Climate change and variability impacts on crop production in the low potential smallholder farming regions of Zimbabwe.

Doctor of Philosophy in Crop Science. University of KwaZulu-Natal, Pietermaritzburg 2016.Climate change and variability is one of the most serious global problems affecting many sectors in the world. It is considered to be one of the most serious threats to sustainable development with adverse impact on environment, human health, food security, economic activities, natural resources and physical infrastructure. Southern Africa is one of the most vulnerable regions to climate change in the world, particularly because of widespread poverty, recurrent droughts, inequitable land distribution, over-dependence on rain-fed agriculture and low adaptive capacity. Yet rural farmers in southern Africa have managed to survive the vagaries of climate change over the years. The central argument in this study was that coping and adaptation strategies to climate change by local smallholder farming communities in Zimbabwe who traditionally relied on indigenous knowledge systems are at risk and less effective because the use of indigenous knowledge systems is becoming unreliable due to climate change and variability. The main objective of this study was to identify local smallholder farmers’ perceptions to climate change and variability and the influence of indigenous knowledge systems in deciding and adopting coping and adaptation strategies. This study used a combination of participatory and field data collection tools in Chiredzi District, one of the areas affected by climate change impacts in Zimbabwe. Household surveys, focus group discussions and key informant interviews were done in selected wards in the district. Field trials were done to identify climate smart cropping options to assist farmers in coping and adapting to climate change and variability. The results indicate that farmers use a variety of local indicators for weather forecasting and climate prediction, for adapting to climate change and variability. Integrating indigenous knowledge systems with climate scientists’ efforts can contribute to effective on-farm adaptation initiatives. One objective of this research was to identify IKS used by farmers to predict seasonal weather patterns, and the subsequent adaptation strategies. The information was collected using focus group discussions, household survey, and ethnographic interviews. Most farmers (72.2%) indicated that low rainfall is the major limitation to agricultural production. Without reliable local scientific weather forecasts the farmers use tree phenology, animal behaviour and atmospheric circulation as sources of local knowledge to predict the onset and quality of the season. These forecasts are then used for designing crop choices, planting dates and agronomic practices. Study results obtained show that the use of IKS in local farming communities is an effective way of building coping and adaptation strategies. The results revealed that IKS are being eroded and becoming less accurate in seasonal weather prediction. Therefore, future studies on IKS should use multiple methods that combine indigenous knowledge and scientific weather data in order to obtain more complete and accurate information for local area season quality prediction. Another study objective was to examine farmer perceptions on climate variability, current adaptive strategies and establish factors influencing smallholder farmers’ adaptation to climate change. The results showed that farmers perceived that there has been a decrease in annual rainfall and an increase in average temperatures. A linear trend analysis of rainfall and temperature data from 1980 to 2011 corroborated the farmers’ perceptions. Farmers’ adaptation options included adjusting planting dates and crop diversification. Off-farm income has reduced the dependence of the farmers on agriculture. A multinomial regression analysis showed that socio-economic factors such as gender, age, number of cattle owned, land size and average crop yields influenced farmer adaptation strategies. We conclude that although farmers are diverse in their socio-economic attributes, they exhibit homogeneous perceptions on changes in climate, which are consistent with observations of empirical climate data. These perceptions help to shape smallholder farmer coping and adaptation strategies. The variability of climate demands the use of a variety of agronomic strategies and crop choices in order to reduce vulnerability and increase resilience and adaptive capacity to climate change and variability. Traditional drought tolerant crops such as sorghum are often chosen when drought seasons are anticipated. However, there are certain crops, originating elsewhere, that could help the smallholder farmers increase diversity of crops that can be grown in changed climates. One such crop is tepary bean (Phaseolus acutifolias). Resource poor farmers, affected by drought effects of climate change, can adopt climate smart crops to achieve food, nutritional and heath security from combinations of cereals and legumes. This study revealed that these rural farmers are highly vulnerable and resilient, largely using indigenous knowledge systems to cope and adapt to climate change. Availability and access to scientific weather information to make cropping and other decisions at the local level remain key issues to usage of climatic data by rural farmers. One the other hand, indigenous knowledge is what they have been using but is also becoming unreliable due to climate change, increasing vulnerability and demanding more resilience. Integration of indigenous knowledge and scientific seasonal forecast seems to be a key possible thrust to reduce vulnerability, enhance resilience of rural farmers and increase their adaptive capacity. This study concludes that farmers can use indigenous knowledge systems to make adaptation decisions. However, there is need to integrate indigenous knowledge systems and scientific knowledge to reduce vulnerability and increase adaptive capacity of smallholder farmers. Climate smart crops provide a useful option for farmers affected by climate change and variability to improve food and nutritional security and livelihoods

Factors Influencing Smallholder Farmers’ Adaptation to Climate Change and Variability in Chiredzi District of Zimbabwe

The study sought to understand household adaptation strategies to climate variability and analyse socioeconomic factors influencing smallholder farmers’ adaptation.  A binary logit model was used to analyse the factors influencing household decision to adapt to climate variability. Results show that at farm level, the adaptation techniques employed included dry planting, conservation agriculture, planting short season crop varieties, holding prayers and religious festivals and crop diversification. From the binary logit model, access to extension , number of members fit to work, livestock holding, access to credit, neatively age of household head  positively influenced adaptation decision while age of household head and farm income  negatively influenced adaptation decision. Keywords: Climate change, Adaptation, binomial logit, smallholder farmers, resources, technolog

El Niño’s Effects on Southern African Agriculture in 2023/24 and Anticipatory Action Strategies to Reduce the Impacts in Zimbabwe

The frequency of El Niño occurrences in southern Africa surpasses the norm, resulting in erratic weather patterns that significantly impact food security, particularly in Zimbabwe. The effects of these weather patterns posit that El Niño occurrences have contributed to the diminished maize yields. The objective is to give guidelines to policymakers, researchers, and agricultural stakeholders for taking proactive actions to address the immediate and lasting impacts of El Niño and enhance the resilience of the agricultural industry. This brief paper provides prospective strategies for farmers to anticipate and counteract the El Niño-influenced dry season projected for 2023/24 and beyond. The coefficient of determination R2 between yield and ENSO was low; 11 of the 13 El Niño seasons had a negative detrended yield anomaly, indicating the strong association between El Nino’s effects and the reduced maize yields in Zimbabwe. The R2 between the Oceanic Nino Index (ONI) and rainfall (43%) and between rainfall and yield (39%) indirectly affects the association between ONI and yield. To safeguard farmers’ livelihoods and improve their preparedness for droughts in future agricultural seasons, this paper proposes a set of strategic, tactical, and operational decision-making guidelines that the agriculture industry should follow. The importance of equipping farmers with weather and climate information and guidance on drought and heat stress was underscored, encompassing strategies such as planting resilient crop varieties, choosing resilient livestock, and implementing adequate fire safety measures

Mineral Nutrition and Integration of Forage Legumes into Smallholder Farming Systems, with Emphasis on Velvet Bean [Mucuna pruriens (L) DC var. utilis].

The major objective of this work was to evaluate and compare forage supply and soil fertility effects of velvet bean (Mucuna pruriens var. utilis) integrated into smallholder cropping systems as ley, intercrop and green manure for farmers engaged in semi-commercial offtake from livestock. The results also present information about the alleviation of mineral nutrient constraints in order to raise the productivity and probability for adoption of velvet bean as a forage and green manure crop in Zimbabwe, through a series of experiments conducted on farm with farmers. Socio – economic assessments of the suitability of these interventions were also incorporated into the work. Experiments were carried out in Zana resettlement and Dendenyore communal areas of Hwedza District, Zimbabwe (18o41'S latitude; 31o42’ E longitude; 1400 m asl) to compare different systems of integrating forage legumes in terms of forage production and effect on a subsequent maize crop. The systems included velvet bean, cowpea and archer (mixed with Katambora Rhodes grass) grown as leys, intercrops or green manure, with or without SSP or lime. A weed fallow and sole maize were also included as controls. A maize cropping phase followed most of the treatments in year 2 to determine the rotational benefits of the legume systems. The trials were conducted at nine farmers’ fields and the soils were generally acidic (pH<5 – calcium chloride method), inherently infertile (low available P, Ca, Mg and mineral N and total C% < 1.5%) sands, loamy sands or light clays. The biomass production in season 1 for velvet bean with inorganic P fertilizer applied at planting (16.4 kg ha-1) ranged from 6.5 to 17 t DM ha-1 (range was 3.7 to 11.8 t DM ha-1 without P fertilizer). There was a 15% increase in velvet bean dry matter yield with lime application. Velvet bean and cowpea showed a greater response to P fertilizer application (30.9% and 29.4%, respectively), compared with Archer and Katambora Rhodes grass (14.5%). Season 2 results showed a significant (P<0.05) residual effect of velvet bean on the maize stover and grain yield. They also pointed to a positive P residual effect of velvet bean, and revealed that biomass production in perennial leys would be greater in the second season than in the first, even when the leys are grazed during the dry season. Overall, there was an increase of more than 300 kg in maize grain yield for every tonne of green manure incorporated. This was a nitrogen use efficiency of 11 kg grain/kg N applied. These results show that the application of P and lime can substantially raise productivity of velvet bean and allow it to input large amounts of N that can benefit following maize crops. A further experiment on the effect of liming on velvet bean showed that the response of velvet bean to liming in season 1 was due to a combination of increase in pH and supply of Ca and Mg. In terms of overall N and P partial nutrient balances in the systems, the green manure velvet bean (with 16.4 kg-1 P) followed by maize (with 30 kg N/ha) system proved to be the most sustainable (overall partial N balance of -88.6 kg/ha and partial P balance of 10 kg/ha), while the maize (with 30 kg N/ha) following limed velvet bean (with P) grown for hay and the maize (with 30 kg N/ha) after weed fallow systems were the least sustainable for N (-389 kg/ha) and P (-9.2 kg/ha) balances, respectively, when comparing these three systems. The results of a gross margin analysis indicated a strong residual effect of P on maize yield and that farmers growing maize after velvet bean benefit in terms of a higher maize yield and reduced inorganic fertilizer costs. A survey revealed the high potential of velvet bean to improve the existing farming systems. Velvet bean appeared particularly beneficial and attractive to commercial oriented livestock smallholder farmers. For this, it would be grown as a ley crop and hay or pods and residue fed to cattle. It appeared less attractive to non-livestock smallholder farmers, where its use would be more as a green manure to feed the soil (and then subsequently maize and humans)

Velvet Bean and Cowpea Residual Effects on Maize Crop in Smallholder Farming Areas of Zimbabwe

On-farm research was conducted in Dendenyore Communal Land and Zana Resettlement areas of Hwedza District, Zimbabwe from 1999 to 2001. The objective of the study was to evaluate the effects of velvet bean and cowpea on growth and yield of maize in legume-maize rotation system. A total of 14 treatments, which consisted of forage legume and maize crops were examined. The experiment was established in a randomized complete block design with 9 replicates. On-farm sites were the replicates. The results show a significant residual effect of velvet bean and cowpea, when grown with single super phosphate fertiliser, on the maize stover and grain yield. They indicate significant phosphorus residual effects on a subsequent maize crop on sandy soils. Forage legumes contribute to residual soil fertility in fallen leaves and roots that increases yield of subsequent crops. The results also reveal that biomass production in perennial leys, grazed during the dry season, would be greater in the second season than in the establishment year. The results also indicate that in the velvet bean systems, especially green manure, nitrogen is lost very early in the season. This may lead to lack of synchrony between nutrient availability and crop uptake. The maize after green manure system had a nitrogen use efficiency of about 11 kg/kg of nitrogen applied. These results show the residual potential of forage legumes in reducing nitrogen fertiliser need for subsequent maize crops in mixed livestock-cropping systems

Tracking the Release of Soil Nitrate and Labile C in A Legume-Maize Rotation in Zimbabwe

This study compared the effect of a weedy fallow (5.2 t/ha biomass), a velvet bean (Mucuna pruriens) cut for hay (7.2 t/ha biomass) and a green-manured M. pruriens (6.49 t/ha biomass) on the dynamics of soil N and C in a maize crop. An on-farm, farmer participatory experiment was established on a farmer’s field in Wedza District, Zimbabwe. Soil mineral N and labile carbon were determined at intervals upto 120 cm depth, at maize planting and at 1 and 2 weeks after planting. Before planting, the soil mineral N content ranged from 28 kg N/ha after weed fallow to 107 kgN/ha following M. pruriens. Total nitrate concentration was highest in the 0-15 cm depth of the M. pruriens treatments in the pre-planting sampling, but following rainfall and maize planting, nitrate concentration declined rapidly. By 2 weeks after planting, 7.5 and 13.5 kg N/ha remained in the 0-120 cm soil depth of the weedy fallow and green-manured M. pruriens, respectively. Improving synchrony of nutrient release and uptake is critical when applying high quality residues which breakdown relatively slowly. This could result in significant inputs of C, release nutrients more slowly and reduce soil nutrient losses

Velvet Bean and Cowpea Residual Effects on Maize Crop in Smallholder Farming Areas of Zimbabwe

On-farm research was conducted in Dendenyore Communal Land and Zana Resettlement areas of Hwedza District, Zimbabwe from 1999 to 2001. The objective of the study was to evaluate the effects of velvet bean and cowpea on growth and yield of maize in legume-maize rotation system. A total of 14 treatments, which consisted of forage legume and maize crops were examined. The experiment was established in a randomized complete block design with 9 replicates. On-farm sites were the replicates. The results show a significant residual effect of velvet bean and cowpea, when grown with single super phosphate fertiliser, on the maize stover and grain yield. They indicate significant phosphorus residual effects on a subsequent maize crop on sandy soils. Forage legumes contribute to residual soil fertility in fallen leaves and roots that increases yield of subsequent crops. The results also reveal that biomass production in perennial leys, grazed during the dry season, would be greater in the second season than in the establishment year. The results also indicate that in the velvet bean systems, especially green manure, nitrogen is lost very early in the season. This may lead to lack of synchrony between nutrient availability and crop uptake. The maize after green manure system had a nitrogen use efficiency of about 11 kg/kg of nitrogen applied. These results show the residual potential of forage legumes in reducing nitrogen fertiliser need for subsequent maize crops in mixed livestock-cropping systems

Urban and Peri-Urban Agriculture as A Pathway to Food Security: A Review Mapping the Use of Food Sovereignty

Renewed interest in the nexus between sustainability and food security has led to growing discussions on the use of food sovereignty principles in agricultural practice. As a result of the transfiguration of the urban and socioeconomic landscape in the global South, urban and peri-urban agriculture has been touted as a potential response to increasing food insecurity in cities. Yet, both urban and peri-urban agriculture and food sovereignty have attracted cursory scholarship and programming in Zimbabwe due to fixation on more dominant rural and conventional agriculture. Beyond the rudimentary idea that the urban landscape is unfit for food production, literature has demonstrated that urban households have ingrained urban and peri-urban agriculture into their livelihoods. Regardless, institutional arrangements governing the practice remain ambivalent towards the practice, bringing to question the ability of households to fully exploit the benefits of the practice. This review underscores that failure to involve of all stakeholders undermines urban and peri-urban agriculture, consequently leading to heightened food insecurity and use of unsustainable practices. By delving into the political economy of food, we hope to stimulate discussion centered on food sovereignty within and urban spaces and beyond

Evaluation of Tillage Practices for Maize (Zea mays) Grown on Different Land-Use Systems in Eastern Zambia

Improved fallows of Sesbania sesban (Sesbania) have been known to improve soil physical and chemical properties and increase crop yield compared to traditional fallows. However, the effects of soil tillage practices after improved fallows on soil properties, weeds, labour and subsequent maize crop have not been assessed in Southern Africa. This study aimed to evaluate how tillage practices affect yield of maize and affect soil properties after two years of fallow and subsequent cropping phase. In this study, done at sites in eastern Zambia, maize yield from a two-year planted Sesbania, natural fallow, continuously fertilized and unfertilized maize were compared under conventional, flat till and zero tillage practices. A split plot experiment, with improved fallow systems in the main plot and the tillage practice in the subplot, was established at the sites. The results showed that the increases in grain yield under conventional tillage over zero tillage practice were 17.8% and 28.2% during 2000/2001 and 2001/2002 seasons, respectively, at Msekera. At Chadiza, the increases in grain yield under conventional tillage over zero tillage were 66.3% and 327.4% during 2000/2001 and 2001/2002 seasons, respectively. Greater maize yields were achieved under Sesbania planted fallows compared to the natural fallow and maize monoculture without fertilizer. Overall, zero tillage practice resulted in lower maize grain yield, higher bulk density, reduced water intake, higher weed infestation and high labour demand during weeding compared to conventional tillage

Integration of indigenous and scientific knowledge in climate adaptation in KwaZulu- Natal, South Africa

Indigenous knowledge has for generations assisted rural subsistence farming communities adapt to climate change and make daily decisions regarding agriculture. This study was conducted in the rural community of Swayimane, uMshwathi Municipality, KwaZulu-Natal, South Africa. The main objective of the research was to determine the indigenous indicators used by rural farmers, identify the means through which seasonal climate information is disseminated and assess the strengths and weaknesses of indigenous and scientific knowledge. The other objective of the research was to evaluate the integration of indigenous and scientific weather forecasting. The research used 100 questionnaires which were administered to the subsistence farmers of the community. Focus group discussions and key informant interviews were conducted with small groups of individuals. Results showed that majority of the indigenous indicators related to rainfall and seasonal predictions. Also, seasonal scientific climate information was mainly disseminated via television and radio. Local farmers highlighted that indigenous knowledge was essential in predicting seasonal changes and rainfall and scientific knowledge was not trusted. Indigenous knowledge is transmitted by oral tradition, from generation to generation and mainly among the elderly, and, thinly, to the younger generation. Scientific information was thought to be too technical and difficult to comprehend. It can be concluded that subsistence farmers were open to the integration of scientific and indigenous weather forecasting. They highlighted that it would improve decision making concerning their agricultural activities