Matching Land Use to Land Use Capability – Overcoming Sector Myopia

The hot topic of reversion of forestry land back to agriculture is attracting a lot of media interest as the naysayers of the MIS industry predict the 'inevitable destruction and burning of thousands of hectares of taxpayer-funded pulpwood plantations.'

Whilst Western Australia has, and will continue to have, a sustainable and profitable forestry industry in both hardwood and softwood plantations, there is some land that was planted in trees where agriculture is clearly the highest and best use. Land receiving rainfall of 500–600mm cannot support plantations, but for a cropping or grazing enterprise it is often productive and viable, particularly if the rain is received at the right time of year. This forest land will ultimately revert back to its highest and best use since internal rates of return for forestry are very low and even negative in the worst areas. Although it is often hard for a forester to advocate the removal of trees as opposed to their re-establishment, simple economics and stricter, tighter management control of the remaining plantation crop will ensure the industry retains its viability for the long-term.

Cropping or grazing?

Cropping is the flavour of the month right now as China re-opens its borders to canola imports from Australia and the live animal export industry continues to struggle for political reasons. Perception of the success of cropping on ex-bluegum land has always been subject to mixed opinion, but never properly tested. Whilst soils are likely to be more depleted in nutrients than a neighbouring farm paddock, the agronomist view is that these soils can be easily restored with lime and fertiliser applications. Less known is the impact of the nitrogen drawdown from the decomposition of the biomass left behind on the land. However, if you have the luxury of time on your hands this impact will lessen and ultimately provide the soil with useful organic matter. Grazing is the lower cost option, and with a natural grass seed bank in most soils, land can be grazed with minimal reversion works.

De-stump or spray coppice?

Full stump removal is expensive but achievable. The most common method is by bulldozer, often with an implement attached to the rip tynes. Stump grinding is gaining popularity as it is less invasive than a bulldozer and it doesn't bring rocks and lateral roots to the surface, allowing cropping machines to safely navigate on this country without risk of damage from stray lumps of wood. Typically you would only de-stump immediately if the intention was to sow a crop, as the initial cash outlay is too high for a grazing strategy.

Spraying coppice has a two-fold effect. Firstly if the coppice is allowed to grow too big, then it becomes more costly to remove, and unmanaged coppice in marginal areas is likely to be negative in real returns for a second rotation. The second aspect of spraying coppice is to start the process of the stump rotting, and allowing the natural grass seed bank enough light to stimulate germination. After a period of two-three years of grazing amongst the rotting stumps, the process of de-stumping becomes a lot cheaper and easier.

If stumps are not physically removed, spraying the coppice re-growth is important for the conversion of land use.

Diversification is important

Plantation MIS was widely blamed for local people leaving communities. Local farmers are now looking at selected bluegum land to restore back to agriculture for their next generation. By killing off the stumps and any resulting coppice after harvest, the stumps can remain in the ground and the property grazed with livestock to start building up stock numbers and generating some revenue. Often a neighbouring or adjacent bluegum reversion block can be grazed to allow for a fallow period on the farmer's own paddocks, or even a cropping venture on their own farm. This diversification allows for growth with little risk for the farmer, and often a win-win in the sale of the land for both parties.

On suitable sites and with appropriate mechanical land preparation and fertilisation, cropping can quickly replace tree growing.

For further information on this article, contact Dale Cameron, Regional Manager, Western Australia, by e-mail on dale.cameron@pfolsen.com.