Research
DARS evaluation of Deep Bed Farming (2020)
Background
The conventional ridge and furrow farming method is used by the majority of Malawi’s population. This method is labour intensive and leads to substantial environmental problems such as soil compaction and erosion as well as decreased organic matter and reduced water infiltration into the soil. Over time, these outcomes contribute to declining crop yields. (Read more about this problem here and here.)
Deep Bed Farming is a method of climate-smart agriculture that addresses these issues to improve crop yields and regenerate the natural environment. This farming method has been taught to smallholder farmers across Malawi by the NGO Tiyeni with outstanding results. However, the technology has not to date received official approval from Malawi’s Ministry of Agriculture. The following research was conducted to evaluate Deep Bed Farming’s performance against other approved farming methods, confirming its applicability for Malawi’s conditions.
Design
Trials were executed during the 2019-2020 cropping season on both farms and research stations. Locations were strategically chosen to include all of Malawi’s three agro-ecological zones (low-, mid-, and high-altitude (Table 1). The study assessed six variables using a 2x4 factorial design (Table 2). To assess the performance of each variable, the study measured soil moisture in trial sites, maize grain yield, and biomass yield.
The conventional ridge and furrow farming method is used by the majority of Malawi’s population. This method is labour intensive and leads to substantial environmental problems such as soil compaction and erosion as well as decreased organic matter and reduced water infiltration into the soil. Over time, these outcomes contribute to declining crop yields. (Read more about this problem here and here.)
Deep Bed Farming is a method of climate-smart agriculture that addresses these issues to improve crop yields and regenerate the natural environment. This farming method has been taught to smallholder farmers across Malawi by the NGO Tiyeni with outstanding results. However, the technology has not to date received official approval from Malawi’s Ministry of Agriculture. The following research was conducted to evaluate Deep Bed Farming’s performance against other approved farming methods, confirming its applicability for Malawi’s conditions.
Design
Trials were executed during the 2019-2020 cropping season on both farms and research stations. Locations were strategically chosen to include all of Malawi’s three agro-ecological zones (low-, mid-, and high-altitude (Table 1). The study assessed six variables using a 2x4 factorial design (Table 2). To assess the performance of each variable, the study measured soil moisture in trial sites, maize grain yield, and biomass yield.
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Table 1
*The Madisi trail was not conducted properly, so results were excluded from the report. |
Table 2
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Results
Grain and biomass yields
Data analysis demonstrated significant differences (p<0.05) in grain yield for the tillage system effect on all sites except for Chitedze. Specifically, Deep Bed Farming (DBF) produced grain yields that were significantly higher than conventional tillage (CT) and pit planting (PT). Compared to CT, DBF increased grain yield between 30-72% across all four of these sites. DBF performed even better against PT, increasing grain yields between 35-125% across all four of these sites.
Statistically significant differences (p<0.05) for the tillage system effect on biomass yields were only observed at Bvumbwe and Chinguluwe. In Bvumbwe, the significant difference was observed for the interaction of tillage system, DBF, with cropping system, maize legume intercrop (MZL). On this site, biomass yield increased by 124% for MZL-DBF compared to MZL-PT. At Chinguluwe, tillage system demonstrated significantly higher biomass yields without the interaction cropping system. On this site, biomass yield was 36% higher for DBF compared to PT.
Soil moisture content
Data analysis showed statistically significant differences (p<0.05) for soil moisture in Chitala, Bvumbwe, and Mtunthama correlated with the tillage system effect. Specifically, DBF increased soil moisture content between 30-238% compared to CT across all three of these sites. Compared to PT, DBF significantly increased soil moisture content at two sites, Bvumbwe (65% increased) and Mtunthama (166% increased).
Conclusion
This study evidenced DBF’s superior performance against other farming methods in increasing both grain and biomass yields while enhancing soil moisture content. Additionally, the increased biomass produced through DBF may have the long-term effect of increasing the build-up of soil organic matter through improved microbial activity. It is recommended that DBF be promoted to farmers across Malawi.
Read the full report here.
Grain and biomass yields
Data analysis demonstrated significant differences (p<0.05) in grain yield for the tillage system effect on all sites except for Chitedze. Specifically, Deep Bed Farming (DBF) produced grain yields that were significantly higher than conventional tillage (CT) and pit planting (PT). Compared to CT, DBF increased grain yield between 30-72% across all four of these sites. DBF performed even better against PT, increasing grain yields between 35-125% across all four of these sites.
Statistically significant differences (p<0.05) for the tillage system effect on biomass yields were only observed at Bvumbwe and Chinguluwe. In Bvumbwe, the significant difference was observed for the interaction of tillage system, DBF, with cropping system, maize legume intercrop (MZL). On this site, biomass yield increased by 124% for MZL-DBF compared to MZL-PT. At Chinguluwe, tillage system demonstrated significantly higher biomass yields without the interaction cropping system. On this site, biomass yield was 36% higher for DBF compared to PT.
Soil moisture content
Data analysis showed statistically significant differences (p<0.05) for soil moisture in Chitala, Bvumbwe, and Mtunthama correlated with the tillage system effect. Specifically, DBF increased soil moisture content between 30-238% compared to CT across all three of these sites. Compared to PT, DBF significantly increased soil moisture content at two sites, Bvumbwe (65% increased) and Mtunthama (166% increased).
Conclusion
This study evidenced DBF’s superior performance against other farming methods in increasing both grain and biomass yields while enhancing soil moisture content. Additionally, the increased biomass produced through DBF may have the long-term effect of increasing the build-up of soil organic matter through improved microbial activity. It is recommended that DBF be promoted to farmers across Malawi.
Read the full report here.