## 3 Results
### Croptype Analyses
This scatterplot (Figure 11b) provides a visual comparison between the importance of different crop types within a country's agricultural sector, using two key metrics:  
* Crop area proportion (blue scatters): the size and color of the blue scatters represent the proportion of agricultural land dedicated to each crop category within a country. Larger scatters indicate a higher percentage of the country's total agricultural land is allocated to that specific crop. This metric reflects the physical footprint of crops, showing their relative importance in terms of land use. * Economic value contribution (red scatters): the size and color of the red scatters correspond to the contribution of each crop category to the country's overall agricultural economic value. A larger red scatter means that a particular crop plays a more important role in generating agricultural revenue. This metric highlights the financial impact of crops, regardless of their land usage, providing insides into which crops are economically more important. The values are averages of the years 2000 to 2020 based on the FAO STAT data [57]. All data on crops provided have been incorporated and classified, but another class for animal and livestock was created and has been excluded as it is not within the scope of this review. Comparing the importance of agricultural areas to the economic value of a crop type in each country provides valuable key insights. For example, a crop may occupy a large area (large blue scatter) but contribute less to the economic value, e.g., a subsistence crop (small red scatter), suggesting low profitability or market value. Conversely, a crop with a small land footprint but a large economic impact indicates high profitability or market value. \"Beans/Legunes\", while underrepresented in the reviewed literature, hold a remarkable agricultural importance across several West African nations. In Cote d'Ivoire, Ghana, Niger, and Mauretania, more than 20% of cropland is dedicated to leguminous crops. Although their economic distribution is modest, accounting for mainly around 10% and over 20% in Cote d'Ivoire of agricultural revenue, they serve as both subsistence and cash crop. Additionally, they play a crucial role in regional food security [7]. The category \"Cereals\" is extensively studied, particularly in Burkina Faso, Mali, Senegal, and Niger. This research focus mirrors the economic and land use prominence of cereal cultivation in these regions. Niger, in particular, stands out with cereals occupying over 30% of its agricultural land and contributing an essential share of economic output, making them a cornerstone of the country's agarian economy. In Senegal, a large agricultural area is referred to as \"Groundnut basin\", which exemplifies the crop's importance in both terms of land area and economic output. Almost 40% of the reviewed literature on groundnuts focuses on Senegal and Mali, whereas the importance of groundnuts in Mali is far less [91]. However, the category \"Maize/Sorghum\" accounts for the largest shares of agricultural land in most countries, with the exception of Senegal, Cote d'Ivoire, Niger, and Ghana, where it still plays a considerable role. The highest share in Mauretania is remarkable, though the country is underrepresented in the studies analyzed. As a key subsistence crop for smallholder farmers, their importance is reflected both in the reviewed literature and real-world agricultural data based on FAO [57], underscoring their central role in food production systems across the West African region. Figure 11: (**a**) Heatmap illustrating the frequency of studies on different crop categories across the West African countries, and (**b**) scatterplot comparing the importance of crop categories using crop area proportion and economic value contribution as metrics. The crop category \"Other\", which includes cassava, demonstrates higher economic than spatial importance due to its status both a cash and a subsistence crop [92].