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Revisiting alfalfa planting dates for the semiarid U.S. Southwest
Author(s) -
Lauriault Leonard M.,
Marsalis Mark A.,
Groesbeck John D.
Publication year - 2020
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.1002/agj2.20169
Subject(s) - sowing , seeding , irrigation , agronomy , randomized block design , biology , zoology
Alfalfa ( Medicago sativa ) growers in the southwestern United States desire to match irrigation allocations better and to recover at least some of the establishment costs in the seeding year by spring planting. Randomized complete block studies at Tucumcari and Los Lunas, NM compared planting date effects on seeding year and subsequent production year yields and seeding year economics. Seeding year yields in each test were statistically separated by the number of harvests taken. The earliest planting at Los Lunas produced 11.3 Mg ha −1 over three harvests in the seeding year to fully recover establishment and harvesting costs, and two harvests (4.3 Mg ha −1 ) from the earliest planting at Tucumcari recovered approximately half the costs. Production year yields from spring and late‐summer to early autumn seedings at Los Lunas were generally not different, but greater than 25 June and 21 July plantings (2‐yr mean yields for 12 May, 1 June, 25 June, 21 July, 11 August, 2 September, and 25 September planting dates were 22.8, 22.1, 20.5, 21.2, 23.3, 21.8, and 22.5 Mg ha −1 , respectively; P < .0001, SEM = 0.4). Four‐year average production year yields at Tucumcari were statistically separated into spring, early to mid‐summer, and late summer plantings (12.8, 10.8, 10.1, 11.1, 8.8, and 8.7 Mg ha −1 4‐yr mean yields for 5 June, 26 June, 17 July, 7 August, 28 August, and 18 September planting dates, respectively; P < .0001, SEM = 0.8). Spring planting can potentially increase seeding year yields as well as throughout the stand life.