Impacts of Fall Nitrogen Application on Seed Production in Leymus chinensis, a Rhizomatous Perennial Grass
2013
Wang, Junfeng | Li, Xiaoyu | Gao, Song | Li, Zhuolin | Mu, Chunsheng
Understanding how the seed production of rhizomatous, perennial grasses responds to fall N application is important for agronomic practices. In this study, a split-plot design with three replicates was used to determine the impacts of time of N application in fall (early-vegetative stage, mid-vegetative stage, or end of the growing season) and the N application rate (0, 28, and 56 kg N ha–¹) on seed production in Leymus chinensis (Trin.) Tzvel. In contrast to N applied at the end of the growing season, N application at the early-vegetative stage significantly increased the inflorescence number (28%) but had little influence on the seed number per inflorescence and 1000-seed weight. Compared with the 0 kg N ha–¹ treatment, the highest N application rate significantly increased the inflorescence number (118%), the seed number per inflorescence (65%), the 1000-seed weight (9%), and the fall tiller density (121%). The increased inflorescence number was closely associated with the increased number of fall tillers and the ratio of reproductive growth to vegetative growth in these tillers. All fall tillers had the ability to head in the following year if there was enough precipitation at the end of the growing season and during the winter. The results suggest that the method of first applying N during the early fall and then watering at the end of the growing season will greatly improve the seed yield in L. chinensis.
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