**1. Introduction**

Spatiotemporal rainfall variability (STRV) and drought are among the primary challenges in rainfed agricultural communities [1,2]. STRV and drought both limit crop production and increase crop yield uncertainties among farmers. The situation is particularly severe in semiarid areas in sub-Saharan Africa (SSA) [3,4], exacerbating chronic food insecurity [5–10]. To address such challenges in these areas, the literature accentuates the importance of adopting more water-saving technologies through the efficient storage and use of water [11]. Several studies described STRV on different scales [12–16]; however, these studies rarely demonstrated the potential relationship between STRV and yield variability among farmer fields located within the same agricultural watershed. Rainfall studies in the forms of trend analyses and spatial variability over large areas are numerous, but these studies have limited connections to local agricultural challenges. These studies have rarely prioritized farmer risk management strategies, including crop upgrading strategies (UPS) [17], which

are important for understanding the cycle of annual harvest losses, either partially or totally, for farmers in semiarid areas.

The population is increasing annually in the SSA region; therefore, the production of staple food crops has been emphasized to meet the increasing food demand. Pearl millet is an important crop in the region. With drought tolerance characteristics, pearl millet crops provide cultivation opportunities for farmers in drier areas. However, pearl millet production can significantly increase if the water needs of the crop are improved and vice versa. Historical data from the Food and Agriculture Organization Statistical Databases of the United Nations (FAOSTAT) indicate that the production of pearl millet in the SSA region has declined over the last two decades (FAOSTAT was visited on 10 December 2018), which can be directly attributed to poor soil and weather conditions, among other factors. The weather conditions are more severely challenging to most farmers, with spatiotemporal variation in rainfall frequently reported [18–20]. The current practices which are being used to address STRV are limited and the influence of STRV on crop yields at higher resolutions is poorly understood.

Since crop yield can vary even within a single farm due to different individual or combined factors, ranging from soil, weather, topography, and management [21,22], studies are required to provide a comprehensive understanding of the harvest losses at the village and farm levels for pearl millet crops, which would aid in providing practical recommendations to improve crop production. Yield losses in small plots accumulate when there are a considerable number of plots, thus reducing small area losses is advantageous for farmers in dry areas. Eventually, too many farmers with significant annual yield losses results in serious food shortages [23]. In the food shortage context, our research aim was to analyse high-resolution spatiotemporal data on daily rainfall, seasonal rainfall, and pearl millet yield to understand their variability and potential reasons for crop yield variability. Therefore, we specifically aimed to (1) analyze the spatiotemporal rainfall variabilities in neighboring fields, (2) evaluate the significance of rainfall variability on pearl millet yields among farmers, and (3) evaluate the effectiveness of tied ridges and scattering fields in reducing the risks of harvest loss.
