Tag Archive for: Fertilizer

Managing Phosphorus for Clean Water

By Nina Prater, NCAT Agriculture Specialist

Almost every day, I am lucky enough to be able to take a quick walk to the creek that runs at the western edge of our property. I watch it change with the seasons. It becomes a tumultuous riot in the spring, sometimes it dries out completely in a droughty summer, in the fall the river birches drop their yellow leaves that float like tiny boats down the calm current, and in the winter ice forms on the banks and on the branches that dip into the water. This stretch of creek that feels like an old friend to me is affected by everything that happens upstream – how people manage their farms, yards, forests, and even their septic systems, as well as development – and it all can impact the clarity of the water, the health of the insects, birds, fish, amphibians and even people who spend time at the water.

This was on my mind when I was researching for an ATTRA podcast I recently recorded with my NCAT colleagues, Guy Ames and Lee Rinehart. We tackled the topic of phosphorus, an element essential for life and productive farming, but one that can have devastating negative impacts on lakes and streams if it washes off the land and into the water.

Over-application of phosphorus either in the form of a synthetic fertilizer or as manure is one of the main reasons for the huge dead zone in the Gulf of Mexico and for miles of beaches being closed every summer because of toxic algae blooms in lakes, rivers, and coastlines around the country.

I personally refuse to accept that this is “the price you pay” for food security. There are so many better ways to manage the essential macronutrient of phosphorus, and to manage waste from livestock operations so it is a resource, not a waste product, while still growing the food our communities need. We can have our clean waters and eat our cake too. (Is that how that expression goes? Something like that.)

Here are some ways to make sure you are being a good steward of your land and all the waterways downstream from you:

Regular soil testing: If your phosphorus levels are already high, don’t apply more!

Manage pH: If your soil pH is above or below the ideal range of 6-7, phosphorus becomes much less plant-available. Try to adjust your soil’s pH first before adding phosphorus.

Encourage mycorrhizal fungi: Mycorrhizal fungi partners with plant roots to help the plants access more phosphorus, in exchange for photosynthates. Try to reduce tillage to avoid damaging mycorrhizal fungi and have a diversity of plant species.

Choose the right cover crops: Some cover crops are good at scavenging and holding phosphorus in organic forms.

Follow the four R’s of fertilization: Right rate, right source, right placement, and right timing.

Keep your soil protected: Prevent phosphorus from leaving your fields in the form of soil erosion.

There are many other strategies for phosphorus management. Find our recent podcast here where we talked about the history of phosphorus fertilizer, the importance of getting it right, more tips and tricks for proper management, and much more. We all deserve to live and work on farms and ranches where you can take a dip in a cool creek after a long day’s work and not worry about fish kills and toxic algae. Proper soil and phosphorus management is essential in order to keep our waterways thriving. I’m sure everyone has their favorite spot like my creek – a swimming hole, a lake, a pond, a stream, a favorite beach vacation spot – some place you have special affection for, some place that can motivate you to find the best way to grow food or fiber, without causing harm. To find out more ways to do this, listen to our podcast, or reach out to me, Guy, Lee, or one of our many other ATTRA specialists. We are more than happy to hear about your favorite fishing hole and help you find ways to be a productive farmer with a good fertility management plan.

Related ATTRA Resources:

Episode 304. Phosphorus and the Beauty of Biology

Toolkit: How to Reduce Synthetic Fertilizer Use

Rising Fertilizer Costs: Look to History for Answers 

Nutrient Management Plan (590) for Organic Systems 

Nutrient Management in Organic Small Grains 

This blog is produced by the National Center for Appropriate Technology through the ATTRA Sustainable Agriculture program, under a cooperative agreement with USDA Rural Development. ATTRA.NCAT.ORG.

Weaning Pasture Soils Off Chemical Dependence

By Lee Rinehart, NCAT Agriculture Specialist

I recently received an email from a farmer in New England. They have put a lot of effort into their beef farm to bring their soil to life after decades of conventional corn and hay production with substantial chemical inputs. They have been working to improve the health of their pasture soils by overseeding with clover and rotationally grazing and have begun a regime of applying organic amendments to help stimulate microbial activity. In their words, they are “weaning their soils off chemical dependance,” even if at times they feel like they are “shooting in the dark.”

I feel that way a lot. Shooting in the dark. Many of my consultations with farmers and graziers over the years have taken on this quality. But really, what is happening is we are having a conversation about a complex living ecosystem that we barely understand. What I have learned is that good grazing comes from experience. And experience is informed by observation and science.

For this most recent conversation, we started off with the idea of kick starting the soil biological community. The single most beneficial way to do this is to increase soil organic matter. After all, it is what soil bacteria eat. This is the best way to build aggregate stability and lower soil bulk density. It turns the soil from a brick to a sponge. A good way to do this inexpensively is bale grazing with livestock in high density for a short period of time, somewhere above 100,000 pounds of live weight per acre (this is highly variable). Bale grazing is an excellent way to build soil over time and is especially useful on pastures in the dormant season or for renovating poor performing fields during the grazing season. An intentional, planned disturbance of short duration with a long rest period for full plant recovery disturbs the soil surface with hoof action, pushes plant residue close to the soil surface for rapid decomposition, and distributes manure and microorganisms from the animals’ saliva and haircoat. Think of it as biological priming for soils.

Sometimes a grazier will ask about planting improved species. After all, when they look across their fields they see a scattering of annual forbs, perhaps the resilient stalks of perennial weeds, and short, closely cropped perennial grasses holding on for dear life. It makes sense, though, to think about planting better grasses. The logic is sound. But I have learned that this seldom works and can be extremely expensive. For success, it just about means farming the field… some kind of tillage, weed control, fertilizer, and water. And it takes time. A grazier can drain their savings account in one season farming this way. Farming is risky enough without adding to our debt load.

Then I learned how many seeds are just sitting in the soil, waiting for the opportune time to emerge. Sure, there are lots of weed seeds. These are often the first to emerge and they do this for a reason. The annuals come up and provide soil cover, a band aid, the first step in healing damaged soil. But this is the time to use animal impact and see if we can release the native seedbank and get the good stuff to emerge.

For the beneficial grass and forb seeds to germinate and grow, we need disturbance. But I don’t mean tillage, I mean the kind of disturbance I described above. Getting organic matter into the soil will help to increase water infiltration, it will make mycorrhizal fungi and bacterial populations explode in numbers. It will create aeration, little passages in the soil for air and water to pass through.

I was talking to Allen Williams a few weeks ago, and he mentioned something that made me think. These little channels, caused by soil aggregation, earthworms, and dung beetles, provide a passage for deeply buried seeds to travel up closer to the soil surface where they can germinate. Think about it… when water infiltrates, the seeds that are buried deep in the soil profile have a route to float up and get within the germination zone. Perhaps this explains what I have seen after a few years of grazing with thoughtful disturbances – fields that become highly diverse and productive with plants I didn’t even know were present in the seedbank.

So that’s one way to establish a better forage stand. Another approach that graziers have been using for years is frost seeding. Remember, frost seeding is when we broadcast a small seeded species in the late winter when the soil is undergoing a sequence of freezing at night and thawing in the day. This action serves to pulse the soil surface ever so slightly to help cover small seeds with soil over the course of a few days or weeks, allowing them to germinate when the temperature gets to around 60°F. Red clover works well for this, as does white clover and many other small seeded legumes. Grass seeds are larger and, because of this, frost seeding is seldom recommended for establishing grass stands, though I know people who have tried it. If you are making your frost seed decision late, you can perhaps mimic the freeze-thaw action by turning livestock into the pasture after broadcasting seed and let them trample it in.

Some other things came to mind as I was talking to this grazier, logistical things to help ensure their animals could provide the impact they needed them to perform when they needed it. One was to ensure their watering systems are portable to give more control of paddock use. It is much easier to time the grazing and rest periods of paddocks when water access is not an issue. Another is to use polybraid and step-in posts to strategically enclose paddocks and try to match herd weight (the herd dry matter intake requirement) with the forage available. As a rule, I have adapted the old adage “take half leave half” to “take half trample half.” The ATTRA publication Paddock Design, Fencing, Water Systems, and Livestock Movement Strategies for Multi-Paddock Grazing goes into detail on water and fencing, so I’ll direct you there if you’d like more on these and other logistical concerns.

Finally, make grazing decisions based on observation of impact on previous fields and the needs of the current field based on goals (animal productivity, weed pressure, renovation, need for incorporating organic matter, going on vacation, etc.). And try not to re-graze a field until the plants have fully recovered. This is the cardinal rule in grazing. And never do the same thing on a paddock season after season and year after year. Nature is fickle and changes things up regularly. Mimicking nature in this way opens the opportunity for various things to happen, from new forages appearing in the fields to providing wildlife habitat for ground-nesting birds. Change it up, observe what happens, and try to capitalize on nature’s methods.

Getting off chemical dependance, and in this case synthetic fertilizer, is achievable in pasture systems. Instead of ammonium nitrate, we rely on nitrogen from mineralization and legumes. Soil aggregation is key. After the soil has begun to wake up and nutrient cycling is running at optimum, you can start the weaning process. I like to recommend Christine Jones’s regime for doing this: 20% reduction in the first year, followed by two years of additional 30% reduction, culminating with two years of minimal applications of about 4.5 pounds per acre to jump-start the grazing season. Many have gone cold turkey and it has worked. But those graziers have been doing regenerative soil management for decades. My advice is to add organic matter, build aggregation, and go off fertilizer slowly.

Related NCAT Resources:

Toolkit: How to Reduce Synthetic Fertilizer Use

Adaptive Grazing – You Can Do It

Managed Grazing Tutorial

No-Till Farmer

Other Resources:

The Soil for Water Forum

Healing Battered Fields, Pastures with Adaptive Grazing

New Toolkit: How to Reduce Synthetic Fertilizer Use

For more than 35 years, the National Center for Appropriate Technology’s ATTRA Sustainable Agriculture program has been helping farmers and ranchers grow nutritious food and operate successful businesses without synthetic fertilizer. Now, NCAT has released a new toolkit with trusted and practical resources for farmers who want to transition away from the use of synthetic fertilizers.

“As the cost of synthetic fertilizers and global food prices continue to climb, NCAT is releasing a roadmap for farmers who are looking for a more self-reliant and resilient method of farming,” said NCAT Southeast Regional Director and Arkansas farmer Margo Hale. “A growing number of farmers are opting out of the high-input model of conventional agriculture, which we see now is so vulnerable to global events like war and supply chain disruption.”

As the world’s farmers watch the cost of synthetic fertilizer continue to increase, and global food prices shatter records kept by the U.N. Food and Agriculture Organization, the global food system is being stressed like never before. There is a more stable, resilient model being used in every corner of the United States. These farmers rely on biological sources of nitrogen, breaking free of an often-volatile global marketplace.

Farming without synthetic fertilizers is within reach for large-scale food producers, and it’s a requirement for certified organic farmers. Montana grain-grower Bob Quinn transitioned his family’s conventional farm to an organic one back in 1989. Quinn brought Khorasan wheat to the mainstream marketplace with his brand KAMUT. In Maryland, Ron Holter manages his 150-cow seasonal dairy on grass alone, with no supplementary grain. Holter’s dairy has been free of synthetic fertilizer since 1995. Dave Brandt began cover cropping his Ohio corn and soybeans in 1978. Cover crops have maintained his cash-crop yields while reducing nitrogen fertilizer use by nearly 90 percent. Brandt credits cover crops with increasing soil microbial activity naturally, which provides nutrients to the food he grows and increases the soil’s water-holding capacity.

Data show consumer demand for certified organic and other regeneratively produced foods continues to increase. The sale of organic products in the U.S. has grown more than 30 percent since 2016, and the number of organic producers is up almost 40 percent. Farmers who use regenerative methods, but might not be certified organic, are no doubt on the rise, too.

Shifting to a production method that is not reliant on synthetic fertilizers can be accomplished strategically over a three- to five-year transitional period. NCAT’s new toolkit guides farmers as they learn to use cover crops, managed grazing, and alternative soil amendments to naturally boost renewable nitrogen levels needed to maintain long-term productivity. These are accessible tools that can result in reduced input costs, increased self-reliance, and more nutritious food grown at small and large scales.

Access the free toolkit and decades of trusted, practical resources here: https://attra.ncat.org/how-to-reduce-synthetic-fertilizer-use/ .

EXPERT VOICES

NINA PRATER
Expertise Areas: Livestock, Soil Health, Organic Crops

Nina Prater has been with the National Center for Appropriate Technology (NCAT) since 2016 as a Soil Specialist and Outreach Coordinator in the Southeast Regional Office. She strives to help farmers understand soils as a living entity so that they are able to farm profitably and build healthy soils for long-term success. Nina also works closely with the Gulf States Regional Office staff to coordinate outreach efforts in that region. Nina served as an Energy Corps member in 2013 and worked for her local conservation district for 2.5 years before joining NCAT. Nina and her husband Jeremy own and operate a small sustainable livestock operation in the Ozarks hills of Arkansas, where they raise meat goats, cattle, hogs, and poultry. They utilize adaptive grazing methods to build soil health in their pastures.

LEE RINEHART
Expertise Areas: Livestock, Organic Livestock, Soil Health, Grazing, Pasture Ecology

Lee Rinehart is a graduate of Texas A&M University, where he studied animal science and agricultural education. He currently works as an agriculture specialist in the National Center for Appropriate Technology’s Northeast Regional Office, where he focuses on pasture and rangeland ecology and grazing systems. He has served as county Extension agent in Texas and Montana, organic farm educator in Pennsylvania, and cattle ranch manager in central Texas. His specialty is developing grazing plans and assisting producers in using animals to renovate pastureland. Lee is a Chief Petty Officer in the Navy Reserve and spends his free time biking, sailing, and renovating his 1925 Cape Cod house in Northeast Pennsylvania.