Recent advancements in on-site robotic construction allow a direct modulation of native soil into architecture. To date, this was mainly explored for extra-terrestrial construction. To promote geomaterial reconstitution in architecture, the paper presents a workflow and methods for additive manufacturing, explored using desert soil and a robotic tool. The workflow provides the steps for linking site, material, design, and fabrication, including the robotic setup, simulation, and technical analysis. The paper explores three methods: continuous, discrete, and a method termed here multimode additive. These methods are demonstrated through experiments detailing their design and fabrication processes, and the paper concludes with their comparative analysis. The research expands additive manufacturing with earthen materials, and the outcomes indicate a potential for combining computational design, robotic fabrication, and manual assembly. The paper also clarifies and expands existing terminology regarding part-to-whole relationships in on-site robotic fabrication, promoting resource-conscious, site-tailored additive manufacturing in architecture.