Set against the backdrop of continuous evolutions in scientific knowledge regarding the impacts of plastics, and particularly of plastic pollution, the Intergovernmental Negotiating Committee process for the establishment of an international legally binding instrument to address plastic pollution, including in the marine environment, has unfolded as an effort to create a legally binding treaty amidst multiple geopolitical challenges and shifts. While much of the focus of the INC process and attention has been on the marine environment, this should not take away from the many avenues through which concerns regarding the impacts of plastic pollution on land and soil resources have been raised in the treaty negotiation process. Indeed, as many states and official observers have emphasized, the full lifecycle of plastics and, necessarily, plastic pollution, starts on land and has some of its most immediate impacts in terrestrial ecosystems and soil resources. This negotiation process has contained a number of lessons and points which will be dissected as efforts to determine the future of multilateralism in the multilateral environmental agreement context are made. This chapter contributes by providing an overview of the INC process that is informed by the documents generated as well as the author’s first-hand participation in the INC process as a legal advisor and delegation member. It then reviews how land, soil, terrestrial ecosystems, and agriculture have been included in the various iterations of documents and national positions taken throughout the INC process to date.