Self-watering soil could expand farmable land to inhospitable areas

A new type of soil created by engineers at The at Austin can pull water from the air and distribute it to plants, potentially expanding the map of farmable land around the globe to previously inhospitable places and reducing water use in agriculture at a time of growing droughts.

As published in ACS Materials Letters, the team’s atmospheric water irrigation system uses super-moisture-absorbent gels to capture water from the air.

When the soil is heated to a certain temperature, the gels release the water, making it available to plants. When the soil distributes water, some of it goes back into the air, increasing humidity and making it easier to continue the harvesting cycle.

“Enabling free-standing agriculture in areas where it’s hard to build up irrigation and power systems is crucial to liberating crop farming from the complex water supply chain as resources become increasingly scarce,” said Guihua Yu, associate professor of materials science in the Walker Department of Mechanical Engineering.

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Environment website wades deeper into water data

An environmental monitoring website, Land, Air, Water Aotearoa (LAWA), is expanding its repertoire to offer more data about New Zealand’s most valuable natural resource, water.

LAWA now displays real-time data on river flow, groundwater and rainfall levels at over 1000 sites, adding to the water quality data on the site.

“We believe LAWA is one of the first of its kind to bring together a whole country’s water quality and quantity data into one place,” said Fran Wilde, chair of Local Government New Zealand’s regional sector.

“Building on the beach and river quality information already available on LAWA, the real-time flow and water level data will allow those who rely on water for business or recreational activities to see the current state of the river or aquifer.”

LAWA also shows how much water is available in different regions and how it is being used.

“Over 27 billion cubic metres of water is consented to be taken from our rivers and aquifers each year to meet our cities’ and towns’, industry, agriculture and hydroelectricity demands. That’s enough to fill almost half of Lake Taupo,” said Ms Wilde.

“In addition to being a life-giving necessity, water is a vital input for the industrial and primary sectors and tourism upon which the New Zealand economy relies. In some regions we are approaching water resource limits where water demand outstrips supply. This can constrain economic opportunities and put pressure on our river ecosystems.”

LAWA was launched in 2014 and is a collaboration between New Zealand’s 16 regional and unitary councils, the Cawthron Institute, Ministry for the Environment and has been supported by the Tindall Foundation. It allows people to access information about the quality and availability of New Zealand’s natural resources on the internet.

Ms Wilde said LAWA would be adding more data about the quality of New Zealand’s lakes in the next few months, followed by air quality monitoring.

LAWA will also contribute to a new national environmental reporting regime being designed by the Ministry for the Environment and Statistics New Zealand.

Lesson from the drought: Nathan Guy promotes investment in irrigation

The drought affecting much of the country emphasises the need for irrigation projects to store and distribute water, Primary Industries Minister Nathan Guy said today.

Guy issued his media statement (here) after speaking to drought-affected farmers on the West Coast and the Central North Island this week.

Water drives NZ’s economy just as much as minerals do in Australia, he said.

“We don’t have a shortage of water or rainfall in this country, we just don’t have the capacity to store and use that water in dry times. We currently use for irrigation less than two percent of the water that lands on New Zealand.

“Done properly, storage and irrigation schemes can help to better allocate water to benefit both the economy and environment.

“If current proposals are advanced there could be another 420,000 hectares of irrigated land available over time. Research from NZIER suggests exports could be boosted by $4 billion a year by 2026, which would support thousands of new jobs.

“This is why the Government is investing $80 million this year into a new Crown company to act as a bridging investor for irrigation projects. This will involve short term, minority investments to help kick-start regional projects.

The Govt has signalled plans to invest up to $400 million in regional-scale schemes to encourage third-party capital investment. It is also supporting development of suitable projects to the prospectus-ready stage through the Irrigation Acceleration Fund.

Guy said projects will succeed only if they are committed to good industry practice that promotes efficient water use and environmental management, particularly around land-use intensification.

Irrigation projects potentially could improve the flow of some rivers in dry summer months, he said.

Collaborative water management in North Canterbury

Waiology, a NIWA-managed blog about NZ’s freshwaters (here) has posted an item on collaborative water management in north Canterbury.

It notes that in July this year the Hurunui-Waiau Zone Committee will notch up three years of work.

It was set up as part of the Canterbury Water Management Strategy – a collaborative process for finding local solutions to water issues within an environmentally sustainable framework.

The post by David Eder (chair of the committee) and Ian Whitehouse (Environment Canterbury facilitator for the committee) reviews the committee’s work and decisions.

The next challenge for the zone committee is to increase the understanding between rural and urban audiences and dispel some of the myths that nothing has changed and farmers are destroying the land. People need to take some time to learn what is going on and begin to understand and appreciate the progress that is being made. The recommendations in the ZIP include setting flow and allocation regimes for the rivers and their tributaries.

Nutrient load limits also need to be set for North Canterbury’s rivers and tributaries and landowners need to improve nutrient management practices to make new irrigation developments feasible.