SEGH Articles

SEGH2018 Prize Winners Series: Nswana Kafwamfwa

10 August 2018
Winner of a Best Poster Prize at SEGH2018: On-farm assessment of carbon stocks under sub-optimal and optimal input CA management in Mpongwe and Chisamba districts of Zambia - this installment of the Prize Winners Series is contributed by Nswana Kafwamfwa.

Kafwamfwa N., 2Chabala L. and 2Shepande C.

1.Zambia Agriculture Research Institute, Soils and Water Management Section., 2.The University of Zambia, School of Agricultural Sciences

Corresponding author: knswana@yahoo.com, chitalu81.nk@gmail.com

Conservation Agriculture (CA) is one of the promising practices being promoted for reducing the greenhouse gas effect in the face of climate change. This study sought to assess the amount of soil organic carbon (SOC) in CA and Conventional Tillage (CT) cropping systems under suboptimal and optimal input management in Mpongwe and Chisamba (GART) districts of Zambia. In the context of this study, optimal input management refers to agricultural production management were maximum available inputs are applied to the field while, suboptimal input management refers to management were the farmers use a blanket recommendation of inputs per hectare, e.g blanket fertilizer recommendation of four top and four basal fertilizers per hectare at small scale farmer level in Zambia. Composite soil samples were randomly collected at a depth of 20 cm to assess the C-stock in fields which have been under CA/CT between 3 and 7 years under suboptimal input management and between 12 and 18 years under optimal input management.

soil sampling zambia 2

 Kafwamfwa conducting soil sampling for the research project

 

Changes on selected soil properties over time were determined using standard laboratory procedures. The amount of soil carbon sequestered was assessed using the adjusted Land Use, Land-Use Change and Forestry (LULUCF) model. The results indicate that Conservation Agriculture (CA) fields had sequestered 1,424 kg SOC /ha,year while the Conventional Tillage (CT) fields had 392 kg SOC/ha,year, representing a threefold difference. At Golden valley Agriculture Research Trust (GART), SOC was 63,180 kg/ha after 15 years of CA compared to 50,622 kg/ha under CT over the same period. These findings suggest that CA can mitigate the effects of climate change by reducing the carbon emission resulting from the crop production practices. Further, there were significant differences between C-stocks under the 18 and 12 years CA fields under faidherbia albida (Musangu) trees at GART. The results also showed increased pH values under the eucalyptus field compared to the other fields at GART suggesting that pH increases when land use is changed from agriculture to forestry.

Kafwamfwa at the 34th International Conference of SEGH in Livingstone, Zambia



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