Land use change has a significant impact on the ecosystem. In this paper the effects of land use change on the physicochemical properties of the soil in Rulindo District, Rwanda have been studied. Three different land use types were selected; forestland, cattle farmland and cultivated land. A randomised complete block research design was used to carry out this research. Nine soil samples were collected and then analysed. The distributed samples were analysed in the Soil Laboratory of University of Rwanda-Busogo campus, while the undisturbed samples were analysed in-situ. Eight physicochemical properties were measured: pH, Organic Matter (OM), available nitrogen, available phosphorus, exchangeable potassium, soil bulk density, moisture content and porosity. The results showed that changing land use from forest or farm to cultivated land reduced the organic matter, available nitrogen, soil moisture and porosity while bulk density and pH were significantly increasing. On the other hand, the exchangeable potassium and exchangeable phosphorus did not change significantly for the both land use changes. Hence, the reduction of forestland and farmland are highly sensible to erosion and will decline soil fertility. The paper proposed few steps and recommendations to be the base for a new sustainable land use management in Rwanda.

Thallium (Tl) is an extremely harmful metal that is substantially distributed in the environment. It can threaten human health via consumption of food potentially derived from Tl-contaminated agricultural production. Little information is available on how to utilize biochar to remediate Tl contamination in agricultural soils. More efforts are urgently needed to be devoted to developing effective techniques to empower biochar with high selectivity of Tl in agricultural soils. In this review, we provided comprehensive information on Tl contamination in agricultural soils. We also discussed recent developments and assessed the current status of biochar applications. We briefly reviewed the bridge between biochar preparation technology and utilization wherein further developments can exhibit potential in terms of Tl remediation. Hence, biochar is expected to exhibit excellent Tl remediation performance in contaminated agricultural soils with promising application prospects. The obtained knowledge provides further insights into the remediation of Tl contamination in agricultural soils.

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