Soil Management for Australian Irrigated Agriculture

superuser — Tue, 09 Sep 2008 23:42:55 +0000

IDs and People

Program:

National Program for Sustainable Irrigation

Research Type:

Research Project

Research Scale:

Farm

Legacy (KMS) Project ID:

SRP5026

Host Organisation:

Soils Research Pty Ltd

Researchers:

Bruce Cockroft

Subjects

Subjects:

Irrigation

Keywords:

Productivity

Soil structure

Project Information

Summary:

Australian soil structure deteriorates rapidly under irrigation with current management practices, resulting in inefficient water use and low yields. These soils lack the mineral montmorillonite present in those overseas soils which maintain porosity and stability under irrigation. This project aims to overcome this deficiency, developing new preparation and management practices enabling large inputs of stable soil organic matter.

Preliminary trials indicate this is feasible through incorporation of stable soil sheaths (rhizosheaths) formed on ryegrass roots. Physical, chemical and biological factors enhancing rhizosheath formation will be investigated to best harness rhizosheath development to improve water use efficiency and irrigated crop yields.

Outcomes:

The benefits of the project will be increased yields, cheaper and simpler orchard and row crop soil management. Reduced water use per tonne of plant product. Improved soil. High carbon sequestration – soil organic carbon increase from 1% to 4%. Improved knowledge on soil management.

Current Activities

Status:

Active

Background

Project Background:

Irrigated agriculture in Australia performs poorly in the dollars it generates. This is because the yields of nearly all crops and fodder are low compared with potential; but also because of low cost, low return (per ha and per Ml) grazing industries. Examples of Australian average and best overseas yields include maize 10t/ha v 40 (dry wt.), Tomatoes 45t/ha v 160 and pears 35 v 180. To consider potential productivity we should not only compare our results with what others can achieve; the ultimate limitation to plant productivity is the available solar radiation.

This is expressed as the conversion of incoming energy to plant dry matter: 6% conversion is possible on farm, 12% has been achieved. A 4% conversion in southern Australian irrigation areas to plant dry matter would give 64t/ha which is 5 times the current yield of, for example, perennial pasture. Cockroft and Mason (1987) discuss this and give examples of a range of crops.

Aims:

To develop a new system of soil management for irrigated orchards, row crops and pastures that increases yields two to three times current (Table 2. System 5) and at the same time improves the soil resource. Is cheap and simple to set up and manage. Is applicable to all Australian irrigation including row crops and the dairying industry. Is equal in productivity to the very best of the best soils overseas e.g. In California and Yangtze delta, that we call ”super soils”.

Open Hydroponics: Risks and opportunities

Mon, 16 Jun 2008 07:19:17 +0000

An open hydroponic system (OHS) is a continuous method of supplying a crop’s water and nutrient needs in a very precise way. Unlike traditional soiless media hydroponic systems, in the open field hydroponic system the soil is used as the medium in which the plant grows and its primary function is to provide the support structure to anchor the plant and accommodate its root system.

IDs and People

Program:

National Program for Sustainable Irrigation

Legacy (KMS) Project ID:

DAN22

Host Organisation:

Department of Primary Industries and Resources New South Wales

Researchers:

Steven Falivene

Subjects

Subjects:

Monitoring and Assessment

Salinity

Soils

Irrigation

Keywords:

Productivity

Environmental risk

water supply

Project Information

Outcomes:

Stage 1:

An understanding of OHS principles and practices and the availability of relevant information for irrigators, policy makers and industry. This opportunity for understanding will lead to better defined OHS design techniques.

An understanding of the feasibility of the system for various locations in Australia and this will build upon other existing tools for crop/climate/soils selection.

An initial assessment of the barriers, environment, social (skills) and economic (capital costs) that will be required to be overcome for successful adoption.

Better understanding of the impacts of adoption on water service providers and environmental agencies that may change the design parameters for infrastructure refurbishment and environmental monitoring.

Stage 2:

An improvement in the sustainability of irrigation by:

better informed investment decisions by industries, producers and lending providers, and
improved understanding of the risks and benefits of broadscale adoption of the technology.

Facilitation of the adoption of more efficient and effective water use and nutrition practices if the technology is proved to be sustainable. Specific improvements will occur through:

the adoption of wide-spread objective management systems for drip irrigation (that includes fertigation),
matching irrigation to crop water use (quantity applied),
understanding the varying nutrient requirements of the plant,

Potential for increased economic viability through improved production (quality and quantity).

Understanding of the social implications that may result from wide-spread adoption of this technology. Also an understanding of the likely rate of adoption of the technology will be an outcome.

Potential for gains for the supply and support industries (eg. manufacturers, designers and consultants)

Current Activities

Status:

Complete

Background

Project Background:

This system is relatively new to Australia and there are a number of commercial citrus operations currently in place using the principles of OHS. Yandilla Park in South Australia is a large commercial operation currently using and marketing a technology imported from Spain(Martínez Open Hydroponics Technology). Other commercial orchards are using their own interpretations and variations of OHS. There is potential that OHS is suitable for a range of other crops (peaches, almonds, grapes, citrus, avocados and several vegetables) with suitable irrigation systems.

Aims:

Stage one of the project is a desktop study to:

Review the current knowledge and status of OHS including grey and published literature
Evaluate the impact of OHS on water supply infrastructure
Examine the potential impact of OHS on the environment

Stage two of the project will work with industry to:

Validate water use, nutrient leakage and salt accumulation of OHS
Determine the potential return on investment from OHS through examination of yield and quality dividends
Develop Best Management Practice guidelines for industry to optimise productivity and minimise environmental impact

All in Productivity

Soil Management for Australian Irrigated Agriculture

Open Hydroponics: Risks and opportunities

Stage 1:

Stage 2: