Dry matter yield and nitrogen content in Lupinus spp. (Leguminosae) with potential as a green manure

Abstract

The potential of Lupinus exaltatus, L. mexicanus and L. rotundiflorus foliage as green manure in terms of total dry matter production and nitrogen (N) content was evaluated. This study was conducted from November 2015 to March 2016 in Zapopan Jalisco, México. The experiment was established in a randomized 3×7 block factorial design. Whole plants, leaves and stems were collected at different periods after sowing and analyzed for N and dry matter content. At the start of the experimental period, a slow growth was observed, based on dry matter production; however, at 93 days after sowing, both biomass and total N increased in the aerial part. The lowest and highest N content was found in L. rotundiflorus (1.2 to 4.0%). The highest dry matter and N accumulated in whole plants were found in L. exaltatus at 169 days after sowing with 21,605 and 410.6 kg ha-1, respectively.