Thursday, 25 August 2016

HIGHER YIELDS, LOW COST


In an effort to attain food security for a growing population and alleviating poverty, there is a need for a paradigm shift in farming practices through eliminating unsustainable parts of conventional agriculture (ploughing/tilling the soil, removing all organic material, monoculture) for future productivity gains while sustaining the natural resources. Depletion of natural resources, negative impacts of climatic change, exorbitant cost of inputs and volatile food prices are the major challenges facing most of the African countries.
In response to the low productivity and perceived negative environmental impact of conventional farming practices, a considerable number of farmers in Kenya are now adopting Conservation agriculture (CA) more than before. Conservation agriculture combines minimum tillage, retention of crop residues and use of crop rotations/ association. As opposed to the conventional practice, CA strengthens soil structure, improves water retention and reduces the production costs while improving the crop yields and soil health. Low production cost is attributed to low usage of external inputs and labour cost saving.This means that it can be adopted by the poorest and most vulnerable farming communities, as well as by those that can afford varying levels of mechanization and external inputs.

“I used to spend well over $370 in my 3 acre piece of land for land preparation, planting and buying seeds but I would hardly harvest anything as all my crops would dry up before maturity as a result of drought.“My farm has kept improving overtime since starting CA in 2013. This season (Short rain 2016), I’m expecting to harvest at least 30bags of Maize, which is 5 times higher than what I got last season after spending $180 for Land preparation, Planting, Weeding  and inputs.”Says Ann Waweru during a field interview.

Ann Waweru is one of the 200 Lead farmers in the CA4FS project being implemented by ACT through a grant from the Alliance for a Green Revolution in Africa (AGRA). The project began on July 2013 and geographical focus is Machakos and Laikipia counties of Kenya. To promote adoption, the project has reached 20,000 farmers through practical demonstrations, field days, trainings, exhibitions and conferences.The project has been focussed in promoting the adoption of conservation agriculture (CA) as a sustainable option for meeting the rising food and income demands in the country. The areas have predominantly small holder farmers with few pockets of large scale farmers.
In the scientific trials, maize and sorghum were used as the main crop and legumes (Dolichos lablab and Pigeon peas) were used as intercrops. The results from the project trials show that CA systems produced higher grain yields than conventional tillage. Maize yield per ha under conventional practice was 1.0 to 1.5 tons which was much lower than 2.3-3.2 tons under CA practices. There was higher yield in drier periods with CA which shows that conservation tillage improves water-use efficiency and greater water holding capacity. Almost the same situation found that biomass yield for maize was higher under conservation tillage at 80% to 110 % higher with CA compared to conventional tillage.


Table 1. Yield comparison between conservation agriculture and Conventional tillage for major crops in Machakos and Laikipia Counties of Kenya
Crop type
            Crop yield (t/ha)
Yield increase (t/ha)
Percentage Increase

Conservation tillage
Conventional tillage


Maize (with Dolichos lablab intercrop)
2.3-3.2
1.0-1.5
1.3-1.7
100-150
Sorghum (With Pigeon pea intercrop)
3.3-3.6
1.3-1.8
2.0-1.8
100-150
In the last 3 years, adoption of CA has grown from 2240Ha to 3000Ha in Laikipia. To encourage Mechanization, specially designed hand CA tools (rippers, Weed scrapper) are manufactured locally by the local artisans. They cost between 3$ to $6 compared to $8 to $ 15 for the conventional practice.
Results of Gross Margin assessment of the different treatments of the project show that it would be profitable for the farmers in Machakos and Laikipia to adopt the use of conservation agriculture (CA) in their farms. Gross margin of $1363/Ha was found in CA practice which translates to virtually 250 % increment from the conventional practice. The Conventional tillage practice exhibited negative gross margin implying that even when mineral fertilizer is used to boost crop yield, CA is critical to provide favourable growth conditions and conducive environment for nutrients uptake by the crops. The total variable costs were about twice lower with CA resulting to a dramatic gross margin than the conventional tillage. Therefore less labor and higher net returns make for higher profitability per labor with Conservation agriculture.