Carrington Research Extension Center North Dakota State University NDSU Extension Service North Dakota Agricultural Experiment Station |
Ag Alert |
April 21, 1999
YOUNG ALFALFA STANDS ARE MOST PRODUCTIVE
As the age of an alfalfa stand increases, its yield potential decreases. Irrigated and
dryland alfalfa studies conducted in North Dakota indicate that two- or three-year stands
may be the age limit to maintain adequate yield. Average yield of eight irrigated trials
at the Carrington Research Extension Center classified by age included 5.6 tons dry matter
(DM)/acre for the first production year (year following establishment), 4.8 tons DM/acre
for second production year, and 3.7 tons DM for third production year. Dryland yield of
Carrington Center trials averaged 4.4 tons DM/acre for year one, 2.4 tons DM for year two,
and 1.5 tons DM/acre for year three. Yield of three-year stands was about a one-third less
under irrigation and about two-thirds less under dryland compared to first-year stands.
The decline in yield with increased age may be due to accumulating winter injury and
disease. The cost of reestablishing alfalfa stands after two or three years of production
should be less than the yield loss with keeping older stands in production.
SULFUR RECOMMENDATIONS FOR CANOLA
It is extremely important to insure that adequate amounts of sulfur (S) are present in the
soil to optimize canola seed yield. NDSU's recommendation for canola is to apply 20 to 30
pounds per acre of S if a soil test indicates medium or lower levels. If S levels are
high, apply 10 to 15 pounds per acre of S. An application of S is recommended even if a
soil test indicates a high level because of field variability and soil tests tend to
overestimate available sulfate-S levels. The sulfate form of S is readily available for
plant uptake and use. Use a sulfate formulation of S such as ammonium sulfate
(21-0-0-24S). Elemental S is not recommended for sole use or as a blend due to its slow
breakdown to sulfate-S. Canola S source trials conducted by NDSU in 1998 at Carrington,
Langdon, and Minot averaged 1555 pounds per acre with ammonium sulfate as the S source
compared to yield of 1260 pounds per acre with elemental S. Details on fertility
recommendations for canola are available in circular SF-1122, 'Fertilizing mustard and
canola', which is available at NDSU Extension Service offices.
Greg Endres, Area Extension Specialist/Cropping Systems, Email: gendres@ndsuext.nodak.edu
1998 Ag Alert Archive
* Carrington R&E Center Home Page
* NDSU Agriculture
Greg Endres, Area Extension Specialist/Cropping Systems, Email: gendres@ndsuext.nodak.edu
1999 Ag Alert Archive
* Carrington R&E Center Home Page
* NDSU Agriculture