Flood-recession
agriculture in the Senegal River Valley

In the Senegal River Valley, where the border between Mauritania and Senegal is located, the same river that marks the boundary of my home village "Louguere Dadi" in Mauritania, farmers there have been using flood-recession agriculture for centuries. There, as the annual floodwaters recede, they plant niébé (Vigna unguiculata), maize (Zea mays), and other crops in riverbanks that are moistened and made fertile by the receding floodwaters. No irrigation. No chemical fertilizer. Just seeds, soil, and traditional knowledge, the same knowledge my grandfather taught me when I was a boy, planting black-eyed peas in the mud with only our hands and a crude hoe.

The agricultural practices in the Senegal River Valley have traditionally followed the natural rhythm of the Senegal River itself. During the rainy season, heavy rainfall occurs in the Guinean and Malian areas in the headwaters of the Senegal River. This results in the river overflowing its banks and flooding the Senegal River Valley. This flooding brings with it fertile soils rich in organic materials and nutrients, which result in naturally fertile soils in the Senegal River Valley (Bruckmann et al., 2025). At the end of the rainy season, the Senegal River slowly recedes from the Senegal River Valley, leaving behind wet lands that are ready for cultivation without any additional irrigation.

For centuries, farmers in the Senegal River Valley have been using this natural flooding to cultivate their lands and produce their agricultural products. This type of cultivation is known as flood recession cultivation and utilizes the residual moisture and fertility provided by the flooding river. Unlike other types of cultivation, flood recession cultivation does not require any additional resources such as pumps and fertilizers, but rather an understanding of the river and its seasonal flooding patterns, which has been built up over centuries of observing and understanding the river and its effects on the Senegal River Valley (Bruckmann et al., 2025).

In addition to the river itself, during the rainy season and because of flooding, several seasonal lakes and depressions throughout the valley also retain water. Once the floods have subsided, these wetlands can hold water for several months, giving farmers more time to cultivate their land by taking advantage of the soil moisture. In the Senegal River Valley, the river, the floodplain, and the seasonal lakes combine to form a dynamic landscape that supports livelihoods and agriculture.

How do farmers know when it is time to plant? The answer is not in any books. The answer is in the mind of the elder, passed down through generations. My grandmother is in her eighties. She knows the rains will come in a few months. The sky speaks of the rains even before the rains arrive. The wind changes from a dry wind to a warm, humid wind with the scent of change. The sky is filled with big white clouds, indicating the rains will be heavy. The animals confirm the message of the sky. The birds start coming or dancing in the air. The cows start giving birth. We call this time of the year "Deminare" in Pulaar. When it is time for Deminare, we go with the cattle to follow the rains and then return with the pasture.

Sometimes the cattle go on their own. They smell the rain before we do. My grandmother taught me to listen for the Francis puddle frog. When the rains are about to start, the frogs start coming out in the temporary ponds. At night, the frogs sing in the air. We say they are saying, "May God bring rain." When the frogs sing, it is time to start preparing the fields. When the rains stop, the Savannah monitor comes out of hiding. The females start laying eggs. The sun is very hot. This is the sign that the rainy season is over. We call this time of the year "Kaawle", the time of the transition from the wet season to the cool dry season.

My grandmother knows the rains will come in a few months. She looks at the trees, birds, frogs, and monitors. The scientists with their computer models may not know. My grandmother knows. The wind tells us. The birds tell us. The frogs, monitors, and cows tell us. We just need to listen and remember.