While all attention is on surviving the current drought, it is vital to plan for once it breaks. This is as vital as dealing with current issues and will impact greatly on future farm profitability and management. No two farms will have the same post drought strategy but the following is an example of issues likely to need addressing.
For many mixed cropping/livestock properties, where massive destocking has/is occurring, full restocking may be very difficult and/or extremely expensive. A major option is to assess diverting significant extra area to cropping for the next winter crop.
An enormous amount of research applicable to most cropping areas of Australia is the need to conserve soil moisture in the fallow prior to crop sowing. Therefore, the need to choose paddocks for cropping now to ensure fallows start conserving moisture.
While zero till is a good option for fallow management with timely herbicide application, the exception may be if there is low soil plant cover, especially in harder setting soils. A cultivation can improve infiltration of rain by breaking crusts and creating roughness. In these conditions, the best bet may be to get a crop or pasture growing to protect soil from wind and water erosion.
Many farmers are contemplating summer crops for grain. Generally these are mainly only a good option if sub soil moisture levels are good. A wet spring can completely alter soil water levels for summer cropping (later sowing feasible) but a dry spring may well see many paddocks best left for next seasons winter cropping. Summer cropping also need to assess implications on planned rotations.
Summer fodder cropping on overgrazed pastures may be a useful option as perennial plants (native or introduced) can be slow to recover. Perennial native and introduced tropical plants can recover quickly if reasonable levels of dry-matter were retained and plants were previously well managed.
Note some summer crops, like Japanese millets (Echinochloa esculenta) and maize, can be established in relatively cools soils (12C - 9am reading) while most sorghum x sudan hybrids prefer warmer soils (around 16C). Cowpeas are even more sensitive to cool soils. If soil temperature is too cool, germination is slow and crops are more vulnerable to pests and weeds.
While two consecutive winter droughts have occurred in many areas, weeds like barley grass, annual ryegrass, brome grass and black oats can still be a big threat. Diseases like crown rot and take all in wheat and barley can be a major risk.
If paddocks are to be converted from long term pastures to cropping because of lack of stock numbers, crop species and variety choice will be important considerations. In many areas seed for next seasons crops may also be scarce. A good guide to varieties best suited to a given situation is the NSW DPI Winter Crop Variety sowing guide. Choosing varieties with sowing time flexibility, as well as suited to soil features like acidity is sensible. For assured seed supply my suggestion is - order now.
Soil fertility can be enhanced for some nutrients after drought. Soil sulphur levels for example can rise significantly in pasture paddocks with existing sulphur becoming more available. Nitrogen can have a similar post drought flush, but not phosphorus.
For the longer term, planning towards long lasting perennial pastures that are capable of surviving hard droughts are worth considering. For example, tropical perennial grasses can survive long-term in environments with average annual rainfall as low as 400mm (or lower). Finally, like all of agriculture there are no “magic bullets” for quick recovery. Make sure there is good science behind any recommendations.
Next week: Update on more winter crop varieties for 2019.