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Anthropocene Emma reports. This is a controversial finding—but it doesn’t mean no-till is a lost cause, the authors are keen to emphasize: it’s still crucial for combating soil erosion and run-off; it retains more water which in turns saves resources; and it nurtures soil microorganisms that support plant growth. But, they say, we should perhaps not be hanging all our hopes on this method to absolve agriculture’s expanding carbon footprint. Their conclusions were drawn from a review of 144 studies from the past 50 years, each of which compared no-till with tilled fields. The studies included a total of 1061 comparisons, forming a rich dataset on how much carbon was stored across these differently-managed soils.
Guy Swanson Reports as your Blue Leader.
Emma Says, But, they say, we should perhaps not be hanging all our hopes on this method to absolve agriculture’s expanding carbon footprint. Their conclusions were drawn from a review of 144 studies from the past 50 years, each of which compared no-till with tilled fields. The studies included a total of 1061 comparisons, forming a rich dataset on how much carbon was stored across these differently-managed soils.
Mr. Swanson says,
at time of paired row seeding. The Fertilizers were, Dry, Liquid and Ammonia deep in the soil and well below the 6 centimeter range. The depth of placement is at 7 to 8 inches (17.7 to 20.3 cm) in No-tillage Exactrix Deep banding today. This 7 to 8 inch depth is more attractive to hide fertilizer from weeds and Nitrous Ammonias and Nitrobacteria. The fertilizer is in a leverage to crop roots with geometric access. This resolves application of volatile fertilizer or the surface fertilizer and seed row application problems of stratification and a quick shift in soil surface acid pH. The NPKS deep banding is located in a narrow soil born dimension of .5 inch wide bands vermiculated to 7 to 8 inch depths. This allows for better and faster root growth when the charge is vermiculated to the 7 to 8 inch depth. It is true going deeper in annual cropping avoids the top dress fertilizer mistakes. . About 5% to 10% to of all crop land acres are being No-tillage banded (no soil movement) to the 7 to 8 inch depth. For sure most no-till farmers are small and will often take fertilizer dealer shortcuts….but you can-not short cut the fertilizer problem. All nutrients applied must are to be banded deep to avoid Nitrous Oxide in the atmosphere. The critical part of the story is soil moisture loss and the mobility problem of nitrate. Nitrate NO3 has a negative valence and mobile nitrate in our rivers and streams. 2. The Era of modern No-tillage is about economics first. Storing more carbon or controlling erosion is a side benefit. This is why fertilizer is placed at time of seeding or planting. In fact banding of corn can occur at the same time of planting. In the Modern Era of No-tillage, Tracks are used on applicators are used to reduce ground pressure to 4 to 8 psi. Compaction is now a minor to non-issue on field lands. Without compaction holding roots back, higher yields are achieved. It is called the fence row effect. The modern Era of No-tillage allowed yields to be increased dramatically because roots went deeper, healthy roots went faster and allowed a 30% to 50% jump in yields. 3. The 50 year No-tillage data was developed during a period of Zero Cover cropping….today cover cropping is a novelty… on about 10% of the acres (20 million in 2020). Some Cover crops have deep roots like Cereal Rye or Winter Rye. Cover cropping actually changes the rotation allowing up to a 4 year rotation in 2 years of Corn and Beans. Tracked vehicles were only used in the Western US for the last 115 years. Fumigant Relay Cover Cropping can also be used with the new Mustards that have the cyanide gas producing Glucosinolates.
Emma Says Read: The hype behind carbon farming comes down to earth. Generally-speaking, research on the effectiveness of no-till typically relies on measurements of soil organic carbon (SOC) taken from the topsoil, which reaches just about 10 centimeters into the ground. But the researchers’ expansive review gave them access to data on what is happening at deeper soil layers as well. This revealed a contrasting picture of what’s been long-assumed about no-till. While it’s true that in the early years, no-till does increase SOC in the uppermost layers, the researchers found that these gains were offset by steeply diminishing amounts of carbon stored deeper down, between 10 and 60 centimeters. This decline—ranging across the studies from 0.28 to 2.29 Mg per hectare—actually resulted in slightly less carbon stored across the whole soil profile of no-till samples, when compared to the soils of conventionally-tilled fields. These differences eventually diminished between the two soil types, but only after a period of 14 years. Why exactly SOC declines in stable, untilled soils is a puzzle the researchers have yet to solve. But there are a few theories to explore. No-till could be limiting opportunities for carbon stores in the topsoil to move into the lower layers, which might explain why they become depleted over time. Untilled soil also becomes very dense and packed over time, which might slow the incorporation of carbon-rich crop residues from above. Furthermore, increasing compaction makes it harder for plants roots to work their way down, thereby limiting another avenue for the transport of carbon through expansive root networks into deeper layers. The overall takeaway? No-till soils don’t seem to do any better at locking away agricultural carbon, than conventional methods do. Where does that leave farmers and their fields? It certainly doesn’t mean that no-till should be abandoned—far from it. This method is still important for its many other benefits, such as water retention, soil stability, and also reducing the need for fuel-guzzling tilling machines. Meanwhile, there are many other agricultural solutions that could step in to take on its carbon-sequestering mantle, such as agroforestry methods and synthetic fertilizer alternatives. But, the study’s authors do sound some caution around the policy implications of no-till. Ultimately, their results draw a question mark over carbon capture models which commonly rely on SOC data from just the first 10 to 20 centimeters of soil—and which also inform major global estimates like those found in the IPCC reports. These could now be “misleading”, and require some recalibration, the researchers suggest. Mr. Swanson Says, “If you place the NPKS plus zinc at 20 centimeters, the SOC or stored soil carbon will jump to much higher levels…..and the carbon will show up faster in No-till.” Guy J Swanson. Emma Says, “Our findings demonstrate that is not a simple guaranteed solution for drawing down atmospheric CO2.” Mr. Swanson says, “Just the opposite is true if you follow a 40 year proven method of fertilizer placement in Exactrix No-tillage.” Cai et. al. “Declines in soil carbon storage under no tillage can be alleviated in the long run.” Geoderma. 2022. Image: NRCS Oregon via Flickr
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