Agronomic package and benchmarking for mildly or periodically saline land allowing for viable pasture and cropping options
In 2006 the Liebe Group in partnership with the Department of Agriculture and Food WA was successful in obtaining funding from the National Landcare Program (NLP) Community Support Component to implement a project aimed at assessing production options for mildly saline and iceplant affected land.
Currently within the Shires of Morawa, Perenjori and Dalwallinu there is 190,000 ha of salt affected land with a further 530,000 ha seen as ‘at risk’ of salinisation in the next 10 years. This land is regarded as a poor option for grazing principally due to the high infestations of slender iceplant (Mesembryanthemum nodiflorum), which is highly toxic to stock and has resulted in many sheep deaths
Landholder perceptions remain, that all salt affected land is unproductive only because of salt, and increasing amounts of land is continually being lost, particularly after wet years. On discovering salt is encroaching on their cropping land most farmers effectively lock up the paddock and cease cropping, along with all other cropping or pasture management practices such as fertiliser applications.
These areas became rapidly colonised with iceplant and have since been considered unproductive saline land with limited grazing potential due to the iceplant monoculture. Iceplant is generally used as an indicator species of saline land and grows in thick matts that manage to out-compete most good pasture and other saltland species, allowing little else to grow. Iceplant is suspected of mobilising salts within the soil profile to the soil surface through its ability to take up and store salt. Very little is currently known about this weed.
This issue of agricultural production on mildly saline land has become more important in light of the recent data on water tables declines due to global warming/ reduced rainfalls. Potentially much land that has become saline in the past 50 years may well be returned to production as saline water tables decline. This is provided that good weed control and a specific agronomy can be developed for this land class.
- To investigate the ability of ice-plant to move salt from depth to the soil surface i.e.; tissue plant analysis.
- The development of benchmarks and diagnostic processes allowing landholders to undertake paddock based test to accurately determine the salinity status of a given area. Benchmarks will be developed through field investigation of site salinity characteristics and stored in a database.
- Research cultural or herbicidal control methods for the toxic exotic weed slender ice-plant. Develop complete weed control packages that include saltland species on current herbicide registrations.
- Trial / demonstration of existing soil ameliorant technologies such as gypsum application and, deep ripping to alleviate soil structure decline due to soil salinity and sodicity.
- Extend project information to growers in the aim of developing a more positive mind-set about how moderately affected saline land can be managed. This will be carried out through the provision of pamphlets, field days, articles in local newspapers etc. Published results will also be extended to the wider agricultural community through the support that has been shown by the various grower and NRM groups.
This project is managed out of the DAFWA Three Springs office. The Project Officer is Lorinda Hunt. If you would like to know more information about this project please contact Chris O’Callaghan on (08) 9661 0570.
View results trial results from the 2006 season:
PRE & POST-EMERGENT HERBICIDE TRIAL ON SLENDER ICEPLANT 2006
CROP & PASTURE DEMONSTRATIONS ON PERIODICALLY & MILDLY AFFECTED SALINE LAND 2006