Morphological development and dry weight distribution of alfalfa cultivars varying in fall dormancy under a short‐term cultivation system

Abstract

Non‐dormant alfalfa (Medicago sativa L.) has been cultivated successfully in the east central regions of China as a short‐term component of a forage‐grain rotation system, but it remains unclear how shoots of alfalfa with different levels of fall dormancy develop in this system. Five alfalfa cultivars with contrasting fall dormancy were sown in the field in Nanjing, China, in October 2012 and 2013, and were harvested three times in the following year. The number and dry weight of shoots that originated from crown (crown shoots) and axillary buds (axial shoots) were recorded at each harvest. The results were analyzed for dormant, semi‐dormant and non‐dormant cultivars over 2 years. At the first spring harvest, axial shoots accounted for an average of 18.3% of dry weight per plant and became the dominant shoot type during later harvests. Crown shoots accounted for 81.7% of plant dry weight in first harvest and the majority of dry weight per plant totaled over three harvests in all fall dormancy types. Fall dormancy had little effect on the relative proportion of crown and axial shoots in dry weight per plant, and the number of crown and axial shoots. Non‐dormant cultivars produced heavier individual crown and axial shoots, resulting in greater dry weight per plant at each harvest. Our results show that non‐dormant cultivars used in our study produce greater dry weight per plant under a short‐term cultivation system, primarily because they have greater dry weight of individual crown and axial shoots.

Soil bacterial community structure at different plant maturity stages in an annual grass–legume production system

“…Inclusion of legume forage is a potential strategy for enhancing carbon and nitrogen resources while sustaining soil health in the annual grass-legume forage systems of southern China (Lu et al, 2017(Lu et al, , 2018. Here, we demonstrate that this practice can affect soil properties and the composition of the soil bacterial community.…”

“…As a consequence, important soil ecosystem services such as nutrient cycling are often impaired. Organic agriculture, including legume-based forage systems, is believed to be more environmentally sound than traditional agriculture and may enhance soil quality and plant diversity (Lu et al, 2017) through incorporation of large amounts of carbon into the soil via organic rather than mineral fertilizers (Lal, 2009).…”