Tag Archives: fertilizer

How to Select the Perfect Fertilizer for Your Varied Plants

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Farmers providing granulated fertilizer to young tomato plants while wearing gloves and using excavators in an organic garden.

“For most plants, a balanced, all-purpose fertilizer would be fine.”

ShutterStock/Encierro

A visit to the garden center reveals a multitude of fertilizers lining the shelves. These vibrant bottles promise optimal results for a range of plants, from lawns and roses to ferns and Japanese maples. But do home gardeners truly require them? Let’s explore the science behind it.

Plants require approximately 16 essential mineral nutrients, most of which are needed in minor quantities. At the heart of plant nutrition—fertilizer—lies three primary macronutrients: nitrogen (N), phosphorus (P), and potassium (K). The main distinction between various fertilizers is the proportion of these nutrients, denoted on the label after the letters “NPK”.

For lush grass, opt for fertilizers with high nitrogen content. However, for flowering and fruiting plants like tomatoes and roses, a greater amount of potassium is necessary. Fortunately, gardeners don’t need to pore over every label; most fertilizers are conveniently labeled to indicate their best uses.

Things become more complicated, however. I recently compared three “expert” plant foods from well-known brands designed for roses, strawberries, and tomatoes. All had the identical NPK ratio of 4-2-6, making their only real difference the packaging. Ultimately, plants synthesize nutrients from the soil as needed. In most cases, a balanced, general-purpose fertilizer is sufficient. Curiously, some specialized feeds are merely repackaged versions of generic fertilizers.

Stocking a wide array of specific fertilizers is not only costly and unnecessary but can also be detrimental. Fertilizers should only be used to replenish deficient minerals in the soil. For instance, excessive nitrogen can result in soft and pest-prone growth or lead to poor-quality crops. In contrast, excess phosphorus is often washed away, contributing to water pollution and causing environmental damage, particularly in fertile regions like the UK, where garden soils are richer compared to agricultural lands. Intensive management practices often exacerbate this issue.

So, what’s the takeaway? Invest in affordable, user-friendly home soil tests instead of unnecessary fertilizers. Of course, there are some exceptions. Acid-loving plants like rhododendrons may need an iron boost, and other nutrients that are harder to absorb from neutral soils. Similarly, container plants (particularly those grown in nutrient-poor media like peat) typically require fertilizer supplements during their growing season. Nonetheless, for most home gardeners—including houseplant enthusiasts—a single balanced fertilizer is enough, giving you more time (and money) to enjoy nurturing your plants.

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Source: www.newscientist.com

Maryland’s Sewage Sludge Fertilizer: Virginians Express Discontent.

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In 2023, Maryland sewage treatment facilities began uncovering alarming issues. Hazardous “forever chemicals” were detected in the state’s wastewater, with many being converted into fertilizers and distributed across agricultural land.

To safeguard its food and drinking water, Maryland has started to limit the application of fertilizers derived from sewage sludge. Meanwhile, Synagro, a prominent manufacturer of sludge fertilizers, is seeking approval to expand their usage across state lines in Virginia.

Environmentalists, fishing associations, and some farmers are opposing this movement, arguing that the pollution poses a significant risk to farmland and delicate waterways that nourish the Potomac River.

“These sewage sludge fertilizers are coming to Virginia because they’re deemed unsafe for Maryland farms,” stated Dean Naujox from the Potomac Riverkeeper Network, who advocates for clean water. “This is unacceptable.”

Virginia is finding itself entangled in a rising national trend as it scrambles to address the spiraling farmland pollution crisis.

In Virginia, Synagro, a key player in providing sludge for fertilizer, is requesting permission to increase its sludge applications in rural areas, based on local accounts. Synagro operates under the Goldman Sachs Investment Fund.

In a statement, Kip Cleverley, Synagro’s Chief Sustainability Officer, noted that the presence of trace levels of PFAS does not necessarily indicate contamination. He emphasized that the company’s expansion into Virginia is independent of Maryland’s guidelines.

According to industry reports, over 2 million tons of dry sewage sludge were utilized on 4.6 million acres of farmland in 2018. Farmers estimate they have secured permission to apply sewage sludge on nearly 70 million acres, or about one-fifth of U.S. agricultural land.

However, increasing research indicates that this black sludge, also known as biosolids, may contain perfluoroalkyl substances or substantial levels of harmful PFAs, resulting from wastewater from homes and industries. These chemicals are believed to heighten the risk for certain cancers and lead to birth defects and developmental delays in children.

For residents in areas like Virginia Gardens, the historical birthplace of George Washington, the threat feels doubly unjust. Much of the biosolids delivered across state lines originate from major urban areas like Baltimore.

The pollution that locals fear flows off farmlands into nearby rivers and streams, endangering farmers and watermen who rely on these resources.

“Water runs off the farms into the waterways,” explained Leedale, a seventh-generation waterman and owner of the Northern Neck Oyster Company, as he navigated his oyster boat through the winding tributaries of the Potomac. “And we’re experiencing substantial rainfall this season.”

His concerns are substantiated. New research published in Nature indicates that PFAS in sludge used as fertilizer can contaminate both farmland and adjacent rivers and streams.

“That stream could be part of your drinking water supply, and downstream, contaminants could accumulate in fish,” remarked Diana Oviedo Vargas, a researcher at the nonpartisan Stroud Water Research Center, who led the federally funded study. “There’s a lot we are yet to understand, but these pollutants are unquestionably reaching our surface waters.”

This presents a complex issue. While sludge fertilizers are nutrient-rich and significantly reduce the need for incineration or landfill disposal, they also counterbalance the use of synthetic fertilizers derived from fossil fuels.

Nevertheless, studies have shown that sludge can harbor pathogens and chemicals like PFAs. Synthetic PFAS compounds are commonly found in everyday items such as non-stick cookware and stain-resistant carpets, and are associated with various diseases.

The EPA regulates several pathogens and heavy metals in sludge used as fertilizers but has not established regulations for PFAs. This year, the EPA issued its first warning regarding health risks linked to PFAs in sludge fertilizers. The Biden administration also introduced the first federal drinking water standard for PFAS, asserting that virtually no safe level of these substances exists.

The absence of federal regulations regarding PFAs in sludge has shifted responsibility to states, leading to a jumble of regulations and the transfer of contaminated sludge into areas with less stringent oversight.

Maine banned the use of sludge fertilizers in 2022, resulting in some sludge being shipped out of state as local landfills could not accommodate it.

Maryland has temporarily halted new permits for sludge use as fertilizer. The Maryland Department of the Environment has also mandated PFAS testing at all sewage treatment facilities statewide. Despite treatment processes, contaminants have been detected in both wastewater and sludge, and while protocols are in place, guidelines are being established to report and dispose of high-PFAS sludge amounts.

In Virginia, groups against the importation of Maryland’s sewage are advocating for state-level PFAS regulation in sludge.

Meanwhile, data from Virginia shows that sludge from Maryland is already being transferred. An analysis by the Potomac Riverkeeper Network indicates that biosolids from 22 Maryland wastewater treatment plants have been approved for use as fertilizer in Virginia, all reporting PFAS contamination.

In Westmoreland County, Synagro is dealing with sludge from 16 plants in Maryland, all indicating PFAS contamination.

In December, Synagro applied for a permit expansion to use sludge on an additional 2,000 acres of farmland in Westmoreland. Following local feedback prompting a hearing, Synagro withdrew the application but is expected to reapply.

In Essex County, Synagro seeks to increase sludge applications over another 6,000 acres, raising this area by a third, according to their permit application.

Cleverley from Synagro assured that the biosolids applied in Virginia comply with Maryland’s PFAS standards.

Irina Karos, a spokesperson for the Virginia Department of Environmental Quality, mentioned that Virginia hasn’t seen a significant increase in the amount of Maryland biosolids applied. The state is still evaluating the request for Synagro’s expansion.

Karos also stated that Virginia is unaware of any biosolids from Maryland exceeding the recommended PFAS levels. Environmental organizations counter that verifying this is challenging.

Maryland spokesman Jay Apperson emphasized that the state’s guidelines and testing protocols aim to assist utilities and farmers while prioritizing public health.

Rob Hinton, a fourth-generation farmer at Cedar Plains Farm in Heathsville, Virginia, has cultivated corn, soybeans, and other crops for 45 years. He worries that farmers in the Northern Neck are not receiving fair treatment.

“It’s tempting when people offer something for free or nearly free. I don’t blame farmers for considering it,” he remarked. “But it’s these large cities that are sending their waste to us.”

“I learned about PFAS only after discussing it with friends in the waterman community,” he shared. “I’m unsure whether Virginia has conducted adequate testing.”

Synagro actively engages with farmers and local residents. During a presentation in March, Synagro representatives, alongside Virginia Tech researchers, shared data suggesting that the PFAS levels from sludge fertilizers were significantly lower than the levels indicated in previous studies, similar to slides reviewed by The New York Times.

Synagro stated it cannot provide comprehensive research verifications since the company isn’t directly involved. The Virginia Tech researchers mentioned did not respond to requests for comments.

At a Virginia Water Management Board meeting in March, Bryant Thomas, the state’s Environmental Quality director, reported receiving 27 public comments on Synagro’s proposal to expand sludge use in Essex County. Of these, 26 expressed concerns regarding the impact of sludge on public health and wildlife, particularly shellfish.

The board subsequently requested further investigation and a report from the agency.

“I find it interesting that while Maryland is revising its regulations, they are still sending biosolids to us in Virginia,” remarked Waterboard Chair Lou Anne Jesse Wallas in an interview. “We in Virginia must remain vigilant to protect our water and our citizens.”

Experts believe Maryland’s approach is a constructive first step. However, a bill introduced to further restrict PFAs in biosolids failed at the last moment. “We are concerned about the regulatory patchwork between states,” expressed Jean Zhuang, senior attorney at the Southern Environmental Law Center, an environmental nonprofit. “The federal government needs to step up.”

President Biden was poised to propose regulations limiting the discharges of PFAS by industrial facilities into wastewater. The Trump administration had previously rolled back this proposal but has recently indicated it may establish its own wastewater restrictions.

In the southern regions, the center is actively urging wastewater treatment facilities to demand local factories and industries clean up their wastewater before it reaches treatment plants. This would compel industries to manage contaminants at their sources or potentially eliminate the use of PFAs altogether, according to Zhuang.

“If a wastewater treatment plant takes action, then the industry will bear the costs of its pollution,” she noted.

On a recent evening, waterman Michael Lightfoot checked on a wire mesh cage of oysters raised in Jackson. He resides with his wife, Phyllis, in the creek. After nearly three decades in federal service, he retired in 2012 and has dedicated himself to waterman activities ever since.

Lightfoot is part of the ongoing oyster cultivation surge in Virginia, recognized as the top oyster producer on the East Coast and one of the largest in the nation. However, his proximity to the polluted farmland raises considerable concern for him. “There aren’t any farms in our waterways that aren’t discharging runoff,” he stated.

Source: www.nytimes.com

Sludge Fertilizer Corporation Abandons Texas Town in Wake of “Forever Chemicals” Crisis

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The city of Fort Worth, Texas, has ended its contract with Cinagro, a Goldman Sachs-backed provider of fertilizers made from sewage sludge over concerns that the “eternal chemicals” of fertilizer are polluting local farmland and groundwater.

This month, Fort Worth also sued several manufacturers of chemicals, also known as palfluoroalkyl substances or PFAs, alleging they contaminated the city’s water supply.

The New York Times reported last year about a group of ranchers in Johnson County, just south of Fort Worth.

The sewage sludge fertilizer comes from Chinagro. Cinagro had a contract to take the sewage from the Fort Worth sewage treatment plant, further treat it and distribute it to farmers as fertilizer. Johnson County then launched a criminal investigation into Cinagro.

An ever-growing number of research has shown that sewage sludge, which is often used as fertilizer, can be contaminated with PFA. PFA is a synthetic chemical widely used in everyday items such as non-stick cooking utensils and dirt-resistant carpets.

Chemicals Links to various diseases Do not break in the environment, including increased risk of cancer. Contaminated sludge can contaminate soil, groundwater, crops and livestock when used as fertilizer in farmland.

In January, the Environmental Protection Agency warned for the first time that PFA, which is present in sewage fertilizers, also known as biosolids, could pose a human health risk. Maine, the only state to systematically begin testing PFA farmlands, has detected chemicals on dozens of dairy farms. However, it has rarely been tested on farms in other states.

Fort Worth City Council I voted unanimously To cancel the 10-year contract signed with Synagro in 2019, the contract ended April 1, with city water utility staff working on a new contract for the biosolid business, according to council records.

The city did not cite any reason to terminate the contract. However, in a recent lawsuit filed by Fort Worth against the manufacturer of PFAS chemicals, the city cited the presence of PFA in the city’s drinking water sources and wastewater infrastructure.

Synagro said in a statement that the company and the city of Fort Worth “have mutually agreed to resolve all claims following ongoing differences in opinion regarding contract requirements.” He said the termination has nothing to do with PFA. The city’s water department did not immediately respond to a request for comment.

Synagro, owned by Goldman Sachs Asset Management, challenges claims that its biosolids contaminated Texas farmland. This month, the company filed an motion to dismiss the claims of a Johnson County rancher. It cited an independent study that concluded that sludge fertilizer was not the source of the high PFA levels found in rancher livestock.

Synagro also said it tested much lower levels of PFA in the soil than ranchers argue. The company has not published the investigation.

The attorney representing the ranch could not be contacted for comment. The rancher stops sending their cows to the market while continuing to care for them, saying they are facing economic ruin.

Dana Ames, the environmental investigator who leads the investigation into Chinagro in Johnson County, said the “intensive investigation” discovered high levels of PFA on the rancher’s property. “We eliminated all other sources of contamination, and we also tested the biosolids and discovered contamination,” she said.

At a council meeting, Luan Langley, a resident of Grandview, Texas, blamed the standing city while Cinagro “dumped biosolids on unsuspecting landowners and farmers.” She said cancelling the contract is not enough. “How does that help families whose lives have been destroyed?” she said.

Source: www.nytimes.com

Turning wastewater into fuel and fertilizer

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Farmers rely on ammonia to fertilize their crops.

Patty Calfee/Getty Images

The environmentally friendly technology uses multi-chamber chemical reactors to turn wastewater into ammonia and harmless by-products. This sustainable alternative requires much less energy than traditional methods to produce this important chemical.

Hundreds of millions of tons of ammonia are used every year in industries such as agriculture, refrigeration systems, paper and cleaning products. Producing this amount of chemical uses about 2% of total energy consumption and accounts for 1.4% of global carbon dioxide emissions.

Part of this environmental cost comes from traditional ammonia production methods, which require high temperatures and pressures. To make ammonia production more sustainable, Fengyan Chen Researchers at Rice University in Texas hoped to translate that technology into a room-temperature reactor.

Their reactor takes in water laced with nitrates, a nitrogen compound commonly found in wastewater, such as industrial or agricultural runoff contaminated with nitrogen fertilizers. When the nitrate water enters the first of three chambers, electrodes, like those found in a battery, create an electrochemical reaction that turns the liquid into its three components. Only ammonia remains in the reactor’s first chamber, purified water flows out of the second chamber, and oxygen flows into the third.

Because ammonia contains only nitrogen and hydrogen, the electrochemical reaction requires no other components than wastewater, and the purified water produced is clean enough to meet World Health Organization (WHO) regulations for drinking water.

Similar reactors have been tested before, Chen says, but the electrodes couldn’t shuffle charges at a high enough voltage for the reaction to work unless the wastewater was mixed with large amounts of salt. Chen and his colleagues made the device more practical by filling the central chamber with a porous material that acts as the salt, allowing wastewater to be fed directly into the reactor without any additives.

In tests using water samples with realistic nitrate concentrations, the reactor processed 100 milliliters in about one hour and continued to operate without problems for 10 days straight. The performance of this reactor is comparable to previous, more complex reactor designs.

Chen says the team only tested the reactor in the lab using nitrate-rich water, not actual wastewater samples that contain more than just nitrates, but the researchers envision local businesses and farms eventually using the reactors to recycle their wastewater, rather than sending it to faraway treatment facilities where it would waste its ammonia-producing potential.

In the best case scenario, the farm would have its own solar- or wind-powered reactor. Farmers would run local wastewater through the device, which would immediately Reusing ammonia It is mined for fuel and fertilizer.

“It’s still at the academic research level, but this is my ultimate dream,” Chen says.

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  • Chemical /
  • Sustainability

Source: www.newscientist.com

Using a combination of crushed rock and fertilizer can decrease nitrous oxide emissions on farms

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Spreading rock dust on fields can sequester carbon and reduce nitrous oxide emissions.

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Spreading crushed basalt on farmland and using special fertilisers to prevent nitrogen loss could cut global agricultural emissions of gases that are a powerful driver of global warming by 25%.

Nitrous oxide is a greenhouse gas with a warming potential 270 times greater than carbon dioxide. It has increased by 40% in the past 40 yearsAgriculture is a major factor, due to increased use of nitrogen-based fertilisers and rising livestock numbers.

Microorganisms in the soil convert ammonium in manure and animal waste into nitrates, releasing nitrous oxide in the process. Compounds that interfere with this process are called nitrification inhibitors, and can be added to fertilizer to reduce nitrous oxide emissions. Applying basalt dust to the soil, a technique called enhanced rock weathering (ERW), can also help by making the soil more alkaline.

However, nitrous oxide emissions are not only a global warming pollutant, they also have a complex relationship with the ozone layer, and in some circumstances even help it recover, so figuring out the best way to mitigate nitrous oxide emissions without damaging the ozone layer is difficult.

To address this, Maria Val Martin Researchers from the University of Sheffield in the UK modelled the impacts of widespread use of both ERW and nitrification inhibitors on nitrous oxide emissions and the ozone layer under two different climate scenarios.

The researchers found that a “moderate” approach, in which ERWs were introduced in key regions around the world and most farmers except the poorest used nitrification inhibitors, could reduce nitrous oxide emissions from agriculture by 25 percent, while nitrous oxide emissions overall would be reduced by 5 percent. These gases also come from combustion engines and industry.

What's more, up to two gigatons of additional carbon could be sequestered in the soil thanks to ERW, and neither scenario would harm the ozone layer, Val Martin says.

“we [carbon] “Enhanced rock weathering would sequestrate carbon dioxide, reduce nitrous oxide emissions, which is 300 times more potent than carbon dioxide, resulting in climate benefits, and protection of the ozone layer,” she says.

Deploying nitrous oxide abatement efforts on this scale would cost billions of dollars. Sequestering carbon using ERW costs between $80 and $180 per tonne of CO2. According to previous researchAccording to Val Martin, reducing nitrous oxide emissions is a “free” side benefit of carbon sequestration. Applying nitrification inhibitors costs about $28-45 per hectare, which would cost $17-27 billion per year to cover the 600 million hectares modelled in the study – roughly one-eighth of all agricultural land.

Still, Val Martin says the scenario is deliberately cautiously ambitious, and one that could play out in the real world. “What we wanted to do in this study is to come up with a realistic scenario, so if governments want to curb nitrous oxide emissions, [these] It’s a strategy we’re implementing.”

Parbhu Suntaralingam Researchers from the University of East Anglia in the UK say new strategies to curb nitrous oxide emissions are urgently needed, and that this research is particularly valuable because it focuses on curbing emissions without damaging the ozone layer.

topic:

  • Agriculture/
  • Greenhouse gas emissions

Source: www.newscientist.com