Agronomy Library > Soil Conservation

Agronomics of Direct Seeding Forages (Proceedings- ARECA Conference, February 2006)
Author: Ron Heller
Date Created: March 10, 2006
Last Reviewed: January 30, 2007

INTRODUCTION
Perennial forage crops play a significant role in reducing the risk of erosion and maintaining soil quality. Forage management practices are changing as new technology for seeding, cutting, and grazing evolve. A proven record for direct seeding [1] (DS) annual crops, need for rotational forage crops, and rising costs for cash inputs including fuel, all pilot the adoption of DS as a forage cropping system for most farms in Alberta.
Because perennial forage is a long-term investment, management over time is critical. Tame [2] or perennial forage fields have never been easy to establish, therefore a grower hates to remove less productive forages and start over. Reduced tillage practices such as DS and sod-seeding [3] remove the risk of erosion and mitigate equipment wear and tear, soil moisture loss, and weed pressures associated with traditional tillage plow-down [4] . The result can be improved establishment and a streamlined approach to cycle perennial forage crops between fields, quickly and more efficiently to maintain flexibility, cash flow, and productivity i.e. livestock feed supply.

KEY POINTS
  • Trust and confidence in many of the same principles learned by experienced DS farmers (annual cropping systems) will help perennial forage producers succeed.
  • Cover-crops [5] are for tillage-based cropping systems. Caution: smother crops!
  • Greater long-term DS production makes up for initial lower production sometimes encountered (but not always) during the forage establishment year.
  • Measures that focus first on the agronomy[6]of perennial forage ultimately improve the economics for establishment, management, and production outcomes.
  • DS forage pays [7] .
  • Establishing perennial forage with DS involves 2 or 3 years of commitment, depending on the circumstance [8] . 

DISCUSSION
In an ongoing project with Reduced Tillage LINKAGES (RTL), a farmer from Vilna, AB. has found DS forage offers an advantage over his traditional management, i.e. tillage. An economic comparison between plow-down and sod-seeding (Table 1) shows cost savings of almost $73.00/acre by eliminating disking, harrowing and rolling which amounted to a total of ten separate field operations from sod break to new crop forage establishment.

Table 1.  ECONOMICS OF SOD-SEEDING COMPARED TO PLOW-DOWN
Sequential FieldOperation
Cost$/ac
PlowDown
SodSeed
Comments^Similar AGRONOMIC operations
Herbicide Termination
21.70
O
P
Hired custom operator
Disking (tillage termination)
21.15
P
O
Hired custom operator
Fertilizer Application*(2yr. Cost)
80.95
O
P
Yr.1} DS airdrill; + fall broadcast
77.58
P
O
Yr.1}broadcast; Yr.2}with seed/Agrotain
Extra Tillage (disk/harrow/roll)
51.49
P
O
New forage-DS rolled after seeding
New forage (seeding method- $/ac)
89.39
79.57
New forage-DS got pre-seed burnoff
3-Yr. NET $/ac** Note: (LOSS)
(87.16)
(101)
^Equivalent actual costs less revenue
*Fertilizer method and rates varied as per site, crop, machinery and year
**Interim crop seeding/harvest costs and revenue are excluded, i.e. oats (sod-seed) and canola (plowdown)

The economic information provided by this project also indicates the cost of his forage seed to be approximately $38 - $42 /acre (Alfalfa / Brome / Timothy), a preferred hay and pasture mix used on two separate sites [9] . In one case, the forage seeding was done with a disc-type airdrill [10] (7.5 inch row spacing) and the other using a Valmar™. broadcast implement Although the forage species seeding-rates (lb/ac) varied within each mix, his overall seeding rate target was 15 lb/ac. By weight, forage seed differs tremendously between species in terms of plant stand density outcomes, i.e. Timothy is tiny and has many more seeds per unit weight or volume than Meadow Brome. Accurate calibration through a DS airseeder may not be easy to achieve, especially with an assortment of different forage species in the mixture. One DS advantage may be in precision placement of both seed and fertilizer into a moist, firm, and shallow seedbed. The opportunity to reduce seeding rates under DS is an important economic factor. [11] 
An examination of the plow-down sequential operations used in our co-operator’s “conventional method of land preparation” [12] reveals a tillage mindset. In August, a Roundup Transorb® treatment to terminate the sod was done (custom sprayed @$21.70/ac). Eighteen days later, a custom disking operation was carried out (12.5 hours @ $110/hr). Additional disking (3 more passes @ 7.50/ac each) and a fertilizer broadcast application were also undertaken in the fall of 2003 (Yr.1). The site had a pasture sage infestation, has a sandy gravel soil structure, and was described as being extremely rough due to previous landowner’s neglect. Despite these obvious differences from his DS site, the results so far are notable, if not somewhat regrettable (i.e. a missed opportunity to split the field for a sod-seeding demonstration compared to his plow-down undertaking).

Traditional seeding of perennial forage, under tillage-based cropping systems, often requires under-seeding, or seeding together with a companion crop.  DS could be changing that. Agronomy-wise, why should 2 different crops be seeded in the same field? An investigation of perennial forage establishment with or with-out a cover-crop was looked at. To date, our co-operator’s economic DS data for no-cover (NC) vs. cover-crop (CC) tends to favour the CC treatment [13] . In this case, the cover crop was oats combined for feed and the straw baled. However, the forage stand outcomes still support NC as a good establishment method (Tables 2 & 3) and appear to be superior in development with NC than CC, under reduced tillage treatments (Table 4). 
Table 2.  Yr. 2 - FORAGE DENSITY: Direct Seeding No-cover (NC) vs. Cover-crop (CC)
Plant
Type
AVERAGE (plants / sq.meter)
July 04
Aug 04
68 Day Regrowth
NC
CC
NC
CC
NC
CC
Alfalfa
28
16
9
15
10
19
Brome
20
3
25
3
6
5
Timothy
5.5
9
3
14
7
16
Weeds - annual
10
10
4
2
0
7
Weeds - perennial
1
0
0
0
0
0
Weeds – winter annual
7
5
11
3
3
0
 
 
 
 
 
 
 
 
 
 
Table 3. TWO-YR.  FORAGE GROWTH (DS)
FORAGE
PLANT
Height (cm)
July 04
Aug 04
Regrowth
NC
CC
NC
CC
NC
CC
Alfalfa
54
47
82
70
52
57
Brome
84
51
105
80
52
50
Timothy
36
58
77
97
45
88
 
 
 
 



Table 4. Yr. 3 – DS FORAGE DENSITY
FORAGE
MEASUREMENT*
NC
CC
STEMS / sq.meter
625
450
PLANTS / sq.meter
78
38
ALFALFA /sq.meter
26
3
 
 
 
 


The NC treatment was swathed and baled in November 2003. The full site was cut twice in 2004 and once in 2005. When I visited the site on July 20, 2005 (Yr.3, two weeks after swathing), it was hot and dry, and there was no visual forage re-growth. Five days later the field was sprayed for grasshoppers. Grasshoppers were also a  problem in 2003, the year of establishment, and the site was sprayed with Matador® plus Pardner® for weeds.

An important discussion topic for DS forage must be weed control. Because there are very few registered herbicide options for spraying weeds in-crop, especially in mixed perennial forage, attention must focus on a pre-seed strategy as well as the forage early establishment phase which is generally slower emerging thus less competitive. As with annual cropping, glyphosate [14] can be effectively used for both a pre-harvest [15] (prior crop) and/or a pre-seed burnoff [16] (time of seeding applies) to reduce the weed pressures on perennial forage. Each has merit for controlling perennial, winter annual, and flushing annual weeds. Another strategy is for species-specific and seeding times that coincide with unique herbicide options. One example is alfalfa (a forage legume that has different characteristics than brome, a forage grass), split-seeded alone (i.e. a separate operation) in a manner that offers the best establishment advantage (agronomy-wise), which is also different than for most grassy species. Forage dormancy phases need investigation.
Readers should also note that our co-operator was selected under RTL’s mandate for the Greenhouse Gas Mitigation Program (GHG) [17] . Nutrient efficiency (i.e. inorganic fertilizers and manure use) is a focal point, while perennial forage in rotation is a major objective for this demonstration activity. Regardless of site and/or treatment (except in 2002 sod-seeding oats for green feed), all fertilizer applications to date have been late fall-broadcast with no incorporation – the manner in which the co-operator’s preference and past experience dictates. His reasons refer to the erosion risk of the course (sandy/dry) soils on his farm, as well as the benefits of seeding with simple box press-drills (a.k.a. not a fancy, expensive airdrill). However, an exception to this was his choice of seeding implement (i.e. Valmar) for the new forage crop (May 2005) on plow-down where forage seed and fertilizer (blended with Urea-N Agrotain®) were spread on the spring-disked (tilled) canola stubble, and subsequently heavy harrowed (HH) [18] and then rolled [19] . Surface broadcast application in similar manner into undisturbed stubble needs to be explored, especially with forage grasses. Advanced DS systems can provide low soil disturbance, one-pass seed and fertilizer placement, and other efficiencies that reduce tillage requirements and that may improve nutrient management for perennial forages.

As a final point of discussion, I will mention the importance of operational diversity and producer goals. No doubt, these are and will be changing significantly as I write, due to an increased and (future) unknown cost of purchased inputs such as fertilizer and fuel. Where once a farmer consistently fertilized or pushed his forage production, he may now have to back off. Cattlemen may be able to stretch their forage longevity beyond what a hay-for-cash operation or forage seed producer will. In this instance, our co-operator lives in an eco-zone [20] that brings July heat waves, hosts thin-black sandy loam soil, and where a surplus $30 bale or so to the acre [of perennial forage] means a decent cash flow. He uses his 100 cow-calf enterprise as value-added revenue from his mature forage land (long-term pasture). Although he is pleased and “happy” about this season’s DS forage yield (3.5 bales/ac [21] ), he is also questioning the economic sense of consistently applying $500/tonne urea to new hayland.
SUMMARY
Our Co-operator has the following goals in this reduced tillage project:
1.      Convert grain land to perennial forage (livestock and cash sales)
2.      Quick turn around into better forage production (old pasture to new hay)
3.      Avoid rocks, and [risk of] drought (experience and erosion concerns)
4.      Maintain cash flow and cattle feed supply
This project addresses important DS principles for perennial forage establishment, which can be summarized by economic value as well as practical agronomy. It is important to apply the information as it may or may not pertain to specific circumstances, including soil zone, seeding method and machinery (including fertilizer placement), weeds, time of seeding, and forage type.

The first activity involved removal (termination) of an existing forage stand. This began in August 2001 at one site (Sod-seeding > green feed oats > new forage-DS) and was repeated in August 2003 at another site (Plow-down > canola > new forage-tilled stubble). Each site has been assessed over a 3-yr. interim period between old forage removal and new forage establishment. Table 1 summarizes the economic information reported by the co-operator (not all shown).
Information also reported by our co-operator from his plow-down site can be used to compare the impact of a tillage-based cropping system on perennial forages. In 2003 (Yr.1), an existing forage field (sod) was terminated, re-seeded to canola in 2004, and a new perennial forage crop was established in 2005. In hindsight, the initial dynamics existed for a split-field comparison with sod-seeding but regrettably this was not done. More evaluation for this site is planned.
A second project activity explored the risk and rewards of DS forage with or without a cover-crop. Salvageable NC forage was baled in 2003 (establishment year @ 2.5 bales/acre). In 2004 the site was cut twice, first on June 23 and again on August 10. The site was cut once on July 6, 2005 and each time the co-operator left uncut strips to compare re-growth (nice visual and good photos). We also took square meter plant counts to compare actual forage and weed densities between NC and CC treatments, along with crop height measurements. In year-3 our co-operator stated, “I can still see the difference in plant stands [between treatments]. On [no-cover] there is a significant heavier [22] and thicker stance of brome grass… one can assume with confidence that the yield will also be greater”.  Table 2 and Table 3 summarize some of the data colleted. [23] 

Despite considerable harvest revenue from the 100 bu/acre cover-crop of oats, observing the superior emergence, early development, and subsequent forage growth of the no-cover treatment convinced this co-operator there is merit in a DS approach.
Another important factor of DS forage is the machinery and operator’s experience [That’s another whole topic best addressed in another forum…]. In this case our co-operator, at first sceptical, was very satisfied with the skill of his custom DS neighbor. The outcome left him wishing in hindsight that he had managed the bulk of the field without a cover crop [24] . Although positive and supportive, these reasons are difficult to verify scientifically, or absolutely. In like fashion, our co-operator is not satisfied with his new crop “tillage” forage. The co-operator’s plow-down site finished the establishment year with a poor quality weed/hay clip in August 2005 (approx. ½ bale/ac). In bales, that amounts to 5 times less production than what he got off the no-cover DS site. He was able to graze cattle for 26 days in late October into Novemeber (96 cows and 43 calves), but remains anxious about what the outcome will be for next year. For him the question remains, “Should there have been a cover-crop along with it?” [Isn’t that what traditional tillage has taught us…?]. Time will show. [25]
I finish with a commentary about the DS advantage in perennial forage production. This farmer’s favorable reduced tillage outcome began with sod-seeding, avoided all tillage, used DS for new crop forage without a cover- crop, and is still going strong.

Agronomy-wise, DS is the best system to provide:
1.      Shallow placement and covering of the seed into firm and moist soil.
2.      Readily available nutrients (i.e. precision placement, soil quality, etc.).
3.      Timely seeding (residue management and weed control must be considered).

Economically, DS is superior to tillage because:
1.      It eliminates all the extra field operations that must continue once soil disturbance has commenced. LEAVE IT ALONE!
2.      It grows at least similar (if not better) crops as traditional tillage ever has.
3.      One person can do it simply and quickly (experience counts).

DS forage must start when decisions are being made about forage termination or removal in the rotation. Sod-seeding methods usually require a re-seeding break [26] between old sod and new forage (i.e. annual crops). Establishing perennial forage on standing stubble without extra tillage can enhance forage production and save costs.


[1] Direct seeding refers to the practice of one-pass seed & fertilizer placement, i.e. to minimize stubble knock-down, soil disturbance, and tillage operations for residue management, weed control, fertilizer application, seed bed preparation, etc. No-till or zero tillage is sometimes used to describe this cropping system. Extensively adopted for annual cropping within the past 25 years, many growers are now finding that the basic principles of direct seeding can be applied for successful establishment of perennial forages.
[2] Tame forage replaces native prairie rangeland, and refers here to perennial hay and pasture land.
[3] Sod-seeding in Alberta is becoming a popular method of terminating a perennial forage crop with herbicide and reseeding for annual cropping without any tillage (i.e. to avoid plowing or discing).
[4] Plow-down refers to removal of perennial forages by extensive tillage, i.e. breaking the sod and preparing the land for re-seeding.
[5] Cover-crop refers to the practice of seeding another crop along with a perennial forage to provide erosion control, protect seedling emergence, improve weed competition, and, in some cases supplement crop revenue or feed supply during the establishment year.
[6] Agronomy (n): the application of soil and plant sciences to land management and crop production [syn: scientific agriculture]. Source: WordNet 2.0, 2003 - Princeton University.
[7] RTL Farm demonstration and co-operator trials example will be referenced in the presentation.
[8] Step-by step procedures and management tips will be given during the presentation.  More detail can be found in the Discussion section of these proceedings.
[9] DS Site/sod-seeding NW29-57-13-W4 (75 acres) and Plow-down site SE13-57-14-W4 (65 acres)
[10] Airdrill refers to a common type of air-seeding implement used for DS.
[11] Not yet addressed in this project, but a future objective i.e. pure alfalfa for hay @ 4 lb/ac seeding rate.
[12] Co-operator’s project description: i.e. essential due to the [rough] field conditions.
[13] He combined oats @ 100 bu/ac and sold straw in the swath (baled). Total 3-yr. NET = $189/ac (CC)
[14] Glyphosate is the chemical name for the active ingredient used in several non-selective herbicides
[15] Pre-harvest refers to a weed control strategy whereby a registered herbicide is applied just prior to harvest. Often used in DS for perennial weed control, and/or in sod-seeding to terminate a forage stand.
[16] Pre-seed burnoff refers to the common DS practice of spraying herbicide on early emerging weeds prior to seeding the crop.
[17] GHGMP: a federal government initiative that links reduced tillage to best management practices (BMP) for carbon sequestration and reduced emissions of offending GHG’s i.e. C02, CH4, and N20.
[18] Heavy Harrows: a DS implement with large (1 –2 cm thick) spring-tines used to spread crop residue  and/or create surface soil disturbance to various degrees depending on settings (aggression) and speed.
[19] Rolling perennial forage crops after seeding is a traditional method of smoothing and packing the seedbed (tillage application). This holds some merit for any cropping system, in terms of avoiding harvest problems such as rocks, soil clumping, etc., however certain soil structures may be subject to adverse effects, i.e. fine clay, low organic matter, and/or high moisture.
[20] Eco-zone refers to climate, soil, and seasonal weather variances that have traditionally influenced what makes sense on the farm, in terms of enterprise (including crop selection and management practices).
[21] Bale refers to big round hay bales. He estimates the 2005 average weight/bale @ 1250 lbs or greater.
[22] Co-operator’s observation and discussion suggests the same size bale weighs more from NC than CC.
[23] 2004 Data: by Lakeland Agriculture Research Association (LARA) & 2005 data by R. Heller, RTL
[24] Reference to comments made July 2004 at the site TOUR, and in personal conversation since.
[25] 2005 was Yr. 3, or the new forage seeding / establishment phase in the plow-down component of this project. Similar observations and data collection is planned for at least another 2 or 3 years of evaluation.
[26] Back-to-back forage is not a recommended practice for sod-seeding.