<table><caption>Table 1. Effect of growth stage and harvest on the feed value of fresh alfalfa (2)</caption><thead><tr><th></th><th>Dry matter (%)</th><th>Crude protein (g kg<sup>-1</sup> DM)</th><th>NDF (g kg<sup>-1</sup> DM)</th><th>OM digestibility (g g<sup>-1</sup>)</th><th>Voluntary intake in cow (g kg<sup>-1</sup> LW<sup>0.75</sup>)</th></tr></thead><tbody><tr><td colspan="6">Growth stage in 1st cycle</td></tr><tr><td>Vegetative (30 cm)</td><td>14.4</td><td>246</td><td>423</td><td>0.77</td><td>156</td></tr><tr><td>Vegetative (60 cm)</td><td>15.6</td><td>225</td><td>449</td><td>0.72</td><td>152</td></tr><tr><td>Bud</td><td>17.6</td><td>193</td><td>488</td><td>0.66</td><td>143</td></tr><tr><td>Early flowering</td><td>18.9</td><td>178</td><td>513</td><td>0.63</td><td>140</td></tr><tr><td colspan="6">Age at second harvest</td></tr><tr><td>5 weeks</td><td>19.3</td><td>222</td><td>487</td><td>0.68</td><td>161</td></tr><tr><td>9 weeks</td><td>22.5</td><td>179</td><td>512</td><td>0.59</td><td>136</td></tr><tr><td colspan="6">Age at third harvest</td></tr><tr><td>5 weeks</td><td>21.0</td><td>241</td><td>468</td><td>0.69</td><td>147</td></tr><tr><td>9 weeks</td><td>24.9</td><td>204</td><td>476</td><td>0.62</td><td>140</td></tr></tbody></table>

<table><caption>Table 2. Effect of conservation type on alfalfa feed value assessed for the same fresh forage harvested at 7 weeks in the second vegetation cycle (2)</caption><thead><tr><th></th><th>Dry matter (%)</th><th>Crude protein (g kg<sup>-1</sup> DM)</th><th>NDF (g kg<sup>-1</sup> DM)</th><th>OM digestibility (g g<sup>-1</sup>)</th><th>Voluntary intake in cow (g kg<sup>-1</sup> LW<sup>0.75</sup>)</th></tr></thead><tbody><tr><td>Fresh forage</td><td>19.7</td><td>198</td><td>513</td><td>0.65</td><td>144</td></tr><tr><td>Silages</td><td>Dry matter (%)</td><td>Crude protein (g kg<sup>-1</sup> DM)</td><td>NDF (g kg<sup>-1</sup> DM)</td><td>OM digestibility (g g<sup>-1</sup>)</td><td>Voluntary intake in cow (g kg<sup>-1</sup> LW<sup>0.75</sup>)</td></tr><tr><td>- Direct cut with preservative</td><td>21.0</td><td>187</td><td>466</td><td>0.64</td><td>135</td></tr><tr><td>- Wilted</td><td>33.5</td><td>198</td><td>488</td><td>0.62</td><td>139</td></tr><tr><td>- Wrapped bale</td><td>55.0</td><td>183</td><td>504</td><td>0.61</td><td>133</td></tr><tr><td>Hays</td><td>Dry matter (%)</td><td>Crude protein (g kg<sup>-1</sup> DM)</td><td>NDF (g kg<sup>-1</sup> DM)</td><td>OM digestibility (g g<sup>-1</sup>)</td><td>Voluntary intake in cow (g kg<sup>-1</sup> LW<sup>0.75</sup>)</td></tr><tr><td>- Barn dried hay</td><td>85</td><td>181</td><td>539</td><td>0.61</td><td>144</td></tr><tr><td>- Field dried, sunny weather</td><td>85</td><td>177</td><td>555</td><td>0.60</td><td>136</td></tr><tr><td>- Field dried, rainy weather</td><td>85</td><td>172</td><td>585</td><td>0.55</td><td>128</td></tr></tbody></table>

<table><caption>Table 3. Feed value of dehydrated alfalfa as a function of its crude protein content (9)</caption><thead><tr><th>Crude protein content (% DM)</th><th>Dry matter (%)</th><th>Crude protein (g kg<sup>-1</sup> DM)</th><th>NDF (g kg<sup>-1</sup> DM)</th><th>OM digestibility (g g<sup>-1</sup>)</th></tr></thead><tbody><tr><td>&lt; 16</td><td>91.4</td><td>151</td><td>503</td><td>0.60</td></tr><tr><td>17-18</td><td>90.6</td><td>175</td><td>474</td><td>0.62</td></tr><tr><td>18-19</td><td>90.6</td><td>184</td><td>461</td><td>0.63</td></tr><tr><td>22-25</td><td>89.8</td><td>233</td><td>379</td><td>0.70</td></tr></tbody></table>

Effect of growth stage and harvest. Cell wall content increases while crude protein, organic matter (OM) digestibility and voluntary intake decreases with alfalfa aging in each growing cycle (Table 1). Compared to temperate grasses like perennial ryegrass or cocksfoot, the cell wall content of alfalfa is lower, but the OM digestibility is similar as a result of lower cell wall digestibility in alfalfa. In contrast, the voluntary intake of alfalfa is always higher than that of grasses, as a result of the lower cell wall content and lower rumen fill effect.

The highest digestibility is obtained at the beginning of the first vegetation cycle. The feed value of alfalfa regrowths decreases with

age at about the same rate during the second cycle as during the first cycle (Table 1). After the second cut, regrowths become leafier, resulting in a lower decrease of feed value with age.

Effect of the conservation as silage or hay. Silage preserves chemical composition of fresh alfalfa and decreases slightly the OM digestibility and the energetic value (Table 2). Cell-wall content can even be slightly decreased due to partial hydrolysis of hemicelluloses during silage fermentation. However, voluntary intake of silage is lower than that of fresh alfalfa, because of the difficulty to obtain well-preserved silages, especially at low DM content.

Hay making has a negative effect on alfalfa digestibility, owing to the loss of leaves during raking and baling (Table 2). Alfalfa hays are very well consumed by animals when they are barn-dried or field-dried under good weather conditions. When made under unfavourable weather conditions, however, they show low digestibility and voluntary intake, making wrapped bale silage preferable (Table 2).

Feed value of dehydrated alfalfa. The feed value of dehydrated alfalfa increases with its crude protein content, which is associated with increased OM digestibility as a consequence of decreased cell-wall content (Table 3).

## Conclusion and prospects

Alfalfa has high interest for ruminant nutrition because of its feed quality and its flexibility of utilization. However, alfalfa proteins are highly and rapidly degraded in the rumen. This can lead to poor nitrogen utilization and excessive nitrogen losses in urine. Decreasing the rate of alfalfa protein degradation in the silage and the rumen is a challenge to further improve its high-protein crop value. Prospects of using polyphenol-oxidase present in red clover or tannins present in other legumes like sainfoin (1) are under investigations. Saponins present in alfalfa might contribute to reduce methane emissions during rumen fermentation, but results on this issue are still controversial (6).

<figure><img src="image_32.png" /></figure>

## References

(1) Aufrere J, Dudilieu M, Poncec C, Baumont R (2013) Mixing sainfoin and lucerne to improve the feed value of legumes fed to sheep by the effect of condensed tannins. Anim 7:82-92

(2) Baumont R, Dulphy JP, Sauvant D, Meschy F, Aufrere J, Peyraud JL (2007) Chapitre 8. Valeur alimentaire des fourrages et des matières premières: tables et prévision. In: Alimentation des bovins, ovins et caprins, Tables INRA 2007, Editions Quae, 149-179

(3) Demarquilly C, Dulphy JP, Andrieu JP, (1998) Valeurs nutritive et alimentaire des fourrages selon les techniques de conservation: foin, ensilage, enrubannage. Fourrages 155:349-369

(4) Frame J, Charlton JFL, Laidlaw AS (1998) Temperate forage legumes. CAB International, Wallingford

(5) Heuzé V, Tran G, Boval M, Lebas F, Lessire M, Noblet J, Renaudieu D (2012) Alfalfa (Medicago sativa). Feedpedia.org. A programme by INRA, CIRAD, AFZ and FAO. http://www feedpedia org/node/275

(6) Niderkorn V, Baumont R (2009) Associative effects between forages on feed intake and digestion in ruminants. Anim 3: 951-960

(7) Robinson (1998) Proceedings, 28th California Alfalfa Symposium., Reno, USA, 3-4 December 1998

(8) Thénard V, Mauriès M, Trommenschlager JM (2002) Interest of dehydrated alfalfa in maize and grass silage diets for dairy cows. INRA Prod Anim 15:119-124

(9) Sauvant D, Perez JM, Tran G (2004) Tables de composition et de valeur nutritive des matières premières destinées aux animaux d'élevage: pores, volailles, bovins, ovins, caprins, lapins, chevaux, poissons. INRA Editions, Paris

(10) Sutie JM (2000) Hay crops-legumes and pulses. In: Hay and Straw Conservation-For Small-Scale Farming and Pastoral Conditions. FAO Plant Production and Protection Series 29. FAO, Rome
# Alfalfa non-feed uses

by JoAnn F. S. LAMB<fnref n="1" />*, Hans-Joachim G. JUNG<fnref n="2" />, Michael P. RUSSELLE<fnref n="1" />, Craig C. SHEAFFER<fnref n="2" />, Deborah A. SAMAC<fnref n="1" /> and Carroll P. VANCE<fnref n="1" />

**Abstract:** Non-feed uses for alfalfa such as biomass energy and phytoremediation could increase alfalfa acreage and improve farm profitability. The new bio-energy alfalfa and production system increased forage yield and ethanol production. New alfalfas with enhanced nitrogen cycling capacities would protect water quality and enhance alfalfa's value in crop rotation systems.

**Key words:** bio-energy, ethanol production, leaf crude protein, nitrate uptake, nitrogen (N) cycling, phytoremediation, symbiotic N₂ fixation

## Introduction

Alfalfa plays an essential role in sustainable agriculture. Its perennial growth habit and extensive root system permits the crop to aerate soil, access deep water resources, capture nutrient run-off and mitigate soil erosion. Using alfalfa in rotation interrupts pest and pathogen cycles and through symbiotic N₂ fixation with soil bacteria, provides up to 100% of the N nutrient requirement of the subsequent crop. Non-feed uses are needed to increase and diversify revenue streams for growers and allow alfalfa a greater role in sustainable agricultural systems. New uses include alfalfa as a renewable biomass feedstock that can help meet the energy demands of the future (2), and as an inexpensive and efficient remediation tool to remove sub-soil nitrate from polluted sites (2).

## Alfalfa biomass energy system

A biomass energy production system using alfalfa would separate leaves from stems creating two products. The stems would be processed to produce electricity (combustion) or biofuel [ethanol (fermentation) or bio-oil (pyrolysis)], and the leaves would generate a secondary income as valuable protein feed for livestock (Fig. 1). Therefore, the key traits of interest for an alfalfa bio-energy germplasm

would include concentrations and seasonal yields of leaf protein, stem biomass, and/or stem cell wall polysaccharides, depending on which the energy conversion platform is being used. Increasing stem yield in alfalfa can be as simple as harvesting forage at a later maturity than early bud, which is typically used in hay production.

An experimental bio-energy alfalfa population was created through selection for large, erect, non-lodging stems when the alfalfa was in bloom. Management protocols have also been modified to (i) reduce population stand density to allow the development of larger crowns and decrease light competition to keep leaves from senescing and (ii) harvest at later maturity stages to maximize both leaf and stem yield. The bio-energy alfalfa under bio-energy management harvested at the green pod maturity stage increased stem yield by 56% and doubled the ethanol yield compared to commercial cultivars grown under standard hay management practices. Leaf crude protein yields were similar between the hay and bio energy production systems for two of three of the site-year combinations (4). In another comparison between the bio-energy and high quality hay cultivars under the two management schemes, stem yields increased 40%, and potential ethanol yield increased between 50% and 97% when harvested at full bloom compared to early bud stage (1). The bio-energy alfalfa under the bio-energy production system shows great potential for helping meet the energy demands of the future.

## Phytoremediation

Nitrogen laden ground water is a well documented human health risk and practical remediation methods are needed when over-fertilization of annual crops with inorganic N threatens ground water quality. Although alfalfa can obtain most of the N required for growth through symbiotic N₂ fixation, it is also very effective at removing nitrate-N from the sub-soil (Fig. 1) (2, 5).

At the site of an anhydrous ammonia spill where nitrate-N concentration of the ground water exceeded drinking water standards, a conventional cultivar and an ineffectively nodulated population (incapable of symbiotic N₂ fixation) were irrigated with the N containing ground water for three years. Cumulative N removal from the site was over three times greater by the ineffectively nodulated alfalfa than would be expected with annual cereal grains (5), and soil nitrate-N concentrations were rapidly reduced to low and stable levels. With these results in mind, we successfully created a selection protocol that produced new, contrasting cultivars that can either reduce N losses to ground water by increased nitrate-N uptake capacity, or decrease fertilizer N requirements in production systems through enhanced symbiotic N₂ fixation (3). These new cultivars could strengthen the crop's role in sustainable agriculture by protecting water quality and enhancing its value in crop rotation systems. ■

## References

(1) Lamb JFS, Sheaffer CC, and Samac, DA (2003) Population density and harvest management effects on leaf and stem yield in alfalfa. Agron J 95:635-641

(2) Lamb JFS, Jung H-JG, Sheaffer CC, Samac DA (2007) Alfalfa leaf protein and stem cell wall polysaccharide yields under hay and biomass management systems. Crop Sci 47:1407-1415

(3) Lamb JFS, Russelle MP, Fenton DM (2008) Field-based selection method creates alfalfa populations that differ in nitrate nitrogen uptake. Crop Sci 48:450-457

(4) Lamb JFS, Jung H-JG, Riday H (2014) Growth environment, harvest management and germplasm impacts on potential ethanol and leaf crude protein yields in alfalfa. Biomass Bioenerg 63:114-125

(5) Russelle MP, Lamb JFS, Montgomery BR, Elsenheimer DW, Miller BS, Vance CP (2001) Alfalfa rapidly remediates excess inorganic nitrogen at a fertilizer spill site. J Environ Qual 30:30-36

<figure><img src="image_33.png" /><figcaption>**Figure 1. The alfalfa bio-energy system with two product streams, stems for energy and leaves for animal feed as well as value added products with enhanced nutrient cycling**</figcaption></figure>

<footnote n="1">¹United States Department of Agriculture, Agricultural Research Service, Plant Science Research Unit, Saint Paul, USA (joann.lamb@ars.usda.gov)</footnote>

<footnote n="2">²University of Minnesota, Department of Agronomy and Plant Genetics, Saint Paul, USA</footnote>
<figure><img src="image_34.png" /></figure>

**25th General Meeting of the European Grassland Federation**
*EGF at 50: the Future of European Grasslands*

Aberystwyth, Wales, UK, 7-11 September 2014

http://www.egf2014.org/

**18th Symposium of the European Grassland Federation**
*Grassland and Forages in High Output Dairy Farming Systems*

Wageningen, the Netherlands, 15-18 June 2015

http://www.europeangrassland.org/events.html

EUCARPIA

<figure><img src="image_35.png" /></figure>

European Association for Research on Plant Breeding

Europäische Gesellschaft für Züchtungsforschung

Association Européenne pour l'Amélioration des Plantes

**Symposium of the Protein Crops Working Group, Protein Crops Section, and**
**Spanish Association for Legumes**

*Plant Proteins for the Future*

Pontevedra, Spain, 4-7 May 2015

http://www.symposiumproteincrops.org/

**Symposium of the Fodder Crops and Amenity Grasses Section**

Ghent, Belgium, 14-17 September 2015

http://www.eucarpia.org/activities/meetings.html

**Grasslands and Herbivore Production in Europe and**
**Effects of Common Policies**

Editors: Christian Huyghe, Alex De Vliegher, Bert van Gils and Alain Peeters

Publisher: Quæ, Versailles, France, March 2014; pp. 320; ISBN: 978-27-592-2157-8

http://www.quae.com/fr/r3371-grasslands-and-herbivore-production-in-europe-and-effects-of-common-policies.html

**Quantitative Traits Breeding for Multifunctional Grasslands and Turf**

Editors: Dejan Sokolović, Christian Huyghe and Jasmina Radović

Publisher: Springer Science+Business Media, Dordrecht, the Netherlands, August 2014; 411 pp; ISBN: 978-94-017-9044-4

http://www.springer.com/life+sciences/agriculture/book/978-94-017-9043-7
# LEGUME PERSPECTIVES
## Sponsorship list

<figure><img src="image_36.png" /></figure>

LEGUME SOCIETY
www.ils.nsseme.com

<figure><img src="image_37.png" /></figure>

INSTITUTE OF FIELD AND VEGETABLE CROPS, NOVI SAD, SERBIA
www.nsseme.com

<figure><img src="image_38.png" /></figure>

CRA

AGRICULTURAL RESEARCH COUNCIL

CONSIGLIO PER LA RICERCA E LA SPERIMENTAZIONE IN AGRICOLTURA, ITALY
www.entecra.it

<figure><img src="image_39.png" /></figure>

INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE FRANCE
www.inra.fr

INRA

<figure><img src="image_40.png" /></figure>

FP7-ARIMNET
PROJECT REFORMA
reforma.entecra.it

<figure><img src="image_41.png" /></figure>

SPANISH MINISTRY OF SCIENCE AND INNOVATION
SPANISH NATIONAL RESEARCH COUNCIL
www.csic.es

<figure><img src="image_42.png" /></figure>

Want to help the legume research network in Europe and worldwide?

Support Legume Society and become its sponsor today!

legume.society@gmail.com