plants use nitrate to make proteins. where do they obtain this nitrate from?

Plants obtain nitrate primarily from the soil. They absorb nitrate ions present in the soil through their roots using specialized nitrate transporter proteins located in the root cell membranes. This nitrate comes from nitrogen compounds in the soil, which are converted by soil bacteria from nitrogen gas in the atmosphere and organic matter into forms usable by plants, such as nitrate and ammonium. The nitrate absorbed is then used by the plants to synthesize amino acids and proteins. Thus, the source of nitrate for plants is soil nitrates formed through natural nitrogen fixation and decomposition processes in the soil environment.