Photo: Farm near Lhasa, Tibet, all manual labor. © 20217 Delena Norris-Tull
Conservation Tillage
Summaries of the research and commentary by Dr. Delena Norris-Tull, Professor Emerita of Science Education, University of Montana Western, September 2020.
Conservation tillage farming is defined as "any tillage or planting system that maintains at least 30% of the soil surface covered by residue” (Conservation Technology Information Center, 2004). Often called “no-till” (although it does allow some soil tillage), it reduces the loss of soil and its organic layers. Through soil conservation, conservation tillage increases the amount of carbon that is sequestered in the soil, which reduces the amount of carbon dioxide in the air, thus assisting in the reduction of the gases that increase global climate change (Horowitz, et al., 2010). It also increases the levels of soil nitrogen and reduces water runoff and reduces air and water pollution, reduces farming expenses and reduces consumption of fossil fuels (Sutton, et al., 2006).
“Agricultural scientists recognize several forms of reduced tillage, including mulch till, ridge till, strip till, and no-till” (Horowitz, et al., 2010). In Tillage Intensity and Conservation Cropping in the United States, Classen, et. al., 2018, provide a thorough overview of the various forms on conservation tillage.
“The adoption by farmers of conservation tillage practices such as no-till is an important step toward achieving sustainable crop production. The objective of no-till is to limit mechanical disturbance of the soil to that required for seed placement. No-till is characterized by limited soil disturbance and increased amounts of crop residue on the soil surface resulting in decreased wind and water erosion, lower labor and fuel inputs, and increased water use efficiency by the crop. The number of no-till hectares in the United States has increased from 5.7 million in 1989 to 6.8 million in 1990. In Ontario, approximately 83 480 ha of no-till crops were grown in 1989. However, the acceptance of no-till has been limited due to expected problems of weed management” (Eadie, et. al., 1992). The good news is that, by 2017, the amount of no-till farming in the US had increased dramatically to 104 million acres. In addition, the amount of acreage in reduced till had also increased significantly (reported in “No-Till Farmer,” July 10, 2019.) Surprisingly, the percentages of no-till or reduced till acreages differs dramatically between States. In addition, “no-till varies substantially across crops…, even for crops that are quite similar. For example, barley has roughly twice the percent of no-till (27 percent in 2003) as oats (14 percent in 2005), even though these crops generally have similar production requirements,” Horowitz, et al., 2010. The report by Horowitz, et al., 2010, identifies for which crops and in which States no-till or reduced till practices are in place.
Hellerstein, at al., 2019, report that, “Many farmers and ranchers use practices that enhance soil health. In 2012, 35 percent of all cropland acres were in no-till and 3 percent were planted with a cover crop, two practices that promote soil health….Conservation tillage, which can reduce soil erosion and sediment loss, is used on around 70 percent of soybean acres, 40 percent of cotton, 65 percent of corn, and 67 percent of wheat.”
Limitations of conservation tillage:
However, Eadie, et. al., 1992, point out that, “The weed suppressing ability of the crop residue may compensate for reduced quantities of herbicide coming in contact with the soil surface and therefore not affect overall weed control.” They conducted a two-year study in Ontario to compare the effectiveness of: “selective application of herbicides in a band, reduced herbicide rates, and inter-row cultivation” in fields that had undergone no-tillage for three to five years prior to the study. The fields had been planted in soybeans the year prior to the study. Several annual weed species were present in the fields. They used paraquat or glyphosate to remove perennial weeds prior to planting corn in the spring. “Herbicide treatments to control annual weeds consisted of atrazine with or without metolachlor.” Results: “Corn grain yield did not differ significantly regardless of whether herbicides were applied in a band in combination with cultivation, or as a broadcast treatment.” At most sites, “banded herbicide treatments combined with one cultivation was adequate to maintain weed control and corn grain yield” when compared with zero or two cultivations. At one site, “two cultivations combined with herbicides applied in bands resulted in significantly reduced weed biomass and greater corn grain yield.” They found that cultivation alone, without herbicides, was not effective at controlling weeds. They concluded that, “Herbicides applied in banded applications combined with inter-row cultivation resulted in adequate weed control and corn grain yields in a modified no-till production system… Application of herbicides in 30-cm bands on 76-cm wide com rows represented an approximate 60% reduction in total herbicide applied into the environment. Another possible benefit of banded herbicide applications in no-till crop production is a reduced chance of herbicides gaining entry into groundwater or surface water runoff” (Eadie, et. al., 1992).
The World Economic Forum developed a report, Transforming Food Systems with Farmers, to assist the European Union nations in developing sustainable agricultural practices, practices the WEF calls Climate-Smart Agriculture. On page 6 & 7 & 13, the report describes the advantages of no-till and other conservation tillage practices. The report states that, "A meta-analysis found that farmers implementing just three climate-smart practices (no-till, cover crops and diversified crop rotations) could increase their profit by more than 11% and reduce the cost per hectare by 37% compared to conventional practices."
References:
Links to additional Agricultural Best Practices:
Links to more Innovative Solutions:
Conservation Tillage
Summaries of the research and commentary by Dr. Delena Norris-Tull, Professor Emerita of Science Education, University of Montana Western, September 2020.
Conservation tillage farming is defined as "any tillage or planting system that maintains at least 30% of the soil surface covered by residue” (Conservation Technology Information Center, 2004). Often called “no-till” (although it does allow some soil tillage), it reduces the loss of soil and its organic layers. Through soil conservation, conservation tillage increases the amount of carbon that is sequestered in the soil, which reduces the amount of carbon dioxide in the air, thus assisting in the reduction of the gases that increase global climate change (Horowitz, et al., 2010). It also increases the levels of soil nitrogen and reduces water runoff and reduces air and water pollution, reduces farming expenses and reduces consumption of fossil fuels (Sutton, et al., 2006).
“Agricultural scientists recognize several forms of reduced tillage, including mulch till, ridge till, strip till, and no-till” (Horowitz, et al., 2010). In Tillage Intensity and Conservation Cropping in the United States, Classen, et. al., 2018, provide a thorough overview of the various forms on conservation tillage.
“The adoption by farmers of conservation tillage practices such as no-till is an important step toward achieving sustainable crop production. The objective of no-till is to limit mechanical disturbance of the soil to that required for seed placement. No-till is characterized by limited soil disturbance and increased amounts of crop residue on the soil surface resulting in decreased wind and water erosion, lower labor and fuel inputs, and increased water use efficiency by the crop. The number of no-till hectares in the United States has increased from 5.7 million in 1989 to 6.8 million in 1990. In Ontario, approximately 83 480 ha of no-till crops were grown in 1989. However, the acceptance of no-till has been limited due to expected problems of weed management” (Eadie, et. al., 1992). The good news is that, by 2017, the amount of no-till farming in the US had increased dramatically to 104 million acres. In addition, the amount of acreage in reduced till had also increased significantly (reported in “No-Till Farmer,” July 10, 2019.) Surprisingly, the percentages of no-till or reduced till acreages differs dramatically between States. In addition, “no-till varies substantially across crops…, even for crops that are quite similar. For example, barley has roughly twice the percent of no-till (27 percent in 2003) as oats (14 percent in 2005), even though these crops generally have similar production requirements,” Horowitz, et al., 2010. The report by Horowitz, et al., 2010, identifies for which crops and in which States no-till or reduced till practices are in place.
Hellerstein, at al., 2019, report that, “Many farmers and ranchers use practices that enhance soil health. In 2012, 35 percent of all cropland acres were in no-till and 3 percent were planted with a cover crop, two practices that promote soil health….Conservation tillage, which can reduce soil erosion and sediment loss, is used on around 70 percent of soybean acres, 40 percent of cotton, 65 percent of corn, and 67 percent of wheat.”
Limitations of conservation tillage:
- Not all crops can use these practices. Potatoes and beets and other root crops are examples of crops wherein the entire plant must be removed for harvest. For these crops, soil conservation practices must rely on the use of a cover crop to protect the soil after harvest of the main crop. In some areas of the northern US, the short growing season makes it challenging to use cover crops that grow fast enough. But if the farmer plants cover crops within the crop, before the harvest, they can produce a cover crop simultaneously. However, they then need a method to harvest the crop without harvesting the newly growing cover crop. The good news is that, as of 2017, US farmers grew 15.3 million acres of cover crops, compared to 10.2 million acres in 2012.
- It can be more challenging to manage noxious weeds.
However, Eadie, et. al., 1992, point out that, “The weed suppressing ability of the crop residue may compensate for reduced quantities of herbicide coming in contact with the soil surface and therefore not affect overall weed control.” They conducted a two-year study in Ontario to compare the effectiveness of: “selective application of herbicides in a band, reduced herbicide rates, and inter-row cultivation” in fields that had undergone no-tillage for three to five years prior to the study. The fields had been planted in soybeans the year prior to the study. Several annual weed species were present in the fields. They used paraquat or glyphosate to remove perennial weeds prior to planting corn in the spring. “Herbicide treatments to control annual weeds consisted of atrazine with or without metolachlor.” Results: “Corn grain yield did not differ significantly regardless of whether herbicides were applied in a band in combination with cultivation, or as a broadcast treatment.” At most sites, “banded herbicide treatments combined with one cultivation was adequate to maintain weed control and corn grain yield” when compared with zero or two cultivations. At one site, “two cultivations combined with herbicides applied in bands resulted in significantly reduced weed biomass and greater corn grain yield.” They found that cultivation alone, without herbicides, was not effective at controlling weeds. They concluded that, “Herbicides applied in banded applications combined with inter-row cultivation resulted in adequate weed control and corn grain yields in a modified no-till production system… Application of herbicides in 30-cm bands on 76-cm wide com rows represented an approximate 60% reduction in total herbicide applied into the environment. Another possible benefit of banded herbicide applications in no-till crop production is a reduced chance of herbicides gaining entry into groundwater or surface water runoff” (Eadie, et. al., 1992).
The World Economic Forum developed a report, Transforming Food Systems with Farmers, to assist the European Union nations in developing sustainable agricultural practices, practices the WEF calls Climate-Smart Agriculture. On page 6 & 7 & 13, the report describes the advantages of no-till and other conservation tillage practices. The report states that, "A meta-analysis found that farmers implementing just three climate-smart practices (no-till, cover crops and diversified crop rotations) could increase their profit by more than 11% and reduce the cost per hectare by 37% compared to conventional practices."
References:
- Claassen, R., Bowman, M., McFadden, J., Smith, D., & Wallander, S. (Sept. 2018). Tillage Intensity and Conservation Cropping in the United States. USDA, Economic Research Service, Economic Information Bulletin Number 197.
- Eadie, A.G., Swanton, C.J., Shaw, J.E., & Anderson, G.W. (Jul.-Sep., 1992). Banded herbicide applications and cultivation in a modified no-till corn (Zea mays) system. Weed Technology, 6 (3): 535-542.
- Hellerstein, D., Vilorio, D., & Ribaudo, M. Eds. (May, 2019). Agricultural resources and environmental indicators, 2019. USDA, Economic Research Service.
- Horowitz, J., Ebel, R., & Ueda, K. (Nov., 2010). “No-till” farming is a growing practice. USDA Economic Information Bulletin, No. 70. USDA Economic Research Service. https://www.ers.usda.gov/webdocs/publications/44512/8086_eib70.pdf?v=0
- Sutton, K.F., Tanini, W.T., Mitchell, J.P., Miyao, E.M., & Shrestha, A. (Oct.-Dec., 2006). Weed control, yield, and quality of processing tomato production under different irrigation, tillage, and herbicide systems. Weed Technology, 20, (4):831- 838.
- World Economic Forum. (April 2022). Transforming Food Systems with Farmers: A Pathway for the EU. World Economic Forum, in collaboration with Deloitte & NTT Data.
https://www.weforum.org/reports/transforming-food-systems-with-farmers-a-pathway-for-the-eu
Links to additional Agricultural Best Practices:
- Ecologically based Successional Management
- Perennial Crops, Intercropping, beneficial insects
- Soil Solarization
- Natural Farming
- Permaculture
- Organic Farming
- Embedding Natural Habitats
- Crop Rotation
- Tree Planting: Pros & Cons
- Water Use Practices
Links to more Innovative Solutions: