Agronomic Profiles of 15 Crops Important to the Sahel

The profiles include critical information on the growth parameters of each crop, which can be used as a "screen" against trends in observed intra-seasonal climate characteristics. This information is useful in determining when critical crop tolerance thresholds may be passed. The profiles were developed for 15 crops grown in the Sahel, mainly in Niger, Burkina Faso, Mali, and Senegal. The crops are presented by type, including cereals (maize, pearl millet, rice, sorghum), fiber crops (cotton), fruit crops (cashew, mango, shea nut), grasses (bourgou [Enchinochloa stagnina]), legumes (néré [Parkia biglobosa], cowpea, groundnut), oilseed crops (sesame), and root crops (cassava, sweet potato). Each profile describes the geographic distribution and importance of the crop, its life cycle, and its known rainfall and temperature requirements at different stages of development. Temperature requirements are a critical factor in crop growth and development. All crops have basic requirements to complete a given phenological stage, and if the temperature falls outside of the thresholds at any stage, crop growth and development can be affected. However, a crop can still be viable even if temperatures exceed the thresholds if other conditions are optimal. For example, excessive heat can be offset by high levels of soil moisture. Rainfall requirements are also essential for crop growth, but they are extremely difficult to correlate with precipitation due to other factors affecting the amount of moisture available to a plant. Evapotranspiration levels, dictated by temperature, solar radiation, and plant architecture, also affect the amount of moisture available to a plant. Soil requirements are complex, and data on the interaction between the crop, soil types, and other growth parameters is incomplete. However, clay soils and soils with higher levels of organic matter have more potential to retain water than sandy soils. Crop variety is another critical factor in crop adaptability to changing climate conditions. Profiles have been created only for general crop types and the range of varieties cultivated in the Sahel, but they do not cover specific varieties. A phenological profile by variety would require extensive, specific data on varietal performances, genetic background, breeding pedigrees, and agronomic features. Crop modeling is also an important tool in understanding the complex interactions of crop, soil type, temperature, and rainfall, but it is currently constrained by a lack of data.