Application of secondary nutrients and micronutrients increases crop yields in sub-Saharan Africa

Rapidly rising populations and likely increases in incomes in sub-Saharan Africa make tens of millions of hectares of cropland expansion nearly inevitable, even with large increases in crop yields. Much of that expansion is likely to occur in higher rainfall savannas, with substantial costs to biodiversity and carbon storage. Zambia presents an acute example of this challenge, with an expected tripling of population by 2050, good potential to expand maize and soya bean production, and large areas of relatively undisturbed miombo woodland and associated habitat types of high biodiversity value. Here, we present a new model designed to explore the potential for targeting agricultural expansion in ways that achieve quantitatively optimal trade-offs between competing economic and environmental objectives: total converted land area (the reciprocal of potential yield); carbon loss, biodiversity loss and transportation costs. To allow different interests to find potential compromises, users can apply varying weights to examine the effects of their subjective preferences on the spatial allocation of new cropland and its costs. We find that small compromises from the objective to convert the highest yielding areas permit large savings in transportation costs, and the carbon and biodiversity impacts resulting from savannah conversion. For example, transferring just 30% of weight from a yield-maximizing objective equally between carbon and biodiversity protection objectives would increase total cropland area by just 2.7%, but result in avoided costs of 27–47% for carbon, biodiversity and transportation. Compromise solutions tend to focus agricultural expansion along existing transportation corridors and in already disturbed areas. Used appropriately, this type of model could help countries find agricultural expansion alternatives and related infrastructure and land use policies that help achieve production targets while helping to conserve Africa's rapidly transforming savannahs. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’.

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Infrastructure for Agricultural & Rural Development in Sub Saharan Africa: Need for a Comprehensive Program and Adequate Investment

Journal of Scientific Research and Reports ◽

10.9734/jsrr/2019/v23i330120 ◽

2019 ◽

pp. 1-8

Author(s):

Nwauwa Linus OnyekaEzealaji

Keyword(s):

Agricultural Development ◽

Crop Yields ◽

Human Life ◽

Strong Relationship ◽

Farming System ◽

Sub Saharan Africa ◽

African Countries ◽

Trading Systems ◽

Rural Infrastructure ◽

Sub Saharan

This study unanimously confirms that rural infrastructure is a sine qua non for significantly improving the quality of human life and phenomenally accelerating the process of agricultural development in Africa. Infrastructure projects, however, involve huge initial capital investments, long gestation periods, high incremental capital output ratio, high risk, and low rate of returns on investments. Rural infrastructure has direct and strong relationship with farmers’ access to institutional finance and markets, and increasing crop yields, thereby promoting agricultural growth. Agricultural infrastructure has the potential to transform the existing traditional agriculture or subsistence farming into a most modern, commercial and dynamic farming system in Sub Saharan Africa. Increase in investment of agricultural infrastructure leads to increase in output and employment, a full investment formulation that meets the needs of domestic or external (multilateral and bilateral) funding sources will have to be carried out. Overall, a flexible, participatory approach will be needed, with full national and local involvement and commitment, while international partners, including Food and Agricultural Organization (FAO), give initial assistance to New partnership for Africa’s Development (NEPAD) in this process. The paper therefore recommends that technical and financial assistance will be required to help build capacity in African countries to face the challenges and take full advantage of the opportunities flowing from the multilateral trading systems.

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Climate Change, Agriculture, and Famine

Heat Advisory ◽

10.7551/mitpress/9780262034876.003.0005 ◽

2016 ◽

Author(s):

Alan H. Lockwood

Keyword(s):

Climate Change ◽

Critical Temperature ◽

Crop Yields ◽

Nutrient Content ◽

Hay Fever ◽

Sub Saharan Africa ◽

Normal Intelligence ◽

Temperature Thresholds ◽

The World ◽

Sub Saharan

Hotter weather and higher atmospheric CO2 levels will have profound effects on plants. Crops such as corn and soybeans, have critical temperature thresholds above which yields fall precipitously. High CO2 levels will foster the growth of many weeds over crops, threatening yields. Stimulated growth and release of ragweed allergens will threaten hay fever sufferers and asthmatics. The nutrient content of many crops falls in a high CO2 environment. As crop yields fall, prices rise, and undernutrition increases, particularly among children who fail to develop normally who, as a result, may not achieve normal intelligence. In many nations, particularly in Sub-Saharan Africa, childhood undernutrition already approaches 50%. Feeding the increasing population of the world may become problematic.

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Smallholder farms in eastern African tropical highlands have low soil greenhouse gas fluxes

Biogeosciences ◽

10.5194/bg-14-187-2017 ◽

2017 ◽

Vol 14 (1) ◽

pp. 187-202 ◽

Cited By ~ 18

Author(s):

David Pelster ◽

Mariana Rufino ◽

Todd Rosenstock ◽

Joash Mango ◽

Gustavo Saiz ◽

...

Keyword(s):

Greenhouse Gas ◽

Crop Production ◽

Crop Yields ◽

N Uptake ◽

Sub Saharan Africa ◽

N2o Emissions ◽

Vegetation Types ◽

Smallholder Farms ◽

Sub Saharan ◽

Ch4 And N2o

Abstract. Few field studies examine greenhouse gas (GHG) emissions from African agricultural systems, resulting in high uncertainty for national inventories. This lack of data is particularly noticeable in smallholder farms in sub-Saharan Africa, where low inputs are often correlated with low yields, often resulting in food insecurity as well. We provide the most comprehensive study in Africa to date, examining annual soil CO2, CH4 and N2O emissions from 59 smallholder plots across different vegetation types, field types and land classes in western Kenya. The study area consists of a lowland area (approximately 1200 m a.s.l.) rising approximately 600 m to a highland plateau. Cumulative annual fluxes ranged from 2.8 to 15.0 Mg CO2-C ha−1, −6.0 to 2.4 kg CH4-C ha−1 and −0.1 to 1.8 kg N2O-N ha−1. Management intensity of the plots did not result in differences in annual GHG fluxes measured (P = 0.46, 0.14 and 0.67 for CO2, CH4 and N2O respectively). The similar emissions were likely related to low fertilizer input rates (≤ 20 kg N ha−1). Grazing plots had the highest CO2 fluxes (P = 0.005), treed plots (plantations) were a larger CH4 sink than grazing plots (P = 0.05), while soil N2O emissions were similar across vegetation types (P = 0.59). This study is likely representative for low fertilizer input, smallholder systems across sub-Saharan Africa, providing critical data for estimating regional or continental GHG inventories. Low crop yields, likely due to low fertilization inputs, resulted in high (up to 67 g N2O-N kg−1 aboveground N uptake) yield-scaled emissions. Improvement of crop production through better water and nutrient management might therefore be an important tool in increasing food security in the region while reducing the climate footprint per unit of food produced.

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Food Crop Yields and Soil Properties under Population Pressure in Sub-Saharan Africa: the Case of Cassava in Southeast Nigeria

Outlook on Agriculture ◽

10.1177/003072709702600107 ◽

1997 ◽

Vol 26 (1) ◽

pp. 29-34 ◽

Cited By ~ 4

Author(s):

Charles L. A. Asadu ◽

Anselm A. Enete

Keyword(s):

Soil Properties ◽

Crop Yields ◽

Exchange Capacity ◽

Parent Material ◽

Sub Saharan Africa ◽

Population Pressure ◽

Southeastern Nigeria ◽

Cassava Root ◽

Sub Saharan ◽

Major Factors

Cassava root yields in three villages in southeastern Nigeria with marked differences in population pressure were related to soil properties using various models. The soils of the low population village, being formed from a different parent material, were more fertile than those of the medium and high population villages and cassava root yields were significantly higher in this village. The specific soil properties which appeared to promote cassava yields included pH and contents of Mn, silt and sand. Absolute values of exchangeable Mg, Ca, acidity and effective cation exchange capacity, although not significantly correlated with root yield, were also most favourable in the low population village. Thus inherent differences in soil properties rather than population pressure may be the major factors contributing to variations in cassava root yields in these villages.

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Assessing Potassium Mass Balances in Different Countries and Scales

Improving Potassium Recommendations for Agricultural Crops ◽

10.1007/978-3-030-59197-7_11 ◽

2020 ◽

pp. 283-340

Author(s):

Kaushik Majumdar ◽

Robert M. Norton ◽

T. Scott Murrell ◽

Fernando García ◽

Shamie Zingore ◽

...

Keyword(s):

Crop Yields ◽

Cropping Systems ◽

Nutrient Status ◽

Sub Saharan Africa ◽

Mass Balances ◽

Input Output ◽

Nutrient Additions ◽

The Usa ◽

Sub Saharan ◽

Production Areas

AbstractEstimating nutrient mass balances using information on nutrient additions and removals generates useful, practical information on the nutrient status of a soil or area. A negative input–output balance of nutrients in the soil results when the crop nutrient removal and nutrient losses to other sinks become higher than the nutrient inputs into the system. Potassium (K) input–output balance varies among regions that have different climates, soil types, cropping systems, and cropping intensity. This chapter illustrates the farm-gate K balances in major production areas of the world and their impacts on native K fertility and crop yields. On-farm and on-station research examples show significant negative K balances in South Asia and Sub-Saharan Africa, while China, the USA, Brazil, and countries of the Latin America Southern Cone highlighted continued requirement of location-specific K application to maintain crop yields and soil K fertility status at optimum levels.

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Improving Crop Yields in Sub-Saharan Africa - What Does the East African Data Say

SSRN Electronic Journal ◽

10.2139/ssrn.3642661 ◽

2020 ◽

Author(s):

Alun Thomas

Keyword(s):

Crop Yields ◽

Sub Saharan Africa ◽

East African ◽

Sub Saharan

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African Smallholder Farmers on the Move: Farm and Non-Farm Trends for Six Sub-Saharan African Countries, 2002–15

10.1093/oso/9780198799283.003.0002 ◽

2018 ◽

Author(s):

Magnus Jirström ◽

Maria Archila Bustos ◽

Sarah Alobo Loison

Keyword(s):

Crop Production ◽

Crop Yields ◽

Smallholder Farmers ◽

Crop Productivity ◽

Sub Saharan Africa ◽

African Countries ◽

Production Area ◽

Sub Saharan ◽

The One ◽

High Degree

This chapter provides a broad descriptive background of central aspects of smallholder agriculture in six countries in sub-Saharan Africa (SSA). It offers an up-to-date picture of the current trends of crop production, area productivity, levels of commercialization, and sources of cash incomes among 2,500 farming households. Structured around smallholder production, commercialization, and diversification in the period 2002–15, the chapter points on the one hand at persistent challenges such as low crop yields, low levels of output per farm, and a high degree of subsistence farming, and on the other hand at positive change over time in terms of growth in crop production and increasing levels of commercialization. It points at large variations not only between countries and time periods but also at the village levels, where gaps in crop productivity between farms remain large. Implicitly it points at the potential yet to be exploited in the SSA smallholder sector.

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Age of Marriage, Weather Shocks, and the Direction of Marriage Payments

Econometrica ◽

10.3982/ecta15505 ◽

2020 ◽

Vol 88 (3) ◽

pp. 879-915 ◽

Cited By ~ 8

Author(s):

Lucia Corno ◽

Nicole Hildebrandt ◽

Alessandra Voena

Keyword(s):

Crop Yields ◽

Marriage Market ◽

Sub Saharan Africa ◽

Economic Conditions ◽

Child Marriage ◽

Economic Role ◽

Weather Shocks ◽

Marriage Behavior ◽

Sub Saharan ◽

Age Of Marriage

We study how aggregate economic conditions affect the timing of marriage, and particularly child marriage, in Sub‐Saharan Africa and in India. In both regions, substantial monetary or in‐kind transfers occur with marriage: bride price across Sub‐Saharan Africa and dowry in India. In a simple equilibrium model of the marriage market in which parents choose when their children marry, income shocks affect the age of marriage because marriage payments are a source of consumption smoothing, particularly for a woman's family. As predicted by our model, we show that droughts, which reduce annual crop yields by 10 to 15% and aggregate income by 4 to 5%, have opposite effects on the marriage behavior of a sample of 400,000 women in the two regions: in Sub‐Saharan Africa they increase the annual hazard into child marriage by 3%, while in India droughts reduce such a hazard by 4%. Changes in the age of marriage due to droughts are associated with changes in fertility, especially in Sub‐Saharan Africa, and with declines in observed marriage payments. Our results indicate that the age of marriage responds to short‐term changes in aggregate economic conditions and that marriage payments determine the sign of this response. This suggests that, in order to design successful policies to combat child marriage and improve investments in daughters' human capital, it is crucial to understand the economic role of marriage market institutions.

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