SOIL SALINITY DISTRIBUTIONS IN DRIP IRRIGATED VINEYARDS OF SOUTHEASTERN AUSTRALIA

摘要

In the Murrumbidgee Irrigation Area (MIA), in southeastern Australia there is concern that saltsrnmay be accumulating in soils under drip irrigation. This paper describes the assessment of thernsustainability of drip irrigation in various vineyards after 4 to 11 years of implementing driprnirrigation. A total of six drip irrigated vineyards were sampled in the row and inter row for soilrnsalinity. Four of the six sites were chosen because there was historical soil salinity datarnassociated with them from before drip irrigation was implemented. This historical data was usedrnfor comparison with current soil salinity data. At all vineyards it was found that saltrnconcentrations in the rootzone were below vine tolerance thresholds of 1.5 dS/m. The results alsornshowed that the salt concentrations in soils under drip irrigation actually tended to decrease withrntime, especially in the inter row that was no longer watered. There were large variations in therndistributions of salinity within vineyards and between vineyards. The salinity profiles werernhighly varied. It would appear that there is little danger of salt accumulation in the rootzone inrnthis context, probably due to the low salinity irrigation water and the potential for leaching byrnrainfall.