Special Issue "The Role of Conservation Agriculture in Sustainable Production Intensification for Smallholder Farmers in Africa"

A special issue of Environments (ISSN 2076-3298).

Deadline for manuscript submissions: closed (31 March 2015)

Special Issue Editors

Guest Editor
Prof. Dr. Amir Kassam

School of Agriculture, Policy and Development, University of Reading, Earley Gate, Reading, RG6 6AR, UK
E-Mail
Guest Editor
Mr. Saidi Mkomwa

African Conservation Tillage Network (ACT), P.O. Box 10375-00100, Nairobi, Kenya
E-Mail

Special Issue Information

Dear Colleagues,

In recent years, production intensification in smallholder farming in Africa is benefitting from the adoption and spread of Conservation Agriculture (CA). CA is an agro-ecological approach to sustainable production intensification that is based on implementing three interlinked principles: (i) minimum soil disturbance, (ii) maintenance of organic soil cover, and (iii) a diversified cropping system, along with other good agricultural practices, including integrated management of crops, nutrients, water, pests, and of farm power and energy.

The Special Issue is comprised of selected papers from the First Africa Congress for Conservation Agriculture, plus additional invited papers from researchers working on CA systems in Africa. The Congress focused on “Building Entrepreneurship and Resilient Farming Systems,” as a basis for sustainable production intensification. Thus, this Special Issue offers papers concerning the research and adoption of CA from across Africa; these papers elaborate on the role of CA in the enhancement of: productivity, efficiency of input use, soil health and quality, and resilience to climate variability.

Prof. Dr. Amir Kassam
Mr. Saidi Mkomwa
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Environments is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) is waived for well-prepared manuscripts submitted to this issue. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • research on CA systems in different agro-ecologies
  • nutrient management in CA systems
  • weed management in CA systems
  • biomass allocation for competing use in CA systems
  • adoption of CA by smallholder farmers
  • soil microbiology under CA systems
  • performance of CA systems in long-term experiments
  • smallholder commercialisation opportunity with CA

Published Papers (6 papers)

View options order results:
result details:
Displaying articles 1-6
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Versatile Strip Seed Drill: A 2-Wheel Tractor-Based Option for Smallholders to Implement Conservation Agriculture in Asia and Africa
Environments 2016, 3(1), 1; doi:10.3390/environments3010001
Received: 25 August 2015 / Revised: 23 November 2015 / Accepted: 18 December 2015 / Published: 13 January 2016
Cited by 1 | PDF Full-text (4338 KB) | HTML Full-text | XML Full-text
Abstract
Smallholders in Asia and Africa require low-cost seed drills for minimal soil disturbance while establishing various crops. A seed drill that can be drawn by the widely-available two-wheel tractor (2WT) is an attractive option for mechanization of no-till in small-sized fields. The Versatile
[...] Read more.
Smallholders in Asia and Africa require low-cost seed drills for minimal soil disturbance while establishing various crops. A seed drill that can be drawn by the widely-available two-wheel tractor (2WT) is an attractive option for mechanization of no-till in small-sized fields. The Versatile Strip Seed Drill (VSSD) was designed with the capacity to make up to 40 mm wide and 60 mm deep strips in untilled land along with seed and basal fertilizer application in a single-pass operation, while powered by the 8.95 to 11.93 kW 2WT. An important innovation of the VSSD was to fit the seed box with both fluted roller-type seed meters for delivery of sufficient small-size seeds to achieve adequate plant density per unit row length; and vertical disk-type seed meters for precision and spaced row planting of larger seeds. Both incessant seed dropping by fluted roller seed meters and spaced planting by vertical disk type seed meters provided optimum plant populations that were generally higher than in conventional, full-tillage plots with the same rate of hand broadcasted seed and fertilizers. Time required for crop establishment by VSSD ranged from 0.13 to 0.18 ha·h−1. When the VSSD was attached to the 2WT for crop establishment, the diesel fuel consumption varied from 4.4 to 6.1 L·ha−1, which was lower than for most 2WT-based planters previously used in Bangladesh. In on-farm multi-locations trials, wheat crops established with the VSSD had statistically similar grain yield compared to conventional tillage; however, significantly higher grain yield was obtained from mustard and lentil, by 14% and 19%, respectively. The VSSD is a unique, minimum-soil-disturbance multi-crop planter, and can be a platform on which to build conservation agriculture systems for small farms in Asia and Africa. Full article
Open AccessArticle Mulching and Fertilization Effects on Weed Dynamics under Conservation Agriculture-Based Maize Cropping in Zimbabwe
Environments 2015, 2(3), 399-414; doi:10.3390/environments2030399
Received: 9 June 2015 / Revised: 10 August 2015 / Accepted: 11 August 2015 / Published: 25 August 2015
PDF Full-text (1058 KB) | HTML Full-text | XML Full-text
Abstract
A two-year study was conducted to assess how mulch influences weed dynamics following imposition of different fertilization treatments under three crop establishment options: (i) conventional; (ii) ripping; and (iii) basin, in a two-year maize-legume rotation. Eight treatments were imposed within each crop establishment
[...] Read more.
A two-year study was conducted to assess how mulch influences weed dynamics following imposition of different fertilization treatments under three crop establishment options: (i) conventional; (ii) ripping; and (iii) basin, in a two-year maize-legume rotation. Eight treatments were imposed within each crop establishment option and received maize stover mulch applied at 0% or 30% cover before planting maize (Zea mays) or cowpea (Vigna unguiculata) as test crops. Maize received nitrogen (N) at 35, 90, or 120 kg·ha−1 and phosphorus (P) at 14 or 26 kg·ha−1 applied alone or in combination with 4 or 7 t cattle manure·ha−1, while cowpea received 8 or 17 N·kg·ha−1 and similar P rates to maize. Results indicated that both weed biomass and diversity were influenced more by fertilization than method of crop establishment. On treatments under high fertilizer application rates, or previously planted to cowpea weed biomass ranged between 220 and 400 g·m−2 under mulch and 370–510 g·m−2 (no mulch). Here species richness ranged between 7–16 and was dominated by dicotyledons. This was in contrast to biomass ranges of 75–200 g·m−2 in the low fertilized and control plots, where only one or two grass types dominated. Overall, weed densities were 6% to 51% higher under conventional tillage compared to the two conservation agriculture (CA) options, although the data indicated that mulch significantly (p < 0.05) depressed weed density by up to 70%. We concluded that mulching could be a potential mechanism for reducing weeding labor costs for smallholders and the general environmental and health concerns associated with the use of herbicides in CA systems. Full article
Open AccessArticle Effects of Conservation Agriculture and Fertilization on Soil Microbial Diversity and Activity
Environments 2015, 2(3), 358-384; doi:10.3390/environments2030358
Received: 30 March 2015 / Revised: 22 June 2015 / Accepted: 1 July 2015 / Published: 13 July 2015
Cited by 3 | PDF Full-text (2933 KB) | HTML Full-text | XML Full-text
Abstract
Soil microbial communities perform critical functions in ecosystem processes. These functions can be used to assess the impact of agricultural practices on sustainable crop production. In this five-year study, the effect of various agricultural practices on soil microbial diversity and activity was investigated
[...] Read more.
Soil microbial communities perform critical functions in ecosystem processes. These functions can be used to assess the impact of agricultural practices on sustainable crop production. In this five-year study, the effect of various agricultural practices on soil microbial diversity and activity was investigated in a summer rainfall area under South African dryland conditions. Microbial diversity and activity were measured in the 0–15 cm layer of a field trial consisting of two fertilizer levels, three cropping systems, and two tillage systems. Using the Shannon–Weaver and Evenness diversity indices, soil microbial species richness and abundance were measured. Microbial enzymatic activities: β-glucosidase, phosphatase and urease, were used to evaluate ecosystem functioning. Cluster analysis revealed a shift in soil microbial community diversity and activity over time. Microbial diversity and activity were higher under no-till than conventional tillage. Fertilizer levels seemed to play a minor role in determining microbial diversity and activity, whereas the cropping systems played a more important role in determining the activity of soil microbial communities. Conservation agriculture yielded the highest soil microbial diversity and activity in diversified cropping systems under no-till. Full article
Open AccessArticle Where to Target Conservation Agriculture for African Smallholders? How to Overcome Challenges Associated with its Implementation? Experience from Eastern and Southern Africa
Environments 2015, 2(3), 338-357; doi:10.3390/environments2030338
Received: 22 May 2015 / Revised: 13 June 2015 / Accepted: 17 June 2015 / Published: 6 July 2015
Cited by 4 | PDF Full-text (967 KB) | HTML Full-text | XML Full-text
Abstract
Since the paper by Giller et al. (2009), the debate surrounding the suitability of conservation agriculture (CA) for African smallholders has remained polarized between proponents and opponents. The debate also gave rise to a few studies that attempted to identify the “niche” where
[...] Read more.
Since the paper by Giller et al. (2009), the debate surrounding the suitability of conservation agriculture (CA) for African smallholders has remained polarized between proponents and opponents. The debate also gave rise to a few studies that attempted to identify the “niche” where CA would fit in the region, but the insight offered by these studies has been limited. In this paper, we first analyze the rationale of adoption where it occurred globally to define “drivers” of adoption. Our analysis suggests that CA has first and foremost been adopted under the premises of being energy-saving (time and/or power), erosion-controlling, and water-use efficient, but rarely to increase yield. We then define the niche where CA fits, based on these drivers of adoption, as systems where (1) the energy available for crop establishment is limited and/or costly (including labor and draft power); (2) delayed planting results in a significant yield decline; (3) yield is limited or co-limited by water; and/or (4) severe erosion problems threaten the short- to medium-term productivity of farmland. In Eastern and Southern Africa, this niche appears rather large and likely to expand in the near future. When implemented within this niche, CA may still be limited by “performance challenges” that do not constitute drivers or barriers to adoption, but limitations to the performance of CA. We argue that most of these performance challenges can (and should) be addressed by agronomic and socio-economic research, and provide four examples where the International Maize and Wheat Improvement Center (CIMMYT) and its partners have been successfully alleviating four very different challenges through research and development (R&D) in Eastern and Southern Africa. Finally, we describe an iterative and multi-scale R&D approach currently used by CIMMYT in Eastern and Southern Africa to overcome challenges associated with the implementation of CA by African smallholders. This approach could also be useful for other complex combinations of technologies aiming at sustainable intensification. Full article
Open AccessArticle Evidence and Lessons Learned from Long-Term On-Farm Research on Conservation Agriculture Systems in Communities in Malawi and Zimbabwe
Environments 2015, 2(3), 317-337; doi:10.3390/environments2030317
Received: 27 February 2015 / Revised: 4 June 2015 / Accepted: 16 June 2015 / Published: 30 June 2015
Cited by 2 | PDF Full-text (891 KB) | HTML Full-text | XML Full-text
Abstract
A long-term study was carried out in the Zidyana Extension Planning Area (EPA), Malawi and in the Zimuto Communal Area, Zimbabwe, to evaluate the effect of different conservation agriculture (CA) systems on crop productivity, soil quality and economic performance. Maize productivity results from
[...] Read more.
A long-term study was carried out in the Zidyana Extension Planning Area (EPA), Malawi and in the Zimuto Communal Area, Zimbabwe, to evaluate the effect of different conservation agriculture (CA) systems on crop productivity, soil quality and economic performance. Maize productivity results from Zidyana showed that CA systems out-yielded the conventional system in seven out of nine cropping seasons. Labour savings relative to the conventional control ranged from 34–42 labour days ha−1 due to reduced time needed to make manual ridges and for weed control, leading to higher net benefits of 193–444 USD·ha−1. In Zimuto, yield benefits were apparent from the second season onwards and there was a much clearer trend of increased yields of CA over time. Greater net benefits (in USD·ha−1) were achieved on CA systems in Zimuto compared with conventional control treatments due to overall higher yields from CA systems. In Zimuto, both increased infiltration and a gradual increase in soil carbon were recorded, which may have contributed to the greater yield response of CA in this area. In Zidyana, yield increases were attributed primarily to enhanced water infiltration since no increases in soil carbon levels were measured. Farmers highlighted critical challenges to the adoption of CA. These will have to be addressed in future research and extension to provide effective solutions to farmers. Full article

Review

Jump to: Research

Open AccessReview Mechanization of Conservation Agriculture for Smallholders: Issues and Options for Sustainable Intensification
Environments 2015, 2(2), 139-166; doi:10.3390/environments2020139
Received: 3 March 2015 / Revised: 14 April 2015 / Accepted: 17 April 2015 / Published: 6 May 2015
Cited by 2 | PDF Full-text (4066 KB) | HTML Full-text | XML Full-text
Abstract
Conservation agriculture (CA) is an increasingly adopted production system to meet the goals of sustainable crop production intensification in feeding a growing world population whilst conserving natural resources. Mechanization (especially power units, seeders, rippers and sprayers) is a key input for CA and
[...] Read more.
Conservation agriculture (CA) is an increasingly adopted production system to meet the goals of sustainable crop production intensification in feeding a growing world population whilst conserving natural resources. Mechanization (especially power units, seeders, rippers and sprayers) is a key input for CA and smallholder farmers often have difficulties in making the necessary investments. Donors may be able to provide mechanization inputs in the short term, but this is not a sustainable solution as a machinery input supply chain needs to be built up to continue availability after external interventions cease. Local manufacture should be supported, as was the case in Brazil, but this is a slow development process, especially in sub-Saharan Africa. A more immediate solution is to equip and train CA service provision entrepreneurs. With the right equipment, selected for the needs of their local clientele, and the right technical and business management training, such entrepreneurs can make a livelihood by supplying high quality CA and other mechanization services on a fully costed basis. Elements of the required training, based on extensive field experience, are provided. To catalyse the growth of CA providers’ business, the market can be stimulated for an initial period by issuing e-vouchers for services and inputs. Full article

Journal Contact

MDPI AG
Environments Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
E-Mail: 
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Environments Edit a special issue Review for Environments
loading...
Back to Top