Smallholder Farms In Zimbabwe Research Articles

Social Capital and Food Security amongst Women in Smallholder Farming in the Face of Climate Change in Bikita, Zimbabwe

Food insecurity is a devastating setback for vulnerable women in smallholder farming in Zimbabwe. Women’s low or limited adaptive capacity is caused by diverse factors, including , which include poverty, an unstable economy, political crisis and climate change. Adaptive strategies that differ from the conventional national and civic interventions to circumvent these factors have yielded subtle food security outcomes. As a result, there are growing calls for the adoption of social capital as an alternative grassroots-based adaptive strategy. This study examined the potential for and challenges faced by women who use social capital in adapting to food insecurity. Using in-depth interviews, focus group discussions and key informant interviews it revealed that women in smallholder farming were utilising bonding, bridging and linking capital as a means of adaptation. These three types of capital were operationalised in four projects: Food For Assets (FFA), community gardening, the Boer goat project and Fushai. It emerged that three of the projects performed better in some wards but did not do well in others. Despite its potential, the Boer goat project was riddled with challenges, which emanated from the absence of bonding capital. I therefore conclude and recommend that social capital is critical for women in food insecurity adaptation. However, it needs to be buttressed by a harmonious relationship between the three forms of social capital and all stakeholders for sustainability to be realised.

Weed community responses to soil type during transition to no‐till practice on smallholder farms in Zimbabwe

AbstractUnderstanding drivers of weed density and diversity is essential for the development of weed management strategies. Here, we compared temporal changes in weed density and diversity under no‐till (NT) and conventional (CONV) tillage systems in cotton–maize rotations on loam, clay loam and sandy loam soils immediately after transition to NT in Kadoma, Zimbabwe. The effect of tillage system on weed density varied through the growth season and was dependent upon soil type and species composition of the weed community. Although weed responses to tillage system varied amongst species, we identified general trend effects on weed density on specific soils. At 3 weeks after crop emergence (WACE), weed density on loam soils was 76% and 96% higher in NT than in CONV during the 2009/2010 and 2010/2011 seasons, respectively, and on clay loam soils it was 37% and 33% higher in NT than CONV, respectively. Weed densities in NT and CONV were similar across all soil types at 6 WACE during the 2009/2010 and 2010/2011 seasons and at 9 WACE in 2009/2010. Tillage system did not affect weed density during the growth season on sandy loam soils. Weed diversity (Shannon index) was at least 75% higher in NT than CONV on loam and clay loam soils at 3 WACE during both seasons. It is likely these increases in weed densities following conversion to NT will exacerbate already prevalent weed management problems in the smallholder sector. Earlier weeding is recommended to suppress weed emergence and reduce likely associated crop yield losses.

Socioeconomic status connected imbalances in arable land size holding and utilization in smallholder farming in Zimbabwe: Implications for a sustainable rural development

Access to land and other natural resources are key means of driving rural people out of abject poverty. Inequalities in access to land and supportive services that ensure full utilization of land are therefore hurting in rural societies. This article enumerates and explain wealth-related imbalances in land size holding and utilization in Zimbabwe’s smallholder farming sector. It relies on cross-sectional household level data collected from 601 smallholder farming households randomly sampled from four districts. Disparities in land size holding and utilization are measured using the Erreygers corrected concentration index. A decomposition exploration is performed to determine the contributing factors to enumerated inequalities in land size holding and utilization. Results reveal a pro-poor distribution of inequalities in low and very low arable land size holding and also in low land utilization. Conversely, a pro-rich distribution of inequalities is observed in high land size holding and high land utilization. Wealth-related inequalities are evident in both men and women farmer groups, youth and non-youth farmer groups and in different geographic regions. A decomposition analysis show that observed inequalities in both land size holding and utilization are hugely explained by asset wealth. Other factors including access to extension, age of farmer, fulltime-farming status and geographic location were also found to minimally explain measured inequalities. In conclusion, low land size holding and low land utilization are phenomenon highly concentrated within the poorest segments of society in Zimbabwe whilst high land size holding and utilization are found within the more affluent population. Asset holding chiefly explain the disparities. Results suggest the need for decision makers in land allocation, distribution, re-distribution, and agrarian transformation in general, to deliberately concentrate on the most vulnerable and poorer segments of society. Such will have far reaching implications for rural transformation and development.

Zinc fertilization increases productivity and grain nutritional quality of cowpea (Vigna unguiculata [L.] Walp.) under integrated soil fertility management

Cowpea (Vigna unguiculata [L.] Walp.) is an important but under-studied grain legume which can potentially contribute to improved dietary zinc (Zn) intake in sub-Saharan Africa. In this study, surveys were conducted on smallholder farms in Zimbabwe during 2014/15 to determine the influence of diverse soil fertility management options on cowpea grain productivity and nutrition quality. Guided by the surveys, field experiments were conducted to investigate the influence of Zn fertilizer on the productivity and quality of cowpea under integrated soil fertility management (ISFM). Experiments were conducted on two soil-types, namely, sandy (6% clay) and red clay (57% clay) in 2014/15 and 2015/16 where cowpea was grown in rotation with staple maize (Zea mays L.) and fertilized with combinations of Zn, nitrogen (N), phosphorus (P) and two organic nutrient resources, cattle manure and woodland leaf litter. Cowpea grain yields on surveyed farms ranged from 0.3 to 0.9tha−1, with grain Zn concentration ranging from 23.9 to 30.1mgkg−1. The highest grain Zn concentration was on fields where organic nutrient resources were applied in combination with mineral N and P fertilizers. Within the field experiments, mean grain yields of cowpea increased by between 12 and 18% on both soil types when Zn fertilizer was applied, from a baseline of 1.6 and 1.1tha−1 on red clay and sandy soils, respectively. When Zn fertilizer was co-applied with organic nutrient resources, grain Zn concentrations of cowpea reached 42.1mgkg−1 (red clay) and 44.7mgkg−1 (sandy) against grain Zn concentrations of 35.9mgkg−1 and 31.1mgkg−1 measured in cowpea grown with no Zn fertilizer on red clay and sandy soils, respectively. Agronomic biofortification of legumes is feasible and has the potential to contribute significantly towards increasing dietary Zn intake by humans. A greater increase in grain Zn of cowpea grown on sandy than red clay soils under Zn fertilization illustrates the influence of soil type on Zn uptake, which should be explored further in agronomic biofortification programs.

Microfinance as a pathway for smallholder farming in Zimbabwe

Microfinance has been viewed as a pathway for smallholder farming. This paper aims to investigate the impact of microfinance on smallholder farming. It examines the role of microfinance in the development of smallholder farming. This paper employs the integrated view of microfinance study as opposed to the ‘credit only’(minimalist) view. Using qualitative research methodology, the paper relies on literature review and primary data. Household level data (primary) were collected from a rural district (Masvingo Rural District) of Masvingo province in Zimbabwe. Data were collected from 250 microfinance participants (household heads) using questionnaires and face-to-face interviews. The findings show that microfinance had positive effects on accumulation of agricultural assets, income from agriculture, agricultural education, agricultural productivity, agri-business, consumption and health. However, the impact is limited due to lack of finance. Basic financial services are essential for the management of their smallholder farming activities. The practical implications are that the study results could be used by the government and development agencies for policy making. The paper recommends that microfinance should be harnessed as a useful intervention that can be employed to economically empower the smallholder rural agricultural sector. Keywords: microfinance, smallholder farming, integrated view, minimalist view. JEL Classification: G21, O13

Where is the limit? lessons learned from long-term conservation agriculture research in Zimuto Communal Area, Zimbabwe

Smallholder farming in Zimbabwe is increasingly affected by dwindling maize (Zea mays L.) yields due to declining soil fertility and the negative effects of climate variability and change. A long-term on-farm study was established between 2004 and 2013 at the Zimuto Communal Area near Masvingo, Southern Zimbabwe to test the feasibility and viability of conservation agriculture (CA) systems under the circumstances of low fertility and erratic rainfall. CA seeding systems based on animal traction excelled and significantly increased maize productivity by up to 235% (1761 kg ha-1) and legume productivity by 173% (265 kg ha-1) as compared to the conventional control treatment. Soil quality indicators such as infiltration and soil carbon improved 64-96% and 29-97 %, respectively, over time. However, a direct link between increased infiltration and grain yield could not be established. Increased plant population, because of greater precision and moisture conservation during direct seeding as well as an improved response to fertilizer application due to gradually increasing soil carbon could be the reasons why yields on CA systems outyielded the conventional control. CA systems were more economically viable than planting crops under the normal conventional practice with mouldboard ploughs and removal of crop residues. Farmers generally rated important crop characteristics of maize planted under CA as high but weed control was rated as low, due to the lack of an appropriate herbicide under the prevailing environment. The results of this study show that CA is a potential option even in areas of climate risk and low soil fertility. However, the adoption of CA was low amongst members of the rural farming community due to the perceived risk of crop failure, lack of appropriate and accessible inputs and markets for farm produce, and lack of appropriate information and knowledge about alternative agricultural methods. This highlights the need for better resource and input availability as well as more vibrant and efficient extension services. Successful CA promotion requires that the systems are adapted to farmers’ circumstances. However, CA cannot expand where farmers depend on remittances, are donor dependent, and where crop production in general is doubtful. Land uses such as extensive livestock production or game ranching may be better and more profitable alternatives for farmers in these situations.

Maize productivity and nutrient and water use efficiencies across soil fertility domains on smallholder farms in Zimbabwe

Strategic targeting of scarce nutrient resources by smallholder farmers on different field types has remained poor partly due to knowledge limitations, resulting in inefficient use of the resources. We sought to establish efficient strategies for use of nutrient resources so as to narrow the yield gap in maize production on heterogeneous light-textured soils under rain-fed conditions in Eastern Zimbabwe. A nutrient omission study was implemented during two cropping seasons, across six on-farm sites with soil organic carbon (SOC) ranging from 3.5 to 8.9gkg−1, and clay content between 4 and 19%. Treatments used were: (i) a zero fertilizer control, (ii) NK, (iii) NPS, (iv) PKS, and (v) NPKS. Rainfall water productivity, RWP, (kggrainmm−1) was used as a proxy for water use efficiency for the different nutrient combinations. During both seasons, only 70kgha−1 N could be applied across all sites as prolonged mid-season droughts forced withholding of the second N topdressing targeted at maize anthesis. Maize productivity was influenced by both nutrient management and initial soil fertility. During the first season, maize yields across sites ranged from 0.25 to 0.84tha−1 for the control and 2.05–3.75tha−1 for the NPKS treatment that represented attainable yields. The corresponding RWP were 0.38–1.13kggrainmm−1 for the control and 3.15–7.66kggrainmm−1 for the NPKS treatment. For the second season, maize yields for the control ranged from 0.2 to 1.2tha−1, while those for the NPKS treatments ranged from 2.4 to 3.60tha−1. Across sites, response to N ranged 1.2–2.35tha−1, response to P ranged 0.71–2.10tha−1 and response to K ranged 0.08–0.30tha−1, indicating little response to K. Overall, balanced nutrient management has an overriding effect on maize grain and water productivity, but only for soils with SOC>4gkg−1 soil. Nitrogen and P remain the most limiting nutrients, in contrast, addition of K did not enhance grain yield, nor did it influence response to N or P. Variable N application strategies must be an integral component of farmer management if losses related to fertilizer investment are to be minimised under the risky rain-fed crop production systems.

Prevalence of mastitis in dairy cows from smallholder farms in Zimbabwe

A cross-sectional study was conducted to determine the prevalence of sub-clinical and clinical mastitis and the associated factors in cows from selected smallholder dairy farms in Zimbabwe. Physical examinations were conducted on all lactating cows for evidence of signs of clinical mastitis. Composite milk samples were collected from all lactating cows for bacterial culture and somatic cell counting. Cows were categorised as clinical if they exhibited clinical features of mastitis, or sub-clinical if no apparent signs were present but they had a positive bacterial isolation and a somatic cell count of at least 300 x 103 cells/mL. Farm-level factors were obtained through a structured questionnaire. The association of mastitis and animal- and herd-level factors were analysed using logistic regression. A total of 584 animals from 73 farms were tested. Overall, 21.1%(123/584) had mastitis, 16.3%(95/584) had sub-clinical mastitis and 4.8% (28/584) had clinical mastitis. Herd-level prevalence was 49.3%. Coagulase-negative staphylococci (27.6%), Escherichia coli (25.2%), Staphylococcus aureus(16.3%), Klebsiella spp. (15.5%) and Streptococcus spp. (1.6%) were the most common isolates. In individual cows, pure dairy herds (OR = 6.3) and dairy crosses (OR = 3.1) were more likely to have mastitis compared to Mashona cows. Farms that used pre-milking teat dipping were associated with reduced mastitis prevalence. Further research is needed on the prevalence of mastitis and a comparison of data for both smallholder and commercial dairy farms in all regions of Zimbabwe should be undertaken.

An integrated evaluation of strategies for enhancing productivity and profitability of resource-constrained smallholder farms in Zimbabwe

In African smallholder agriculture, improved farm-scale understanding of the interaction between the household, crops, soils and livestock is required to develop appropriate strategies for improving productivity. A combination of models was used to analyse land use and labour allocation strategies for optimizing income for wealthy (2.5 ha with eight cattle) and poor (0.9 ha without cattle) farms in Murewa, Zimbabwe. Trade-offs between profitability, labour use and partial nutrient balances were also evaluated for alternative resource management strategies. Farm data were captured using the Integrated Modelling Platform for Mixed Animal-Crop Systems (IMPACT), which was directly linked to the Household Resource use Optimization Model (HROM). HROM was applied to optimize net cash income within the constraints specific to the households. Effects of alternative nutrient resource management strategies in crop and milk production were simulated using the Agricultural Production Systems Simulator (APSIM) and RUMINANT models, respectively, and the output evaluated using HROM. The poor farm had a net income of US$ 1 yr −1 and the farmer relied on selling unskilled labour to supplement her income. The poor farm’s income was marginally increased by US$18 yr −1 and the soil nitrogen (N) balance was increased from 6 to 9 kg ha −1 yr −1 by expanding groundnut production from the previous 5–25% of the land area. Further increases in area allocated to groundnut production were constrained by lack of labour. On the poor farm, maize production was most profitable when cultivated on a reduced land area with optimal weeding. The wealthy farm had a maize-dominated cropping system that yielded a net cash balance of US$290 yr −1, mainly from the sale of crop produce. Net income could be increased to US$1175 yr −1, by re-allocating the 240 hired labour-days more efficiently, although this reallocation substantially reduced partial soil N and phosphorus (P) balances by 74 kg N ha −1 and 11 kg P ha −1, respectively, resulting in negative nutrient balances. Few opportunities existed to increase productivity and income of the smallholder farms without inducing negative nutrient balances. On the wealthy farm, groundnut was the least profitable crop; shifting its production to the most fertile field did not improve income unless the groundnut residues were fed to lactating cows. The analysis carried out in this paper highlights the need to develop practical technological recommendations and development interventions that consider farm resource endowment (land, fertilizers, manure and labour), variability in soil fertility within farms and competing resource use options.

The influence of conservation tillage methods on soil water regimes in semi-arid southern Zimbabwe

Planting basins and ripper tillage practices are major components of the recently introduced conservation agriculture package that is being extensively promoted for smallholder farming in Zimbabwe. Besides preparing land for crop planting, these two technologies also help in collecting and using rainwater more efficiently in semi-arid areas. The basin tillage is being targeted for households with limited or no access to draught animals while ripping is meant for smallholder farmers with some draught animal power. Trials were established at four farms in Gwanda and Insiza in southern Zimbabwe to determine soil water contributions and runoff water losses from plots under four different tillage treatments. The tillage treatments were hand-dug planting basins, ripping, conventional spring and double ploughing using animal-drawn implements. The initial intention was to measure soil water changes and runoff losses from cropped plots under the four tillage practices. However, due to total crop failure, only soil water and runoff were measured from bare plots between December 2006 and April 2007. Runoff losses were highest under conventional ploughing. Planting basins retained most of the rainwater that fell during each rainfall event. The amount of rainfall received at each farm significantly influenced the volume of runoff water measured. Runoff water volume increased with increase in the amount of rainfall received at each farm. Soil water content was consistently higher under basin tillage than the other three tillage treatments. Significant differences in soil water content were observed across the farms according to soil types from sand to loamy sand. The basin tillage method gives a better control of water losses from the farmers’ fields. The planting basin tillage method has a greater potential for providing soil water to crops than ripper, double and single conventional ploughing practices.

Soil type, management history and current resource allocation: Three dimensions regulating variability in crop productivity on African smallholder farms

Soil fertility varies markedly within and between African smallholder farms, both as a consequence of inherent factors and differential management. Fields closest to homesteads (homefields) typically receive most nutrients and are more fertile than outlying fields (outfields), with implications for crop production and nutrient use efficiencies. Maize yields following application of 100 kg N ha −1 and different rates and sources of P were assessed on homefields and outfields of smallholder farms in Zimbabwe. Soil organic carbon, available P and exchangeable bases were greater on the homefields than outfields. In each of three experimental seasons, maize yields in homefield control plots were greater than in the outfields of farms on a granitic sandy and a red-clay soil. Application of mineral N significantly increased maize yields on homefields in the first season (2.1–3.0 t ha −1 on the clay soil and 1.0–1.5 t ha −1 on the sandy soil) but the effects of N alone were not significant on the outfields due to other yield-limiting factors. Greatest yields of about 6 t ha −1 were achieved on the clayey homefield with 100 kg N ha −1 and 30 kg P ha −1 applied as single super phosphate (SSP). Manure application gave greater yields (3–4 t ha −1) than SSP (2–3 t ha −1) in the sandy homefield and in the clayey outfield. Maize did not respond significantly to N, dolomitic lime, manure and P on the sandy outfield in the first and second seasons. In the third season, manure application (∼17 t manure ha −1 year −1) on the sandy outfield did result in a significant response in grain yields. Apparent P recovery in the first season was 55–65% when P was applied at 10 kg ha −1 on the clayey homefield (SSP), clayey outfield (SSP and manure) and sandy homefield (manure) with apparent P recovery less than 40% when P was applied at 30 kg ha −1. On the sandy outfield, P recovery was initially poor (<20%), but increased in the successive seasons with manure application. In a second experiment, less than 60 kg N ha −1 was required to attain at least 90% of the maximum yields of 2–3 t ha −1 on the sandy homefield and clayey outfield. N use efficiency varied from >50 kg grain kg −1 N on the infields, to less than 5 kg grain kg −1 N on the sandy outfields. Apparent N recovery efficiency by maize was greatest at small N application rates with P applied. We conclude that blanket fertilizer recommendations are of limited relevance for heterogeneous smallholder farms. Targeted application of mineral fertilizers and manure according to soil type and past management of fields is imperative for improving crop yields and nutrient use efficiencies.

Influence of nutrient management strategies on variability of soil fertility, crop yields and nutrient balances on smallholder farms in Zimbabwe

An improved understanding of soil fertility variability and farmers’ resource use strategies is required for targeting soil fertility improving technologies to different niches within farms. We measured the variability of soil fertility with distance from homesteads on smallholder farms of different socio-economic groups on two soil types, a granite sand and a red clay, in Murewa, northeast Zimbabwe. Soil organic matter, available P and CEC decreased with distance from homestead on most farms. Soil available P was particularly responsive to management, irrespective of soil type, as it was more concentrated on the plots closest to homesteads on wealthy farms (8–13 mg kg−1), compared with plots further from homesteads and all plots on poor farms (2–6 mg kg−1). There was a large gap in amounts of mineral fertilizers used by the wealthiest farmers (>100 kg N and >15 kg P per farm; 39 kg N ha−1 and 7 kg P ha−1) and the poorest farmers (<20 kg N and <10 kg P per farm; 19 kg N ha−1 and 4 kg P ha−1). The wealthy farmers who owned cattle also used large amounts of manure, which provided at least 90 kg N and 25 kg P per farm per year (36 kg N ha−1 and 10 kg P ha−1). The poor farmers used little or no organic sources of nutrients. The wealthiest farmers distributed mineral fertilizers evenly across their farms, but preferentially targeted manure to the plots closest to the homesteads, which received about 70 kg N and 18 kg P per plot (76 kg N ha−1 and 21 kg P ha−1) from manure compared with 23 kg N and 9 kg P per plot on the mid-fields (26 kg N ha−1 and 10 kg P ha−1), and 10 kg N and 1 kg P per plot (and ha−1) on the outfields. Crop allocation on the homefields was most diversified on the wealthiest farms where maize was allocated 41% of the area followed by grain legumes (24%) and paprika (21%). Maize was allocated at least 83% of the homefields on farms with less access to resources. All the farmers invariably applied nutrients to maize but little to groundnut. Maize grain yields were largest on the homefields on the wealthy farms (2.7–5.0 t ha−1), but poor across all fields on the poor farms (0.3–1.9 t ha−1). Groundnut grain yields showed little difference between farms and plots. N and P partial balances were largest on the wealthy farms, although these fluctuated from season to season (−20 to +80 kg N per farm and 15–30 kg P per farm; average 21 kg N ha−1 and 8 kg P ha−1). The partial balances on the wealthy farms were largest on the homefield (20–30 kg N and 13 kg P per plot; >26 kg N ha−1 and >13 kg P ha−1), but decreased to 10–20 N and 6–9 kg P per plot (<20 kg N ha−1 and 13 kg P ha−1) in mid-fields and −7 to +10 kg N and −1 to +1 kg P per plot (<10 kg N ha−1 and <2 kg P ha−1) in the outfields. N and P balances differed little across plots on the poor farms (−2 to +4 kg per plot; −5 to +4 kg ha−1) due to limited nutrients applied and small off-take from small harvests. This study highlights the need to consider soil fertility gradients and the crop and nutrient management patterns creating them when designing options to improve resource use efficiency on smallholder farms.

Organic Matter Management as an Underlying Cause for Soil Fertility Gradients on Smallholder Farms in Zimbabwe

Management of spatial and temporal variability of soil fertility within fields and farms is one major challenge for increasing farm-level crop productivity in smallholder agriculture. A study was conducted across 120 on-farm field sites in three agro-ecological regions of Zimbabwe to identify management factors influencing the formation of within-field/farm soil fertility gradients. Using farmer participatory research approaches, host farmers were put into three classes according to resource endowment, namely, Resource-endowed, Intermediate and Resource-constrained farmers. Each host farmer identified the most (rich) and least (poor) productive field or field section, which were then studied over two years. Farmer criteria for defining soil fertility ranged from colour through elements of soil structure to crop response following external nutrient inputs. The fertility ranking of fields consistently matched with laboratory indices, with rich fields containing significantly more soil organic carbon (SOC) and nutrients than the corresponding poor fields. Fertility gradients were evident within and across farms belonging to different farmer classes. The mean SOC content for rich fields were >6.0 g kg−1 compared with <4.6 g kg−1 for the designated poor fields. Rich fields belonging to Resource-endowed farmers had 16–28% more SOC than those belonging to their resource-constrained counterparts, suggesting differences in organic matter management. Differences in SOC and fertility status between rich and poor fields were wider in two of the study areas which had more than 70 years of cultivation in contrast to the third site which had been under smallholder farming for only 20 years, suggesting that the observed fertility gradients are a cumulative effect of years of differential management practices by different farmer classes. Analysis of potential benefits from in situ organic biomass inputs suggested that the processes of organic matter capture and utilization discriminated against Resource-constrained farmers. About 50% of in situ biomass, preferentially maize stover, was lost in three dry season months, and up to 72% of potentially recyclable N is lost from poor fields managed by Resource-constrained farmers. In contrast, Resource-endowed farmers incorporated more than 1.5 t C, 25 kg N and 5 kg P ha−1 season−1 because of their access to draught power during the early dry season. Such inputs could make a difference on these nutrient-depleted soils. Intermediate farmers represented a diverse transitional group whose size and variability could be indicative of the dynamism of technology usage. It was concluded that management of soil fertility gradients to increase crop productivity on smallholder farms hinges on increasing the capacity and efficiency with which organic matter is generated and utilized by different farmer weaclth groups across temporal scales.

The control of heartwater on large-scale commercial and smallholder farms in Zimbabwe

As part of a series of studies associated with the development of improved vaccines for heartwater (a tick-borne disease of ruminant livestock caused by Cowdria ruminantium), field surveys were carried out to assess losses associated with the disease and the costs associated with controlling it in the two main agro-ecological zones of Zimbabwe (lowveld and highveld) where heartwater is believed to be endemic and epidemic, respectively. In each zone, a cross-sectional study was performed in the main farming systems (smallholder (SH) and large-scale commercial (LSC) beef and dairy), followed by longitudinal studies in the same sectors to improve data accuracy for some parameters. Suspected heartwater-specific mortality in cattle was similar in all LSC sectors ( p = 0.72) accounting for a median 1% mortality risk. Heartwater-specific mortality in SH areas was not assessed due to poor diagnostic ability of the farmers. Few LSC farms and SH households kept sheep; suspected heartwater-specific mortality in LSC sheep was 0.8% in the lowveld and 2.4% in the highveld. Goats were a major enterprise in SH areas but not on LSC farms. Suspected heartwater mortality in LSC goats was 0.8% at one site in the highveld and 17.5% on a farm in the lowveld. Application of acaricides was the major control method for heartwater and other tick-borne diseases on both SH and LSC farms. On LSC farms, plunge dipping was used most frequently and the number of acaricide applications ranged widely between 3 and 52 per year. The total cost of acaricides per head per annum was higher in highveld dairies than in highveld and lowveld beef enterprises ( p = 0.03). In SH areas, cattle plunge dipping was conducted by the government with an average frequency of 8 ± 2 (sd) immersions per annum in both the lowveld and highveld. The type of tick control on sheep and goats in all production systems was highly variable (ranging from none to hand removal or intensive acaricide treatment). Suspected heartwater cases on LSC farms were treated with tetracyclines; treatment was not reported in SH areas. Reported treatment costs were high (median Z$120) and highly variable (range Z$4–833). Vaccination against heartwater with the live, blood-based vaccine was reported on only one LSC farm. LSC farms applying acaricide 30 or more times per year reported higher morbidity ( p < 0.0001) and mortality ( p < 0.0001) than farms applying acaricides less than 30 times a year. This finding supports the use of reduced tick control in the management of heartwater in Zimbabwe.

Annual legumes for improving soil fertility in the smallholder maize-based systems in Zimbabwe.

Annual legumes are widely grown by smallholder farmers in Zimbabwe. In addition to providing food, these crops are widely recognised to help maintain soil fertility. In this review we highlight their soil fertility benefits and shortcomings and suggest areas for future work. Most of our knowledge about the soil fertility benefits from annual legumes has come from research stations where they have been demonstrated to input large amounts of N and organic matter. But we still know surprisingly little about the magnitude and dependability of those gains on smallholder farms in Zimbabwe where acidic sandy soils, rainfall extremes and pests often place severe limits on legume growth. Recent work suggests that benefits under those conditions with traditional annual legumes such as groundnuts are much smaller and take longer to achieve than on research stations. We need to screen new legumes for local adaptation to see if there are new species or accessions that do better on smallholder farms. Some green manures, especially velvet beans, have given a reasonable biomass on extremely nutrient depleted and fairly acidic soils, and have potential to help rehabilitate degraded fields when coupled with lime and P. Green manuring will be difficult for smallholders to adopt unless large benefits can be obtained quickly. More work with velvet beans is required on farms to establish the size and speed of yield gains for following maize crops. Also, more participatory work amongst farmers is needed to integrate green manures into existing farming systems. Smallholder farmers already rotate grain legumes with maize. In many cases the rotation does help maintain productivity and soil fertility although at levels much reduced from those found on station. Further long-term on-farm work with the farmers being closely involved is needed to measure benefits from the rotations, and to examine the technology and management options to help farmers grow better crops of existing and new (such as promiscuous soybeans) grain legumes both for their direct benefit as food and the subsequent benefit to succeeding cereal crops. These options would include use of fresh seed, lime and perhaps P. The intercropping of grain legumes with maize can often raise the productivity of land, except in dry areas. Although farmers are rarely going to intercrop annual legumes primarily to improve soil fertility, spin-off benefits on soil fertility may still be worthwhile and have recently been achieved on station in Zimbabwe. These have yet to be demonstrated and quantified on smallholder fields through longer-term trials. In conclusion, although benefits will often not be large, annual legumes can help to maintain soil fertility on smallholder farms in Zimbabwe. The farmers will need more help to access seed of a range of annual legumes that they can integrate into their farming system. A bigger effort by research, extension and seed houses to produce and distribute seed at prices affordable to smallholder farmers is necessary, along with more appropriate guidance on crop management. Transactions of the Zimbabwe Scientific Association Volume 72 (Supplement) 1998, pp. 15-26

Use of donkeys and their draught performance in smallholder farming in Zimbabwe.

Animal traction constitutes the most important source of power for agricultural work in smallholder farming in Zimbabwe. Two studies, a survey and a short term on-farm trial were conducted to evaluate the use of donkeys as draught animals. The survey covered 59 households in 2 smallholder farming areas. For the on-farm trial, 12 donkeys and 12 cattle were spanned separately in teams of 4 animals to plough 40 m x 70 m plots of medium textured soil. The survey findings highlighted the drought tolerance of donkeys compared to cattle. Mortality rates of donkeys were lower. Results of the draught performance trial indicated that donkeys ploughed less area per day (P < 0.05) and their walking speed was slower (P < 0.05) than cattle. There was no significant difference (P < 0.05) in draught force between the 2 species. The work rate per hour for ploughing with donkeys was 65% of that of cattle. It was concluded that donkeys play a critical role in providing draught power for smallholder farmers but that their potential is not fully utilised.