Better crop, pasture and soil management have been themes for this column, now running for 40 years (first issue was October 7, 1982). That's about 2090 issues.
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As far as possible, articles are based on solid science relevant to upgrading farm businesses.
A farmer's son, an agronomist all my working life, and owning our own property helps, I hope, to write articles relevant to today's farmers and agronomists.
Many outstanding changes have occurred in agriculture over the last 40 years.
While many farming aspects remain similar and important, such as the timeliness of fallow weed control, much research has impacted on improved productivity and soil.
Perhaps the widespread adoption of zero till (no-till) farming combined with stubble retention has had the most impact from a production and sustainability perspective.
A major part of my work has been research into improving the productivity of once considered near useless light, acid soil country.
Much of it was infested with weeds, was overgrazed, and grew poor crops and pastures.
This column has highlighted research that gradually overcame these issues.
Today light acid soil is largely regarded as valuable and, in drought years, commonly performed ahead of loam and clay soils, making better use of limited rainfall.
Our own property, with a lot of light acid country, like others, validated these research findings.
Acid soil tolerant legumes like serradella and biserrula, crops like triticale, oats and lupins, and tropical grasses like Premier digit, combined with addressing soil fertility issues, have all been important in transforming light soils.
Lime use has also been critical, especially when mainly only surface soils are acid but subsoils are not.
Much of NSW's pastures are non-arable.
Their upgrading has largely been via soil fertility improvement, adding legumes, including acid soil tolerant ones, and grazing management.
Modern cropping has evolved enormously over the last 40 years. Aspects covered regularly in this column highlight cropping research.
Rotations are critical for crop yield improvement.
Greater knowledge about the control of diseases like crown rot and pests like nematodes are also related to rotations.
Soil fertility is a big area of changing practice in cropping and is also responsible for big impacts on yield.
It has been appreciated for many years that stored subsoil moisture is important for improved crops (summer and winter ones).
Research has defined average yield gains (compared to poor fallow water storage) for most NSW cropping areas of at least 1t/ha extra cereal yield. Plus, higher available soil nitrogen.
Upgraded plant breeding of all crops has also played a big role in improving yields and yield reliability.
Much science has been involved in developing new herbicides to address weed issues.
Development of improved rotational crops like chickpeas, lentils, lupins, faba beans and canola, as well as improved cereal varieties, have all been important.
More so than ever, farmers are challenged with reliable science-based information.
A recent article I read, for example, promoted products that when added to seed and applied to crops and pastures, reduce the rate needed for conventional fertilisers.
I could not find any independent or acceptable science to back these claims.
The research quoted seemed devoid of scientific aspects such as randomisation, replication, scientific analysis, an independent assessment or peer-reviewed.
Crop and pasture weed control has been an important theme of Down to Earth.
Weeds are increasingly developing resistance to many herbicides.
Strategies for maintaining high value from herbicides involve what is called "integrated" weed control measures.
These include rotating use of products, crop rotations, and agronomic aspects such as higher sowing rates, more vigorous varieties and closer sowing rows.
Apps like CliMate and Soil Water are other innovations that help make decisions like the level of soil water and rainfall probabilities.
Tests such as Predict B are other aids for crop decision-making.
Climate variability and how we can better understand it, predict it, and soil carbon and health are other areas with substantial research that aims to help with future farming practices.
Next week: The science behind cereal genetic rust protection.
- Bob Freebairn is an agricultural consultant based at Coonabarabran. Email robert.freebairn@bigpond.com or contact 0428 752 149.
