205-4 Chloride Fertilization Decreases the Dietary Cation-Anion Difference of Various Forage Species.

See more from this Division: C06 Forage and Grazinglands
See more from this Session: General Forage & Grazinglands: I
Tuesday, November 2, 2010: 2:00 PM
Long Beach Convention Center, Room 302, Seaside Level
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Gaetan Tremblay1, Sophie Pelletier1, Gilles Belanger1, Denis Pageau2 and Raynald Drapeau2, (1)Agriculture and Agri-Food Canada, Quebec, QC, Canada
(2)Agriculture and Agri-Food Canada, Normandin, QC, Canada

Chloride fertilization is known to increase Cl concentration and to decrease the dietary cation-anion difference (DCAD) of timothy but little information exists for other forage species. Eight forage species were sown at Normandin, QC, Canada (4851'N, 7232'W) in 2006 and 2007, and harvested in 2007 and 2008, respectively, to determine their response to two Cl fertilization treatments (0 and 140 kg Cl ha-1 as CaCl2) applied in a split application: 64% in early spring and 36% after first harvest. Each species was harvested twice a year at around their recommended harvest stage of development. The experimental design was a split-plot with four replicates; species as main plots and Cl fertilization as sub-plots. Forage Na, K, Cl, and S concentrations were determined and the DCAD (Na + K Cl S) was then calculated.

Forage DCAD (mEq kg-1 DM) of eight species fertilized or not with Cl.

Spring growth (kg Cl ha-1)

Summer regrowth (kg Cl ha-1)

Species

0

90

0

50

Alfalfa

438

338

504

397

Red clover

486

307

612

375

Smooth bromegrass

387

309

471

264

Meadow bromegrass

376

298

504

335

Tall fescue

413

224

566

297

Timothy

369

213

298

121

Reed canarygrass

342

141

303

84

Kentucky bluegrass

217

127

226

138

Chloride fertilization decreased the DCAD of all forage species; this decrease ranged from 78 (smooth and meadow bromegrass) to 201 mEq kg-1 DM (reed canarygrass) in spring and from 88 (Kentucky bluegrass) to 269 mEq kg-1 DM (tall fescue) in summer. Species differed in their DCAD with legume species having the highest and timothy, reed canarygrass, and Kentucky bluegrass having the lowest. Producing forage with a DCAD lower than the target maximal value of 250 mEq kg-1 DM is possible without Cl fertilization in Kentucky bluegrass and with Cl fertilization in timothy and reed canarygrass.

See more from this Division: C06 Forage and Grazinglands
See more from this Session: General Forage & Grazinglands: I