Raw experimental data from a greenhouse study evaluating green manuring with Crotalaria juncea and mineral nitrogen fertilization in lettuce

This dataset contains raw experimental data from a greenhouse experiment evaluating the effects of green manuring with Crotalaria juncea L. combined with mineral nitrogen fertilization on lettuce (Lactuca sativa L.). The experiment was conducted from May to December 2025 at the Luiz de Queiroz College of Agriculture (ESALQ/USP), University of São Paulo, Piracicaba, São Paulo, Brazil. The experiment followed a randomized complete block design in a 2 × 6 factorial scheme, combining the presence or absence of green manuring with six mineral N rates (0, 25, 50, 75, 100, and 125% of the reference rate), with five replicates. The dataset contains observations from the individual experimental units, including plant growth, plant N status, N accumulation, soil N forms, soil organic matter, and N use efficiency. It also includes raw measurements of C. juncea fresh biomass. For more information, see "readme.txt".