Grazing crops

| Date: 16 Mar 2011

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Grazing Crops
Tim Condon, Delta Agribusiness

Grazing or Dual-Purpose crops are an integral part of mixed farming systems across our region. Every season grazing crops have provided a benefit to the whole farm bottom line, from the wetter years of the eighties and nineties when grazing wheat was the outstanding enterprise, through the dry years from 2002 to 2009, where grazing crops provided a crucial “fall back” position for winter dry matter production; thus reducing and often avoiding the otherwise required supplementary feeding. Again in 2010 with a return to more favorable conditions, grazing cereals and grazing canola performed extremely well, providing benefits right across the farm with a resulting increase in whole farm profitability.

Over the last decade there has been several industry research projects aimed at developing grazing crop opportunities and maximizing the benefits to both the livestock and cropping enterprises. From the use of magnesium supplements for stock grazing winter wheats, the winter/early spring sowing of forage brassicas for lamb finishing systems and the development of grazing canola as another dual purpose grazing crop option. Whilst these topics have been covered at meetings such as this previously it would be worth taking time to re-iterate the three key points with utilizing grazing crops:

1. Firstly the timing of the autumn break heavily influences how soon feed will be available in the autumn winter period. In previous editions of these notes it has been highlighted that grower’s need to be very well prepared to ensure that this happens. In most years there will be an opportunistic storm or rainfall event through autumn, to be able to sow crops straight after such an event, seed, fertliser, the machinery and the paddock all have to be ready to go as the sowing window is usually very narrow. If such an opportunity is missed, it is generally another four to six weeks before the next one.

2. The emphasis of any review of livestock profitability always focus on the need to maximize the utilistaion of all available feed, that is to turn as much feed into as many dollars as possible. Whilst it is possible to increase the overall farm stocking rate with the addition of grazing crops it is the pasture management whilst stock are on grazing crops that is critical to the success of integrating grazing crops into the whole farm system.

3. Whilst stock are on the crops, pastures paddocks can be specifically targeted to achieve different outcomes. A range of paddocks can be set up for lambing or calving by allowing the winter growth to accumulate to a level that optimizes weaning percentage and weights. Other paddocks can be set up for fodder conservation by controlling weeds to significantly improve the quality and quantity of conserved fodder.

Grazing Canola
Many growers have now trialed this concept over the last five seasons. The livestock side of the equation has worked particularly well with paddock results mirroring those of the research trials. Live-weight gains with lambs in the range of 200-300 g/day have been recorded regularly and this would be the expected outcome moving forward. At the other end of the season, the impact on final grain yield has been very difficult to assess due to the spring droughts.

The number of Canola paddocks being used for grazing and grain production is rapidly growing, with a significant increase in the number of grower’s using this concept in 2010. In our region, 2010 was the first opportunity to look at the performance of canola as a grazing crop with good seasonal conditions and a good spring finish.
Again the results were very similar to that of all grazing crops, when comparing earlier sown grazing crops to straight grain crops sown in early May, yields and gain quality have been similar. The area sown will increase again in 2011 as many growers expand the area sown and more growers try the idea. To date most growers have used this crop to run ewes prior to lambing and for finishing lambs. Whilst this crop has been successfully utilized by cattle, when grazing with weaners for weight gain, it is important to ensure that they will be on the crop for long enough to allow the rumen to re-balance and subsequent weight gains to be attained. Supplementation with a source of roughage has also proven to be beneficial. In several instances over the last few seasons cows and calves have been used very successfully to come in for a short period and take the bulk off areas ungrazed or only lightly grazed by the sheep, evening the entire paddock prior to lock up. This ensures a more even crop maturity and windrowing timing.


Table 1: On-Farm Grower Paddock scale evaluations 2010:

 Site
 Sowing Date
 Variety
 Grazing intensity (dse.days/ha)
Timing
Yield t/ha
Harden
15th April
46Y78
10 days @ 23 dse = 230
15/06 – 25/06
2.6
Jugiong
14th April
46Y78
24 days @ 21 dse = 504
09/07 – 02/08
2.5
Harden
22nd April
46Y78
28 days @ 23 dse = 644
05/07 -  02/08
1.5 (hail)
Junee
18th April
45Y82
14 days @ 49 dse = 686
05/07 – 19/07
2.8
Harden
9th April
46Y86
40 days @ 122 dse = 4880
21 days @ 110 dse = 2310
14/06 – 25/07
01/07 – 21/07
2.2

 

As canola is still a relatively new grazing crop option it is worth reviewing the key factors to consider when planning a grazing canola program:

• Earlier sowing produces significant winter biomass.
• The forage is of high quality, and good live-weight gains are achieved, with no negative animal health issues observed to date.
• Grazing delays crop development – which leads to later flowering.
• The timing and intensity of grazing influences yield. (As with all grazing crops the longer and harder they are grazed the lower the grain yield)
• Seasonal conditions in late spring have a large influence on crop recovery and subsequent grain yield.
• Grazing before buds appear and elongate minimises flowering delay and subsequent yield loss.
• Grazing tends to increase blackleg severity, particularly with varieties that have a resistance rating less than 7 (MR-MS).
• Herbicide withholding periods can be restrictive.
• Grazing Management is critical
• Crop Agronomy – sowing date, variety, seed rate, weed control need to be carefully considered and planned.

Grazing Crop Options
There are many grazing crop options available; these are outlined in the table 2 below. For each crop the most relevant varieties are listed with a guide to the sowing window opportunity. Obtaining objective data that compares the dry matter produced for grazing and the relative grain yield recovered is proving to be very difficult.
Public funding for these trials has dried up and because of the infinite number of combinations of crop type, variety maturity differences, sowing dates, grazing dates and lock up dates; it is very difficult to compare one crop to another let alone one variety to another. The only recent data available is from the NSW I&I trials in 2007 and 2009, the 2007 results are included again as a guide to the relative performance of each species and some common varieties.

Table 2: Grazing Crop Options
 
Variety
Crop Type
Sowing
Dry Matter
Grain
Grain
Comment
 
 
Window
Production
Recovery
Value
 
Outback
Forage Oats
February
Excellent
Poor
Nil
 
White Stallion
Forage Barley
February
Excellent
Poor
Nil
Lodging
Yiddah
Oats
March
Good
Good
Low
 
Endeavour
Triticale
March
Good
Good
Low
MT
Yambla
Barley
March
Good
Good
Low
Acid Tolerant
Urambie
Barley
March
Good
Good
Low
 
Wedgetail
Wheat
Mid April
Good
Good
High PH
Stripe Rust
Whistler
Wheat
Mid April
Good
Good
Mod ASW
Stripe Rust
46Y83
Canola
April/May
Moderate
Good
High
 
Greenland
Forage Brassica
Late Winter
Excellent
Nil
Nil
Spring Feed
 
 
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 Whole Farm Impacts
The trend now is to grow grazing crops that will produce the highest value grain, and to use the grazing period as a means of reducing the overall risk of cropping. If significant income can be derived from the grazing operation then there is less reliance on grain income. Setting up your farm business and your livestock enterprises to be able to capitalize on the utilization of grazing crops will take some careful planning.
Determining the balance of crop type and area will be determined by sowing opportunities, livestock requirements, target markets and seasonal conditions.

Whilst the productivity of individual grazing crop paddocks can be outstanding it is the positive synergistic impact that they have on the whole farm business that has driven their integration into mixed farming operations. These added benefits include:
• Increasing winter stocking rate / capacity
• Wider distribution of workload, sowing grazing and harvest
• Flexible grazing options / potential opportunities
• Weed management benefits – in crops and pastures
• Reduced production risk for crops and livestock
The pure economic value of these added benefits has been difficult to determine and quantify and had not been done to any great extent prior to last season. In 2010, a systems research project was started by a team of CSIRO researchers including Hugh Dove and John Kirkegaard. One of the aims of this work was to quantify the value of spelling pasture paddocks whilst stock were grazing dual purpose crops. The data generated from this work shows that impact is very real and measurable as shown in graph xx below.

The trial was set up so that sheep grazing days could be measured across a range of grazing scenarios, which were compared to set stocking the same area of a good phalaris and sub clover pasture. Each block of crop or pasture is 0.27 ha in size and very even, as can be seen in the aerial shot of the site last spring. All plots were grazed with merino hoggets and the grazing period was from May to December with the area being stocked at 12.8 dse/ha . The grazing scenarios were:
1. Continuously grazed pasture.
2. Pasture locked up – sheep onto grazing wheat – then back onto the pasture.
3. Pasture locked up – sheep onto grazing canola – then back onto the pasture.
4. Pasture locked up – sheep onto canola then wheat – then back onto the pasture.

Figure 1: 2010 CSIRO Research Project – Ginninderra Experiment Station 

The results are listed in table 4 below and are presented as sheep grazing days. The main driver of the extra grazing attained from the crops is that they accumulate dry matter at 30 – 50 kg/ha per day as opposed to the pastures growing at around 15 kg/ha/day.
Then whilst the stock were on the crop the pasture was accumulating dry matter and building a feed wedge for use in late winter early spring. Utilising this wedge or these extra grazing days is the where the productivity increases will come from. How this is done will be relative to each business but alternatives include:
• Increasing the whole farm stocking rate
• Agistment / trading stock
• Use the opportunity to winter clean / renovate pastures
• Increase the cropping area, and run stock on less area
In the current climate the opportunity to buy stock is limited to some extent by the capital required, but it can still be an economically viable option, alternatively many producers are retaining more young stock – both ewes and wethers. With the very strong grain price outlook there has also been an increase in the level of opportunity cropping, which is the ideal fit for dual purpose grazing crops.

Table 4: Extra sheep grazing days (SGD/ha) obtained by grazing wheat, canola, or canola+ wheat in sequence, and the extra grazing days obtained by the subsequent grazing of winter spelled pasture (all relative to continuously grazed pasture).

1000 SGD = 24 dse (20 midterm ewes) on 40 ha for 42 days (six weeks). 

Treatment
Crop
extra SGD/ha
Spelled Pasture
extra SGD/ha
Total
extra SGD/ha
Wheat
1188
521
1709
Canola
822
739
1561
Canola + Wheat
2076
1380
3456

Source: CSIRO – Hugh Dove & John Kirkegaard – “The Stockade Experiment”

This is a valuable research outcome after the first season of this trial, as it quantifies the potential for productivity gains that can be achieved in our region by utilizing dual purpose grazing and grain crops.




Tim Condon
Farm Consultant
Delta Agribusiness - Harden
Mobile 0427 426 501
Email: tcondon@deltaag.com.au
www.deltaagribusiness.com.au