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posted by janrinok on Tuesday June 21 2022, @05:10AM   Printer-friendly
from the industrial-optimization dept.

A new data-driven approach looks at practices that are good for the earth and profitable for farmers:

[T]he agricultural industry contributes about 10% of U.S. greenhouse gas (GHG) emissions. Because the amount of land dedicated for agriculture is limited, farmers need to find more ways to operate efficiently, sustainably and profitably while also reducing GHG emissions. With new practices, farmers can make farms a net sink of CO2, helping the U.S. reach its goal of achieving net zero emissions by 2050.

Sustainable intensification is a two-prong approach many think could help. It tries to optimize land use and management practices for maximum farmland productivity at the same time it tries to minimize associated environmental impact. The trick is finding the right balance between the two objectives.

[...] "The concept of sustainable intensification of farming was applied into more broadscale landscape application," said one of the article's co-authors, Hoyoung Kwon, a principal environmental scientist in Argonne's Energy Systems and Infrastructure Analysis (ESIA) division. ​"We considered productivity and GHG emissions, attempted to optimize land management tactics and products, and investigated different trade-offs that improve the land and land productivity."

For example, farmers can clear and repurpose corn crop residue (or ​"stover") for biofuel, but a percentage of stover can remain in the soil for valuable nutrient and carbon sources for future crops. Farmers can plant cover crops during the winter (or ​"fallow") season, to supplement removed stover. The authors took into account energy, which has an emissions cost of planting of cover crops to holistically address net benefits of stover removal and cover crop planting. Farmers can also reduce how much land they till after a growing season ends, which lessens decay and reduces the amount of CO2 that emanates from the soil. However, the farmer has to till some of the land to be ready for the next growing season.

[...] According to the study, harvesting 30% of the corn stover for biofuel production would increase farm revenues, double net profitability and increase overall biofuel production from the landscape by 17–20%. Removal of the stover would also mitigate GHGs somewhat, but it reduced the baseline amount of good carbon in the soil by 40%. In comparison, integrated approaches that include winter cover cropping and/or tillage intensity reduction would increase carbon in the soil, improve farm profitability and mitigate more GHGs.

"We focused on corn and soy but our approach could be extended to other crops," said Hawkins. ​"Many farms today are large, industrial farms that are high-tech and rely much more on high resolution data. We want to give farmers, regional planners and others in agricultural management a tool to calculate how to use land sustainably and get the most value out of the land. This will further both profitability and environmental goals."

Journal Reference:
Trung H.Nguyen et al., A multi-product landscape life-cycle assessment approach for evaluating local climate mitigation potential [open], JCleanProd, 354, 2022. DOI: 10.1016/j.jclepro.2022.131691


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  • (Score: 0) by Anonymous Coward on Wednesday June 22 2022, @08:10PM (2 children)

    by Anonymous Coward on Wednesday June 22 2022, @08:10PM (#1255438)

    Hold on just a moment. Hold on just one stover-gathering moment.

    You want no-till to be part of the answer. Do you understand that this involves huge dollops of various biocides, and actively avoids turning crop residue into the soil, leaving it to rot on the surface? You need the biocides because otherwise you will be growing mostly weeds, and if you want to sequester carbon it helps to actually get it into the soil itself where the nutrients are less apt to wash away or volatilise as opposed to adding nutrients and fibrous structures to the soil. Tillage is a sensible part of land management, and often a more friendly alternative than no-till.

    There are alternatives such as low-till, conservation tillage and pasture cropping that give more options while spreading fewer toxins.

  • (Score: 2) by ElizabethGreene on Thursday June 23 2022, @03:27AM (1 child)

    by ElizabethGreene (6748) Subscriber Badge on Thursday June 23 2022, @03:27AM (#1255510) Journal

    You are correct that no-till does not actively turn under residue on the surface, but that's just a fraction of the biomass of a mature plant. Generally speaking the above-ground mass of a plant is roughly equal to the below-ground mass. The big difference with no-till is that residue takes much longer to break down vs. if it were tilled. Tilling introduces oxygen which causes it to break down faster.

    My experience talking to farmers* that drank the no-till kool-aid is that it produces a measurable increase in organic matter in the soil over time.

    * - About 15 years ago I considered abandoning my IT career and moving into agribusiness full time. This research was part of formal business planning for that transition. I couldn't make the numbers work, so I still fix computers.

    • (Score: 0) by Anonymous Coward on Thursday June 23 2022, @04:46PM

      by Anonymous Coward on Thursday June 23 2022, @04:46PM (#1255619)

      If you're not turning the residue under, you have a few problems:

      a) rot releases greenhouse gases, including some methane depending on exactly what's rotting and the local conditions

      b) if you leave the above-ground mass around, it becomes a haven for pest species ranging from rodents to fungi

      c) if you take the above-ground mass away without somehow replacing the nutrients caught in it, you're impoverishing your soil over and above the losses captured in the crop itself

      d) if you don't somehow retain the solid mass, many of the nutrients will leach or wash out anyway

      e) the doses of biocide that you'd need to inhibit weed growth, fungal pests, insects and so on also wreak havoc on your soil biota (not to mention other risks such as cancer)

      f) no-till will increase organic matter in the soil compared to tillage-enforced monoculture, because if you're constantly disrupting your soil you're limiting how much organic activity it will have as well as ripping up old root systems, but if you're engaging in something like conservation tilling, low-till rather than no-till, pasture cropping or a similar system then the outcome can still be quite positive without going no-till. You can also do things like aggressively composting your above-ground residues and then incorporating them into the soil, or layering them into the soil along with fast-growing cover crops. Outright no-till is basically a gift to 3M and Bayer. There are alternatives.

      g) if you're fertilising in a no-till system you're faced with the problem of how to get the volatiles (especially nitrogen-related) to stay around the root systems rather than leaving by solution, evaporation or similar. If you're turning in granules, or using something like a seed drill to do it, you have better retention. Even a roller or cultipacker doesn't do as well as getting it down to where it will stay. Downward-facing sprays are better than nothing, but aren't perfect and you're still losing a lot.

      I'm not opposed to revisions of how we manage our soil, but there are good reasons to want to till, rather than the alternatives. This includes turning soil, subsoiling, and harrowing among other approaches. Even if you decide to leave the crop residue on the surface as a mulch, you'll probably want to use something like a notched disc harrow or cultipacker to compact it a bit and punch it into the soil to some extent, to reduce the level to which it blows around. This is analogous to the way that snow, in high snowfall areas, will pack down old grasses to form a bed of dead vegetation.