Climate Adapted Farming Methods in Zambia: Improving CA performance through appropriate mechanization
Are small-scale and emergent farmers able to practise mechanized Conservation Agriculture in Zambia? The Mechanized Conservation Agriculture (MCA) on-farm experiment at the Zambian-German Knowledge and Training Centre, situated at the Golden Valley Agricultural Research Trust is the surest answer.
Everybody in Zambia concurs with the reality of climate change since the impacts are visible across the entire nation. Small and medium-scale farmers who entirely rely on rainfed agriculture for both crops and animals’ production are the most affected. In the recent past, the unpredicted rainfall patterns have resulted in late planting leading to yield losses due to drought that follows. The rains come as late as December-January and end too early in the season, as opposed to the previous years when rainfall could start as in October and lasts until April. Because the rains are very erratic, they often cause unprecedented floods and massive soil erosion. This phenomenon is not only a scene in Zambia but also across entire sub-Saharan Africa (SSA) and the world over.
These challenges facing the Zambian farmers call for viable and sustainable solutions. The solutions should be not only feasible but also sustainable while mitigating the impacts of climate change and adapting to its effects. Like other developing countries, Zambia is faced with the reality of poverty and food insecurity due to unsustainable agriculture. Thus, through climate-adapted farming approaches, the agricultural sector can secure farmers from climate-related losses.
Figure 1: Signboard showing MCA experimental field layout. Left: Godfrey Omulo, PhD candidate from the University of Hohenheim, Right: Abrahan Kapela research assistant. Photo courtesy of Innocent Maphango.
The climate-adapted farming methods project (CAFM), an initiative of the Zambian-German Agricultural Knowledge and Training Centre (AKTC), could not be timelier and more relevant. AKTC is a bilateral cooperation between the German Federal Ministry of Agriculture and Food and the Zambian Ministry of Agriculture. It is located at the Golden Valley Agricultural Research Trust (GART) in Chisamba. The CAFM project, which started in 2019, is aimed at minimizing climate-related yield losses and securing income among small-scale and emergent farmers through the practice of MCA.
Even though Conservation Agriculture (CA) is widely known and appreciated in Zambia, its practice and adoption had not reached the desired threshold. However, steadfast efforts of the promoting NGOs organizations like CFU and also the Zambian government through the Ministry of Agriculture, has led adoption spanning to over 300,000 ha. Zambia leads with the largest area of farms under CA in entire sub-Saharan Africa. Nevertheless, despite CA’s immense potential to spur agricultural productivity in Zambia, its adoption has been mainly by small-scale farmers who mostly face challenges due to high drudgery and lack of mechanization. The farmers use hand hoes for making planting basins while others use animal-drawn implements. The manual digging of holes is too labour intensive and time-consuming. This has made basins-based CA practice unappealing to emergent and large-scale farmers who operate on large pieces of land.
The benefits of CA among small-scale farmers compared with conventional counterparts under the same climatic conditions cannot be overemphasized. The benefits include improved soil structure, water infiltration, soil microbial activity, time and labour reduction and yield. Thus, to effectively tap on these potentials, barriers facing small and medium-scale farmers must be dismantled. The greatest barrier to CA adoption and up-scaling in Zambia being the lack of appropriate mechanization for land preparation, planting and weed control.
Even though some emergent and large-scale farmers have acquired tractors, they are not necessarily practising MCA. What could be the reason? Are MCA implements like ripper and no-till planters available in the Zambian market? Can the standard small four-wheel tractors achieve the desired CA operations?
Indeed tractors, rippers and no-till planters are available in the Zambian market. However, few on-farm research or experiments based on MCA are available for farmers’ demonstration and learning. Besides, the research based on the use of purely four-wheel tractors and the associated implements would provide better comparisons with the performance of animal traction and two-wheel tractors common among smallholder farmers. Thus, the CAFM on-farm experiment on a 27 ha of rainfed farming, was set to access the performance of MCA versus conventional farming with maize and soybean crops, and to analyze whether they are economically viable.
Figure 2: A modified MF100 planter mounted on 60 hp 2-wheel MF tractor being tested by Mr. De Jager. Photo: Courtesy of Mr. Anschuetz, the AKTC Zambia Team Leader.
Experimental Description
To effectively access the effects of MCA and conventional farming on maize and soybean performance, three tillage practices were employed: discing (conventional), ripping and direct planting (conservation). The residues on the conventional plots were first burnt before discing; this was following the common practice of burning of residues every season among conventional farmers. With the 60 hp tractor, land preparation, planting, fertilizer application and weed control was made in time. A two tandem compact disc harrow was used to prepare all the conventional plots, and a two-tine ripper, modified with cutting coulter and depth control wheel was used to rip all the ripping plots. A 2-row no-till planter, modified with cutting coulter and trash wheels was used for planting, and basal fertilizer application on the no-till plots as well as on the disc harrowed and ripped plots. Topdressing fertilizer application was done using a tractor-drawn PTO driven spreader while both the pre-emergent and post-emergent weed control was done using a 600 litres 12m wide boom sprayer.
All agronomic considerations seeds, fertilizers, herbicides, pesticides and fungicides for the two crops were done appropriately while crop development monitored and observations made throughout the season. Key components like operation time, fuel consumption, labour charges, rainfall amounts and soil moisture readings were also noted throughout the operations. Being the first trial, the maize-soybean rotation will be done in the subsequent 2020-2021 season.
The GART weather station has recorded a total 707 mm of rainfall this season. However, compared to other regions of the country, the rainfall amount is quite low even though it is more than last season. With this constrained rainfall, interesting observations were made throughout the crop’s development under the various tillage types.
Preliminary results
In general, good plant population was observed on the three tillage types. However, uneven germination was noted on disced plots, effects of which translated to the growth of crops throughout the season. Seeds planted on the disced plots were deprived of moisture due to the excessive evaporation during the dry spell, which resulted in soil surface crusting. The residue cover on the CA plots cushioned the crops from birds and ants attack. The crops on the CA plots received least water stress during a two-week dry spell in December. Because of better water infiltration, soil moisture contents were highest in no-till plots and least in disced plots. Soil temperature and evaporation were higher in disced plots than in the ripped and no-till plots.
Figure 3: Maize in No-Till plots at 14 weeks after planting. Photo: Courtesy of Mr. Omulo
The time taken in land preparation and planting was double in the disced and ripped plots compared to no-till plots. 54% and 53% less fuel was used on the no-till plots compared to the disced and ripped plots respectively. Similarly, labour costs were highest in disced plots ($45/ha) compared to ripped ($41/ha) and no-till plots ($22/ha). Weed control, top-dressing and insect control operations recorded insignificant time, labour and fuel differences. Yield measurements per crop will be computed at the end of the season. However, physical inspections reveal taller crops with bigger cobs in MCA plots compared to disced plots. These preliminary results indicate that MCA is not only a climate-smart way of farming but also time-saving and more economically sound. The reduced fuel consumption and low labour costs can be used to more farm inputs while the time saved invested in other economically viable activities.
Farmers from the neighbouring districts of Chisamba and Chibombo got hands-on experience on MCA land preparation, planting and weed control at AKTC during the on-farm demonstrations throughout the season. This culminated by a successful field day on the 25th February 2020 which attended by close 200 farmers and stakeholders. During this field day, the crop’s development under different tillage types was showcased. The farmers, partners and the stakeholders present appreciated the immense role mechanization can play in boosting CA performance. Among the institutions and stakeholders present were: GART, Conservation Farming Unit (CFU), Bayer Ag, BHBW, Omnia fertilizers, Precision Farming, Seed Co, University of Zambia (UNZA) and the University of Hohenheim in Germany. The National Agricultural Information Services (NAIS) enlightened the nation of the CAFM field day events on the National Broadcasting Cooperation (ZNBC) TV2 news on 26th February 2020.
Figure 4: Soybean on a No-Till plot, eight weeks after germination. Photo: Courtesy of Mr. Omulo
Conclusion
The outcomes of the CAFM project are sure demonstrations that MCA has the potential to up-scale CA adoption and overall agricultural productivity in Zambia. Through MCA, agriculture can become more profitable while offering farmers an opportunity to cope with the effects of climate change. This is true because, farmers can conserve moisture, use less time in their farming activities and minimize cost on fuel. Through MCA, farming as a business is only economically viable but also sustainable since the conservation of soil and water translates to better soil quality and improved yields. To achieve this desired goal, CA mechanization in all its forms: animal traction, 2-wheel tractors, four-wheel tractors and the associated implements should be the focus of both the farmers as well as the government and the private sectors promoting the technology.
Author
Godfrey Omulo,
Godfrey Omulo is currently pursuing his PhD studies at the Center for Agriculture in the Tropics and Subtropics, University of Hohenheim. Mr. Omulo holds a Masters of Science degree and a Bachelors Degree in Agricultural Engineering from Makerere University and JKUAT respectively. He earlier research centred on bio-renewable energy and biosystems engineering. His current research focuses on sustainable agricultural mechanization and Conservation Agriculture in sub-Saharan Africa with a specific focus on Zambia.