Water Quality Archives | Sustainable Food Trust

When the water runs out: How native grasses and cattle are restoring parts of California

Alice Frost — Tue, 04 Nov 2025 16:05:28 +0000

With water an ongoing issue in California’s San Joaquin Valley, ranchers have stepped in to rethink how to restore the land, in valuable and creative ways. At the centre of this are cattle who play a key role in reviving native and non-native grasses, along with innovative farmers exploring diverse opportunities – from firebreaks to solar farm management.

The San Joaquin Valley stretches some 400 kilometres from California’s capital Sacramento to Bakersfield in the south. With its mild climate and fertile soils, the Valley is one of the world’s most productive agricultural regions; some 250 crops can be grown here, from lettuce to carrots, garlic, onions, melons and peppers and, most important of all, almonds. However, nothing grows without irrigation – the climate is semi-arid. California’s highly complex water system consists of hundreds of dams and reservoirs to catch rainwater and snow melt: a network of canals that measures roughly 6,500 kilometres distributes water to farms and cities like Los Angeles and San Diego.

In the past decades, California has seen long periods of drought. Farmers who could afford it paid for additional wells, some as deep as 400 meters. Thousands of these wells reach into the aquifer like straws, sucking it dry very quickly. Over-pumping has led to subsidence, causing roads to buckle and buildings to crack. To preserve what’s left of the groundwater, California has passed the Sustainable Groundwater Management Act (SGMA). From 2040, well owners can only pump as much water from the ground as can be recharged during the rainy winter months.

The consequences for agriculture in the Valley are stark: at least 20% of agricultural land will have to be fallowed for lack of water, and some estimates are even higher. But according to a recent study by the University of California Merced, the frequency of dust storms has already increased. Leaving ground bare on up to 900,000 acres, would be catastrophic.

Cows to the rescue

Before European settlers arrived in the 19th century, the San Joaquin Valley used to be a sea of grass, grazed not by bison, but Pronghorns and Tule elks. The native grasses were well adapted, and in winter, cold season grasses flourished, while in summer, heat tolerant warm season varieties dominated, and some grasses even tolerated highly saline soils on the west side of the valley. Could these grasses be reintroduced and could ranching make a comeback?

Diane Bohna is a fifth-generation rancher. In 2021, she rented 7,600 acres of land from UC Merced; the land was over grazed, showing more bare patches than remnants of grass. Bohna was an early adopter of Allan Savory’s principles of holistic management, and now, just three years later, 320 cow-calf pairs and a few bulls munch their way through a sea of knee-high grasses. “In the first year, we were lucky and got a wet winter,” says Bohna. There was still a seedbank of native grasses in the soil, and having the cattle graze them right – ‘bunched’ as a tight group and for a short period of time – helped re-establish those grasses. The animals will stay over winter, and during the summer months Bohna and her crew drive them to high altitude pastures in the Sierras on horseback, like the cowboys of old.

Diane Bohna explains the grazing system

Bringing back native grasses

A 45-minute drive to the east of Bohna’s ranchland lies the Sierra Foothill Conservancy (SFC). “Grazing is essential for re-establishing native grasses,” says rangeland manager Billy Freeman. Perennial native grasses have long and deep roots, often going 20-30 feet deep. Most pastures in the valley are re-sown regularly with annual Mediterranean grasses which make for much better feed because of their high sugar content. But their roots grow to just two or three feet and, like other non-native annuals, they are green and palatable earlier and compete heavily with the long rooted native varieties. In order to re-establish native grasses, Freeman has to time very precisely when and for how long the cattle are allowed to graze: non-native species will be rich in sugar and palatable earlier than the native species and therefore will be grazed harder. That leaves them little or no chance to develop seeds and mature. Because the annual grasses are so tasty, native species get grazed lightly which exposes the growth nodes, and once the cattle have been moved these grasses will be able to develop seed heads. Over time, native species recover and soil fertility increases. “We are seeing a lot of changes,” says Freeman. The level of biodiversity and water infiltration has increased. The bank of the creek was eroded, and the cattle rounded off the sharp edge so the vegetation has come back on the bank – there are cottonwoods and willows once again. And the thick layers of dead grass, which prevented fresh growth, have gone, and the grazing has restarted decomposition. Ninety acres of riparian pastures have been re-established next to creeks, by having them grazed once or twice a year for four to six days only.

“Grazing is essential for re-establishing native grasses,” says ranchland manager Billy Freeman

“Land needs cattle more than we need meat”

The SFC is a non-profit research facility, but can anyone make a living from ranching? Joe Morris, a cattle rancher in San Juan Bautista, says yes, it’s possible. For him, too, holistic management is key: “Attend to the needs of the whole – livestock, plants and soil microbes,” says Morris, and most of all, observe! He points out the huge variety of cool and warm season grasses on a pasture close to his house. He says, he was extremely surprised when he learnt in a workshop run by ecologist and soil scientist, Christine Jones, that grasses only make up about 10% of the species in grassland – the rest are forbs, broad leaves, shrubs and lots of flowers.

The ranch gets on average just 16 inches of rain, most of it from October to April. The grasses start to dry up by April, and even though it hadn’t rained in six months, there were vernal pools with rushes and, nearby, patches of wet soil underneath green salt grasses.

The ranchland on the San Andreas Fault

Unlike Billy Freeman, Morris does not use grazing to establish particular varieties, rather using perennials in general, which were in short supply when he took on the ranch. He has been finishing cattle since the late 90s. He buys animals aged 15-20 months directly from ranchers or at auction and finishes them at 24 to 30 months. This gives him the flexibility he needs for grass management and to react to factors such as weather events. The second enterprise is an Angus and Hereford cow/calf herd. To raise and finish all animals on the ranch wouldn’t be feasible because such a system is complicated and inflexible, and the market does not always reward it, says Morris. Lastly, he grazes cattle for other ranchers.

Morris markets the meat of his animals directly. Customers order ¼ or ½ an animal online, which means they will receive a mix of meats. Between June and November he delivers orders to 60 people at five different pick-up locations on each trip. The schedule is tight, customers have 15 minutes for pick up. The meat isn’t cheap, but Morris has a customer base of around 400 people who are willing to pay not just for high quality meat from grass-fed animals, but also for the land stewardship and ecoservices provided.

For [Joe Morris] holistic management is key: “Attend to the needs of the whole – livestock, plants and soil microbes,” says Morris, and most of all, observe!

More than meat

Ranchers should be paid for the ecosystem services their animals deliver, says Rob Rutherford. Before his retirement, he was a professor in the Animal Science department at Cal Poly in San Luis Obispo. Raising sheep has been a life-long passion, as is playing golf. When his local golf club had to retire nine holes due to lack of water, and thistles took over, Rutherford brought in his sheep. It did not take long until 90% of Italian thistle was gone because “the sheep have changed the biology,” he says. Marketing the meat and playing as much golf as he wants for free suits Rutherford well. But to him, using sheep and cattle as ‘land managers’ is much more than a quirky idea: “We don’t know what ecosystem services are worth,” says Rutherford, “the Reagan Library was protected by grazed areas around the building, which acted as a firebreak and saved the library from burning down in 2019.”

Together with others, he is lobbying Cal Fire (California Department of Forestry and Fire Protection) to change the regulations and officially recognize grazing as a fire-fighting tool. Costs for fire insurance have increased dramatically, so much so that it’s become unaffordable for many homeowners, some properties can’t be insured at all. In view of the recent fires that ravaged parts of Los Angeles, premiums will likely increase further. “If homeowners were to get a rebate if their houses were surrounded by a fire break, they would likely be happy to pay a rancher to bring in animals to maintain it.”

Solar farms need livestock too

For 11 years, Katie Brown, one of Rutherford’s former students, worked on establishing a “sheep ecoservice schedule” for what at the time was the world’s largest solar farm project. Once the panels were erected, the area was seeded with a perennial and annual seed mix, containing grass and forb species that naturally occur in the area such as foothill needle grass, pine blue grass and goldfields. The grasses established so well that the team realised they’d need to move in sheep immediately. Today, the grass under the solar panels is grazed by 3,000 to 6,000 sheep, at about 60 sheep per acre.

Dakota Glueck, rancher and cattle coordinator at TomKat, tends to the cattle

The panels create a unique microclimate that changes the plant species composition, says Brown. Because they provide shade, evaporation, transpiration and ambient temperature are reduced. That leads to increased biodiversity, and native perennials from dormant seed banks start to flourish and the total biomass production goes up, which means the number of grazing animals can be increased.

Brown believes that ‘solar farm ranching’ or ‘agrivoltaics’ can work financially – ranchers get paid for the grazing services, and their sheep provide wool and meat for local markets. The cost of grazing a solar site is typically cheaper for the solar farm.

As for the San Joaquin Valley, Brown believes that fallowed land there can be restored to a native mix of perennial and annual vegetation. For any such project grazing is essential – sheep can even graze salt grasses – and holistic management is the tool.

Creating a market

From creating firebreaks to solar farm ranching and golf course management, sheep and cattle can provide a whole host of ecoservices, as well as providing us with food.

Kathy Webster is the Food Advocacy Manager at TomKat Ranch Educational Foundation in Pescadero. She sees her role as a maker of connections. Holistic management benefits the environment, increasing biodiversity and soil health. But ranching is also a business and needs to be profitable. One way to achieve this is to encourage more people to eat grass-fed beef.

For Webster, getting beef into schools, universities and hospitals is key. In 2018, TomKat Ranch started the ‘Beef2Institution’ initiative and hosted ranchers like Joe Morris as well as university, hospital and school food procurement managers to discuss how to get meat from local, grass-fed animals into institutions. Most institutional kitchens source everything from companies such as US Foods or Sysco. And some schools can’t buy raw meat because they either don’t have access to a full kitchen or are not set up to receive raw beef product. The ‘Beef2Institution’ initiative was able to create cooked products, like cooked beef crumble and patties, which schools can use.

Webster also began working with Santana Diaz, a trained chef and Director of Culinary Operations & Innovation at UC Davis Medical Center. Their goal is to get more local, grass-fed beef into all UC campuses and five affiliated hospitals, and Diaz has been coming up with ideas for meals that are tasty but use cheaper cuts of meat.

A unique sales pitch

Sound data on the nutritional value of grass-fed beef, and research done on the benefits of holistic grazing for soil quality and biodiversity, have helped Webster to come up with unique arguments about why buying grass-fed beef from ranchers at a fair price through public procurement ticks all the boxes. Hospitals and other institutions have sustainability and climate goals. Webster does not focus on the low emissions of locally produced, grass-fed meat nor does she attempt to compete on price. Her argument is: buy grass-fed meat for a fair price as a means to reach the sustainability goals of your organization or institution. With the research done at TomKat Ranch, she has the data to show that beef produced in a holistic grazing system increases biodiversity and soil health, helps to mitigate drought conditions and flooding, creates wildlife habitat and, as a healthy, nutrient dense food, actually gives chefs and the people they cater for a lot of bang for their buck.

Photos courtesy of M. Kunz.

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Why livestock could have a key role in cleaning up our rivers

Alice Frost — Tue, 02 Sep 2025 14:43:36 +0000

The UK’s rivers and wetlands are under pressure from pollution, droughts and floods, with livestock farming both part of the problem and the solution. In this article, Robert Barbour, Senior Research Manager at the SFT, explores how agroecological livestock systems could help restore water quality and build resilience to climate extremes.

For all that the UK is famed for its reliably damp climate and lush green landscapes, the reality is that it faces a major water problem. This year, an exceptionally dry spring and summer is likely to result in the fifth worst harvest since 1984. Yet it was only last autumn that the south of the country witnessed record-breaking heavy rain that led to the third worst harvest on record. It’s been a bewildering, historic year of weather, but these are far from isolated aberrations. The climate crisis has already increased the likelihood of extreme weather events, and as the planet warms, these are only going to become more frequent and intense, both in the UK and globally.

At the same time, many of our rivers, lakes and wetlands are in a desperate state, choked by sewage and agricultural pollution. While some chemical indicators of water quality have, in fairness, improved over recent years, by most measures our freshwater environment continues to deteriorate – a damning indictment of decades of political and market failure.

These are serious issues, that pose some major challenges for the future of livestock farming in the UK. Intensive production systems, with their often-heavy use of fertiliser and high concentrations of animals – and therefore slurry – are a leading source of nitrogen and phosphate pollution in many catchments, the Wye and Lough Neagh being perhaps the two most infamous examples. Livestock farming is also hugely vulnerable to changes in climate, and the greater extremes in precipitation we are already seeing, pose a real threat to the way in which many farms operate. This is something the sector hasn’t fully come to terms with yet, but if the predictions are right, a much more unstable climate is a reality every farm is going to have to face up to.

How we confront these challenges is, like all things livestock, a contentious issue. Some would argue that livestock have no role to play at all in a food system that works for water. But while every farm and catchment is different, and no one solution will work everywhere, livestock can play a hugely positive role in restoring our aquatic environments and increasing our resilience to extreme wet and dry weather, by helping enable a nationwide transition towards a food system based on agroecological principles.

Realising this will require a shift from the largely production-focused systems which remain commonplace today, to a more multifunctional approach, where animals are rotationally grazed on diverse pastures for most or all of the year, with minimal use of synthetic fertilisers, pesticides or arable feed inputs. Such a transition would help alleviate the massive pollution problems associated with intensive livestock systems touched on above. It could also deliver more direct benefits for freshwater biodiversity, by supporting the sorts of low-intensity grazing practices which benefit a number of wetland plant species. Grazing livestock can even help reduce water pollution from conventional all-arable systems, through the re-integration of fertility-building grass and legume ‘leys’, grazed by livestock, into crop rotations. By naturally fixing nitrogen, increasing soil carbon levels and disrupting pest, weed and disease cycles, leys minimise the need for fossil fuel-intensive synthetic fertilisers and pesticides, both of which are major water pollutants in the east of the country.

These more nature-friendly, agroecological approaches to livestock production could also improve the resilience of our farming systems to drought and heavy rain, in various ways. Shifting from all-arable to ley-arable systems could, for example, help increase the genetic, landscape and enterprise diversity of farms, so spreading weather-related risks. Agroforestry expansion, meanwhile, would provide more shade and shelter for crops and livestock. But perhaps the biggest climate adaptation benefit of an agroecological approach to food production is that it tends to increase a farm’s soil water holding capacity, thanks, in particular, to the higher levels of soil organic matter generally found in biologically based systems.

This is something which grasslands are key to delivering. Stable organic matter can absorb several times its own weight in water, just one of the reasons why increasing soil organic matter levels is a crucial objective. Grassland soils contain much higher levels of organic matter than arable soils, and this means they soak up water much more effectively than arable land, reducing the speed of runoff and the risk of rivers bursting their banks. This is particularly true with semi-natural and extensively managed grasslands, which are far more effective at reducing the risk of flash flooding than those which are too heavily grazed. Culm grasslands in North Devon, for example, hold more than four times as much water as intensive grassland, and have much slower rates of water runoff, even when the soil is already waterlogged. But there is also considerable scope to improve water holding capacity of improved grasslands too, by encouraging more species-diverse, deep-rooting swards. The integration of trees into grassland can also dramatically improve water infiltration rates in pastures, significantly slowing the flow of water and helping reduce peak river flows during heavy rain, as the Pontbren Project in Wales has shown.

Grasslands can play an even more direct role in flood prevention, in the form of floodplain meadows. Clifton Ings and Rawcliffe Meadows, for example, are a crucial part of York’s flood defences, with their combined water-storage capacity of approximately 2.3 million cubic metres helping reduce the level of floods by up to 15 cm. The capacity of grasslands to store huge quantities of water can bring major benefits during periods of drought, too – including, again, in arable rotations that incorporate temporary leys.

Realising this sort of approach to livestock production at a national scale will obviously be difficult to achieve, requiring major changes in farming practice, and a shift to diets more closely aligned to what the land can sustainably support.

There are reasons for hope, though. The sorry state of our freshwater environment is now a headline issue that has energised a large swathe of society, and this has helped force government into action. There have, for instance, been some promising announcements around policy and regulation, two intensive poultry units have recently had their planning permission removed, and the massive problem of nitrogen pollution is now finally beginning to receive the attention it deserves, in no small part thanks to the work of the Sustainable Nitrogen Alliance (of which the SFT is a member) and others. However, this is only a start, and governments – and indeed every actor in the food system – need to go much further in helping farmers produce food in a way that delivers plentiful clean water.

You can read more about grazing livestock and their role in a sustainable food system in our report, Grazing Livestock: It’s not the cow but the how.

Featured image taken at Treehill Farm by Cath Shellswell.

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Helmy Abouleish: SEKEM, sustainable water management in Egypt and the Economy of Love

Alice Frost — Wed, 05 Jun 2024 15:40:27 +0000

Helmy Abouleish is the CEO of SEKEM, a sustainable development initiative that has transformed desert into vitally productive agricultural land in Egypt through biodynamic and organic agricultural principles. It is now a thriving enterprise, reflecting the incredible impact of land restoration on climate, nature and people. We invited Helmy to gives us his thoughts on climate change, water, sustainable development and the Economy of Love.

SEKEM is such an amazing project, and it has achieved so much in terms of realising meaningful sustainability in a broad-based way, but as we face a rapidly changing climate, what do you feel is most important to be doing to preserve a liveable world?

“Since 1977, we have been pioneers in sustainable development, promoting organic and biodynamic farming as a key solution to global challenges including food security and climate change. As the climate crisis intensifies, we need to act quickly. We believe organic agriculture is a crucial part of the solution.

This holistic system emphasizes biodiversity, biological cycles and soil activity, significantly enhancing the health and resilience of agro-ecosystems. Studies have shown that organic farming practices can store significant amounts of carbon in the soil, helping to mitigate climate change. Ultimately, this approach will lead to ecosystem restoration, and a more resilient and liveable world for current and future generations.”

SEKEM’s sustainable farms in Egypt

Water is such a critical issue across the globe and SEKEM has been so successful in terms of managing water systems sustainably – do you think what has been learned from SEKEM can be disseminated more widely, especially in arid climates? And more broadly, what do you see as the future of water on our planet? How do we manage it in a way that is fair?

“In terms of sustainable water management systems, we need more action, we need more change. It needs the expansion of concepts like agroforestry, and also really up-to-date technologies to reduce water use. In a country like Egypt that only has 50% of the water it needs to survive, even the 20% that we save if we switched to biodynamic agriculture is not enough. We need many, many more researchers and projects, looking at biodiversity, agroforestry and technological innovations. I’m very happy to tell you that we have a lot of research going on.

I could tell you that even with only 50% of the water, we could feed the whole population – but it would need collaborative research and initiatives. But I’m very optimistic that with a bit more wisdom, we can live a meaningful life with the systems available on mother earth. Some of it is going on already at SEKEM and at the Heliopolis University for Sustainable Development. We are happy to share our research regarding sustainable water management.”

You’ve been hugely committed to sustainable development – what is needed to drive it forward faster?

“Sustainable development from our understanding is holistic development. A development where political development, economic development, cultural development and ecological development go hand in hand. We feel that this kind of basic development will approach us out of the future, whether we wish to or not, or we want to or not, it’s coming. And it will either come out of our enlightenment, so we understand why we choose the light, or out of crisis. What we can do today is opt for enlightenment, opt for contributing to sustainable development, opt for innovating and engaging with sustainable development. It is the development of the future, there is no other option, there is no plan B or alternative to it, and hence, it’s very important that we engage and work with it sustainably. We want to make sure that it provides all goods and services in a competitive way – it doesn’t harm nature, it helps society and supports societal development and ultimately contributes to the unfolding potential of each individual human being. I don’t think that there’s any alternative, it’s just the degree of engagement and emotional interaction of a person to another person which will differ, but in the end, it is something which I believe will come because mother earth will not leave us to destroy nature or abuse the natural kingdom.”

SEKEM’s sustainable farms in Egypt

How do we prepare ourselves for the impact of climate change on agriculture? It’s already clearly visible across the globe – how do we turn the tide?

“In Egypt, we have 7 million acres managed by 7 million small-holder farmers, with each one of them having approximately an acre or less, and obviously climate change with the temperature rise and humidity is already affecting us, changing the varieties that we grow. And on the other side, today, Egypt’s 7 million farmers are contributing to climate change in the same way as all other farmers, in the UK and across the world, just by emitting three to four tonnes of CO₂every year. The whole of the agricultural sector contributes nearly 30% of all emissions. But our organic and biodynamic farmers can prove that there’s an alternative, they can sequester carbon in their soils, sequester carbon in their trees, they fight the emission of methane by their system of waste management, turning wastage into compost into black gold for farmers. In the end, they contribute to carbon sequestration in the soil, at five, six, seven tonnes an acre – at least – a year. When you put this together and evaluate it, it’s a real ecosystem service and farmers could do a fantastic job if you honour that work and pay them for this service by issuing carbon credits, which would allow them to simply grow biodynamic crops and sell them at the conventional price and still have a much better income to survive on. And at the same time, it would improve biodiversity and reduce water consumption in Egyptian agriculture. All this together shows us that there are alternatives and that by engaging in organic and biodynamic farming, we can turn around this huge challenge.”

SEKEM’s sustainable farms in Egypt

Tell us about the Economy of Love? It’s such a vivid idea; how does it work?

“The inspiration for the Economy of Love comes from my late father. At the very beginning, when we started 47 years ago in the desert to set-up SEKEM farm, it was very clear that biodynamic agriculture, which is the method that we applied, was fantastic. It really supports the stability of soil in the Sahara and generates a real contribution to systems change. It also feeds a different management of the supply chain, a different management of the economic system – it has transparency, and everyone gets a fair part of the value. We ultimately aim for a fair and just price for the consumer. And at the same time, we ask all the time, can this farmer develop himself and his family? Can this farmer develop his abilities and contribute to his village? The Economy of Love tries to include social, cultural, economic and ecological criteria, bringing in many more dimensions. Only those farmers who enter this Economy of Love, in the end can apply for carbon credits, which will enable them to sell their biodynamic products in the market at the same price as conventional products which makes it much easier.”

All photos courtesy of Samuel Knaus.

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Is ammonia from green hydrogen a false prophet?

Imogen Crossland — Fri, 01 Apr 2022 11:00:00 +0000

Defra has just launched a package of measures to help farmers facing huge increases in the price of fertiliser.

The cost of nitrogen fertiliser is currently three times higher than it was last year. This makes it an appropriate moment to consider the dependence of intensive agriculture on synthetic nitrogen and whether the prospect of green hydrogen to make fertiliser with a lower environmental footprint offers a long term solution.

A brief history of nitrogen fertiliser

Since the Second World War, synthetic fertilisers, especially those made from ammonia, have played a major role in agriculture on almost all farms except those using organic methods. These have driven a dramatic increase in production through higher yields, but that has come at a high environmental cost in terms of greenhouse gas emissions, air pollution from ammonia, water pollution from high levels of nitrate and biodiversity decline in terms of delicate wild flowers and plants outcompeted by ranker vegetation better able to ulitise nitrogen.

Today, the UK uses just over one million tonnes of nitrogen every year, in over three million tonnes of nitrogen fertiliser, with different products containing different proportions of nitrogen. Ammonia is produced by the Haber-Bosch process – named after German scientists Fritz Haber and Carl Bosch who developed a method to produce synthetic ammonia in 1911. This process turns the inert nitrogen in the air we breathe into reactive nitrogen, by breaking the triple bond which holds nitrogen atoms together in pairs, then forcing them to combine with hydrogen. This requires a temperature of 500°C, 250 atmospheres of pressure (approximately 120 times the pressure in a typical car tyre) and an iron catalyst.

The initial motivation was the prospect of war with Britain. Ammonia is essential for the production of explosives and had Haber and Bosch not made their breakthrough, the huge scale of the carnage during the First and Second World Wars would not have been possible.

At the end of both wars, the world was left with massive industrial capacity to produce ammonia for which there was suddenly no demand. However, in the 1940s it was realised that this ammonia could also be used to create nitrogen fertilisers, with the Rockefeller Foundation in the US pioneering their development for use in Mexican agriculture. While the programme was not well suited to Mexico, the experience gained underpinned the promotion of synthetic nitrogen fertilisers in developed countries from about 1950.

Haber and Bosch originally produced the hydrogen they needed to make amononia by passing an electrical current through water. However, producing hydrogen through electrolosis in this way is extremely energy intensive and it was later found that by using natural gas as the source of hydrogen the amount of energy needed could be reduced considerably. Even today, however, the process of making ammonia still requires a lot of energy. It accounts for 1.4% of global carbon dioxide equivalent emissions (much of this in the form of nitrous oxide and CO2) and consumes 1% of the world’s total energy production. Hydrogen (and the ammonia produced with it) is currently made using either Steam Methane Reforming or Auto Thermal Reforming with natural gas. This is known as grey hydrogen (or blue hydrogen, when the associated CO2 emissions are captured and stored underground). Given the significant contribution to the climate crisis, finding an alternative, less carbon intensive method of creating ammonia has long been desirable. This is where green hydrogen comes in.

Green hydrogen

The concept of ‘green hydrogen’ is now being promoted as a new climate friendly way to create and store energy to reduce our dependency on fossil fuels, with the potential to make greener nitrogen fertilisers as well. Green hydrogen production relies on the original Haber-Bosch method of splitting water by electrolysis (using electricity from renewable energy sources), which results in only two outputs: hydrogen and oxygen, neither of which directly contributes to global warming or air pollution. The hydrogen can be stored safely under pressure in fuel cells and the oxygen can be vented to the atmosphere with no negative impact. There are many uses for green hydrogen, including a potentially important role within agriculture as a replacement for the fuel used by tractors and other heavy machinery. However, of greater interest to many is that green hydrogen fed into the traditional Haber-Bosch process can be used for ammonia production which is then used to make fertilisers like ammonium nitrate.

Since this green ammonia is 100% renewable and largely carbon-free switching to green ammonia would greatly reduce the carbon footprint of nitrogen fertiliser production. This is a good thing. In theory, it would help us get closer to net carbon zero. Any steps we can take to reduce our global carbon footprint are clearly essential to the efforts to limit global warming to below 1.5 degrees by 2050 and 2 degrees by the end of the century, avoiding the worst predicted aspects of climate change. As such, it makes sense to support a switch to green ammonia from both grey and blue ammonia production. Price, however is still a limiting factor. The cost of green hydrogen is currently still high, but given the impact of the Ukrainian conflict on energy prices and the finite nature of natural gas reserves, the option to produce ammonia from green hydrogen is appealing since it is expected that at some point over the next 5-10 years, it will become lower in price and possibly also less susceptible to price fluctuations than when grey (or blue) hydrogen is manufactured and used. This could eventually help farmers, already under financial pressure and worried about rising input costs – a challenge that Defra is partly addressing though a package of measures unvailed recently.

But might green hydrogen be a false prophet?

One big advantage of green hydrogen is that it provides a way to store energy from wind turbines and solar panels to use overnight and on days when the wind isn’t blowing and the sun isn’t shining. But one of the biggest questions is whether it will be possible to produce enough renewable electricity in the UK to make sufficient green hydrogen for all our needs? As already mentioned, using electricity to make hydrogen for fertiliser production instead of natural gas is significantly more energy intensive overall. There is a great deal less pollution, but much more energy is needed in total. Given the need to use hydrogen to replace diesel and the dramatic increase in renewable energy we will need to achieve net zero carbon emissions by 2050, the scale of the problem is huge. There has to be a further question over whether we have enough land in the UK for sufficient solar panels and windmills, without taking excessive areas of land out of food production? As such, it seems likely that we will remain dependent on other countries for much of our energy needs, even once green hydrogen becomes a financially viable option. The obvious place to produce energy from solar power is in deserts, but the hydrogen would need to be made close to vast sources of water as, according to our initial calculations, it will require approximately six litres of water to make enough hydrogen to replace one litre of diesel.

Seeking an altogether greener approach

The current model of industrial agriculture relies on artificial inputs to maintain high yields and productivity. This has been achieved to the detriment of the environment and human health. Agriculture is the source of over 80% of ammonia emissions in the UK and ammonia is a major cause of air pollution. Even if it is possible to produce a ‘greener’ form of synthetic fertiliser at scale, green ammonia-based synthetic fertilisers will still cause some of the same environmental problems associated with current nitrogen fertiliser use, including fertiliser run-off into streams, which creates dead-zones in rivers, lakes and even some oceans through eutrophication. Producing enough hydrogen to make the 190 million tonnes of fertiliser nitrogen used globally each year could also put additional strain on the planet’s already inadequate supplies of fresh water in many regions.

Recognising the damage caused by synthetic fertiliser, the SFT and others in the sustainable farming sector have long been advocating a switch toward more agroecological farming systems. We believe that we need bold change if we want to create a more sustainable food and farming system. A switch to agroecology would be that change. Agroecology employs natural methods of nutrient cycling to build soil health. For example, using forage legumes in grassland, in rotation with crops and as cover crops, which bring natural nitrogen into the soil. The benefits of adopting such methods is that this allows farming to function in harmony with nature and available natural resources, it also aims to reduce negative externalities while still ensuring a productive and viable farming sector.

Of course, it is unrealistic to think that the world will ditch its dependency on nitrogen fertilisers overnight, and so where these continue to be used green hydrogen is likely to have a valuable role in reducing the emissions associated with their manufacture. Yet, green hydrogen should not be viewed as the primary solution to the nitrogen fertiliser ‘problem’. Ultimately, as opposed to challenging that long-entrenched dynamic of high-input industrialised agriculture, switching to green hydrogen could merely maintain the status quo of ammonia-dependent and polluting farming systems. Despite lowering the carbon footprint, it may create additional problems while enabling food to be produced with the same high levels of synthetic fertiliser, without introducing more fundamentally sustainability components into production methods.

Conclusion

As a result, adopting an approach that sees green ammonia as a solution to creating a more sustainable farming system might be misguided. It could help a little but it is not a panecea. Rather than moving towards the systemic change and a shift to agroecological practices that is needed, this could undercut delay the urgent need to transition in the direction of agroecology. We need to continue to push for bolder change, ultimately ensuring we stay within all planetary boundaries, allowing us and future generations to maintain a healthy and habitable planet.

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The Brecon Beacons Mega Catchment: A proactive and collaborative approach to delivering a resilient drinking water supply

Anna Kilcooley — Fri, 09 Apr 2021 13:13:00 +0000

The ongoing debate around the sustainable production of food and the inextricable links with the climate and nature crises is vitally important, but there is an extra element which is often overlooked. In a country like Wales blessed with our wonderful rivers, lakes and abundant (occasionally too abundant) rain, it seems odd to worry about the quality and availability of drinking water sources. However, there are a number of challenges that we need to respond to, so that we can ensure we protect our drinking water supplies for current and future generations.

The cluster of drinking water catchments across the Brecon Beacons supply almost half of the drinking water Dŵr Cymru Welsh Water provides to customers every day – that’s more than 400 million litres of water, equivalent to 160 Olympic-sized swimming pools. But it’s not just water that make the Beacons extraordinary. Communities, biodiversity, agriculture, forestry and tourism all play a part in making it such an iconic landscape that provides so much for so many.

As a water company, we need to treat water to remove a range of contaminants to ensure we serve our customers safe, wholesome drinking water.

For example, pesticides enter our water ways from a variety of sources including our gardens and allotments, parks and sports grounds and from farms. Our routine water monitoring programme has detected increasing traces of pesticides in areas we have never seen them before, and therefore more treatment is needed.

Sediment, which has to be filtered out, enters water courses from a number of sources including landslips and cultivation, and that sediment can carry pathogens, nutrients and agricultural chemicals, all of which need to be removed as they can impact the safety and enjoyment of our drinking water.

And these are just some of the water quality risks we deal with daily. As a result of climate change, we can expect to see more erratic floods and droughts, and we may even see different animal and plant diseases that we have not encountered before in the UK. This could mean more erosion of soils, new pathogens or veterinary medicines finding their way into drinking water catchments. We may start to see changes in food production trends – for example more home-grown fodder and horticulture expansion could mean detecting more pesticides being used in areas where we aren’t used to dealing with them.

While we already work hard to respond to these changes, we believe there is a huge benefit to be gained from trying to get ahead of the risks. That is why we are shifting our emphasis from reactive treatment of water to proactive measures to reduce or prevent water quality issues before they happen. We will, of course, treat water to make it safe and wholesome to drink, but we believe that by focusing on the management of water within the wider environment we can reduce the chemicals and energy needed in the treatment process – which is better for everyone.

Considering some of these issues in the context of drinking water may help clarify why it is important to adapt certain practices. However, we don’t want to implement more actions for overstretched farmers to juggle, because many of the actions needed to improve water quality are the same actions being discussed in relation to sustainable food production – improved soil husbandry, proactive animal health planning and caring for our precious habitats – including restoring them where needed.

The Brecon Beacons Mega Catchment (BBMC) is a Welsh Water-led initiative, and we’re now getting underway with an active programme of collaborative land management and engagement trials. We want to explore new ways of working – on the land and with each other.

We are a growing partnership of individuals and organisations representing farming, forestry, community, tourism, academia and ecology. This is a network we want to expand further to encompass other elements, but the most valuable partnerships we have are with the farmers and community members at a grass roots level who can bring their experience and ideas to bear, helping us develop and trial these new ways of working. Collaboration has recently become another fashionable term to use in land management discussions. But we believe the value of coordinating our expertise and resources with others, means that we can achieve far more together than we can achieve individually. We are not a major landowner in these drinking water catchments, so we must work in partnership with others if we are to have a positive impact.

For example, inspired by a knowledge exchange with our friends working in the Catskills catchment which supplies New York (widely recognised as one of the most successful catchment management examples globally) we are trialling a new approach to smarter nutrient applications with the Beacons Water Group – a farmer led group in the heart of the Beacons. Here, we will be using data on drainage patterns across individual fields and whole farms to identify ‘spread / no spread’ zones to reduce nutrient run off to water courses and make more efficient use of manures.

We’re also scoping out the restoration of damaged areas of peatbog to reduce water quality risks of sediment and colour compounds from eroding peat. In addition, this restoration should prevent further carbon emissions and regulate peak water flow. But again, we will need to work with a range of partners to deliver this. There are many peat restoration activities taking place across the country, but importantly, we will be working closely with local graziers to explore how best to share information on the importance and ambitions of peatbog management, and how to monitor the success of the project and make more locally based management decisions that are right for the conditions and the season.

We are also exploring opportunities for working with groups of farmers to develop more integrated livestock health planning, biosecurity and quarantine that will support livestock health as well as reducing pathogens and medicines lost to water.

We will be trialling these initiatives in the Brecon Beacons with a view to rolling these new ways of working out in the drinking water catchments throughout Wales. These results cannot be achieved over night and our ambition is to deliver long term sustainable solutions to safeguard our environment and drinking water for generations to come. We are keen to hear from any new partners who would be interested in working with us to deliver these ambitions.

For more information contact bbmc@dwrcymru.com.

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Here’s the catch

Anna Kilcooley — Fri, 19 Mar 2021 13:35:00 +0000

The journey of an agricultural pollutant from its source, along its flow path (often in surface water flooding across fields), to its end destination, where it has the potential to do damage to the natural environment, is an essential concern of Catchment Sensitive Farming officers (CSFOs) on every farm they advise. Understanding how pollutants manifest on a farm, and the journey they subsequently take into the surrounding environment, enables farm advisers including CSFOs to evaluate how to address water and air pollution from agriculture.

Successful reduction of this diffuse pollution from food production can best be achieved by the adoption of practices which stop nutrients or pesticides becoming a pollutant in the first place. This not only has benefits for the environment but also for the farmer who saves money by wasting fewer inputs. Inevitably though, some agricultural inputs (such as fertiliser and manure) escape down a field or out of a livestock shed. Here, measures to intercept the errant material along its flow path come into play.

To mitigate this, a buffer strip of grassland and trees protecting a river or a ditch from waterborne nitrates or a shelterbelt of trees trapping ammonia emanating from a poultry house are just two examples of how Catchment Sensitive Farming is helping farms to address such diffuse pollution. And in flood prone areas of farmland, these practices can also help slow the flow of surface water encountered during storm events, enough to reduce the worst of its impact further down river catchments.

It takes careful consideration of each field and cropping rotation, each hedge or drystone wall boundary, farm track and gateway for the full benefits of Catchment Sensitive Farming to be realised. Farm advice is key and input from a Catchment Sensitive Farming officer is required to implement measures which are potentially available as funded options through the mid-tier of the English Countryside Stewardship scheme. To make the most of what funding is available, only farms in the highest priority areas for measures addressing air and water pollution are currently eligible to apply for funding.

Water and agri-food companies such as those involved in WRAP’s ‘Courtauld Commitment 2025’, are increasingly interested in encouraging farmers to apply measures that address water pollution. It makes sense for Catchment Sensitive Farming and other government farm advice initiatives to work in close partnership with private sector interests and their delivery partners and NGOs, like the Sustainable Food Trust.

The Sustainable Food Trust came to our attention three years ago, when we worked with Adele Jones on the ground-breaking Harmonised Farm Sustainability Metrics project. We invited Adele to deliver a keynote speech at our first ‘Catchment Sensitive Farmers Partners Conference’ back in November 2019. The Sustainable Food Trust presentation went down so well with delegates, we invited Adele and her team to help deliver our ambitious two-day online CSF Partners’ Conference for 2020 on the theme of Measuring, Managing and Delivering Transformational Change on Farms. Despite all that was thrown at us pandemic-wise, the Conference was a success. Keynote presentations from Tony Juniper, Natural England’s Chair and Patrick Holden, Sustainable Food Trust’s Chief Executive at the event can be viewed below.

The e-Conference included much consideration and debate on the role of trees on farm, particularly with respect to helping to address water issues including water pollution, drought and flood mitigation. An excellent break out session led by John Tucker from the Woodland Trust on agro-forestry brought the role of trees in sustainable food production into sharp focus. As International Day of Forests (21^st March) and World Water Day (22^nd March) approach, it is worth reflecting on some of the messages from the session. Any mix of trees in a farm setting should be thought of as agro-forestry.
Clear objectives and careful consideration of the role trees are playing, are important for best results.
Trees can make important contributions to agricultural soil health such as scavenging of surplus nutrients and improving the hydrology of soils with their root systems.
Agro-forestry is about trees increasing the productivity of sustainable food production on farms.
Hedges are very much part of this mix, providing sources of pollen for crop production and shelter for livestock as well as intercepting and cleaning surface water.
The separation of the disciplines of forestry and agriculture have hindered effective integration of trees into farm systems. The need to train more farm advisers in agro-forestry techniques is an important action for CSF to help take forward.

The role of trees in addressing pollution and ensuring clean water and healthy soil cannot be underestimated. This highlights the way all components of a farm are interconnected and must be viewed holistically. When assessing pollution and sustainability, we therefore must assess the whole system. I look forward to a time when the sustainability of every farm is accounted for through a clear, unified system of annual assessment which is communicated across supply chains and across continents.

Photograph credit.

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Human manure: Closing the nutrient loop

Imogen Crossland — Fri, 15 May 2015 15:27:00 +0000

Using human urine and faeces as fertiliser may seem an unappetising concept but it’s been common practice for centuries. In the sewage systems of today, which deal with millions of tonnes of domestic waste and industrial effluent, this human fertiliser comes in the form of treated sewage sludge.

Promoting a waste product that some consider hazardous as a resource to grow your food may seem like a paradox, but in Britain, a world leader in recycling sewage into agriculture, it is recognised by the government and the EU as the best environmental option. It diverts waste away from oceans and landfill and provides essential plant nutrients to the soil. Nevertheless, EU organic regulations don’t permit the use of sewage sludge on organic farms. So, what are their concerns? Is this form of manure safe for agriculture? Are we putting our health and our soils at risk when we spread human waste on land?

“1% of wastewater is waste. The rest is wasted water.”

Human urine and faecal matter are a rich source of essential plant nutrients. Historically, human excreta, ‘nightsoils’, were collected from towns and villages and spread in raw or composted form on fields in the surrounding farmland. This informal treatment is still practiced in some areas of China, South East Asia, Africa and Latin America, where municipal sewage works don’t exist or are poorly functioning. In the 1850s, Europe’s growing urban populations and the discovery of the link between raw sewage and cholera led to the implementation of large-scale sewage systems. These water-based systems combined all domestic waste, industrial effluent and road surface run-off. For the next century the resulting sewage sludge was disposed of in landfill and directly into the oceans. Eventually, in the 1970s, growing awareness of the environmental impact of sewage on aquatic life led to widespread bans on ocean dumping across the developed world. Since then, research, technology and regulation of wastewater management have progressed to a high standard.

In Britain, sewage sludge goes through a tertiary anaerobic digestion process that kills off up to 99.99% of pathogens. The treated sewage sludge this produces is referred to as ‘biosolids’ and most commonly comes in the form of dried cake digestate.

Matt Taylor is an environmental scientist and consultant at ADAS, Britain’s largest independent provider of environmental solutions, services and consultancy on recycling materials to land. He says that “the most common outlet for biosolids is agricultural recycling. Around 1 million tonnes of dry solids (that’s equivalent to 3.5 million tonnes of fresh solids) were used as fertiliser [in Britain] in 2013.”

Biosolids can increase agricultural yields and improve soil condition. They provide nitrogen, phosphorous and potassium in a less soluble form than farmyard manure and artificial fertilisers, which means they remain in the soil for longer and are less prone to leaching into groundwater or run-off, which pollutes waterways. Biosolids also contain useful levels of sulphur and magnesium and trace levels of micronutrients. Unlike artificial fertilisers, biosolids contain 20%-80% organic matter, which is critical for the health of soils.

Could biosolids replace our reliance on artificial fertilisers?

Manufacturing fertilisers requires fossil fuels, so as the price of fuel increases this has a knock-on effect for the price of artificial fertilisers, food production and ultimately the price of food. Our reliance on mined phosphorous is a major concern. The extraction of phosphate rock is not only a very toxic and energy intensive process but it’s also a non-renewable resource that’s predicted to reach peak supply in 2033. After that the price of phosphorus will increase significantly, bringing the price of food up with it. According to the Soil Association’s peak phosphate report, without mined phosphate, crop yields in conventional farming could be reduced by half.

On a global scale we could be recovering much more phosphorus from human waste. It’s estimated that only 10% of the phosphate lost from human excreta is recycled back to the land due to inefficiencies in wastewater treatment or the absence of wastewater treatment altogether. Results from a 2009 study in Chemosphere suggest that, if properly collected, the phosphorus available from urine and faeces could account for 22% of the total global phosphorus demand.

Already in Britain we recycle 77% of our sewage onto agricultural land. Could biosolids eventually replace the need for artificial inputs?

According to Taylor, “biosolids can play a role but it’s not going to replace other forms of fertiliser. We could do more but we are using the vast majority of sewage sludge already.” However, with improved technology we could extract more nutrients. “We’re getting more phosphorous out of waters in the form of struvite. This is a mineral build up on pipes, which causes blockages in pipelines. Thameswater has started harvesting this struvite as it contains phosphorous.”

Wastewater treatment is improving all the time in Britain as regulations become more stringent and require treatment plants to remove more nitrogen and phosphorous from sewage. As a result the volume of biosolids produced is increasing every year, making more fertiliser available for agriculture.

But is it safe?

There are understandable concerns from farmers, consumers and food retailers about pathogens, heavy metals, pharmaceuticals and other hazardous organic chemicals in sewage sludge. The good news is that biosolids are the most researched and well regulated of organic materials applied to land in Britain and the framework for regulating sewage sludge is more stringent than that of farmyard manures. Numerous pieces of legislation and best practice guidelines, like the Safe Sludge Matrix, must be adhered to by everyone involved in the treatment and use of sewage sludge.

Heavy metals are the main concern. These are strictly monitored, however, and regular testing shows that the levels of heavy metals in soils fertilised with biosolids are significantly below the maximum permissible levels. In fact the levels are so low now that the Soil Association has recommended the European Commission lifts the ban on using biosolids in organic farming. The Soil Association still recognises that the existence of other potential contaminants from organic compounds, such as GMOs and pharmaceuticals, need to be considered.

But there’s still a big question mark hanging over the impact of industrial chemicals and personal care products in domestic waste as well as the huge amounts of medicines that pass through the human system. Whilst the vast majority of these are biologically degraded in the treatment process, trace levels of some persist.

WaterUK, a member organisation of the water utilities, states “there are no reported cases of human, animal or crop contamination due to the use of sludge on agricultural soils.” Yet studies have found the artificial hormones used in birth control pills affect the endocrine systems of fish exposed to sewage effluent water, which affects fish fertility. There’s concern about how this would affect livestock that graze on grassland treated with sludge. Despite the lack of scientific evidence to prove long-lasting damage, there is also not enough evidence to prove it’s 100% safe either.

Sanitation fit for the future

The risk of chemical contaminants and pharmaceuticals could be reduced by preventing human waste from mixing with all other domestic and industrial waste in the first place. Ecological sanitation systems are starting to come into use all over the world that separate human excreta from other waste streams. Ecological sanitation (ES) includes urine diverting toilets, high-tech vacuum systems and composting toilets. These inexpensive systems can be used in various contexts from small villages to large municipalities. ES separates greywater, human faeces and urine and stores them in underground tanks.

A great advantage of ES is this separation. The majority of nutrients in human excreta are in urine – if uncontaminated by faeces it’s relatively sterile and can easily be used on crops with little treatment. This low-cost solution makes most sense in rural areas where houses are not connected to centralised sewage systems or in close proximity to agricultural land.

It’s harder to justify the cost of retrofitting ES into existing centralised sewage systems that already supply safe drinking water and recycle waste to a sufficient level. WaterUK estimates the total value of nutrients in biosolids recycled to agricultural land in Britain at £40-£50 million per annum. The value of preserving life in our oceans, the health of our soils and the quality of our water is priceless, and as water and energy become more scarce and costly, and phosphorous reserves run out, ES could become a much more attractive and cost-effective prospect.

According to the UN 90% of wastewater in the developing world is expelled, untreated, into the oceans. Whilst rich countries have had the finances and governance to manage sewage effectively, there’s still a long way to go in making this universal. How will we, as a global community achieve it? Perhaps that will give you something to ponder when you’re next on the toilet.

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