Are conservation agriculture (CA) systems productive and profitable options for smallholder farmers in different agro-ecoregions of Zimbabwe?

2016 ◽  
Vol 32 (1) ◽  
pp. 87-103 ◽  
Author(s):  
W. Mupangwa ◽  
M. Mutenje ◽  
C. Thierfelder ◽  
I. Nyagumbo

AbstractContinuous conventional tillage coupled with unsystematic cereal/legume rotations has promoted low crop productivity on smallholder farms. A multi-locational study was established in three agro-ecoregions (AEs) of Zimbabwe. The aim of the study was to determine the effect of four tillage systems (conventional plowing, planting basins, rip-line and animal traction direct seeding systems) on maize (Zea mays L.), cowpea [Vigna unguiculata (L.) Walp] and soybean [Glycine max (L.) Merrill] yields, and evaluate the economic performance of the conservation agriculture (CA) systems relative to conventional plowing. Each farmer was a replicate of the trial over the three cropping seasons. In the high (750–1000 mm per annum) and low (450–650 mm) rainfall AEs, conventional practice and CA systems gave similar maize grain yield. Under medium rainfall conditions (500–800 mm) planting basins, rip-line and direct seeding systems gave 547, 548 and 1690 kg ha−1 more maize yield than the conventional practice. In the high and low rainfall AEs, conventional practice and planting basins had the lowest maize production risk. Cowpea yield was 35 and 45% higher in the rip-line and direct seeding than conventional practice. Soybean yield was higher in rip-line (36%) and direct seeding (51%) systems than conventional practice. Direct seeding system gave the highest net benefits in all AEs. A combination of long-term biophysical and socio-economic assessments of the different cropping systems tested in our study is critical in order to fully understand their performance under different AEs of Zimbabwe.

2017 ◽  
Vol 34 (5) ◽  
pp. 380-394 ◽  
Author(s):  
W. Mupangwa ◽  
M. Mutenje ◽  
C. Thierfelder ◽  
M. Mwila ◽  
H. Malumo ◽  
...  

AbstractClimate variability and declining soil fertility pose a major threat to sustainable agronomic and economic growth in Zambia. The objective of this study was to assess crop yield, land and labor productivity of conservation agriculture (CA) technologies in Eastern Zambia. On-farm trials were run from 2012–2015 and farmers were replicates of a randomized complete block design. The trials compared three CA systems against a conventional practice. Yield and net return ha−1 were determined for maize and legume yield (kg ha−1) produced by ridge and furrow tillage, CA dibble stick planting, CA animal traction ripping and direct seeding. The dibble stick, ripline and direct seeding CA systems had 6–18, 12–28 and 8–9% greater maize yield relative to the conventional tillage system, respectively. Rotation of maize with cowpea and soybean significantly increased maize yields in all CA systems. Intercropping maize with cowpea increased land productivity (e.g., the land equivalent ratio for four seasons was 2.01) compared with full rotations under CA. Maize/cowpea intercropping in dibble stick CA produced the greatest net returns (US$312-767 ha−1) compared with dibble stick maize-cowpea rotation (US$204-657), dibble stick maize monoculture (US$108-584) and the conventional practice (US$64-516). The net-return for the animal traction CA systems showed that maize-soybean rotations using the ripper were more profitable than the direct seeder or conventional ridge and furrow systems. Agronomic and economic benefits of CA-based cropping systems highlight the good potential for improved food security and agricultural productivity for smallholder farmers.


2012 ◽  
Vol 28 (4) ◽  
pp. 350-363 ◽  
Author(s):  
Amos Robert Ngwira ◽  
Christian Thierfelder ◽  
Dayton M. Lambert

AbstractConservation agriculture (CA) systems are based upon minimal soil disturbance; crop residue retention and crop rotation and/or intercrop association are increasingly seen to recycle nutrients, increase yield and reduce production costs. This study examines the effects of CA practices on crop productivity, profitability and soil quality under the conditions encountered by smallholder farmers in two farming communities from 2005 to 2011 in Malawi, as part of the contribution to remedy a lack of supporting agronomic research for these relatively new systems. The drier agroenvironment of Lemu of Bazale Extension Planning Area (EPA) is characterized by sandy clay loam soils and lower rainfall. Here, CA showed positive benefits on maize yield after the first season of experimentation, with highest increases of 2.7 Mg ha−1 and 2.3 Mg ha−1 more yield in CA monocrop maize and CA maize–legume intercrop, respectively, than the conventional tillage in the driest season of 2009/10. In the high rainfall environment of Zidyana EPA (characterized by sandy loam soils), substantial maize yield benefits resulted in the fifth season of experimentation. Farmers spent at most 50 days ha−1 (US$140) producing maize under CA systems compared with 62 days ha−1(US$176) spent under conventional tillage practices. In Lemu, both CA systems resulted in gross margins three times higher than that of the conventional control plot, while in Zidyana, CA monocrop maize and CA maize–legume intercrop resulted in 33 and 23% higher gross margins, respectively, than conventional tillage. In Zidyana, the earthworm population was highest (48 earthworms m−2 in the first 30 cm) in CA monocrop maize, followed by a CA maize–legume intercropping (40 earthworms) and lowest (nine earthworms) in conventionally tilled treatment. In both study locations CA monocrop maize and CA maize–legume intercrop gave higher water infiltration than the conventional treatment. Improvements in crop productivity, overall economic gain and soil quality have made CA an attractive system for farmers in Malawi and other areas with similar conditions. However, for extensive adoption of CA by smallholder farmers, cultural beliefs that crop production is possible without the ubiquitous ridge and furrow system and residue burning for mice hunting have to be overcome.


2019 ◽  
Vol 17 (1) ◽  
pp. 49-63
Author(s):  
K Pariyar ◽  
A Chaudhary ◽  
P Sapkota ◽  
S Sharma ◽  
CB Rana ◽  
...  

The effects of two tillage methods (zero tillage and conventional tillage), two residue managements (residue kept and residue removed) and two levels of cropping system (maize + soybean and sole maize) were studied over 3 years (2015-2017) at Dailekh district of Nepal. Arun-2 and Puja were the varieties of maize and soybean used respectively, followed by winter wheat. The results revealed that the maize + soybean system had significantly higher plant population and ear population (34.83 thousands ha-1 and 34.35 thousands ha-1, respectively), grains per row (37.1), ear length (16.6 cm) and 20.5% higher grain yield as compared to sole maize. The highest maize equivalent yield (7.92 t ha-1) was recorded in maize + soybean as compared to the lower grain yield equivalent (7.06 t ha-1) in sole maize. Zero tillage accounted relatively higher benefits (high net income and B:C ratio) as compared to conventional tillage. The residue kept plot resulted significantly higher B:C ratio (2.41) than the residue removed (2.11) and the maize + soybean recorded 82.5% greater B:C ratio compared to sole maize. Net annual income was significantly higher in zero tillage, residue kept and maize + soybean system (NRs. 223072.00, 222958.00 and 269016.00 ha-1 respectively). Such combinations are recommended for Dailekh district of Nepal to have profitable crop productivity. SAARC J. Agri., 17(1): 49-63 (2019)


2017 ◽  
Vol 54 (3) ◽  
pp. 452-466 ◽  
Author(s):  
SANDRA M. MADAMOMBE ◽  
ISAIAH NYAGUMBO ◽  
BRIGHTON M. MVUMI ◽  
PHILLIP NYAMUGAFATA ◽  
MENAS WUTA ◽  
...  

SUMMARYNematode infestation in Sub-Saharan Africa's (SSA) cropping systems, worsened by poor crop rotations, is a major factor contributing to limited utilisation of applied nutrients and water, leading to low maize (Zea mays L.) yields particularly on sandy soils. The effects of nematode infestation on maize productivity were evaluated under conservation agriculture (CA) on granitic sandy soils in sub-humid smallholder farms of Goromonzi district of Zimbabwe. Four treatments were tested for three seasons on six smallholder farmers’ fields in a randomised complete block design, each farm being a replicate: fenamiphos 40EC (a commercial synthetic nematicide), lime + fenamiphos 40EC, lime and an untreated control. Results of the study showed that independent application of fenamiphos 40EC and lime significantly reduced plant parasitic nematode infestations in maize roots by more than 10 times those present in the untreated plots while maize yield also increased significantly. Yield increase from fenamiphos and lime applications amounted to 53 and 42% respectively, compared to the untreated controls. Maize yield was negatively correlated with density of Pratylenchus spp. nematodes. Nematode management strategies involving fenamiphos 40EC or lime could significantly reduce maize yield losses in maize-based smallholder farming systems of SSA under CA. It was more economical to use fenamiphos than lime to control nematodes.


2014 ◽  
Vol 50 (4) ◽  
pp. 591-610 ◽  
Author(s):  
A. R. NGWIRA ◽  
JENS B. AUNE ◽  
C. THIERFELDER

SUMMARYAn on-farm study was conducted from 2009 to 2012 with communities in the Manjawira, Mpingu and Zidyana Extension Planning Areas in the Ntcheu, Lilongwe and Nkhotakota districts of central Malawi. The aim of the study was to evaluate the effects of the principles (no-tillage and mulching) and components (fertilization and weeding) of conservation agriculture (CA) on crop productivity and weeds, and the interactions between principles and components, and to suggest strategies for introducing CA to smallholder farmers. The treatments consisted of tillage, fertilizer application, residues management and weed control strategies. While combined analysis showed that mulching is as effective as tillage in controlling weeds, the interaction between site and treatment revealed that in the more humid environment of Zidyana, weed dry matter obtained under no-tillage and residues plus fertilizer (NT+F+R) was 0.6 mg ha−1lower than under CP+F. Results suggest that about 6.0 mg ha−1of mulch is required to have a similar effect as tillage in controlling weeds. Fertilizer had an overriding effect on maize yield, regardless of tillage and crop residue management. Mulching was beneficial over tillage in the drier environment of Manjawira, where maize yield obtained under NT+F+R was 1.2 mg ha−1greater than under CP+F. Our results show that the introduction of no tillage has benefits only if it is accompanied by fertilizer application, retention of crop residues as surface mulch, and improved weed control. Increasing availability and accessibility of inputs (fertilizers and herbicides) to farmers is critical for adoption of CA at scale in Malawi.


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.


2009 ◽  
Vol 44 (8) ◽  
pp. 949-953 ◽  
Author(s):  
Cécile Villenave ◽  
Bodovololona Rabary ◽  
Jean-Luc Chotte ◽  
Eric Blanchart ◽  
Djibril Djigal

The objective of this work was to assess the effects of conventional tillage and of different direct seeding mulch-based cropping systems (DMC) on soil nematofauna characteristics. The long-term field experiment was carried out in the highlands of Madagascar on an andic Dystrustept soil. Soil samples were taken once a year during three successive years (14 to 16 years after installation of the treatments) from a 0-5-cm soil layer of a conventional tillage system and of three kinds of DMC: direct seeding on mulch from rotation soybean-maize residues; direct seeding of maize-maize rotation on living mulch of silverleaf (Desmodium uncinatum); direct seeding of bean (Phaseolus vulgaris)-soybean rotation on living mulch of kikuyu grass (Pennisetum clandestinum). The samples were compared with samples from natural fallows. The soil nematofauna, characterized by the abundance of different trophic groups and indices (MI, maturity index; EI and SI, enrichment and structure indices), allowed the discrimination of the different cropping systems. The different DMC treatments had a more complex soil food web than the tillage treatment: SI and MI were significantly greater in DMC systems. Moreover, DMC with dead mulch had a lower density of free-living nematodes than DMC with living mulch, which suggested a lower microbial activity.


2019 ◽  
Vol 111 (6) ◽  
pp. 2636-2646 ◽  
Author(s):  
Simon M. Kidane ◽  
Dayton M. Lambert ◽  
Neal S. Eash ◽  
Roland K. Roberts ◽  
Christian Thierfelder

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