scholarly journals Complementary practices supporting conservation agriculture in southern Africa. A review

Author(s):  
Christian Thierfelder ◽  
Frédéric Baudron ◽  
Peter Setimela ◽  
Isaiah Nyagumbo ◽  
Walter Mupangwa ◽  
...  
2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Blessing Mhlanga ◽  
Laura Ercoli ◽  
Elisa Pellegrino ◽  
Andrea Onofri ◽  
Christian Thierfelder

AbstractConservation agriculture has been promoted to sustainably intensify food production in smallholder farming systems in southern Africa. However, farmers have rarely fully implemented all its components, resulting in different combinations of no-tillage, crop rotation, and permanent soil cover being practiced, thus resulting in variable yield responses depending on climatic and soil conditions. Therefore, it is crucial to assess the effect of conservation agriculture components on yield stability. We hypothesized that the use of all three conservation agriculture components would perform the best, resulting in more stable production in all environments. We evaluated at, eight trial locations across southern Africa, how partial and full implementation of these components affected crop yield and yield stability compared with conventional tillage alone or combined with mulching and/or crop rotation. Grain yield and shoot biomass of maize and cowpea were recorded along with precipitation for 2 to 5 years. Across different environments, the addition of crop rotation and mulch to no-tillage increased maize grain by 6%, and the same practices added to conventional tillage led to 13% yield increase. Conversely, adding only mulch or crop rotation to no-tillage or conventional tillage led to lower or equal maize yield. Stability analyses based on Shukla’s index showed for the first time that the most stable systems are those in which mulch is added without crop rotation. Moreover, the highest yielding systems were the least stable. Finally, additive main effects and multiplicative interaction analysis allowed clarifying that mulch added to no-tillage gives stable yields on sandy soil with high rainfall. Similarly, mulch added to conventional tillage gives stable yield on sandy soil, but under low rainfall. This is the first study that highlighted the crucial role of mulch to enhance the stability and resilience of cropping systems in southern Africa, supporting their adaptability to climate change.


2016 ◽  
Vol 222 ◽  
pp. 112-124 ◽  
Author(s):  
Christian Thierfelder ◽  
Rumbidzai Matemba-Mutasa ◽  
W. Trent Bunderson ◽  
Munyaradzi Mutenje ◽  
Isaiah Nyagumbo ◽  
...  

2015 ◽  
Vol 14 (2) ◽  
pp. 142-165 ◽  
Author(s):  
Cathy Rozel Farnworth ◽  
Frédéric Baudron ◽  
Jens A. Andersson ◽  
Michael Misiko ◽  
Lone Badstue ◽  
...  

2021 ◽  
Vol 3 ◽  
Author(s):  
Hambulo Ngoma ◽  
Arild Angelsen ◽  
Thomas S. Jayne ◽  
Antony Chapoto

Conservation Agriculture (CA) aims to concurrently promote agricultural productivity, local livelihoods, climate resilience and other environmental objectives. We review the emerging evidence base in Eastern and Southern Africa to address whether CA is climate smart and why adoption rates by smallholders remain generally very low. We first develop an adoption framework that can be used to assess when and where the different components of CA are expected to be adopted under different conditioning factors and consider options to make CA climate smart. Our results suggest that CA can contribute positively to productivity and adaptation/resilience objectives, although the degree of success varies considerably by farm, household and regional characteristics. Overall, we find that capital-intensive (mechanized) CA is more likely to be adopted in areas of economic dynamism where capital is cheap relative to labor. Labor-intensive CA practices are more likely to be adopted in regions of economic stagnation where capital is expensive, and labor is abundant and cheap. A subnational focus is needed to identify economic conditions of different regions and agro-ecological zones and to test hypotheses derived from the framework in this paper and to propose the most appropriate CA packages for promotion. Our findings suggest that labor using variants of CA such as planting basins are more likely to be adopted than are capital using mechanized options in densely populated parts of Malawi, Ethiopia, Kenya, Tanzania, Zambia and Zimbabwe where labor is abundant, and presumably cheap, but capital is expensive. However, rising land scarcity (prices) and wages in the region present an opportunity for capital intensive, mechanized CA operations to be adopted if the cost of capital can be kept low and if there is a supportive environment for mechanization. We conclude that CA is climate smart and if adopted widely, it has the potential to help build resilience in smallholder farming systems. CA can be more climate smart, and its uptake can be enhanced by reframing, better targeting, adapting CA to location-specific economic and biophysical, and through greater and more effective public spending on agricultural research and development.


2019 ◽  
Vol 35 (3) ◽  
pp. 322-335 ◽  
Author(s):  
W. Mupangwa ◽  
C. Thierfelder ◽  
S. Cheesman ◽  
I. Nyagumbo ◽  
T. Muoni ◽  
...  

AbstractConservation agriculture (CA) and no-till (NT)-based cropping systems could address soil degradation and fertility decline in southern Africa. A multi-location and multi-year experiment was carried out between 2008 and 2014 to assess the effects of different levels of maize residue biomass (0, 2, 4, 6 and 8 t ha−1) and nitrogen (N) fertilizer (0, 30, 90 kg ha−1) on maize performance under no-tillage. In some sites, different (N) fertilizer levels were superimposed to test their effects on maize grain yield and leaf chlorophyll content under different maize residue biomass levels. The different residue levels had no significant effect on maize yield in most growing seasons. Maize residue cover increased grain yield in eight out of 39 site-years across the sites used. However, in some sites, maize yield decreased with increases in residue level in cropping seasons that had average to above average rainfall. At a few sites maize yield increased with increase in residue level. Seasonal rainfall pattern influenced the effect of different residue levels on grain yield at most sites. Nitrogen fertilizer increased maize yield regardless of the residue level applied. This study demonstrates that mulching with maize residues in CA/NT systems results in limited maize yield gains – at least within the first 6 years in different agro-ecological conditions of southern Africa.


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