This study aimed to evaluate the response to water deficit of different ecotypes and a variety of Lotus corniculatus on growth, productivity, and yield components, through seasonal times. A randomized block experimental design in a 2 × 5 factorial arrangement with three replicates was used. The first variation factor was soil moisture contents: field capacity (FC) was 26.5% ± 1.5, and water deficit (WD) was 85% of FC (22.5% ± 1.5); the second variation factor was the ecotypes identified with the codes 255301, 255305, 202700 and 226792 and of the variety Estanzuela Ganador. The best responses in plant cover and weight of accumulated fresh biomass were obtained in the ecotype 202700 under WD, with values of 1649.0 cm² and 583.7 g plant⁻¹, and 1661.2 cm² and 740.1 g plant⁻¹ in ecotype 255305 under FC. The leaf clover was the main component of yield during the summer and autumn seasons. Ecotype 226792 was tolerant to low temperatures during the winter season with better leaf development. Ecotype 202700 is the best option for forage clover production when water is limited, and ecotype 255305 when water is not resource-limited, but these preliminary conclusions need to be confirmed in field studies.

O Objective: To evaluate the leaf nutrient content of four accessions and one variety of Lotus corniculatus L. trefoil throughout the seasons of the year and under optimum and sub-optimal soil moisture content, established under a shade mesh in northern Mexico. Design/Methodology/Approach: During the 2021-2022 period, an experimental randomized block design, in a split-plot arrangement, with three replicates was established. The large plots had an optimum (26±1.5%) and sub-optimal (22±1.5%) soil moisture content. The small plots consisted of the trefoil accessions: 255301, 255305, 202700, 226792 origin code, and the Estanzuela Ganador variety. Results: At optimum soil moisture content, the 202700 accessions recorded a K deficiency throughout the year. Meanwhile, regardless of the soil moisture content, the 255301 accessions recorded a Mg and a Mn deficiency only in summer. N, P, Fe, and Mn recorded deficient contents: N and P throughout the year and Fe and Mn only in winter and spring. Study Limitations/Implications: These results could require a field validation, since the experiment was carried out in semi-controlled conditions, under shade mesh. Findings/Conclusions: Developing an adequate annual nutrition program for L. corniculatus L. that improves its forage productivity requires several key factors, including the behavior of the nutritional status (dependent on the type of nutrient), the growth stage of the plant, the season of the year, and the soil moisture content.