scholarly journals Can Tanzania’s adaptation measures prevent future maize yield decline? A simulation study from Singida region

2021 ◽  
Vol 21 (4) ◽  
Author(s):  
Johanna Volk ◽  
Christoph Gornott ◽  
Stefan Sieber ◽  
Marcos Alberto Lana
Keyword(s):  
Crop Production ◽  
Agricultural Sector ◽  
Crop Management ◽  
Maize Yield ◽  
Adaptation Strategies ◽  
Sub Saharan Africa ◽  
Climate Projections ◽  
Yield Decline ◽  
Maize Yields ◽  
Semi Arid

AbstractCereal crop production in sub-Saharan Africa has not achieved the much-needed increase in yields to foster economic development and food security. Maize yields in the region’s semi-arid agroecosystems are constrained by highly variable rainfall, which may be worsened by climate change. Thus, the Tanzanian government has prioritized agriculture as an adaptation sector in its intended nationally determined contribution, and crop management adjustments as a key investment area in its Agricultural Sector Development Programme. In this study, we investigated how future changes in maize yields under different climate scenarios can be countered by regional adjusted crop management and cultivar adaptation strategies. A crop model was used to simulate maize yields in the Singida region of Tanzania for the baseline period 1980–2012 and under three future climate projections for 2020–2060 and 2061–2099. Adaptation strategies to improve yields were full irrigation, deficit irrigation, mulch and nitrogen addition and another cultivar. According to our model results, increase in temperature is the main driver of future maize yield decline. Increased respiration and phenological development were associated with lower maize yields of 16% in 2020–2060 and 20% in 2061–2099 compared to the 1980–2012 baseline. Surprisingly, none of the management strategies significantly improved yields; however, a different maize variety that was tested as an alternative coping strategy performed better. This study suggests that investment in accessibility of improved varieties and investigation of maize traits that have the potential to perform well in a warmer future are better suited for sustaining maize production in the semi-arid region than adjustments in crop management.

scholarly journals Dead level contour technical design parameters required for sustainable crop production in semi-arid areas of Zimbabwe

2021 ◽  
Author(s):  
Douglas Gumbo ◽  
Menas Wuta ◽  
Isaiah Nyagumbo
Keyword(s):  
Crop Production ◽  
Smallholder Farmers ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
Design Parameters ◽  
Sustainable Crop Production ◽  
Spacing Interval ◽  
Dry Spells ◽  
Sub Saharan ◽  
Semi Arid

Abstract Smallholder farmers in sub-Saharan Africa are increasingly exposed to risks such as erratic rainfall, prolonged dry spells, and frequent droughts that threaten sustainable crop production. This study assessed the effectiveness of dead level contours with innovations (DLC INN), dead level contours with infiltration pits (DLC INFIL), dead level contours with open channels (DLC OPEN) and standard graded contours (SGCs) in harvesting and storing water in the channel, improving crop conditions during the critical stages of maize growth on different soil textural groups in the Zvishavane District of Zimbabwe. The DLC INFIL, DLC OPEN and DLC INN outperformed the SGC under medium- and heavy-textured soils, with yields ranging between 1.7 and 2.36 t/ha compared to 0.9 t/ha for the SGC. For light textured soils, the DLC INN had the highest maize yield, averaging 0.8 t/ha. On heavy textured soils using DLC INN, DLC INFIL and DLC OPEN, smallholder farmers may use a spacing interval of 24–27 m. On medium textured soils, DLC INN and DLC INFIL can be used at a spacing interval of 18–21 m and 12 to 15 m with DLC OPEN. On light textured soils, farmers are advised to invest in DLC INN only, using a spacing interval of 12–15 m.

scholarly journals Identifying maize yield and precipitation gaps in Uganda

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Terence Epule Epule ◽  
Driss Dhiba ◽  
Daniel Etongo ◽  
Changhui Peng ◽  
Laurent Lepage
Keyword(s):  
Cropping Systems ◽  
Growing Season ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
World Bank Group ◽  
Precipitation Data ◽  
Yield Data ◽  
Yield Gaps ◽  
Maize Yields ◽  
Growing Season Precipitation

AbstractIn sub-Saharan Africa (SSA), precipitation is an important driver of agricultural production. In Uganda, maize production is essentially rain-fed. However, due to changes in climate, projected maize yield targets have not often been met as actual observed maize yields are often below simulated/projected yields. This outcome has often been attributed to parallel gaps in precipitation. This study aims at identifying maize yield and precipitation gaps in Uganda for the period 1998–2017. Time series historical actual observed maize yield data (hg/ha/year) for the period 1998–2017 were collected from FAOSTAT. Actual observed maize growing season precipitation data were also collected from the climate portal of World Bank Group for the period 1998–2017. The simulated or projected maize yield data and the simulated or projected growing season precipitation data were simulated using a simple linear regression approach. The actual maize yield and actual growing season precipitation data were now compared with the simulated maize yield data and simulated growing season precipitation to establish the yield gaps. The results show that three key periods of maize yield gaps were observed (period one: 1998, period two: 2004–2007 and period three: 2015–2017) with parallel precipitation gaps. However, in the entire series (1998–2017), the years 2008–2009 had no yield gaps yet, precipitation gaps were observed. This implies that precipitation is not the only driver of maize yields in Uganda. In fact, this is supported by a low correlation between precipitation gaps and maize yield gaps of about 6.3%. For a better understanding of cropping systems in SSA, other potential drivers of maize yield gaps in Uganda such as soils, farm inputs, crop pests and diseases, high yielding varieties, literacy, and poverty levels should be considered.

scholarly journals Constraints to crop production and adaptation strategies of smallholder farmers in semi-arid Central and Western Zimbabwe

2017 ◽  
Vol 25 (2) ◽  
pp. 221 ◽  
Author(s):  
V. Makuvaro ◽  
S. Walker ◽  
A. Munodawafa ◽  
I. Chagonda ◽  
P. Masere ◽  
...  
Keyword(s):  
Crop Production ◽  
Smallholder Farmers ◽  
Adaptation Strategies ◽  
Semi Arid

scholarly journals Unravelling the variability and causes of smallholder maize yield gaps in Ethiopia

Food Security ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 83-103 ◽  
Author(s):  
Banchayehu Tessema Assefa ◽  
Jordan Chamberlin ◽  
Pytrik Reidsma ◽  
João Vasco Silva ◽  
Martin K. van Ittersum
Keyword(s):  
Stochastic Frontier Analysis ◽  
National Level ◽  
Total Yield ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
Yield Gap ◽  
Potential Yield ◽  
Frontier Analysis ◽  
Yield Gaps ◽  
Maize Yields

AbstractEthiopia has achieved the second highest maize yield in sub-Saharan Africa. Yet, farmers’ maize yields are still much lower than on-farm and on-station trial yields, and only ca. 20% of the estimated water-limited potential yield. This article provides a comprehensive national level analysis of the drivers of maize yields in Ethiopia, by decomposing yield gaps into efficiency, resource and technology components, and accounting for a broad set of detailed input and crop management choices. Stochastic frontier analysis was combined with concepts of production ecology to estimate and explain technically efficient yields, the efficiency yield gap and the resource yield gap. The technology yield gap was estimated based on water-limited potential yields from the Global Yield Gap Atlas. The relative magnitudes of the efficiency, resource and technology yield gaps differed across farming systems; they ranged from 15% (1.6 t/ha) to 21% (1.9 t/ha), 12% (1.3 t/ha) to 25% (2.3 t/ha) and 54% (4.8 t/ha) to 73% (7.8 t/ha), respectively. Factors that reduce the efficiency yield gap include: income from non-farm sources, value of productive assets, education and plot distance from home. The resource yield gap can be explained by sub-optimal input use, from a yield perspective. The technology yield gap comprised the largest share of the total yield gap, partly due to limited use of fertilizer and improved seeds. We conclude that targeted but integrated policy design and implementation is required to narrow the overall maize yield gap and improve food security.

scholarly journals RCP 8.5 Ghana. High-end climate change impacts on crop production

2020 ◽  
Author(s):  
Sylvia Tramberend ◽  
Günther Fischer ◽  
Harrij van Velthuizen
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Crop Production ◽  
Agricultural Sector ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Change Impacts ◽  
Development Planning ◽  
Sub Saharan Africa ◽  
Sub Saharan

<p>Climate change threatens vulnerable communities in sub-Saharan Africa who face significant challenges for adaptation. Agriculture provides the livelihood for the majority of population. High-resolution assessments of the effects of climate change on crop production are urgently needed for targeted adaptation planning. In Ghana, next to food needs, agriculture plays an important role on international cocoa markets. To this end, we develop and apply a National Agro-Ecological Zoning system (NAEZ Ghana) to analyze the impacts of high-end (RCP8.5) global warming on agricultural production potentials until the end of this century. NAEZ Ghana uses an ensemble of the CORDEX Africa Regional Climate Model, a regional soil map, to assess development trends of crop production potentials for 19 main crops. Results highlight differential impacts across the country. Especially due to the significant increase in the number of days exceeding high-temperature thresholds, rain-fed production of several food and export crops could be reduced significantly compared to the historical 30-year average (1981-2010). Plantain production, an important food crop, could achieve under climate change less than half of its current potential already in the 2050s and less than 10% by the 2080s. Suitable areas for cocoa production decrease strongly resulting in only one third of production potential compared to today. Other crops with detrimental effects of climate change include oil palm, sugarcane, coffee, and rubber. Production of maize, sorghum, and millet cope well with a future warmer climate. The NAEZ Ghana database provides valuable high-resolution information to support agricultural sector development planning and climate change adaptation strategies. The expansion of irrigation development will play a central role in some areas. This requires further research on Ghana’s linkages between food, water, and energy, taking into account climate and socio-economic changes.</p>

scholarly journals Effect of legume intercropping on N<sub>2</sub>O emissions and CH<sub>4</sub> uptake during maize production in the Great Rift Valley, Ethiopia

2020 ◽  
Vol 17 (2) ◽  
pp. 345-359
Author(s):  
Shimelis Gizachew Raji ◽  
Peter Dörsch
Keyword(s):  
Rift Valley ◽  
Crop Production ◽  
Growing Season ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
Ethiopian Rift ◽  
N2o Emissions ◽  
Mineral N ◽  
Total N ◽  
N Input

Abstract. Intercropping with legumes is an important component of climate-smart agriculture (CSA) in sub-Saharan Africa, but little is known about its effect on soil greenhouse gas (GHG) exchange. A field experiment was established at Hawassa in the Ethiopian rift valley, comparing nitrous oxide (N2O) and methane (CH4) fluxes in minerally fertilized maize (64 kg N ha−1) with and without Crotalaria (C. juncea) or lablab (L. purpureus) as intercrops over two growing seasons. To study the effect of intercropping time, intercrops were sown either 3 or 6 weeks after maize. The legumes were harvested at flowering, and half of the aboveground biomass was mulched. In the first season, cumulative N2O emissions were largest in 3-week lablab, with all other treatments being equal to or lower than the fertilized maize mono-crop. After reducing mineral N input to intercropped systems by 50 % in the second season, N2O emissions were comparable with the fully fertilized control. Maize-yield-scaled N2O emissions in the first season increased linearly with aboveground legume N yield (p=0.01), but not in the second season when early rains resulted in less legume biomass because of shading by maize. Growing-season N2O-N emission factors varied from 0.02 % to 0.25 % in 2015 and 0.11 % to 0.20 % in 2016 of the estimated total N input. Growing-season CH4 uptake ranged from 1.0 to 1.5 kg CH4-C ha−1, with no significant differences between treatments or years but setting off the N2O-associated emissions by up to 69 %. Our results suggest that leguminous intercrops may increase N2O emissions when developing large biomass in dry years but, when mulched, can replace part of the fertilizer N in normal years, thus supporting CSA goals while intensifying crop production in the region.

scholarly journals Evaluating the Effectiveness of Different Rhizobia Strains and Their Effect on Crop Yields in Acid Soils of Western Kenya

2018 ◽  
Vol 6 (2) ◽  
pp. 195
Author(s):  
Janet Kemuma Ogega ◽  
Beatrice Ang’iyo Were ◽  
Abigael Otinga Nekesa ◽  
John Robert Okalebo
Keyword(s):  
Soil Amendment ◽  
Crop Yields ◽  
Acid Soils ◽  
Maize Yield ◽  
Positive Control ◽  
Sub Saharan Africa ◽  
Soil System ◽  
Western Kenya ◽  
Arachis Hypogea ◽  
Maize Yields

Food insecurity in Sub - Saharan Africa (SSA) is on the rise due to soil fertility depletion and in Kenya, Nitrogen (N) is one of the widely deficient nutrients. Biological nitrogen fixation (BNF) can replenish N into the soil system. A study was carried out in acid soils at Koyonzo and Ligala sites of western Kenya to determine the effectiveness of different inoculants after agricultural lime application in enhancing BNF and yields of groundnuts (Arachis hypogea L.) and maize (Zea mays L.) intercrop. Red Valencia groundnut variety was intercropped with Hybrid 513D maize variety. A6w, W1w and V2w indigenous rhizobia strains were tested alongside a commercial rhizobia strain called biofix. Nitrogen treatment was included as a positive control. The results showed that inoculation significantly increased nodule number and weight per plant. There were significant differences among indigenous rhizobia in fixing N. Rhizobia inoculation accounted for 58.91% and 78.95% increase in the amount of N fixed above the control at Koyonzo and Ligala respectively. The strain that fixed the highest amount of N was A6w followed by V2w and W1w at both sites under the dolomitic soil amendment with the values of 14.67, 9.56, 3.53 and 11.37, 8.20 and 1.50 kg N ha-1, respectively at Koyonzo and Ligala sites. Rhizobia inoculation accounted for 80.96% and 47.09% maize yield increase at Koyonzo and Ligala respectively. The best inoculant A6w, gave maize yields of 3.76 and 2.78 t ha-1 at Koyonzo and Ligala, respectively. In conclusion soil amendment with dolomitic lime and inoculating groundnuts with rhizobia strain A6w resulted in increased groundnut and maize yields. This practice can, therefore, be adopted by farmers in western Kenya to improve the productivity of the groundnut maize intercropping systems.

scholarly journals Climate change impacts on rainfed maize yields in Zambia under conventional and optimized crop management

2021 ◽  
Author(s):  
Siatwiinda Mabele Siatwiinda ◽  
Iwan Supit ◽  
Bert van Hove ◽  
Olusegun Yerokun ◽  
Gerard H. Ros ◽  
...  
Keyword(s):  
Climate Change ◽  
Nutrient Management ◽  
Crop Management ◽  
Yield Decline ◽  
Global Circulation Models ◽  
Maize Varieties ◽  
Northern Regions ◽  
Maize Yields ◽  
Near Future ◽  
Far Future

Abstract Maize production in Zambia is characterized by significant yield gaps attributed to nutrient management and climate change threatens to widen these gaps unless agronomic management is optimized. Insights in the impacts of climate change on maize yields and the potential to mitigate negative impacts by crop management is currently lacking for Zambia. Using five Global Circulation models and the WOFOST crop model, we assessed expected climate change and the impacts on maize yields at a 0.5° × 0.5° spatial resolution for RCP 4.5 and RCP 8.5 scenarios. Impacts were assessed for two future periods (i.e. near future: 2035–2066 and far future: 2065–2096) in comparison with a reference period (1971–2001). The average surface temperature and summer days (above 30°C) are projected to increase strongly in the southern and western regions. Precipitation is expected to decline, except in the northern regions while the number of wet days decline everywhere, indicating a shortening growing season. The risk of crop failure in western and southern regions increases due to dry spells and heat stress while crops in the northern regions will be threatened by flooding or waterlogging due to heavy precipitation. The simulated decline in the water limited and water- and nutrient- limited maize yields varied from ca 15–20% in the near future and from ca 20–40% in the far future, mainly due to the expected temperature increases. Optimizing management by adjusting planting dates and maize varieties can counteract these impacts by 6–29%. Quantitatively, the existing gaps between water limited yields and nutrient limited maize yields are substantially larger than the expected yield decline due to climate change. Improved nutrient management is therefore crucial to avoid crop yield decline and might even increase crop yields in Zambia.

scholarly journals Effect of legume intercropping on N<sub>2</sub>O emission and CH<sub>4</sub> uptake during maize production in the Ethiopian Rift valley

2019 ◽  
Author(s):  
Shimelis G. Raji ◽  
Peter Dörsch
Keyword(s):  
Rift Valley ◽  
Crop Production ◽  
Growing Season ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
Ethiopian Rift ◽  
N2o Emissions ◽  
Mineral N ◽  
Total N ◽  
N Input

Abstract. Intercropping with legumes is an important component of climate smart agriculture (CSA) in sub Saharan Africa, but little is known about its effect on soil greenhouse gas (GHG) exchange. A field experiment was established at Hawassa in the Ethiopian rift valley, comparing nitrous oxide (N2O) and methane (CH4) fluxes in minerally fertilized maize (64 kg N ha−1) with and without crotalaria (C. juncea) or lablab (L. purpureus) as intercrops over two growing seasons. To study the effect of intercropping time, intercrops were sown either three or six weeks after maize. The legumes were harvested at flowering and half of the above-ground biomass was mulched. In the first season, cumulative N2O emissions were largest in 3-week lablab, with all other treatments being equal or lower than the fertilized maize monocrop. After reducing mineral N input to intercropped systems by 50 % in the second season, N2O emissions were at par with the fully fertilized control. Maize yield-scaled N2O emissions in the first season increased linearly with above-ground legume N-yield (p = 0.01), but not in the second season when early rains resulted in less legume biomass because of shading by maize. Growing season N2O-N emission factors varied from 0.02 to 0.25 and 0.11 to 0.20 % of the estimated total N input in 2015 and 2016, respectively. Growing season CH4 uptake ranged from 1.0 to 1.5 kg CH4-C ha−1 with no significant differences between treatments or years, but setting off the N2O-associated global warming potential by up to 69 %. Our results suggest that high yielding leguminous intercrops entail some risk for increased N2O emissions when used together with recommended fertilization rates, but can replace part of the fertilizer N without compromising maize yields in the following year and thus support CSA goals while intensifying crop production in the region.

scholarly journals Crop production in relation to cultural practices in the Chromolaena odorata fallow system in South-West Cote d'Ivoire

1998 ◽  
pp. 305-317
Author(s):  
J.J.P. Slaats ◽  
B.H. Janssen ◽  
M. Wessel
Keyword(s):  
Crop Production ◽  
Crop Yields ◽  
Cultural Practices ◽  
Maize Yield ◽  
Chromolaena Odorata ◽  
Maize Production ◽  
Fallow Period ◽  
Yield Decline ◽  
Cropping Seasons ◽  
Over Time

Farmers grow food crops alternated by short fallow periods of the naturally re-establishing Chromolaena odorata in response to the growing demand for land in humid Africa. It is unknown whether current cultural practices in this system are appropriate and how land use can further be intensified. Maize production was measured in experiments on three sites cleared from a two-, three- and four-year-old C. odorata fallow, respectively. On the two-year-old site, bearing the lowest quantity of vegetation biomass, maize response to removing, burning and intensively burning (i.e.: burning after adding vegetation from outside) the slashed vegetation was studied as well. Various weeding frequencies and fertilizers were applied in the experiments to better assess the effects of the length of the fallow period and the clearing methods. The experiments were conducted during three consecutive cropping seasons to provide an indication of changes in yield over time. During the first season after clearing, maize yield decreased from 3.8 on the four-year-old fallow to 2.6 t ha-1 on the two-year-old fallow. This reduction was due to a lower availability of P and N, and to a higher competition from weeds. Burning or intensively burning the vegetation raised yields of the unfertilized crop, up to 1.2 t ha-1. It increased the availability of phosphorus but did not clearly reduce competition from weeds. In the second and third season, yield fell to 1.5 t ha-1 irrespective of the fallow age. Burning slowed down the yield decline over time. Application of P- and N-fertilizers raised crop yields under all conditions and maintained them up to 5 t ha-1 during the three seasons. Weeding twice instead of once reduced the yield decline over time on the young fallow only. Results suggest that in the C. odorata crop production system a fallow period of two years is too short to be fully effective, that burning the C. odorata slash benefits crop production, even when its amount is limited, and that growing maize for more than one season is worthwhile only where fertilizers are applied.

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