Management and profitability of dual-purpose crops

Take home messages

• Sound summer fallow management will allow the soonest possible establishment when an opportunity arises
• Getting crops up and away at the earliest opportunity (once safe to do so) is critical to allow a decent grazing period
• Select species and varieties to suit each individual operation and enterprise
• Grazing management will directly impact liveweight gains and grain yields
• Excellent gross margins are on offer from grazing both home bred and trade cattle, especially when this allows cattle to be marketed at premium prices rather than being forced to take the going market price for store cattle
• Careful consideration needs to be given to nutrition (primarily nitrogen) through the longer growing season
• Most profitable outcome may not necessarily be from managing to maximise grain yield at the expense of liveweight gains.

The key drivers to success of dual-purpose crops can be considered in two main areas, management practices and decisions involved in getting the crop to a grazeable state, and then the management through the grazing period until lockup and on to grain harvest.

‘Dual purpose’ or ‘graze and grain’ crops allow potential increases in productivity, profitability and diversity of a farm’s enterprises and incomes and can also arguably reduce overall risk. Management of dual-purpose crops is involved and certainly not set and forget. A well-managed dual-purpose crop has the potential to return greater gross margins than both grain only and grazing only crops, though when not managed well, this performance can be significantly reduced.

On our family owned mixed farm near Mendooran NSW, the vast majority of crops sown are dual purpose and are primarily utilised to grow weaner cattle to feedlot entry weights. In good seasons when feed allows, a percentage of cattle may be kept and grown out to heavier weights for processors. We find that having dual purpose crops provides high quality feed for the young (10-month-old) weaners through a time of year when other pastures would be very limited and the timing of their sale to feedlots generally coincides with a suitable time for the crops to be shut up for grain recovery. This leaves some significant upside in grain harvest, if and when the season allows. If well managed, the dual-purpose cropping phase also leaves paddocks clean of weeds and ready to be sown to improved perennial pastures at the end of the crop rotation.

Pre-grazing management – ‘getting the crop up and away’

The process begins with a clean and disciplined summer fallow program, preferably no-till though in some cases cultivation may be required when bringing new paddocks into the cropping phase to level them up to allow zero or minimum till from that point on. Ideally this commences in the spring before barley grass, ryegrass, silver grass and other weeds set viable seed. Well maintained summer fallows have been shown to have up 86mm more plant available water and up to 69 more units of stored nitrogen per hectare (McMaster and Graham 2014) when compared to uncontrolled summer fallows. More stored moisture increases the chance of an early sown crop germinating and surviving warm periods through March soon after sowing, and often allows for positive growth to continue despite limited rainfall through March and early April. More stored nitrogen is vital for these longer dual-purpose crops which can have up to a 10-month growing season.

In many years in our area, (2018 was one of them), an early sowing opportunity arises in late February or early March only to be followed by significant periods of limited rainfall through March and April (13mm 19^th Feb 2018, then 25mm 25^th Feb, 26mm 5^th March, 25mm 26^th March followed by no rain in April, 13mm in two falls 21 days apart in June and no rain in July). If crops aren’t sown in a timely fashion to capitalise on available moisture, patchy and disappointing or late crop establishments occur, and the result is limited dry matter production for hungry stock come May-June-July.

There are numerous species and varieties suitable for dual purpose cropping ventures. Oats, triticale, barley and wheat in the cereals, as well as canola in more recent times. Given we are a cattle operation, we have stuck with cereals to date.

There are a number of considerations when selecting which crop and variety to grow. The sowing of awnless varieties in frost prone areas allows crops to be grazed out late or cut for hay in the event the crop is frost damaged. Spread crop maturity and dry matter production via either varying sowing dates or sowing several varieties.  We find keeping one variety with a true and strong winter habit means we can capitalise on early sowing opportunities in late February, while also being a good fit if no sowing opportunity arises until April. Variety selection may also be based on the likelihood of the crop being harvested.  For example; in a more livestock focused operation where grain harvest may be a nice benefit in the right season, an awnless variety which can easily be grazed out late may be the best fit, even if it comes at the cost of a lesser disease and grain package. While for an enterprise more focused on the grain harvest where the manager seeks to capitalise on a quick grazing opportunity, a quicker variety perhaps with less dry matter production and a better grain and disease package could be the best option. Finally, where weed control is paramount, selecting the best species to keep open the most weed control options for the problem weeds is often a big factor.

Getting crop nutrition right early is an important factor in getting early sown dual-purpose crops away and to a grazeable state in the least possible time. Shallow and deep soil testing 2-3 months prior to sowing allows fertiliser budgets to be designed to ensure supply of sufficient nutrients, namely phosphorus (P) and nitrogen (N) to the crop. Some rules of thumb when nitrogen budgeting for dual purpose crops are that; 25-35 units of N are required for each tonne of dry matter to be grown.  This is then followed by another large N requirement when the crop is locked up and expected to make grain.   For H2 wheat at 11.5% protein, this requires another 44 units per tonne of grain produced. At 5 tonnes of dry matter and 3 tonnes of grain per hectare, that totals 282 units of nitrogen required per hectare to grow the crop (not all is removed from the paddock, but it is required through the season). See the nitrogen supply curve (Figure 1) for a paddock which was summer fallowed and sown to a dual-purpose crop of winter wheat.   Note the extremely low N availability by early winter, when the crop still has more dry matter and grain to produce.

Figure 1. Nitrogen availability over a 12-month period in a winter wheat cropped paddock - ‘Yallambee’, Cassilis, 2014

Finally, early in-crop weed control and insect management are often vital in ensuring the crop is grazeable in the least amount of time possible. Controlling weeds early, often results in the best possible kill and also minimises their competing with the crop for resources. This is particularly important in paddocks which are destined to be sown to improved pastures. Early control of insects, namely aphids, prevents both crop damage and perhaps most importantly, the infection of the crop with barley yellow dwarf virus for which they are a vector. When spraying insecticides and herbicides consideration needs to be given to grazing withholding periods of products used.

Grazing management of the crop – ‘maximising utilisation, regrowth and grain recovery’

Being able to graze crops in a timely manner and move stock onto the next area, cell or paddock to allow recovery before re-grazing is an important management consideration. By grazing a smaller paddock with a good number of animals, an even grazing to an ideal height or amount of ground cover can be achieved.  This increasesutilisation and maximises the crops recovery ready for the second and sometimes third grazing.

A key consideration is the number of stock required to graze the crop at certain times, or alternatively how many stock will need to be on hand (bred, purchased or agisted) at certain times to properly graze the crops to optimise grazing income. This is something that needs to be considered well before sowing when planning the cropping rotations. In our case, we work on stocking crops for around half of the grazing period at a rate of 1 tonne of liveweight per hectare of crop. For example, three 330 kg cattle weaners or 40 x 25 kg lambs per hectare. At this rate we would normally expect a paddock to last around 4 to 6 weeks, before moving them to the next area and allowing around 4 weeks recovery before grazing again. This is often a hard budget to do as it can be so variable with the seasons. In 2016 for example, a very wet year, we couldn’t graze crops down at that stocking rate even when they were left on the one paddock for 2-3 months, while in 2017, we had around 4 weeks grazing at that stocking rate and then recovery for a second grazing was extremely slow given the dry conditions which saw more crops then left to be grazed out into the spring than had been planned initially. Most years we allow 0.8 ha per weaner, as well as 1 ha per calving heifer which are drifted on after they calve.

Nitrogen management is an important issue to consider throughout the crop, with earlier applications towards the end of, or after the first grazing hastening recovery and bulk for the second grazing, and also providing nitrogen for the grain production phase later in spring. We find nitrogen management in dual purpose crops to be quite variable with each season different as it unfolds. Supplying enough up-front to ensure good establishment and growth until the first or second grazing is a good approach.  This then allows a decision to be made depending how the season is shaping up (primarily on the moisture front) as to whether a top-dressing will take place. In good rainfall years, in the majority of paddocks, it is likely that without decent in-crop nitrogen applications later (around July-August), grain yield will not be able to be maximised due to a short-term nitrogen deficit.  This is often reflected in low grain protein percentages. In these cases, yield potential has been left in the paddock. As good work by Grain Orana Alliance (GOA) has shown over past seasons, a large percentage of applied nitrogen, even if not utilised by the crop to which it was applied, will remain for the following crop/s (provided good fallow management in between crops).

Animal health management is a big part of ensuring weight gains are maximised and risk of mortality is minimised. Ensuring 5 in 1 or 6 in 1 vaccinations are up to date and young animals are free of parasite burdens, reduces the risk of losses to clostridial diseases and improves animal performance.

How hard and how long into spring to graze the crop are important decisions.  Often the choice is a difficult one, with the most profitable formula depending on livestock and grain prices at that point in time and how likely grain yield will be affected by each extra day’s grazing. A trial conducted at ‘Tongy Station’ Coolah, in 2014 in conjunction with Dr Lindsay Bell of CSIRO, found that yield of dual-purpose crops was determined by both timing of stock removal and the amount of residual dry matter at the time of lockup (Table 1). In essence, it was a sliding scale where locking crops up earlier with good amounts of dry matter gave the best grain yield, through to the treatments which were locked up late and had lower amounts of dry matter giving the lowest grain yields. It is important to note that the most profitable outcome may not necessarily be from managing to maximise grain yield at the expense of liveweight gains.

Table 1. Summary of results for winter wheat lockup timing and grazing intensity trial
- ‘Tongy Station’, Coolah, 2014.

Different varieties will reach the ideal growth stage for lock-up at different times.  This will often vary year to year. The ideal growth stage to maximise grain recovery is around Zadok’s growth stage 32. This can be determined by slicing the cereal primary stem open longitudinally to assess where the growing point is up to and whether or not the nodes have begun to move up. The GRDC publication ‘Disease management and crop canopies’, details different cereal growth stages and shows how to distinguish the crop growth stage. The publication also gives an idea of what percentage of yield each of the reproductive leaves contribute and importantly, when (and where) the crops reproductive capacity is being set.  Knowledge of the latter in particular, helps inform decisions as to when stock are removed.

After stock removal it is important to continue to monitor the crop. This is primarily to ensure everything is going to plan for grain production. Depending on variety, seasonal conditions and an assessment of inoculum load, foliar fungicides for leaf and stripe rust may be required. Note that disease susceptibility ratings do change for varieties over time and varieties once resistant may now be susceptible to infection as the pathogens overcome plant genes for resistance or tolerance. A potentially more devastating occurrence is a late frost which can see crops written off.  Given the time at which these crops are often flowering, periodic monitoring for frost damage is important. As mentioned earlier an awnless variety can be easily cut for hay as soon as frost damage is identified (if severe enough) and a good income still salvaged.

Profitability considerations of dual-purpose crops

The profitability of dual-purpose crops, as with all cropping and pasture enterprises is driven by the costs incurred, the quantity of commodities they produce and the price of those commodities. Every year on the back of ever variable cattle, sheep and grain markets, variable dry matter and grain yields and varying prices and amounts of inputs such as fertiliser and herbicides, gross margins will go up and down.

Over the years we have found that on average we manage to run around 2.5 weaners or steers/ha for 60 of the 90 days of June-July-August and while doing so, achieve average daily gains (ADG) most often in the vicinity of 1.4-1.6 kg per head (cattle). Even at a more conservative 1.25 kg ADG, that is 250 kg meat produced per hectare, and at $3/kg into feedlots is $750 income per hectare just from the grazing. In an average year, grain yields are generally around 2.5t/ha and in good years have been above 5t/ha. At 2.5t/ha and $300/t on farm for H2, that is another $750 income per hectare for the grain.

A big feature we like about dual purpose crops, (other than of course being able to grow our young cattle to feedlot entry weights), is the position you are in the day before harvest. In the gross margin tables below, you will see that the dual-purpose crop has already made money, whilst the main season crop is still standing in the paddock yet to return a cent. If insured, this income is protected, though this risk management aspect is something we really like about the dual-purpose crop option.

Table 2. Winter wheat vs main season wheat gross margin

The other big fit for dual purpose crops in our system is that they allow us to bring old run-down pasture paddocks into a cropping phase to be cleaned up from weeds without totally losing livestock feed production from those paddocks. In a year of oversupply of dry matter for the young stock, cows (particularly younger cows) and their calves can be utilised to help graze down crops and allow pasture country to rest and get away for spring.  This also allows the cows to gain more weight, which is a safety net for later on, with generally little impact on grain yield if managed correctly.

A 2018 case study to finish

2018 was one of the worst rainfall years on record (the worst on record for many areas).  The market for young store condition cattle was very weak, with prices often $1.80-$2/kg liveweight (LWT) for 200-250 kg weaners (even lower if lighter than that). In this case without dual purpose crops, or perhaps a dual-purpose crop which became grazing only in the end, you would either be forced to hand feed at high cost per head or sell and take whatever price you can get. At this time, the feedlot price for light feeder steers weighing 300-500kg was around $3.10/kg and relatively firm.   This presented a very enticing trading opportunity and/or allowed the value of homebred stock to be drastically increased. While growth of most crops was very disappointing last year, many would have run 2 light steers per hectare for 2.5 months (it must be said many crops never germinated or germinated and died, unfortunately in those cases very little could be salvaged).

A 250 kg steer at $1.90/kg was worth $475 (either home bred or traded). Growing at 1.25 kg ADG for 75 days, the steer would have weighed 343.75 kg and at $3.10/kg into the feedlot, was suddenly worth $1,065, an improvement of $590 in just 75 days. Two per hectare gives $1,180 gross income per hectare, even with a complete grain production failure in a terrible drought year.

References

McMaster and Graham (2014) Summer Weed Control Reduces Moisture And Nitrogen Losses

Contact

Edward Blackburn
BAgrSci, BBus
Agronomist
M: 0428 025 205
Email: eddyblackburn@gmail.com

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