Nitrate is an essential plant nutrient and is added to farm fields to increase crop yields. While the addition of nitrate is important for production, over-fertilization with nitrate can lead to leaching and contamination of water bodies. Increased nitrate loading in water sources then leads to eutrophication and hypoxia in downstream regions. Many efforts are being made to accurately control nitrate fertilizer additions to fields. Here, we present a soil sampling device that directly samples soil nitrate. First, water is injected into soil, collected and filtered through a porous ceramic filter via vacuum/suction. Next, this filtered sample is analyzed for nitrate using an electrochemical sensor with disposable electrodes also developed in this work. Specifically, these disposable sensors utilize paper electrodes functionalized with gold nanoparticles. Gold acts as a catalyst for the reduction of nitrate to nitrite. This reduction is then detected using electrochemical methods with a limit of detection of 8.6 µM. This direct sample collection and analysis system provides rapid, accurate detection of nitrate without the need for laborious soil sample collection and shipment for subsequent laboratory analysis. This system can aid both farmers and researchers as they monitor nitrate levels in soil over the course of a growing season and reduce the impact of agricultural leaching and drainage losses on water quality.