Treat dual purpose crops the same as grain crops

While we didn't experience droughts in 2017, 2018 and 2019 as tough as some areas, they nevertheless were pretty testing. Dual purpose crops treated the same way as high standard grain only crops, especially in regard to storing as much fallow water as possible, made all the difference to being able to sow on time and to provide useful feed over winter. Not as much feed as in a good year but it did allow better finishing of steers and a more orderly sale in good condition.

It's not uncommon for some farmers to use winter grazing fallows for summer grazing. But that in most years is at the expense of winter feed. There is the philosophy that maintaining summer herbage is good for biodiversity and soil health. These plusses are questionable and at the expense of a lot of winter feed.

Part of not needing grazing from fallows used for winter cropping is pastures that are summer productive. Lucerne and tropical grasses are standout examples. In our case we now have 50 per cent of the farm established to tropical grasses and summer feed is only a problem in a drought where there mainly is not much feed from summer fallows.

Timely sowing is critical for dual purpose and grazing crops. We have tended to bring our sowing window forward to increase probability of being in time to ensure good winter feed. One needs to watch temperature forecasts carefully if sowing earlier than normal for a given district. Summer this year has been mild and allowed February sowing for our area, although March is the norm.

The probability for our area receiving a sowing rain of 10 millimetres, between mid-February to end of April is 96pc (10mm is normally sufficient on a medium to lighter soil with stubble retention and stored soil water). However, if our sowing window was mid-March to end of April probability would drop to 82pc. If 15mm of rain was required, maybe because of less sub soil moisture, probability would drop to 75pc. These estimates are based on App CliMate.

Early sowing of dual purpose or grazing only crops tend to perform more reliably if varieties with "winter habit" are chosen. "Winter habit" means varieties will not prematurely run to head, a problem if sowing "spring habit" varieties early, even slow maturing ones. There are good "winter habit" varieties in most species used for dual purpose or grazing only, including oats, triticale, brassica, wheat and barley.

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Apart for stored soil water, high soil fertility is very important for productive dual purpose or grazing only crops. Nitrogen is commonly the critical issue. As with all crops adding extra nitrogen is only efficiently used if other deficiencies, especially phosphorus, are also corrected. Because phosphorus is mainly corrected via application with or near seed, adding nitrogen from now on is for best results dependent on sufficient phosphorus already applied to established crops.

Grazing management of winter crops is where common sense mainly dictates what is best, as research is relatively limited. First grazing is best if plant biomass has built up to 2t/ha drymatter or better. This generally coincides with well-developed roots and plants that can recover quickly. If set stocking, or stocking for extensive periods, ensure good biomass levels are maintained for best use of sunlight.

A highly intensive grazing system like on some dairy farms where grazing can be restricted to what animals can utilise in a day's gazing, close to 100pc feed utilisation can occur. In a typically large area grazing system, perhaps 50pc of feed is wasted via trampling.

Our experience suggests there may not be that much difference between set stocking or a degree of rotational grazing in a broadacre grazing system. More important is maintaining between insufficient plant cover (perhaps of a minimum of 1.5t/ha drymatter) and not too much drymatter that results in senescence as fast as regrowth.

Next week: Where best to place fertiliser with canola.

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