social. Buscando o entendimento desta afirmação este artigo possui como objetivo geral analisar as principais transformações ocorridas no espaço agrário do município de Pinhal Grande/RS no período de 1993-2017, identificando os reflexos diante da agricultura familiar. Especificamente objetivou-se (a) avaliar as transformações espaciais e técnicas presentes no espaço agrário ao longo da escala temporal analisada; (b) Conhecer a organização da matriz produtiva e seus reflexos para o desenvolvimento da agricultura familiar, (c) Identificar os impactos econômicos e sociais ocorridos no espaço rural do município. A metodologia foi organizada em torno das matrizes teóricas e da coleta de dados em fontes primárias (agricultores familiares e órgãos públicos) e secundárias (Censo Agropecuário e produção agrícola municipal). O trabalho desenvolvido permitiu elencar os elementos que influenciaram as transformações no espaço agrário do município, sobretudo a partir da modernização da agricultura e da expansão da cultura da soja. Neste contexto, os dados demonstram que a partir deste processo, o espaço agrário vem se organizando de forma contraditória, apresentando espaços dinâmicos, abrangendo a maior área territorial do município, onde predomina culturas comerciais, como a soja e a pecuária em propriedades familiares e não familiares e espaços em que a agricultura familiar “tenta” manter-se em áreas minifundiárias, tendo o fumo como principal cultura responsável por agregar renda na propriedade.

Nutrient status of sandy soils in smallholder areas of Zimbabwe and the need to develop site-specific fertiliser recommendations for sustainable crop intensification

Sustainable crop intensification in sub-Saharan Africa cannot be achieved if farmers cultivate inherently infertile soils that are deficient in key essential nutrients, such as nitrogen and phosphorus. Most smallholder farmers in sub-Saharan Africa are resource-constrained and apply suboptimal fertiliser amounts, which cannot support optimal plant growth and replenish depleted soil reserves, resulting in food insecurity and soil nutrient mining. Conversely, farmers who can afford adequate fertiliser amounts use outdated recommendations, which are blanket in nature, and which ignore spatial variability in soil nutrients across fields and farms, resulting in inefficient nutrient uptake and consequently depressed crop yields. There is a need to revise the blanket fertiliser recommendations in order to develop site-specific recommendations that are based on soil nutrient status and production system. This can be achieved through systematic soil sampling and analysis, and integration of soil analysis data with GIS in order to develop soil fertility maps that can be used to target fertiliser application. Data from identified soil fertility units can be extrapolated to similar soil units in areas were soil analytical data are not available.

From carbon sink to carbon source: extensive peat oxidation in insular Southeast Asia since 1990

Tropical peatlands of the western part of insular Southeast Asia have experienced extensive land cover changes since 1990. Typically involving drainage, these land cover changes have resulted in increased peat oxidation in the upper peat profile. In this paper we provide current (2015) and cumulative carbon emissions estimates since 1990 from peat oxidation in Peninsular Malaysia, Sumatra and Borneo, utilizing newly published peatland land cover information and the recently agreed Intergovernmental Panel on Climate Change (IPCC) peat oxidation emission values for tropical peatland areas. Our results highlight the change of one of the Earth’s most efficient long-term carbon sinks to a short-term emission source, with cumulative carbon emissions since 1990 estimated to have been in the order of 2.5 Gt C. Current (2015) levels of emissions are estimated at around 146 Mt C yr−1, with a range of 132–159 Mt C yr−1 depending on the selection of emissions factors for different land cover types. 44% (or 64 Mt C yr−1) of the emissions come from industrial plantations (mainly oil palm and Acacia pulpwood), followed by 34% (49 Mt C yr−1) of emissions from small-holder areas. Thus, altogether 78% of current peat oxidation emissions come from managed land cover types. Although based on the latest information, these estimates may still include considerable, yet currently unquantifiable, uncertainties (e.g. due to uncertainties in the extent of peatlands and drainage networks) which need to be focused on in future research. In comparison, fire induced carbon dioxide emissions over the past ten years for the entire equatorial Southeast Asia region have been estimated to average 122 Mt C yr−1 (www.globalfiredata.org/_index.html). The results emphasise that whilst reducing emissions from peat fires is important, urgent efforts are also needed to mitigate the constantly high level of emissions arising from peat drainage, regardless of fire occurrence.

Sugar, People and Politics in Zimbabwe’s Lowveld

The expansion of outgrower areas linked to large lowveld sugar estates has been an important component of Zimbabwe’s land reform since 2000. This has involved the transfer of nearly 16,000 ha to over 800 resettlement farmers on irrigated ‘A2’ plots of around 20 ha each. These farmers now produce around a quarter of the sugar output linked to the Triangle and Hippo Valley mills. Tongaat Hulett, a large South African conglomerate, is the dominant shareholder in Zimbabwe’s sugar industry, and its Zimbabwe operation represents a crucial part of the overall multi-million-dollar business. The new outgrowers are a mix of former civil servants, sugar industry professionals and business people, with some politicians and security service personnel also with land. Through a detailed analysis over 12 years of the changing fortunes of a group of new outgrowers linked to Hippo Valley estate, the paper explores the patterns of production, employment and wider livelihood contexts of outgrowers and their workers. In particular the paper examines the tensions and conflicts that have arisen, particularly between the new outgrowers and the estate. The paper in turn explores the implications for sugar politics in Zimbabwe’s Lowveld. The new outgrowers were drawn from a range of previous occupations and, compared to land reform beneficiaries in nearby dryland smallholder areas, were richer, better educated and more well-connected politically. The paper asks how this new group negotiated a relationship with a large-scale South African capitalist enterprise, and with what outcomes. More broadly, the paper examines how outgrowers, the state and capital brokered a politically and economically acceptable post-land reform deal, suiting all parties. Based on the longitudinal case study insights, the paper concludes with an assessment of whether Zimbabwe’s very particular sugar outgrower model of land reform will work, and if it does, for whom.

Conservation of indigenous cattle genetic resources in Southern Africa's smallholder areas: turning threats into opportunities - A review.

The current review focuses on characterization and conservation efforts vital for the development of breeding programmes for indigenous beef cattle genetic resources in Southern Africa. Indigenous African cattle breeds were identified and characterized using information from refereed journals, conference papers and research reports. Results of this current review reviewed that smallholder beef cattle production in Southern Africa is extensive and dominated by indigenous beef cattle strains adaptable to the local environment. The breeds include Nguni, Mashona, Tuli, Malawi Zebu, Bovino de Tete, Angoni, Landim, Barotse, Twsana and Ankole. These breeds have important functions ranging from provision of food and income to socio-economic, cultural and ecological roles. They also have adaptive traits ranging from drought tolerant, resistance to ticks and tick borne diseases, heat tolerance and resistance to trypanosomosis. Stakeholders in the conservation of beef cattle were also identified and they included farmers, national government, research institutes and universities as well as breeding companies and societies in Southern Africa. Research efforts made to evaluate threats and opportunities of indigenous beef cattle production systems, assess the contribution of indigenous cattle to household food security and income, genetically and phenotypically characterize and conserve indigenous breeds, and develop breeding programs for smallholder beef production are highlighted. Although smallholder beef cattle production in the smallholder farming systems contributes substantially to household food security and income, their productivity is hindered by several constraints that include high prevalence of diseases and parasites, limited feed availability and poor marketing. The majority of the African cattle populations remain largely uncharacterized although most of the indigenous cattle breeds have been identified.

Assessment of farmer preferred organisations and institutions by gender in different smallholder areas of Zimbabwe

Information on institutions and organisations preferred by male and female farmers is important for technology adoption and mainstreaming gender in climate change planning. The objective of this study was to analyse institutions and organisations preferred by male and female farmers in smallholder areas of Zimbabwe. Study sites from sub-humid areas were Mazowe/Goromonzi and Kadoma districts, and from semi-arid areas Matobo and Chiredzi districts. Information collected through household surveys and focus group discussions included farming practices, sources of agricultural technologies, membership to farmer groups, and roles of farmer organisations and farmer preferences. Farming systems differed whereas roles of farmer-oriented institutions and NGOs were mostly similar across the study sites. Institutions, organisations, and technologies preferred by farmers differed by both gender and site. There is need for different information and technological interventions for male and female farmers in different smallholder areas of Zimbabwe.

Implications of Climate Variability and Change for Smallholder Crop Production in Different Areas of Zimbabwe

Sustainable food production in the rain-fed smallholder sector of Zimbabwe is imperative in current and future climates given the increasing proportion and role of the sector in food security. Backgrounds of the smallholder sector include low resource bases, declining soil productivity, climate variability and increasing human population. Impacts of climatic and non-climatic variables on crop production vary in different Agro-Ecological Regions (AERs). The study identifies the main climatic opportunities and constraints for sustainable rain-fed smallholder crop production systems in current and future climates. Estimated changes in rainfall and temperature by 2050 are not likely to negatively impact crop production in smallholder areas in AER I, increases in temperature may have negative impacts for most of AER III and IV. Most of AER V is likely to become unsuitable for sustainable maize production. Overall projections indicate increased differences in agricultural potential between smallholder farmers in AER I compared to those in AER II and III as well as those in AER IV and V and different management options. Proposed adaptation and coping strategies in AER I and some in AER II include intensification of agriculture and optimization of both C3 and C4 crop production while in AER III to V adoption of stress tolerant crops for family subsistence may be imperative.

Issues and concerns in smallholder livestock genetic improvement programs in Africa.

Improvement of smallholder livestock genetic resources is of vital importance to agriculture, food production, rural development and the environment on the African continent. Inconclusive considerable debate on smallholder livestock improvement strategies and utilization of local livestock genetic resources has been going on since the past two decades. This has been necessitated by the realization of the need to reduce poverty and enhance food security and produce more animal products to feed the ever increasing national populations in Africa, which seen more compelling than ever. It has been acknowledged that partly the overall continental increase in livestock productivity can be achieved through appropriate and support of the smallholder livestock improvement programs. It is believed that within the smallholder livestock production systems which is characterized by a generally low input-output system, the sustainability of animal breeding efforts to improve animal productivity becomes a dominant factor. Smallholder livestock improvement is not achieving the expected increase in livestock productivity to meet the growing demand for animal products for several reasons, including poor infrastructure, investment environment, financial resources and lack of local expertise and scientific research in addition to poor livestock support services. There is perceived need for improved livestock production in the smallholder areas, however livestock productivity has remained very low, but indigenous livestock are numerous which makes them attractive as potential tool for poverty reduction and improvement of family food security and livelihoods in smallholder farming in Africa. Changes in the demand for livestock products will be largely be driven by human population growth, income growth and urbanization, however the production response in different livestock production systems to meet this demand will be associated with livestock improvement thrust which take into account the modern science and technology in livestock improvement. This discussion attempts a rapid summary of some issues and concerns perceived important in promoting smallholder livestock improvement programs, in relation to recent and previous outcomes, coupled with a brief assessment of some of the challenges faced in implementation of smallholder livestock improvement programs. Some of the challenges and opportunities such as unfavorable livestock policies, dilapidated infrastructure and limited livestock research and characterization of local livestock populations are highlighted. Genetic improvement of livestock indigenous to Africa for targeted performance characteristics of economic benefit for smallholder farmers is necessary for effective selection for both use in straight breeding and crossbreeding. In future, livestock improvement programs are likely to be increasingly characterized by differences between developed and developing countries, and between highly intensive production systems on the one hand and smallholder livestock production on the other hand. How smallholder livestock improvement programs will be implemented in the coming decades is highly uncertain, however, of the many uncertainties, one seem over-arching. Can future demand for livestock products be met through sustainable intensification of smallholder livestock improvement programs on the African continent? With the right institutional and financial arrangements, government, research institutions and donor agencies support can assist in successful implementation of smallholder livestock improvement programs on the continent, improving the capacity of smallholder livestock resource poor farmers to contribute significantly to individual national economies.

Effect of hand-hoe based conservation agriculture on soil fertility and maize yield in selected smallholder areas in Zimbabwe

Conservation agriculture (CA) based on hand-hoe prepared planting basins is being widely promoted in southern Africa, targeting resource-constrained farmers with limited access to draft power. This study was conducted across 15 districts covering four agro-ecological zones in Zimbabwe where paired CA and conventional animal drawn tillage (CADT) plots had been established on 450 farms as part of CA promotion. The aim of the study was to assess the effect of CA on soil pH, organic C, total P and maize (Zea mays L.) grain yield compared with CADT, and also to evaluate the yield benefits of mulching and crop rotation in CA with or without mineral fertilizer use. It was hypothesized that CA improved the pH, organic C, total P of the soils (Arenosols) and grain yield compared with CADT and that mulching and crop rotation in CA increased maize grain yield. A total of 1014 soil samples (0–0.2m depth) were taken at the end of the 2009/10 cropping season and analyzed for pH, organic C and total P. Grain yield was determined in 2009/10 and 2010/11 from 0.01ha net plots. There was no significant difference in average soil pH, total P and organic C between CA and CADT plots and therefore the hypothesis that CA improves these soil properties was rejected. Average concentration for organic C for both CA and CADT plots was less than 10gkg−1, a minimum threshold for well managed soils. When combined with mineral fertilizer: mulching, crop rotation, and mulching+crop rotation in CA increased maize grain yield by 20–33%, 7–9% and 58–69%, respectively. With no mineral fertilizer application, mulching, crop rotation, and mulching+crop rotation depressed maize grain yield by 48%, 28% and 36%, respectively. Therefore the hypothesis that mulching and crop rotation increase maize grain yield was accepted when mineral fertilizer was added and rejected when the fertilizer was not added. It was concluded that the yield benefits of CA can only be realized when mineral fertilizer is also applied. All the three CA principles in combination with mineral fertilizer results in highest yield benefits compared with one or two principles as currently done by most smallholder farmers in Zimbabwe. Access to mineral fertilizer is an important factor in the targeting of CA promotion in smallholder areas of Zimbabwe and similar socio-ecological zones in sub-Saharan Africa.

Effect of soil fertility management strategies and resource-endowment on spatial soil fertility gradients, plant nutrient uptake and maize growth at two smallholder areas, north-western Zimbabwe

We investigate the effects of smallholder farmer resource—endowment and soil nutrient management strategies on plant nutrient uptake and growth across soil fertility gradients under semi-arid conditions. Soil fertility gradients as influenced by farmers’ resource availability may affect the response of crops to fertilizer addition and therefore productivity. The study was conducted in Njelele and Nemangwe smallholder areas (450-800 mm per annum, unimodal) in north-western Zimbabwe. Soil and maize cobleaf samples were collected from fields of farmers (varying resource endowment) located near to (homefields) and far away (outfields) from the farmers’ homesteads during the 2005–6 season. The samples were analysed for selected soil fertility indicators and soil samples were further used to test maize growth response to various nutrient applications under greenhouse conditions. Soil fertility (organic C, total N and available P) significantly (P<0.05) decreased from resource-endowed to resource-constrained farmers, and from outfields to homefields, but the latter differences were only significant for available P. Besides resource-endowment and field type, response to nutrient applications also depended on soil texture. In sandy soil, both N and P were limiting to MAIZE growth in outfields while N was most limiting in the homefield. It was concluded that resource-endowment and nutrient resource management strategies employed by farmers result in soil fertility gradients which affect response of crops to fertilisation and therefore need to be factored in the development of fertiliser recommendations.

Water availability, demand and reliability of in situ water harvesting in smallholder rain-fed agriculture in the Thukela River Basin, South Africa

Abstract. Water productivity in smallholder rain-fed agriculture is of key interest for improved food and livelihood security. A frequently advocated approach to enhance water productivity is to adopt water harvesting and conservation technologies (WH). This study estimates water availability for potential in situ WH, and supplemental water demand (SWD) in smallholder agriculture in South Africa's Thukela River Basin (29 000 km2, mean annual precipitation 550–2000 mm yr−1). The study includes process dynamics governing runoff generation and crop water demands, quantification of prediction uncertainty, and an analysis of the reliability of in situ WH. The agro-hydrological model SWAT (Soil and Water Assessment Tool) was calibrated and evaluated with the Sequential Uncertainty Fitting algorithm against observed discharge (at ten stations) and maize yield (the dominant crop type) for the period 1997–2006. The water availability was based on the generated surface runoff in smallholder areas. The SWD was derived from a scenario where crop water deficits were met from an unlimited external water source. The reliability was calculated as the percentage of years in which water availability ≥SWD. This reflects the risks of failure induced by the temporal variability in the water availability and the SWD. The calibration reduced the predictive uncertainty and resulted in a satisfactory model performance. For smallholder maize yield, the Root Mean Squared Error was 0.02 t ha−1 during both the calibration and the evaluation periods. The width of the uncertainty band was reduced by 23% due to the calibration. For discharge during the calibration (evaluation) period, the ten-station range in the weighted coefficient of determination (Φ) was 0.16–0.85 (0.18–0.73), and in the coefficient of determination (R2) 0.42–0.83 (0.28–0.72). The calibration reduced the width of the uncertainty band by 25% on average. The results show that the smallholder crop water productivity is currently low in the basin (spatiotemporal median: 0.08–0.22 kg m−3, 95% prediction uncertainty band (95PPU)). Water is available for in situ WH (spatiotemporal median: 0–17 mm year−1, 95PPU) which may aid in enhancing the crop water productivity by meeting some of the SWD (spatiotemporal median: 0–113 mm year−1, 95PPU). However, the reliability of in situ WH is highly location specific and overall rather low. Of the 1850 km2 of smallholder lands, 20–28% display a reliability ≥25%, 13–16% a reliability ≥50%, and 4–5% a reliability ≥75% (95PPU). This suggests that the risk of failure of in situ WH is relatively high in many areas of the basin.

Milk production and calf rearing practices in the smallholder areas in the Eastern Cape Province of South Africa

Farmer perceptions on milk production and calf rearing practices on communal rangelands in the smallholder areas of the Eastern Cape Province, South Africa were evaluated on a total of 218 cattle farmers using structured questionnaires, semi-structured interviews with key informants and personal observations. Nearly 70% of the households in the small-scale areas milked twice a day compared to 60% in the communal areas. About 62% of the interviewees weaned calves between 6 and 12 months of age. Milk yield/cow/day (7.5 +/- 0.5 litres), fresh milk consumption/household/day (3.2 +/- 0.5 litres) and sales/household/day (3.1 +/- 1.1 litres) were highest in the sour-veld, small-scale farms (P < 0.05). Sour milk consumption/household/day (2.6 +/- 0.2 litres) and sales/household/day (0.8 +/- 0.2 litres) were significantly high in communal farms with a sour-veld. It was concluded that, calf rearing practices were poor and milk yield, consumption and sales were generally low and varied with production system and rangeland type. Further research is required to improve calf management practices, cow nutrition, milk yield and quality and how milk production can be used as a toll for rural development in the smallholder areas of South Africa.

Opportunities for improving Nguni cattle production in the smallholder farming systems of South Africa

A total of 218 structured questionnaires were administered to determine the influence of production and socioeconomic factors on Nguni cattle farmers' constraints in the smallholder areas of South Africa. Cattle were mainly used for cash, milk and ceremonies. Cattle herd sizes were higher ( P < 0.05) in the small-scale (23 ± 5.2) compared to the communal (9 ± 3.1) areas and mainly composed of cows. Most (75%) of the cattle owners were adult males and were more involved in herd management than adult females and youths. Shortage of feed and diseases/parasites were ranked by farmers as the most important constraints. The logistic regression model showed that odds ratio estimates of households experiencing cattle feed shortage and disease/parasite challenges were high for rangeland type, production system and gender of the household head. About 40 and 75% of the respondents in the sour and sweet rangelands reported that cattle condition deteriorates during winter, respectively ( P < 0.05). Tick-borne diseases were the common causes of cattle mortality, especially in summer. Local crossbreds and Nguni were the common cattle breeds in the smallholder areas. African tradition worshippers had higher ( P < 0.05) Nguni herd sizes (6 ± 3.2) than Christians (1 ± 0.5). Breeding season was undefined and mating system was largely uncontrolled in the communal areas. Farmers' socioeconomic and pedo-climatic situations should be considered when planning strategies for cattle development in the smallholder farming systems.