Fall Harvesting of Alfalfa in North Dakota Impacts Plant Density, Yield, and Nutritive Value

Abstract

Alfalfa (Medicago sativa L.) is often not harvested in North Dakota during the fall because producers fear the risk of winter‐kill and stand reduction. The objective of this study was to determine the impact of a fall harvest on plant density, forage yield, and nutritive value of alfalfa. Two replicated experiments were planted and evaluated in Fargo, ND. Experiment 1 was conducted from 2004 to 2008 and Experiment 2 from 2007 to 2011. Treatments in the two experiments were either a 3‐cut system with no fall harvest or a 4‐cut system with a fall harvest. Analysis was conducted across experiments and years. In certain years, plant density was significantly reduced when alfalfa was harvested in the fall. The 4‐cut system, which included a fall harvest, had significantly greater seasonal forage yield. The total seasonal forage yield for the 4‐cut system was approximately 1.04 to 3.88 Mg/ha greater than that of the 3‐cut system. However, including a fall harvest decreased forage yield in the first cut the following season. In general, a fall harvest of alfalfa increases seasonal forage yield without reducing stand persistence and overall forage nutritive value.

Cutting management of alfalfa‐based mixtures in contrasting agroclimatic regions

“…(1999) and probably explains to some extent the lack of a negative effect of fall cutting on annual forage DM yield. Our results confirm that a fall cut, if taken at the appropriate time, does not reduce the annual forage DM yield and might even increase it as was shown in North Dakota (Berti et al., 2012).…”

“…A fall cut also reduced the alfalfa contribution to DM yield and increased the contribution of the seeded grasses and weeds to DM yield. In North Dakota, however, a fall cut of alfalfa increased annual forage DM yield without reducing stand persistence and forage nutritive value (Berti et al., 2012).…”

“…Cutting alfalfa in the fall in the northern agricultural regions of North America is often of interest to growers but it increases the risks of winter damage (Bélanger et al., 1992; Sheaffer et al., 1986), primarily because of the reduced accumulation of carbohydrates and N in the taproots and less snow cover (Bélanger et al., 2006). In North Dakota, however, a fall cut did not reduce stand persistence (Berti, Nudell, & Meyer, 2012). Studies conducted in the northern regions of North America revealed that, if a fall cut is to be taken, the timing of the cut should be based on a minimum interval between the last two cuts (Bélanger et al., 1999; Sheaffer & Marten, 1990; Sheaffer et al., 1986; Tesar & Yager, 1985).…”

Fall Dormancy and Harvest Stage Impact on Alfalfa Persistence in a Subtropical Climate

“…2), which may be explained by declining intraspecific competition as the alfalfa stand aged (Hall et al, 2004). In November 2007, there was a stand density of 110 to 135 plants m −2 , which appear to be high absolute values in comparison to previous field experiments (Gramshaw et al, 1993; Kallenbach et al, 2002; Ventroni et al, 2010; Berti et al, 2012). The relatively high plant density observed here may be due to a high seeding rate used (i.e., 30 kg ha −1 ); however, the mortality dynamics were similar to those of Kallenbach et al (2002), who described an exponential reduction.…”

“…However, these results were in contradiction with those of numerous other researchers that reported no effect (Gross et al, 1958; Hoveland et al, 1996; Borreani et al, 2000) or limited influence (Bélanger et al, 1992; Kallenbach et al, 2002) of harvest schedules on alfalfa persistence. Also, several other factors influence stand persistence and alfalfa winter survival, such as fall harvest timing (Bailey, 1983; Dhont et al, 2002, 2003; Berti et al, 2012), soil moisture (Paquin and Mehuys, 1980; van Ryswyk et al, 1993), snow cover (Leep et al, 2001), stand age (Suzuki, 1991), and soil content of nutrients (Bailey, 1983; van Ryswyk et al, 1993; Macolino et al, 2013).…”