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United States Department of Agriculture

Agricultural Research Service

Title: Maturity and Plant Density Effects on Stem and Leaf Traits for Alfalfa Biomass Production

Authors
item Lamb, Joann
item Sheaffer, Craig - UNIVERSITY OF MINNESOTA
item Samac, Deborah
item Martin, Neal - UNIVERSITY OF MINNESOTA

Submitted to: North American Alfalfa Improvement Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 3, 1998
Publication Date: N/A

Technical Abstract: Alfalfa was chosen as the dedicated biomass feed stock resource for a 75 MW power station at Granite Falls, MN. In this biomass production system alfalfa hay will be fractionated into stem material for conversion to electricity and leaf meal will be sold as a high quality livestock protein supplement. A study was established to assess environmental and harvest management effects on biomass production in alfalfa. Two Flemish and thre moderately dormant North American germplasms were established at two locations at four population densities (450, 180, 50, and 16 plants per square meter). All germplasm by plant density combinations were harvested at two stages of plant maturity, early bud (three harvests per season) and early pod (two harvests per season). Preliminary data from 1 year and location showed that the greatest seasonal leaf and stem yield for all germplasms was at the 180 plants per square meter density at the early pod maturity under a two harvest management. Stems harvested at the early pod maturity had lower percent CP and greater % NDF than those harvested at early bud, and the 450 plants per square meter density had significantly greater stem percent CP and lower % NDF compared to the rest of the plant density treatments. Leaf % CP was greater under early bud management treatment, but season total harvested leaf crude protein was the same when harvested at either the early bud (three cuts) or the early pod (two cuts) maturity stages. The three moderately dormant North American germplasm sources had greater leaf yield than the Flemish types, but the Flemish types had fewer lodged plants. Preliminary results indicate that decreased plant population densities and harvesting forage at later maturities may enhance the profitability of an alfalfa biomass production system.

Last Modified: 7/24/2014
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