Soil and Water Management
Major Funded projects
Reducing the persistence of Izamethapyr residues in acid soils

Enhancing the beneficial effect of pulses on wheat production

Sorption characteristics and degradation of some herbicides in Australian soils

Processes causing pH stratification of surface soils

Sustainable rotations through recharge control by enhanced lucerne water uptake

Effect of a polymer on soil water retention/release characteristics and plant water use efficiency

Controlled root zone irrigation

Effect of pulsing on wetting patterns with T-tape subsurface irrigation system

Duration:
1996 _ 1998

Project Summary:
Two subsurface drip irrigation products were studied on their subsurface water distribution patterns. The two products were conventional drip tapes and controlled root zone irrigation (CRZI). The CRZI system consists of a special sub-surface configuration which may help reduce the deep percolation and enhance the lateral and upward water movement. The study consisted of characterization of CRZI product materials in a laboratory experiment and testing the CRZI against conventional subsurface irrigation products.

A consultancy report was submitted in August 1998. The report covered the hydraulic properties of the CRZI materials and a comparison of the performance of CRZI against the conventional subsurface irrigation products. The major findings were that the CRZI prevented the tunnelling problem and increased lateral water movement which are widespread problems with conventional subsurface drip irrigation systems and the increased lateral water distribution. However, the depth of installation affected the lateral water movement with CRZI. Compatibility of CRZI with different soil types and pulsed irrigation were suggested as further studies.