Piet van Asten is a Senior Vice-President at Olam and Head Agronomy of its coffee plantations team, providing support to the teams in Laos, Tanzania, Zambia and Brazil. The aim is to jointly apply, adapt and develop technologies and approaches that improve the productivity and profitability of Olam's coffee plantations while ensuring the sustainability of the natural and social environment in which these plantations operate. Climate change adaptation and mitigation will form an integral part of the approach. Piet is also leading ofi’s Regenerative Agriculture agenda, including the design and implementation of decarbonization pathways. Piet holds a PhD on agronomy from Wageningen University with a strong focus on soil science, crop production, farming systems and sustainable development. He has worked for the CGIAR (IITA and AfricaRice) from 1998-2016 as an award-winning scientist on sustainable intensification of cropping systems, including coffee, banana, cocoa and rice. He has a strong scientific track record that he now converts into productive support for the plantations. Phone: +256752787812 Address: 15 East Naguru Road
PO Box 7878 Kampala
Uganda
In the East-African Great Lakes Region, low crop yields due to widespread soil infertility involv... more In the East-African Great Lakes Region, low crop yields due to widespread soil infertility involve difficulties to cope with demographic pressure. Banana cropping systems are widespread and crucial for people livelihood. Improving their sustainability requires a better understanding of nutrient dynamics and soil fertility. We studied highly weathered soils in four sites from Rwanda and Burundi. The soils differed in parent rock: granite, shale, and other pelitic rocks. In four homesteads at each site, soils were sampled as a function of depth and distance to farmer’s house. We determined soil physico-chemical properties and total elemental contents, as well as soil mineralogical constitution.Typical black anthropogenic soils similar to the Amazonian Dark Earths (Terra Preta) occurred where banana cropping was ancient and soils benefited from frequent supply of organic manure and ash cooking residues. Close to home buildings, the thickness of dark Ah horizons could be above 160 cm. Soil management practices and accumulation of organic matter significantly increased soil porosity and root exploration allowing enhanced uptake of water and nutrients, thereby increasing biomass of banana plants. PCA-analysis (Matlab Student Version R2007a)involving eight soil properties yielded to 78% of total variance born by the two first principal components (PC). PC1 (53%) was positively correlated to CEC and total contents of C, Ca, P, and Mg. PC2 (25%) was defined by a strong negative correlation between total Fe content and total contents of Si and K. Our data thus show that two major types of soil properties discriminated the soil samples: (1) organic matter content and major plant nutrients (Ca, Mg, P), both linked to past and current soil management practices, (2) nature of parent rock, linked to the abundance of iron and the occurrence of muscovite as residual mineral
This article examines the effect of membership in farmer groups (MFG) on the adoption lag of agri... more This article examines the effect of membership in farmer groups (MFG) on the adoption lag of agricultural technologies and farm performance in the Democratic Republic of Congo, Burundi and Rwanda. We use duration and stochastic production frontier models on farm household data. We find that long period of MFG reduces adoption lag and much more so if combined with sustainable extension service delivery from government or development agencies. Farmer groups function as an important mechanism for improving farm productivity through reduced technical inefficiency in input use. We discuss the policy implications under which farmer groups are a useful channel to reduce adoption lag, and by what means improved farm performance can be achieved.
Highland bananas grown near the homestead in Eastern Democratic Republic of Congo receive organic... more Highland bananas grown near the homestead in Eastern Democratic Republic of Congo receive organic household residues and are often mulched. Farmers also tend to allocate their best land for banana cultivation. However, due to an increased demand for bananas, farmers have started establishing banana plots on less fertile land. An experiment was conducted to assess plant growth on plots further away from the homestead and with minimal amounts of organic matter input. Two sites with contrasting soil fertility were chosen. Soil samples taken at the onset of the trial were analysed. The organic matter input consisted of Loudetia sp., the dominant weed species found on marginal soils, while Tithonia diversifolia was added to facilitate the decomposition of Loudetia sp. Pared lateral shoots of the east African highland cooking banana ‘Barhabesha’ (AAA-EA) were planted. The treatments consisted of 2 kg of organic matter added in the planting hole at planting, 2 kg of organic matter applied ...
Although the political context in Uganda exhibits democratic deficit and patronage, research and ... more Although the political context in Uganda exhibits democratic deficit and patronage, research and development actors have given little attention to the possible negative impact these may have on agricultural policymaking and implementation processes. This article examines the influence of power in perpetuating prevailing narratives around public participation in agricultural policymaking processes. The analysis is based on qualitative data collected between September 2014 and May 2015 using 86 in‐depth interviews, 18 focus group discussions, and recorded observations in stakeholder consultations. Results indicate that while the political setting provides space for uncensored debates, the policymaking process remains under close control of political leaders, technical personnel, and high‐level officers in the government. Policy negotiation remains limited to actors who are knowledgeable about the technical issues and those who have the financial resources and political power to influe...
Banana-bean intercropping systems are used by many small-scale farmers in eastern Democratic Repu... more Banana-bean intercropping systems are used by many small-scale farmers in eastern Democratic Republic of Congo to maximize land use and intensify crop production. A study was conducted at the INERA Mulungu research station to determine the effect of banana leaf pruning on banana (Musa spp.) and bean (Phaseolus vulgaris, Fabaceae) yield. The East African highland cooking banana 'Barhabesha' was established in April 2007 at a spacing of 2 by 3 meters. The treatments consisted of different levels of banana leaf canopy coverage (5 leaves [5L] and all leaves [ALL]) and leguminous crop varieties (the bush bean 'Ngwaku Ngwaku' and the climbing bean 'AND10') which were planted in the banana plot. Bean yields were assessed during 4 cropping seasons (2008B, 2009A, 2009B and 2010A). Banana leaf pruning did not have a significant effect on time from planting to bunch harvest in either legume intercropping treatment. Banana leaf pruning did not have a significant effect o...
Journal of Geophysical Research: Biogeosciences, 2018
This study aims to explain effects of soil textural class, topography, land use, and land use his... more This study aims to explain effects of soil textural class, topography, land use, and land use history on soil greenhouse gas (GHG) fluxes in the Lake Victoria region. We measured GHG fluxes from intact soil cores collected in Rakai, Uganda, an area characterized by low‐input smallholder (<2 ha) farming systems, typical for the East African highlands. The soil cores were air dried and rewetted to water holding capacities (WHCs) of 30, 55, and 80%. Soil CO2, CH4, and N2O fluxes were measured for 48 h following rewetting. Cumulative N2O fluxes were highest from soils under perennial crops and the lowest from soils under annual crops (P < 0.001 for all WHC). At WHC of 55% or 80%, the sandy clay loam soils had lower N2O fluxes than the clay soils (P < 0.001 and P = 0.041, respectively). Cumulative soil CO2 fluxes were highest from eucalyptus plantations and lowest from annual crops across multiple WHC (P = 0.014 at 30% WHC and P < 0.001 at both 55 and 80% WHC). Methane fluxes...
Banana systems in the humid highlands of sub-Saharan Africa: enhancing resilience and productivity, 2013
The Great Lakes countries of East and Central Africa, including Rwanda, Burundi and the Democrati... more The Great Lakes countries of East and Central Africa, including Rwanda, Burundi and the Democratic Republic of Congo (DR Congo) are a secondary centre of Musa diversity, especially for East African highland bananas (Musa AAA-EA group) and plantains (ABB). Musa cultivation in this region is characterized by low annual productions (5-30 t/ha). This is caused by biotic (pests and diseases) and abiotic (soil fertility and drought) factors. The impacts of these factors are, however, influenced by the different agronomic practices that are applied on farm. This study assessed the use of some key agronomic practices by Musa farmers across districts of Rwanda and Burundi, and the South and North Kivu provinces of eastern DR Congo. Farms in North Kivu were less intensively managed than those in Burundi, Rwanda and South Kivu. For example, farms in North Kivu were the least de-trashed (removal of dead leaves from the pseudostem, 66%) and de-suckered (63%) compared with 88% and 100% in Burundi...
In the East-African Great Lakes Region, low crop yields due to widespread soil infertility involv... more In the East-African Great Lakes Region, low crop yields due to widespread soil infertility involve difficulties to cope with demographic pressure. Banana cropping systems are widespread and crucial for people livelihood. Improving their sustainability requires a better understanding of nutrient dynamics and soil fertility. We studied highly weathered soils in four sites from Rwanda and Burundi. The soils differed in parent rock: granite, shale, and other pelitic rocks. In four homesteads at each site, soils were sampled as a function of depth and distance to farmer’s house. We determined soil physico-chemical properties and total elemental contents, as well as soil mineralogical constitution.Typical black anthropogenic soils similar to the Amazonian Dark Earths (Terra Preta) occurred where banana cropping was ancient and soils benefited from frequent supply of organic manure and ash cooking residues. Close to home buildings, the thickness of dark Ah horizons could be above 160 cm. Soil management practices and accumulation of organic matter significantly increased soil porosity and root exploration allowing enhanced uptake of water and nutrients, thereby increasing biomass of banana plants. PCA-analysis (Matlab Student Version R2007a)involving eight soil properties yielded to 78% of total variance born by the two first principal components (PC). PC1 (53%) was positively correlated to CEC and total contents of C, Ca, P, and Mg. PC2 (25%) was defined by a strong negative correlation between total Fe content and total contents of Si and K. Our data thus show that two major types of soil properties discriminated the soil samples: (1) organic matter content and major plant nutrients (Ca, Mg, P), both linked to past and current soil management practices, (2) nature of parent rock, linked to the abundance of iron and the occurrence of muscovite as residual mineral
This article examines the effect of membership in farmer groups (MFG) on the adoption lag of agri... more This article examines the effect of membership in farmer groups (MFG) on the adoption lag of agricultural technologies and farm performance in the Democratic Republic of Congo, Burundi and Rwanda. We use duration and stochastic production frontier models on farm household data. We find that long period of MFG reduces adoption lag and much more so if combined with sustainable extension service delivery from government or development agencies. Farmer groups function as an important mechanism for improving farm productivity through reduced technical inefficiency in input use. We discuss the policy implications under which farmer groups are a useful channel to reduce adoption lag, and by what means improved farm performance can be achieved.
Highland bananas grown near the homestead in Eastern Democratic Republic of Congo receive organic... more Highland bananas grown near the homestead in Eastern Democratic Republic of Congo receive organic household residues and are often mulched. Farmers also tend to allocate their best land for banana cultivation. However, due to an increased demand for bananas, farmers have started establishing banana plots on less fertile land. An experiment was conducted to assess plant growth on plots further away from the homestead and with minimal amounts of organic matter input. Two sites with contrasting soil fertility were chosen. Soil samples taken at the onset of the trial were analysed. The organic matter input consisted of Loudetia sp., the dominant weed species found on marginal soils, while Tithonia diversifolia was added to facilitate the decomposition of Loudetia sp. Pared lateral shoots of the east African highland cooking banana ‘Barhabesha’ (AAA-EA) were planted. The treatments consisted of 2 kg of organic matter added in the planting hole at planting, 2 kg of organic matter applied ...
Although the political context in Uganda exhibits democratic deficit and patronage, research and ... more Although the political context in Uganda exhibits democratic deficit and patronage, research and development actors have given little attention to the possible negative impact these may have on agricultural policymaking and implementation processes. This article examines the influence of power in perpetuating prevailing narratives around public participation in agricultural policymaking processes. The analysis is based on qualitative data collected between September 2014 and May 2015 using 86 in‐depth interviews, 18 focus group discussions, and recorded observations in stakeholder consultations. Results indicate that while the political setting provides space for uncensored debates, the policymaking process remains under close control of political leaders, technical personnel, and high‐level officers in the government. Policy negotiation remains limited to actors who are knowledgeable about the technical issues and those who have the financial resources and political power to influe...
Banana-bean intercropping systems are used by many small-scale farmers in eastern Democratic Repu... more Banana-bean intercropping systems are used by many small-scale farmers in eastern Democratic Republic of Congo to maximize land use and intensify crop production. A study was conducted at the INERA Mulungu research station to determine the effect of banana leaf pruning on banana (Musa spp.) and bean (Phaseolus vulgaris, Fabaceae) yield. The East African highland cooking banana 'Barhabesha' was established in April 2007 at a spacing of 2 by 3 meters. The treatments consisted of different levels of banana leaf canopy coverage (5 leaves [5L] and all leaves [ALL]) and leguminous crop varieties (the bush bean 'Ngwaku Ngwaku' and the climbing bean 'AND10') which were planted in the banana plot. Bean yields were assessed during 4 cropping seasons (2008B, 2009A, 2009B and 2010A). Banana leaf pruning did not have a significant effect on time from planting to bunch harvest in either legume intercropping treatment. Banana leaf pruning did not have a significant effect o...
Journal of Geophysical Research: Biogeosciences, 2018
This study aims to explain effects of soil textural class, topography, land use, and land use his... more This study aims to explain effects of soil textural class, topography, land use, and land use history on soil greenhouse gas (GHG) fluxes in the Lake Victoria region. We measured GHG fluxes from intact soil cores collected in Rakai, Uganda, an area characterized by low‐input smallholder (<2 ha) farming systems, typical for the East African highlands. The soil cores were air dried and rewetted to water holding capacities (WHCs) of 30, 55, and 80%. Soil CO2, CH4, and N2O fluxes were measured for 48 h following rewetting. Cumulative N2O fluxes were highest from soils under perennial crops and the lowest from soils under annual crops (P < 0.001 for all WHC). At WHC of 55% or 80%, the sandy clay loam soils had lower N2O fluxes than the clay soils (P < 0.001 and P = 0.041, respectively). Cumulative soil CO2 fluxes were highest from eucalyptus plantations and lowest from annual crops across multiple WHC (P = 0.014 at 30% WHC and P < 0.001 at both 55 and 80% WHC). Methane fluxes...
Banana systems in the humid highlands of sub-Saharan Africa: enhancing resilience and productivity, 2013
The Great Lakes countries of East and Central Africa, including Rwanda, Burundi and the Democrati... more The Great Lakes countries of East and Central Africa, including Rwanda, Burundi and the Democratic Republic of Congo (DR Congo) are a secondary centre of Musa diversity, especially for East African highland bananas (Musa AAA-EA group) and plantains (ABB). Musa cultivation in this region is characterized by low annual productions (5-30 t/ha). This is caused by biotic (pests and diseases) and abiotic (soil fertility and drought) factors. The impacts of these factors are, however, influenced by the different agronomic practices that are applied on farm. This study assessed the use of some key agronomic practices by Musa farmers across districts of Rwanda and Burundi, and the South and North Kivu provinces of eastern DR Congo. Farms in North Kivu were less intensively managed than those in Burundi, Rwanda and South Kivu. For example, farms in North Kivu were the least de-trashed (removal of dead leaves from the pseudostem, 66%) and de-suckered (63%) compared with 88% and 100% in Burundi...
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