## 1 Introduction  
The decline in plant-available nutrient content in soil is one of the most serious challenges confronting developing countries, particularly those in Sub-Saharan Africa [1]. Crop yield declines due to poor fertile soils have been linked to low agricultural production [2]. Furthermore, the growth of marginalized communities leads to environmental overex exploitation through intensive agricultural activities. Human agricultural activities eventually place more strain on agricultural lands [3, 4] causing loss of soil nutrients. Continuous soil nutrient loss limits the agricultural sector's contribution to the country's economy [2]. Botswana is a semi-arid region that faces the same problem of lower crop yields due to Arenosols occupying the majority of the land. Arenosols (sandy soils) typical of arid deserts cover the majority of the country, accounting for roughly two-thirds of arable land area. The soils are classified as arid climate soils with low Cation Exchange Capacity (CEC) and inherent fertility, specifically nitrogen (N) and phosphorus (P) [5]. The Botswana government implemented the Integrated Support Programme for the Arable Agriculture Development (ISPAAD) program in 2008 to assist farmers with chemical fertilizers; however, the problem of declining crop yields in Botswana persists. From 2008 to 2019, the area planted (227,000 ha to 88,000 ha) and harvested (126,000 ha to 23,000 ha) decreased [6]. Despite having the highest per capita gross national income in 2019, Botswana has been identified vulnerable to food insecurity due to the declining agricultural sector's contribution to the economy [7]. Despite the challenges of soil nutrient depletion, agriculture is a critical sector of the country's economy because 70 percent of rural households still rely on it for a significant portion of their income, so sustainable agriculture measures are critical [8]. Organic waste, particularly poultry litter, has grown in popularity as an alternative organic fertilizer source for improving soil quality and crop yields [9; 10; 11]. Subsistence farmers--who make up the vast majority of farmers in the agricultural system--have used poultry litter [12]. It has enormous socioeconomic benefits due to its high nutrient content, which is required for improving soil nutrient concentrations [13; 14]. Besides improving soil nutrient content, the use of organic waste greatly aids waste management [15; 16]. In contrast to the benefits brought about by the expansion of the poultry industry, the rapid increase of poultry waste on the land has become a significant environmental challenge because waste management strategies are insufficient [17; 18; 19]. It has been determined that the excessively increasing amounts of solid waste exceed the collection and disposal capacities of local governments [20]. Local farmers in Botswana primarily use accumulated poultry litter as alternative fertilizers at unrecommended rates, so best application guidelines must be recommended. To effectively use organic waste feedstock, the best techniques for improving feedstock quality are required; thus, the study converted poultry litter into biochar to improve feedstock quality. Biochar is a pyrogenous organic material that is created through the pyrolysis of various biomass (plant/animal) wastes [21]. Biochar's primary advantage is that it is a stable carbon that improves soil fertility, nutrient retention, and crop growth [19; 22; 23; 24]. Furthermore, the carbon in biochar is sequestered in the soil for a much longer period of time than the original feedstock, which is easily degradable [25; 26]. In Botswana, there is still a lack of understanding about biochar, its production and its use. Therefore, the aim of this study was to evaluate the effects of poultry litter and its biochar on selected soil physicochemical properties and _Jatropha curcas_ L. morphological growth.