AgAlerts 2002 From Griggs County
By John Swenson, Griggs County Extension Agent

Issue # 4, May 17, 2002

• Late Seeded Crops

• Seeding Depth for Soybeans

• Renovating Thin or Weak Lawns

• Lawn Fertilization

Late Seeded Crops

    As this cold and wet spring lingers on, decisions must be made whether to change crops.  Canola, field peas and flax are cool season crops that should be planted early to avoid hot, dry summer weather conditions during flowering.  Normally we like to see these crops planted in late April or early May.  As of this writing, we are pushing the late side of seeding dates.  But one must look at what mother nature is doing.  At this time the soil temperatures are having a hard time getting above the mid 40's and the trees are just beginning to leaf out.  So if we look at the current conditions, they are similar to early spring conditions.  Yet when we look at planting dates, we are on the late side.  The decision is a gamble on whether this will be a cool summer such as a few years in the early 1990's or like the past years when we had high accumulations of growing degree days in July and August along with a late fall frosts for long maturing crops. 
    So the decision still remains "do I still plant canola, field peas or flax"?  Canola:  NDSU recommendations for planting dates for acreage south of U.S. Hwy. # 2 is before May 15th if possible.  For acreage north of Hwy. # 2, no later than May 25th.  Canola is the most sensitive to heat stress, thus the early planting dates.  Canola  is also quite tolerant to spring frosts.  Field Peas:  Are probably the most tolerant to cold spring conditions but flowering is the main concern.  Flax:  Yield decreases approximately 2 bu/week for each delay in seeding beyond late April to early May.  More severe yield decline occurs when planting after May 15th.

Seeding Depth For Soybeans

    Seeding depth for soybeans should not exceed 1 1/2 to 2 inches in depth.  Soybeans planted at depths greater than 2 inches will have more difficulty in penetrating the soil crust and extend the time between planting and emergence.  This time frame is very important when looking at a possible short growing season.  Other row crop such as corn, dry beans and sunflower can emerge from depths greater than 2 inches without noticeable stand reduction.  

Renovating Thin or Weak Lawns

    Winter snow plow injury, disease, rodents and poor nutrition will often weaken a lawn so over seeding and fertilization are needed to re-establish decent turf.  If the existing cover ranges from 20 to 50 percent, seed at a rate of 1.5 to 2 pounds per 1,000 square feet.  If the existing cover is 50 to 70 percent, seed at a rate of 1.5 pounds per 1,000 square feet.  Once spread, lightly rake the seed into the upper surface of the soil.  Begin a cycle of watering lightly and frequently until seeds germinate.  Start mowing when three inches tall.  Do not lower the mowing height lower than two and one half inches.  Lower mowing heights weaken turf and promote weed competition.  For more information on turf renovation and establishment, consult the NDSU Extension publication "Turfgrass Establishment and Maintenance for Home Lawns and Athletic Fields ".

Lawn Fertilization

    It is not desirable to fertilize heavily in early spring because this simply promotes excessive shoot growth and in turn additional mowing requirements.  It is preferable to wait until May 25 to June 10  after early flush of growth has occurred.  Fertilizing  non-irrigated lawns from mid-July to mid- August is not recommended due to heat and drought stress encountered by our cool season grasses.  Irrigated lawns will require more fertilizer due to the increased growth and leaching of nitrogen.  When applying fertilizer, avoid the use of high analysis nitrogen fertilizers under the drip line of trees and shrubs from mid-June to mid-September.  Such applications could induce late season growth which may inhibit natural hardening -off and predisposing woody plants to possible winter injury.  The following table lists fertilizer recommendations for minimal and adequate lawn maintenance levels in North Dakota.

Please Contact Our Office For Additional Information
E-mail: griggs@ndsuext.nodak.edu
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