Aug 31, 2011 by Jawoo Koo

With limited resources to cope with weather variability, smallholder farmers in Sub-Saharan Africa (SSA) are facing highly unreliable crop production from year to year. In this modeling exercise we quantified how much area is under such condition and what are their production potential under intensification. The simulation result indicates that, without further intensification, only 15% of current maize growing area has the potential to reliably produce more than 3 t/ha, a yield level suggested as being sufficient to sustain the cereal needs of a typical smallholder household. However, with well-managed intensification, 82% of the current maize area showed the potential to reliably produce 3 t/ha or more.


Mar 21, 2011 by Jeff Horwich

We're not normally focused on this part of the world, but something like the Japanese tsunami tends to divert your attention.

Screen-capture from NHK World

Feb 21, 2011 by Lieven Claessens

Despite a common (trust us, it's not just you) misconception, sweet potato (Ipomoea batas L. Lam) is not at all related to potato (Solanum tuberosum), nor to the true yam (Dioscorea batatas). In fact, they are all quite different. Sweet potato is a root crop, and potato and yams are tuber crops. Even researchers sometimes get confused that their publications mistakenly relate the crop species and data.

Sweet potato harvest in Uganda

Feb 16, 2011 by Jawoo Koo

What's the reported level of maize yield in Chad? Or, how about for all Sub-Saharan Countries? What's the time trend of groundnut yield in Ghana? Please be quick; you have one minute to find the answers! OK, good questions.


Feb 12, 2011 by Jawoo Koo

"How to compile and run DSSAT v4.5 on Linux?" Good question.


Feb 11, 2011 by Jawoo Koo

HarvestChoice uses a so-called meso-scale spatial grid typically at 10km or 5-arc minute resolution.


Illustration by Mike Shibao, based on imagery from CMMAP.

Feb 4, 2011 by Jawoo Koo

Crop systems models can help researchers estimate the future of food security under climate scenarios. Many crop models are known to exist around the world - for different crops with varying complexities, yet it is not easy to find the right model for the right problem. To better understand the global extent of crop model development and to identify gaps in capabilities, HarvestChoice participated in an initiative to conduct a rapid meta-analysis of crop models using on-line survey to the crop modeling community in the world. Here are the key findings.

Word cloud of crops that respondents modeled

Jan 30, 2011 by Chris Legg

Cassava is one of the most important staple crops in sub-Saharan Africa, yet it stands out from other crops in many ways. In fact, cassava has been even imposing challenges for us to analyze its production data and modeling growth and productivity. This post briefly explains why.

Drying cassava

Dec 22, 2010 by Jawoo Koo

How to use the weather generator in the DSSAT Crop Systems Model for climate change studies, and what should I know? Good question.


Dec 16, 2010 by Jawoo Koo

Long-term yield trials are great resources for agricultural researches in multiple disciplines, but such dataset have not been readily available in Sub-Saharan Africa. The Hatfield Experimental Farm in Pretoria, South Africa, is an exceptional case that has been providing maize yield and fertilizer trial dataset with 32 treatments since 1939. In collaboration with University of Pretoria, HarvestChoice facilitated the re-discovery of raw yield dataset from the trial to study the measured long-term yield variability.

Long-term maize trial plots at the Hatfield Experimental Farm, U of Pretoria