Plough less, grow more? Higher yields from strip tillage in Ethiopia
The full reading behind my Short: what a two-year trial found, where to read it, what it could mean for small farmers, and what it can't tell us yet.
The study in plain English
In much of northern Ethiopia, farmers prepare their fields with the maresha, a traditional ox-drawn plough, usually going over the whole field three or four times before sowing. Every pass breaks up the soil surface and lets it dry out.
Strip tillage does less. Only narrow strips where the seed will go are worked; the soil between the rows is left undisturbed. In this trial the strips were cut with traditional maresha equipment, 0.75 m apart, so no new machine was needed.
A two-year field trial (2019 and 2020) at the Shire-May-Tsebri Agricultural Research Center in Tselemti district, Tigray, compared five ways of preparing the soil: the usual ploughing, zero tillage, mulch tillage, reduced tillage and strip tillage. Each was tested on four plots, with the same crop, an improved maize variety (Melkassa-2), and the same fertiliser on every plot.
What the paper reports: strip tillage gave the highest grain yield in both seasons, 4.60 tonnes per hectare against 3.11 t/ha under conventional ploughing, which the author calls a 47.9% increase. More seeds came up (germination 89.1% vs 68.8%). Below the surface, at 15 to 45 cm, strip-tilled soil held more water than ploughed soil, and its total porosity was slightly higher (51.75% vs 49.65%). Over two seasons, soil organic carbon, nitrogen and pH did not change significantly, which the author says is expected for such a short trial.
Read the original study
Kebede M. (2026). Evaluating conservation tillage as a strategy for soil and water conservation and yield stability in Ethiopian dryland agriculture. Discover Agriculture 4, article 317. Open access (CC BY-NC-ND 4.0).
Watch the Short
The idea from first principles
Rain that soaks in and stays in the soil is water your crop can use later. Every time soil is turned over, more of it is exposed to sun and wind and dries out faster, and surface crumbs break down.
The author explains the results this way: less disturbance keeps more pore space and slows evaporation, so more water is held where roots can reach it. FAO's conservation agriculture principles start from the same place: minimum soil disturbance, keeping the soil covered (at least 30% with crop residues or cover crops), and growing a variety of crops.
What this could mean for small farmers
These points come only from the sources listed below. They are not a substitute for advice from your local extension service.
A familiar tool, used differently
In this trial, strip tillage used traditional maresha equipment to cut only the planting lines [1]. An earlier study in Ethiopia's central Rift Valley (2003–2005) also tested strip tillage using modified maresha ploughs, because its authors judged full no-till not feasible for many smallholders there [2].
Gains vary from place to place
In that earlier Rift Valley study, strip tillage gave 1,840 kg/ha against 1,720 kg/ha for conventional ploughing, and 2,130 kg/ha when strips were also subsoiled: a smaller gain than in Tigray [2]. Don't expect +48% everywhere.
Timing matters
In the Rift Valley study, the best results came when the crop was sown soon after the strips were prepared; the authors concluded the gap between subsoiling and planting should not exceed about a week [2].
Cover helps, but residues have other uses
FAO recommends keeping at least 30% of the soil covered [3]. A widely cited review warns that many smallholders need crop residues as livestock feed, leaving little to keep as mulch [4].
Plan for weeds and labour
Ploughing also controls weeds. Without herbicides, less tillage can mean more hand weeding, and that extra work often falls on women [4]. The Tigray trial weeded all plots by hand and did not measure labour costs [1].
Physical gains first, chemistry later
Over two seasons the trial saw changes in moisture and soil structure, but not in organic carbon or nitrogen. The author notes those usually need 5 to 10 years of monitoring [1].
Honest limits
- One site, two seasons. The trial ran at a single research station in 2019 and 2020. The author says results may differ on other soils and at other altitudes [1].
- Not the driest land. Headlines call it "drylands", but the site is classed as moist lowland, with about 1,209 mm of rain a year on average (2006–2020) [1].
- No cost analysis. The paper did not weigh labour against yield gains, which the author calls critical for adoption [1].
- The paper's yield numbers don't all agree. The abstract and conclusion give 4.60 vs 3.11 t/ha (+47.9%), but the results text gives 4,562 vs 2,440 kg/ha ("approximately 87% higher"). We use the paper's headline 48% and treat the exact gap with caution.
- Method wording is unclear in places. Strip tillage is defined as leaving most soil undisturbed, but the methods also mention three to four ploughings "in adherence to local agricultural norms", so exactly how much less the soil was disturbed is not fully clear.
- Single author; data on request. The study has one author, and the underlying data are available only on request [1].
Full narration (transcript)
What if ploughing less of your field gave you higher yields? In northern Ethiopia, a two-year trial tested strip tillage: working only narrow strips where the seed goes, and leaving the rest alone. More seeds came up: 89 percent, versus 69 with the usual ox plough. And yields were about 48 percent higher: 4.6 tonnes per hectare, versus 3.1. The soil also held more water below the surface, where the roots reach. Disturb the soil less, and keep the moisture in. But this was one research site, over two seasons. Promising, not proven.
Sources
- [1] Kebede M. (2026). Evaluating conservation tillage as a strategy for soil and water conservation and yield stability in Ethiopian dryland agriculture. Discover Agriculture 4, 317. https://doi.org/10.1007/s44279-026-00801-2
- [2] Temesgen M., Savenije H.H.G., Rockström J., Hoogmoed W.B. (2012). Assessment of strip tillage systems for maize production in semi-arid Ethiopia: effects on grain yield, water balance and water productivity. Physics and Chemistry of the Earth 47–48, 156–165. https://doi.org/10.1016/j.pce.2011.07.046 (free preprint: HAL / HESSD 2007)
- [3] FAO. Conservation Agriculture. https://www.fao.org/conservation-agriculture/en/
- [4] Giller K.E., Witter E., Corbeels M., Tittonell P. (2009). Conservation agriculture and smallholder farming in Africa: the heretics' view. Field Crops Research 114, 23–34. https://doi.org/10.1016/j.fcr.2009.06.017
- [5] News write-up: "Strip Tillage Boosts Maize Yields Nearly 48% in Ethiopia's Dying Drylands", Bioengineer.org / Scienmag, 9 October 2026. Link
Image credits for the Short
Satellite imagery: NASA Blue Marble Next Generation and NASA Terra/MODIS corrected reflectance, via NASA GIBS / Worldview (public domain). Field, seedling, yield, moisture and other animations: own work (illustrations, not to scale).