The Zimbabwean dairy industry is massively underperforming, as evidenced by a reduction in milk yield from 262 million liters in 1990 to <37 million liters in 2009 and a steady but slow increase to 82 million liters in 2021. The current demand for milk in Zimbabwe stands at 130 million liters, and there is a national capacity for processing 400 million liters per annum. This study used literature, stakeholder inputs and expert knowledge to provide a perspective on practical options to reduce the national milk deficit and, simultaneously, accelerate the transition to a sustainable dairy value chain in Zimbabwe. Following a discussion on the key barriers and constraints to developing the milk value chain, we explored opportunities to improve the performance of the underperforming smallholder and medium-scale dairy farmers. Specifically, we discussed innovative management, creative policy instruments and alternative technological options to maximize milk production in Zimbabwe. We also highlight the need for an inclusive and creatively organized dairy value chain to optimize stakeholder linkages and improve information flow and equity. Examples of crucial investments and incentive structures for upgrading the existing value chain and monitoring greenhouse gas emissions and carbon uptake are discussed. Furthermore, the socio-economic effects (i.e., profitability, women empowerment and employment creation), milk quality, safety and traceability issues linked to a better organized and performing dairy value chain are highlighted.

Organic agriculture in smallholder sub-Saharan African farming areas faces a lot of challenges that are different from those experienced in other regions of the world. While local farmers use organic resources in some way, the adoption of organic agriculture as a means of commercial production is lagging. Peer-reviewed literature on organic agriculture in Zimbabwe and most of Africa is limited. This review identifies regional situational differences in the farming environment in sub-Sahara Africa and Zimbabwe and discusses the opportunities and challenges peculiar to smallholder organic agriculture farmers. Results show that organic agriculture in Zimbabwean smallholder farming areas is mainly promoted by non-governmental organisations and supporting public policy is lacking. Local markets for organic produce are not well developed and an opportunity exists to develop local markets through supportive public policies, private sector engagement and further training and farmer support. While most soils present challenges to crop production due to nutrient deficiencies, yield increases are possible with organic management and research on mixing/fortifying organic amendments is needed.

Key messages Close to 100 million farmers, half of them extremely poor, live in the African agropastoral farming system characterized by highly variable, semi-arid climate and poor soil conditions. Agropastoral livelihoods rely on the integration of crop and pastoral livestock production and soil, crop and tree-based adaptive management practices that optimize resources and reduce risk and vulnerability. Key trends include rapid population growth and urbanization, resulting in the development of domestic markets, increased monetization of the food system including for the poorest, improved access to information, and climate change. Changes in natural resources management include reduced fallow area and duration, increased competition between cropping and pastoral activities, sedentarization of mobile pastoral production and farmer-managed regeneration of tree cover on farms. Yield gaps can be bridged with soil and water conservation technologies combined with both organic and inorganic amendments, yet intensification is constrained by system bottlenecks in agricultural chains from production to marketing. Sustainable intensification requires systemic investment planning and integrated multi-stakeholder intervention approaches along the value chain that contribute to maximizing profitability and minimizing risk and for farmers. Key investment priorities include opportunities for the youth, enhancing women’s access to land resources, a strengthened role of farmer organizations in agricultural value chains, effective scaling-up approaches for adapted technology and market innovations, specific policy focus on the development of sorghum, millet, cowpea and groundnut improved urban-rural linkages and enabling policies.

Purpose The implications of increased applications of high quality cattle manure to agricultural systems in Africa on N₂O emissions are still only partially understood. Methods A field experiment was carried out in a wetland in central Zimbabwe to determine the effects of cattle manure quality on emissions of N₂O during the growing seasons of rape and tomato crops. The static chamber and gas chromatography techniques were used to capture and measure fluxes of N₂O. Results The substitution of low N by high N manure significantly increased N₂O fluxes and total N lost through N₂O emission. Emissions of N₂O increase with increasing content of N in applied manure. Conclusions Given that N₂O in agricultural soil is produced predominantly through the microbial transformations of inorganic N, the potential of a soil to emit N₂O increases with the increasing availability of N and consequently the N content in applied manure. The applications of lower rate of high and low N manures were followed by lower emissions of N₂O, a result that is favorable to the objective of lowering the contribution of agricultural sources to the global greenhouse gas emissions. The loss of N in emissions of N₂O expressed per unit mass of harvested dry matter yield decreases with increasing manure application, dry matter yield and N uptake. Improved agronomic practices for increased crop productivity can be used as a mitigation factor for reducing the contribution of agriculture in the global emissions of N₂O.

An understanding of the contribution of manure applications to global atmospheric N2O loading is needed to evaluate agriculture’s contribution to the global warming process. Two field experiments were carried out at Dufuya wetland (19°17′S; 29°21′E, 1260 m above sea level) to determine the effects of single and split manure applications on emissions of N2O from soil during the growing seasons of two rape and two tomato crops. Two field experiments were established. In the first experiment the manure was applied in three levels of 0, 15, and 30 Mg ha−1 as a single application just before planting of the first tomato crop. In the second experiment the 15 and 30 Mg ha−1 manure application rates were divided into four split applications of 3.75 and 7.5 Mg ha−1 respectively, for each of the four cropping events. Single applications of 15 and 30 Mg ha−1 manure once in four cropping events had higher emissions of N2O than those recorded on plots that received split applications of 3.75 and 7.5 Mg ha−1 manure at least up to the second test crop. Thereafter N2O emissions on plots subjected to split applications of manure were higher or equal to those recorded in plots that received single basal applications of 30 Mg ha−1 applied a week before planting the first crop. Seasonal split applications of manure to wetland vegetable crops can reduce emissions of N2O at least up to the second seasonal split application.

Nitrogen (N) is an essential macronutrient for plant growth and productivity, but deficient in most Zimbabwean soils and its dynamics under conservation tillage are not well documented. The objective was to determine the effects of fertilizer application on mineral N dynamics and yield of maize (Zea mays L) and soybean (Glycine max (L) Merr) under conservation tillage in sub-humid tropical conditions of North Western Zimbabwe. Soil N mineralization was measured using in-situ incubation of undisturbed soil cores and soil N was determined using the method of extraction with 0.5M K2SO4. Nitrogen in aboveground plant tissue and grain was determined using spectrophotometry after Kjeldhal digestion. Soil N mineralization steadily increased as the growing season progressed and soil mineral N was 6.9% higher under conventional tillage compared to conservation tillage. The effects of mineral fertilizer application on soil N mineralization were highest in mulched plots and lowest in maize monocropping. Similar to N uptake at 5 weeks after planting (wap), grain and stover N uptake were highest when a combination of reduced tillage and mulching practices were used and lowest under conventional tillage. Highest soil N mineralization, maize N uptake, soybean N uptake and grain yield are achievable when all the three practices of conservation agriculture are applied compared with application of one or two practices as currently adopted by smallholder farmers in sub-Saharan Africa. Combining mineral fertilizer application with conservation agriculture results in higher soil N mineralization, N uptake and grain yield when compared with fertilizer application under conventional tillage.