Maize yield increases and stabilisation under CA in semi-arid districts of Tanzania. Saidi Mkomwa
Maize Yield Increases and Stabilizationunder CA in semi-arid Districts of Tanzania by Saidi Mkomwa1; Zakaria Mkoga1; Wilfred Mariki2 and Marietha Owenya2 1African Conservation Tillage Network (ACT); 2Selian Agricultural Research Institute (SARI) Presented at The Fifth World Congress on Conservation Agriculture, Brisbane Convention & Exhibition Centre, Brisbane Australia 26 – 29 September 2011
Contents1. Introduction2. Materials and Methods3. Results and Discussions4. What are the Implications for smallholder adoption of CA?5. Acknowledgements
Introduction–study sites &farmersCA SARD project phase 2 from 2007 toMarch 2011.Funded by German Govt, Implementedby FAO with the Tanzania and KenyaGovernments8000 households learned CA by doing
Materials and Methods Study of 8 FFS from Arumeru & Karatu Districts, Arusha Region Tanzania For three consecutive years from 2005 to 2007. Gender mixed farmer groups with 20 – 25 farmers each cultivating about 2ha. Learning CA by experimenting with alternative crop production technologies
Treatments1. Jab planter, glyphosate weed control, lablab cover crop planted after first weeding,2. Ripping, glyphosate weed control, jab planting in the ripper furrow, pigeon peas intercrop,3. Jab planter, glyphosate weed control, pigeon peas intercrop,4. Ripping, glyphosate weed control, jab planter, lablab cover crop and5. Farmers practice - ox ploughing, hand hoe weed control.
Schematic Plot-layout vs Treatments Plot 1 Plot 2 Plot 3 Plot 4 Plot 5 Jab Ripper Jab Ripper Plough Reduced; Farmer’sCOVER SEED PLA- TILLAGE None Reduced; None AD ripper A/Drawn Practice – ripper (Plough) Jab AD direct Jab AD direct Hand hoe CEMENT planter seeder planter seeder (for Maize & Beans) Lablab Pigeon Pigeon Lablab Traditional CROP peas peas (Beans - crop)
Plot 1 Plot 2 Plot 3 Plot 4 Plot 5 Jab Ripper Jab Ripper Plough Maize All All All All cropMAINTENANCE OF SOIL stover tops residues residues residues residues COVER only retained retained retained removed removed Lablab None None Pigeon NoneCOVER CROP years 1& 2 Maize Maize peas for Maize / ROTATIONS Pigeon only only years 1&2 beans peas years Lablab for intercrop 3 and 4 years 3&4
Plot sizes varied from one FFS to another, ranging from 390 - 1440 m2. Data collected on: rainfall, labour input, soil property changes, maize grain yield and cover crop grain yield. Recommended crop spacing and use of improved maize seeds were practiced. Neither industrial nor inorganic fertilizers were used.
Maize Grain Yield (Means for 6 FFS plots) No Treatment Maize grain yield (kg/ha) Each FFS treated as a replication . 2005 2006 2007 1 Data analysed using by SAS Jab planter, glyphosate, lablab programme 1,735 2,889 2,738 2 Ripping, glyphosate, jab, p/peas 1,949 3,018 1,973 3 Jab planter, glyphosate, p/peas 1,770 2,566 1,369 4 Ripping, glyphosate, jab, lablab 2,043 2,357 1,320 5 Farmer’s practice, ox ploughing 1,353 1,502 993 Grand mean 1,770 2,466 1,679 Annual rainfall 528 755 988 (mm) (532)Source: ARI Selian field data, 2007; Arusha foundation seed farm (some rainfall records).
CROP YIELDS DUE TO CA WITH TIME 3,500 3,000 2,500YIELDS (kg/ha) 2,000 Jab planter, glyphosate, 1,500 lablab Ripping, glyphosate, jab, p/peas Jab planter, glyphosate, 1,000 p/peas Ripping, glyphosate, jab, lablab 500 Farmers practice, ox ploughing - 2005 2006 2007 YEAR
Effect of tillage Ripping with either lablab or pigeon peas produced significantly different and higher grain yields (of 1,949 & 2,043 kg ha-1 ) vs direct seeding with the jab planter (1,735 &1,770 kg ha-1 ) and conventional ox ploughing (1,353 kg ha-1) during year 1 of CA. 528 mm rainfall The trend in yield increase differences continued during the second year (755 mm)
Jab planter with lablab & p/peas was highest in year 3 (2,738 kg/ha) followed by ripping (1,973 with lablab and 1,320 kg ha-1 with pigeon peas). The ox ploughed plots produced the lowest grain yield throughout
Effect of cover crops. The yield increase trends with time and rainfall variations were consistent for lablab. It produced and maintained the highest yield of 2,738 kg ha-1 in year 3 (in a year with a grand mean of 1,697 kg ha-1) while pigeon peas dropped drastically to 1,320 kg ha-1
Yield variations across sites Yields across different FFS varied greatly (from a maximum of 7.6 tons/ha in Rhotia Kati for ripper with pigeon peas to 0.2 tons/ha for the farmers’ practice in Getamock), which was understandable due to the differing farmer management skills and the initial degraded status of the fields.
Preferred CA technologies Of the 352 households practicing 66% are women 64% are FFS members 36% are non-FFS members enticed by the benefits of CA; The preferred planting/tillage technologies are: the ripper (61%) for FFS members; complimented by the jab planter for seed placement, or manual
CONCLUSIONS CA increases and stabilise yields with time and with fluctuations in rainfall compared to conventional ploughing. Increases in grain yields increase food security. POINT OF DEPARTURE: Increased yields for smallholders owning small pieces of land (typically 1 ha) does not enable them to eradicate poverty.
Conclusions .. CA translates to saved time (up to 57% of the growing season) – which might not necessarily translate into meaningful utilisation if opportunity costs are not accessible What is 2 months of saved time if there is nothing productive to do in the remaining 8 months of the year?
THE WAY FORWARDMake full use of CA based value chains Walking tractor seeder development Value addition of oil seeds under CA rotations Access to equitable markets
ACKNOWLEDGEMENTS CA SARD was funded by theGovernment of the Federal Republic of Germany and implemented byFAO, The Governments of Tanzania and Kenya. ACT coordinated the project at the Regional Level. Their support is sincerely acknowledged
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