Productive and nutritional parameters in diverse pastures composed of complementary species (Lolium perenne L., Bromus valdivianus Phil., Dactylis glomerata L., and Trifolium repens L.) under the leaf regrowth stage defoliation criterion

The diversification of plant species within intensively managed pastures has been proposed as an alternative to conventional pure sward systems in an effort to address climatic-driven issues of pasture-based livestock production. In a diverse pasture composed of complementary species (DPCS), individual species fulfil different agroecological niches and complement each other. It is expected that DPCS have a greater capability to tolerate and perform under increasingly extreme climate events; however, appropriate grazing management strategies for diverse pastures still need to be fully elucidated. In the present study, DPCS comprised Lolium perenne L., Bromus valdivianus Phil., Dactylis glomerata L., and Trifolium repens L. The leaf regrowth stage [LS; L. perenne (2.5–3.0LS), B. valdivianus (3.5–4.0LS) and D. glomerata (3.5–4.0LS)] is proposed to be an applicable method of defoliation management for DPCS due to a potential overlapping of their optimal defoliation intervals. The productive, morpho-physiological, and nutritional parameters of DPCS and their respective single-grass and T. repens pastures were assessed for two years under the LS criterion for defoliation. Within the DPCS, the three grass species presented a temporal overlapping of their respective LS intervals. Significant differences were found in the dry matter seasonal accumulation; DPCS exhibited seasonal asynchronous growth among species and presented an enhanced ability to withstand the ingress of volunteer species. In all pastures, the nutritional parameters were mostly influenced by season and LS criterion. Lolium perenne , B. valdivianus, and D. glomerata were shown to be complementary grass species, presenting growth asynchrony and an overlapping defoliation interval that optimised production. In this study, grazing management that focuses on the morpho-physiological development of grasses within a diverse pasture was successfully applied, with B. valdivianus LS optimal interval for defoliation being the most appropriate criterion for determining a grazing regime for DPCS. • Lolium perenne, Bromus valdivianus, Dactylis glomerata and Trifolium repens comprise a diverse pasture of complementary species (DPCS). • The leaf regrowth stage (LS) criterion for defoliation is a plant-focused grazing management tool. • The optimal LS interval for the defoliation of L. perenne is 2.5–3.0LS, and B. valdivianus Phil. and D. glomerata L. is 3.5–4.0LS. • A common window of opportunity for optimal defoliation of all species was achieved mostly when utilising the B. valdivianus LS as the criterion for defoliation. • DPCS showed high annual yield, seasonal overyielding in relation to single-grass pastures, low susceptibility to weed invasion, and satisfactory nutritive quality.