Unmanned aerial vehicles (UAVs) are tools for mechanized agriculture: they are used to alleviate maladies in a variety of fields through commercial, scientific, agricultural, and infrastructure enhancement. The purpose of the paper is to illuminate knowledge on mechanized agriculture using unmanned aircraft systems for pesticides and fertilizer application in obstacle rich farm. Various journal papers were reviewed to ascertain the state-of-the-art in agricultural unmanned aerial vehicles. X-rayed are unmanned aerial vehicle agrochemicals spraying architecture and efficacy, deployment and control strategies, obstacle sensing and avoidance systems, development/studies, and the limitations of the technology. The review shows that great strides have been made to develop agricultural unmanned aerial vehicles that can autonomously identify obstacle type, realize desired avoidance actions, and carry out variable rate agrochemical application. It is however noted that studies should continue on developing protocols and standard operation procedure, more human friendly interface platform, power technology, higher payload, real time quality imagery and robust mechanical features as well as enhanced sense and avoidance technology to meet the requirement of agricultural unmanned aerial vehicle for real time autonomous actions, flight endurance, low speed and low altitude. The paper therefore addressed the lack of awareness and absence of dedicated education on precision agriculture in the farming sector that has since ensured that its adoption level as a preferred system of farming remains very low in Nigeria despite the many benefits of unmanned aircraft vehicle farming technology

The study is fundamentally geared toward the investigation of the influence of Manual Metal Arc (MMA) welding on the mechanical and microstructural properties of low carbon steel immersed in a 0.5 M nitric acid environment having a pH of 0.3. The corrosion and mechanical behavior of the substrates are investigated prior to and after 336 h of immersion in the test environment. The outcome of the experiment shows that the structural integrity of the immersed substrates is affected due to corrosion in the test environment. Prior to immersion, the bending resistance is seen to decrease at the welded joints relative to the blank sample and then decrease further after immersion in the test solution respectively as 3.95, 3.53, and 4.21KN. Similarly, the tensile strength of the immersed substrate decreases as compared to the unexposed and blank samples; exposed to test environment (30.60%), welded unexposed to test environment (33.25%) and for the control sample (36.33%). Furthermore, the hardness value is observed to be higher at the heat‐affected zone (HAZ) of the test substrate than at the weldment and parent metal, respectively, as 11.3, 17.7, and 15.7HV. Optical micrographs prior to and after immersion have evidently revealed that heat input during welding has caused recrystallization leading to coarser grains at the HAZ.