No-till Forage Establishment to Improve Soil and Water Conservation and Reduce Associated Production Risks

No-till Forage Establishment to Improve Soil and Water Conservation and Reduce Associated Production Risks

Summary

The effectiveness of no-till forage establishment was assessed at six locations in Alaska. Direct seeding of grass into established grass stands usually did not improve forage yields. Seeding rate and N rate had little effect on establishment of newly seeded forages, but N rate had positive impact on forage yield in established stands. Grass yields were usually depressed when nurse crop yields were high and sometimes did not recover in subsequent years. Red clover did not establish under no-till at two of the sites but established well and produced good forage yield under no-till at another site.

Objectives/Performance Targets

1. Evaluate the efficacy of no-till planting as compared to conventional till under various N fertilizer rates for establishing timothy (Phleum pratense L.) and smooth bromegrass (Bromus inermis Leyss.) in Alaska.

2. Evaluate promising annual crops for feed production and as nurse crops during grass establishment in no-till and conventional planting systems.

3. Determine the effectiveness of no-till establishment of grasses and red clover (Trifolium pratense L.) at various seeding rates for renovation of thinning grass stands.

Accomplishments/Milestones

Methods and Materials

Studies were established on farmers’ fields at two locations in interior Alaska and four locations in southcentral Alaska. The interior Alaska sites were at Fairbanks (64o55’N, 147o43’W) on Columbia Creek Farm and at Delta Junction (63o55’N, 145o44’W) on Schultz Farms. The southcentral Alaska sites were at Palmer (61o39’N, 149o07’W) on Peter Scorup’s farm, at Point MacKenzie (61o24’N, 149o04’W) on the Trytten Farm, at Sterling (60o32’N, 150o39’W) on Paul Rumley’s farm, and near Anchor Point (59o45’N, 151o39;W) on Edna Anderson’s farm. The interior Alaska sites experience strongly continental climates, the Palmer, Point MacKenzie, and Sterling sites are moderately continental, and Anchor Point site experiences a moderately maritime climate. All of the soils were silt loams and were moderately (most sites) to strongly (Anchor Point) acid.

Objective 1 (nitrogen rate study under till and no-till). At Fairbanks, Delta Junction, and Palmer, Manchar smooth bromegrass was planted at a rate of 20 lbs viable seeds per acre to compare no-till and conventional planting and N fertilizer rates. The other sites were planted to Engmo timothy at a seeding rate of 9 lbs/acre. For the tilled plots, soils were planted within one day of tilling. All plots were seeded with a plot drill designed to seed into untilled soil. At Fairbanks and Delta Junction, triple superphosphate to supply P at a rate of 17 lbs/acre (40 lbs P2O5/acre equivalent), and potassium sulfate to supply 36 lbs K/acre (45 lbs. K2O/acre equivalent) was banded in the seed row in all plots. At the other four sites, P was applied with the seed at a rate of 15 lbs/acre (37 lbs P2O5) and K at a rate of 30 lbs (37 lbs K2O equivalent) per acre. Nitrogen was applied as ammonium nitrate with the seed at rates of 0, 20, 40, and 60 lbs/acre. Control plots which were not seeded but received N at rates of 0 and 40 lbs/acre were included. At Sterling and Anchor Point, only no-till treatments were used. At Fairbanks, only no-till treatments were used in 2000.

Objective 2 (companion crop study). Toral oats (Avena sativa L.), Gulf Westerwold ryegrass (Lolium multiflorum Lam.), and Dwarf Essex fodder rape (Brassica napus L.) were planted as companion crops with Manchar bromegrass at Delta Junction and with Engmo timothy at Point MacKenzie and Anchor Point. At Anchor Point, only no-till was used, at the other two sites, seed was drilled into tilled or untilled sod. Fertilizer rates were the same as for objective 1 for P and K; N was applied at 30 lbs/acre as ammonium nitrate.

Objective 3 (seeding rate study). Manchar smooth bromegrass (Delta Junction) or Engmo timothy (Point MacKenzie and Anchor Point) and Altaswede red clover (all three sites) were planted at 0.5x, 1x, or 2x the normal seeding rate. Planting was by direct drilling into sod. For red clover the 1x rate was 13 lbs viable seed/acre, for timothy it was 9 lbs/acre and for smooth bromegrass it was 20 lbs/acre. Nitrogen was applied as ammonium nitrate at 44 lbs N/acre to the timothy plots and 30 N lbs/acre to the bromegrass plots. Nitrogen was not applied to the red clover plots, but powdered Rhizobium inoculant was applied with the seed.

Each of the above experiments was established in adjacent locations in spring of 1998, 1999, and 2000.

All plots received a uniform application of N as ammonium nitrate in the years subsequent to the seeding-year. At Palmer and the interior Alaska sites, 60 lbs N per acre was applied in spring and 40 lbs N/acre was applied at the time of the first harvest. At the other sites, 80 lbs N/acre was applied in spring. At Anchor Point, the entire plot area was harvested by the farmer prior to sample collection in 2000, therefore, no yield data are available for that site in 2000.

Daily rainfall, air temperature, and soil temperature (4 inch depth) data were collected at each site with electronic data recorders.

Plots were harvested by clipping biomass from 1 square meter areas in each plot. Harvest was done when grass plants were in early heading stage. Two harvests were obtained in some years for some treatments at Delta Junction, Palmer, Point MacKenzie, and Fairbanks; other plots were harvested once each year. Weed and crop biomass was separated at time of harvest. Samples were dried and then weighed to obtain dry matter yield. Crop biomass is currently being analyzed for forage quality (protein, ADF, NDF).

Results

Objective 1 (nitrogen rate study under till and no-till). Forage grass yields were usually very low (often < ¼ ton/acre) for no-till seedings, especially when seeded into sod which consisted of species different from those seeded, and seeding rarely increased yields above that of the no-seed control treatments. In tilled soil, crop yields were usually highest with the highest N rate, indicating that in Alaska, N fertilizer can be applied with grass seeds up to at least 60 lbs N/acre without harm to the germinating seedlings. When timothy or bromegrass were seeded into degraded stands of timothy or bromegrass, respectively, yields were usually similar to those of conventional plots, both for the seeded plots and unseeded controls, in years subsequent to the establishment year. This indicates that if a reasonably good stand of grass exists, the Alaskan farmer's best option may be to manage the existing stand to bring production up to expectations rather than reseeding. Part of this management should consist of application of adequate N fertilizer and good weed control methods.

Objective 2 (companion crops study). Companion crop yields were much higher under tillage than under direct seeding, with only oats at Delta Junction providing acceptable yields under no-till. Smooth bromegrass yields at Delta Junction were low under no-till with all companion crops, and were greatly depressed with high yielding companion crops, especially oats, in tilled soil. At Point MacKenzie, growth of both companion crops and timothy were so low under no-till that no harvest was made in the establishment year. When planted into tilled soil, oats, yielded much higher than other companion crops. Total herbage yields at both sites were higher with than without companion crops when planted into tilled soil. Yields were quite low for both companion crops and timothy at Anchor Point (no-till only). Bromegrass yields at Delta Junction did not recover under high yielding companion crops in years subsequent to the establishment year. At Point MacKenzie, grass yields were not affected in subsequent years by inclusion of companion crops in the establishment year. These results indicate companion crops are probably not a good option for farmers wishing to establish perennial forages in interior Alaska, but may be a good way to increase establishment year yields without harming subsequent year grass yields in southcentral Alaska.

Objective 3. Seeding rate study with grass and red clover. Seeding rate (0.5 x to 2x recommended rates) did not affect yields of grass or clover at any of the sties. At Delta Junction and Anchor Point, yields were quite low ( 3 tons/acre) and red clover (almost 2 tons/acre). For timothy, yields for seeded plots were not different from unseeded plots, indicating that timothy stands were adequate for good yields prior to applying the treatments. The high red clover yields show good success, even at low seeding rates, of no-till seeding of red clover into existing sod. These results indicate that direct seeding of red clover into sod may be successful under some situations in Alaska, but are likely to fail under other conditions. We do not yet understand which conditions are good for establishment of red clover by direct seeding in Alaska.

Work remaining to be completed

Forage quality analyses are currently underway and will be completed by the end of the project period.

Conclusions to date

No-till seeding of perennial grasses into declining grass stands is not likely to be successful in Alaska.

Direct seeding of red clover and oats into existing sod may be successful under some conditions in Alaska.

Companion crops can greatly improved seeding year forage yields in Alaska, but under some conditions, they are likely to substantially depress subsequent year grass yields.

If stands are not too weedy, an Alaskan farmer’s best option for restoring declined grass stands may be simply to improve management practices to bring production back up to expectations.

Impacts and Contributions/Outcomes

These results provide Alaskan farmers with new information for improving or reestablishing perennial forage crop stands in Alaska.

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