Effects of Conservation Agriculture based cropping systems and herbicide use on maize yields in Malawi and Mozambique. African Congress on Conservation Agriculture March 2014, Lusaka, Zambia Nyagumbo, I. 1, Kamalongo, D. 2, Dias, D 3 and Mulugetta, M 1 1. International Maize and Wheat Improvement Centre (CIMMYT), Box MP 163, Mt. Pleasant, Harare, Zimbabwe. Corresponding Author: 2. Department of Agricultural Research Services, Chitedze Research Station, Malawi 3. Instituto de Investigação Agrária de Moçambique (IIAM), Estação Agrária de Sussundenga, Moçambique

1. Introduction Food security among Africa’s smallholder farmers remains a key issue drawing the attention of Africa’s leaders. Hence The New Partnership for Africa's Development (NEPAD) seeks to achieve 6% annual growth in agricultural production by Sustainable Intensification technologies (Garnett et al., 2013) could contribute towards this goal

Sustainable Intensification Sustainability Ecologically and technically sound Socially and Culturally acceptable Economically viable Adaptable Intensification Increased yield or outputs per unit area/inputs Diversification from maize for diet diversification Integration of crops and livestock Improved resilience to market shocks and climate risks Improved food security and livelihoods

SIMLESA Sustainable Intensification of Maize - Legume Cropping Systems for Eastern and Southern Africa Operates in 5 countries in ESA since 2010 Managed and coordinated by CIMMYT Funded by Australian government through Australian Centre for International Agricultural Research (ACIAR) Increased farm-level food security (30% increase in productivity in 10 yrs) Lower risks for farm food security and income (reduce downside yield risks by 30%) Increased farm-level income Increased sustainability of maize-legume farming systems

Study Objectives To evaluate the effects of CA based sustainable intensification cropping systems on maize yields in Malawi and Mozambique after 3 seasons of implementation since 2010.

2. Materials and Methods

2.1 The process Community awareness meetings Farmer consultations and agreement on treatments Identification of 6 host farmers per community On-station trials : Exploratory trials establishment and monitoring: Outscaling activities through IPs and partnerships Farmer field days

Kasungu District (mid-altitude agro-ecologies) Mchinji District (mid-altitude agro-ecologies) Lilongwe District (mid-altitude agro-ecologies) Ntcheu District (low-altitude agro-ecologies) Salima District (low-altitude agro-ecologies) Salima District Balaka District (low altitude agro-ecologies) Ntcheu and Balaka district ADD=Agricultural Development Division KASUNGU ADD ( mm annum -1 ) SALIMA ADD (500 – 600 mm annum- 1 ) LILONGWE ADD ( mm annum -1 ) MACHINGA ADD (500 – 600 mm annum- 1 ) 2.2 SIMLESA Sites in Malawi

2.3 Cropping Systems tested in Malawi TreatmentsLow altitude agroeccologies Mid altitude agroecologies 1 Conventional ridge and furrow system ( recommended by extension) 1 2 CA basins maize + pigeon pea intercrop with glyphosate and harness +residues 2 CA Sole maize + hand weeding with residues, no herbicide applied 3 CA Maize + p.pea intercrop + glyphosate+ harness herbicides+residues 3 CA Sole maize + glyphosate + Harness herbicides + residues, herbicides 4 CA dibble stick sole maize + glyphosate+ harness + residues 4 CA Maize-soyabean rotation + glyphosate + Harness herbicides + residues 5 Maize – g/nuts rotation + glyphosate+ harness herbicides + residues 5 CA Soyabean-maize- rotation + glyphosate + Harness herbicides + residues 6 G/nuts – Maize rotation with residues and herbicides

2.4 Cropping systems tested in Mozambique: Sussundenga and Gorongosa districts Manual cropping systems Maize, cowpea/beans (improved varieties) Maize varieties: Tsangano-OPV Trt 1 1. Conventional flat manual hoeing Trt 2 2. CA Basin maize sole +glyphosate+ residues Trt 3 3. CA Jab planter maize sole +glyphosate+ residues Trt 4 4. CA Basin Maize-Cowpea rotation sole +glyphosate+ residues Trt 5 5. CA Basin Cowpea/beans-Maize rotation + glyphosate+ residues Trt 6 6. CA Basin maize-Cowpea intercrop +glyphosate+ residues

2.4 Sites with CA Exploratory Trials: Mozambique Site Map & Communities (2012): Angonia (R10)-Ciphole & Cabanco Avg altitude: 1270 masl Rainfall: 1200 mm Manica (R10&R4) – Chinhamdombwe Avg altitude: 723 masl Rainfall: 1014 mm Gorongosa (R4) – Canda- sede Avg altitude: 450 masl Sussundenga-sede (R4) Altitude: 635 masl

Materials and Methods.... CA basins : 15cm wide *15 cm deep. Fertilizer basal and top dressing followed local extension recommendations Herbicides: Glyphosate (2-3 l/ha) in both countries Harness (preemergent herbicide) used in Malawi Improved Maize and legume varieties used

3. Results..... Based on 3 seasons 2010/11 to 12/13 3. Results..... Based on 3 seasons 2010/11 to 12/13

3-yr mean maize yields from different cropping systems in the Mid-altitude agro- ecologies of Malawi (Kasungu, Mchinji and Lilongwe districts: ) Cropping System 3yr mean maize yield (kg/ha) % yield increase Conventional Ridge/furrow system3743 a 0 CA maize sole+ no herbicide3867 ab 3 CA maize sole+ herbicide4303 bc 15 CA maize-soya rotation4524 c 21 Note: N=36, df=24, LSD (0.05) =529kg/ha

3-yr mean maize yields from different cropping systems in lowland agro-ecologies of Malawi (Salima, Ntcheu and Balaka districts: ) Cropping System 3yr mean maize yield (kg/ha) % yield increase Conventional Ridge/furrow system 3034 a 0 CA Basins Mz/ppea intercrop+glyphosate+Harness 3295 ab 9 CA Dibble stick Maize sole +glypphosate+Harness 3807 bc 25 CA Dibble stick Mz-p.pea intcrop glyphosate+Harness 3824 bc 26 CA Maize/gnuts rotation +glyphosate +Harness 4267 c 41 Note: N=45, df=32; LSD (0.05) =757

3-yr mean maize yields from different cropping systems in central Mozambique (Sussundenga and Gorongosa districts: ) Cropping System 3yr mean maize yield (kg/ha) % yield increase Conventional flat manual hoeing1487 a 0 CA basins maize/cowpea intercrop1686 ab 13 CA jab planter maize sole+ glyphosate1734 bc 17 CA basins maize sole + glyphosate1812 bc 22 CA maize-cowpea rotation +glyphosate1972 c 32 Note: N=30; df=20; LSD (0.05) =233kg/ha

Yield stability across environments in the lowlands of Malawi

CA basins sometimes depressed yields compared to other tCA techs in Malawi !

Yield stability across environments and seasons in Mozambique

4.Emerging Issues from results so far Malawi’s mid-altitude results show that manual weeding in CA if done properly can be as effective as systems using herbicides with no yield penalties. This suggests that CA can also be implemented successfully without herbicides provided weeds are removed timely. Use of herbicides was however very popular with farmers in both countries due to labour reduction associated with weeding. Yield differences between conventional and CA practices progressively increased with time but also depended on quality of season and management (E*M).

4.Emerging lessons Overall analysis of results over the three seasons show that maize yields from rotation systems to be significantly higher than that from the conventional systems in both countries with yield increases ranging 21 to 41 % as found in other regional studies (Thierfelder et al., 2014). CA basins (15*15cm) found to be inconsistent and risky especially under Malawian conditions but often more advantageous under Mozambique’s conditions: drainage & rainfall distribution important!

5.Future Outlook! Need to develop strategies for enabling farmers to access critical inputs for CA such as herbicides found to be popular with the region’s farmers There is need for developing functional (input/output) markets for legumes to drive the use of crop rotations in outscaling initiatives

Literature

Thank you!!