Problem:
Agriculture currently encompasses ~ 1/3 of the earth’s land surface, and replaced almost the entirety of the grassland ecosystems which originally occupied these semi-arid regions (UNEP 2014). However the serious erosion and degradation of lands globally due to long-term agricultural practices of clearing, tilling, harvesting, and overgrazing is a major impediment to increasing food production to meet the needs of our rapidly growing human population (WRI 2013). Globally, soil erosion is estimated to impact 1.3 billion ha of land area (Lal 2003). In the U.S., the historically high productivity of the Great Plains depended on deep organic soils, but their conversion into corn, wheat and rangelands has significantly impacted these systems, with an estimated 1.7 billion tons of soil eroded annually (NRI-USDA 2007). This chronic removal of soil organic matter impacts fertility and crop yields. It also reduces the soil’s ability to capture and store rainfall in semi-arid regions which receive less than 600 mm of precipitation annually (MEA 2005). Thinner soils have less resiliency as regions experience more and hotter droughts due to climate change (IPCC 2014). Irrigation demands, which already account for ~70% of all human water consumption, will increase to compensate for the poorer soils. It is absolutely critical that we focus on restoration of agricultural grassland systems to achieve food and water security in coming decades.
Researching Solutions:
Over the past decade, an international team of researchers, lead by Cornell faculty, has been working on the development of techniques and “recipes” for jumpstarting soil health and the restoration of degraded and desertified agricultural grasslands. The cornerstone of our approach is the use of coarse woody organic matter, incorporated both subsurface and aboveground, to capture and store infrequent rainfall, along with fertilizer for nutrients, a microbial innoculum, and biochar where needed and feasible. Through a combination of laboratory-based microcosms and scaled-up field plot experiments, we have successfully demonstrated that these techniques increase rainfall capture and maintain higher soil moisture contents for several weeks post-rainfall (Soil Science Society America –Special Session, Phoenix, Arizona, 2016).
We have successfully demonstrated that addition of fertilizer into the recipe leads to increased wheat and alfalfa production, with positive applications in saline soils as well. Selection of biochar (Lehmann 2015) and slow-decomposing wood species show particular promise as a mechanism for significant carbon sequestration. We have also documented that night-time condensation within a healthy grass canopy can replace 23.3% of water lost daily in transpiration and reduce evaporation losses, thus providing a significant, but previously overlooked, source of water which augments scarce rainfall. Re-establishment of grass communities will be critical for self-sustaining, non-irrigated systems, so we are developing a portfolio of options that includes switchgrass for biofuels, limited livestock grazing, and perennial grains. Thus far, we have demonstrated the success of this approach, first in the severely degraded soils of the Yellow River Valley, Ningxia, China.
In 2021, our efforts are focused on using Cornell’s comprehensive Soil Health Protocols as a diagnostic tool for evaluating degraded soils in the Great Plains and eastern China. We have developed a system for creating a reference health soil profile to guide restoration by characterizing soils in regional, remnant or undisturbed prairies. We have completed the remnant soil health characterization of tallgrass prairies in eastern Nebraska, and are starting work in the mixed grass / steppe habitat of Northern Central Great Plains.
Program Achievements:
- New funding awarded by The Nature Conservancy and Cornell University’s Atkinson Center Partnership Program for improving soil health in China (2020).
- Grassland restoration proposal was awarded Honorable Mention in the 2016 MacArthur $100 Million Global Challenge Competition (2016).
- Received Flagship status for the USDA-China Ministry of Science and Technology Collaborative Program (2011-2017).
- Was highlighted in the keynote address at the C20 Conference (G20 subcommittee) on 5 July 2016 in China.
- Was highlighted in 2015 by US Ambassador M. Baucus as one of the three most collaborative programs between the US and China.
Publications:
- R. L. Schneider, and S. J. Morreale. 2021. Soil Health Restoration to Address Food and Water Security. In: Leal Filho W., Azul A.M., Brandli L., Lange Salvia A., Wall T. (eds) Life on Land. Encyclopedia of the UN Sustainable Development Goals. Springer, Cham. https:// doi.org/10.1007/978-3-329-95981-8_147
- R. L. Schneider, S. J. Morreale, Z. Li, E. Menzies Pluer, K. Kurtz, X. NI, C. LI and H. Van Es. 2020. Restoring soil health to reduce irrigation demand and buffer the impacts of drought. Frontiers of Agricultural Science and Engineering 7(3): 339-346. https://doi.org/10.15302/J-FASE-2020348
- Menzies Pluer, E.G., R.L. Schneider, W.T. Pluer, S.J. Morreale, M.T. Walter. 2020. Returning degraded soils to productivity: water and nitrogen cycling in degraded soils amended with coarse woody material. Ecological Engineering 157: https://doi.org/10.1016/j.ecoleng.2020.105986
- Menzies Pluer, E.G., R. L. Schneider, S. J. Morreale, M. A. Liebig, J. Li, C.X. Li, and M.T. Walter. 2019. Returning degraded soils to productivity: an examination of the potential of coarse woody amendments for improved water retention and nutrient holding capacity. Water, Air, and Soil Pollution. 231: 15 (https://doi.org/10.1007/s1127019-4380-x)
- Li, Z., K. Qui, R.L. Schneider, S. J. Morreale, and Y. Xie. 2019. Comparison of microbial community structures in soils with woody organic amendments and soils with traditional local organic amendments in Ningxia of Northern China. PeerJ: e6854 https://peerj.com/articles/6854/.
- Li Z., R.L. Schneider, S.J. Morreale, Y. Xie, J. Li, C. Li, and X. Ni. 2019. Using woody organic matter amendments to increase water availability and jump-start soil restoraiotn of desertified grassland soils of Ningxia, china. Land Degradation and Development 1-12. https//doi.org/10.1002/ldr.3315
- Li, Z., R.L. Schneider, S.J. Morreale, Y. Xie, C. Li, and J. Li. 2018. Woody organic amendments for retaining soil water, improving soil properties and enhancing plant growth in desertified soils of Ningxia, China. Geoderma 310: 143-152. https://doi.org/10.1016/j.geoderma.2017.09.009
Related Research:
Wetland Soil Restoration
Ballantine, K. and R.L. Schneider. 2009. Fifty-five years of soil development in restored freshwater depressional wetlands. Ecological Applications 19 (6): 1467-1480. DOI: 10.1890/07-0588.1
Ballantine, K., R.L. Schneider, P. Groffman, and J. Lehmann. 2011. Soil properties and vegetative development in four restored freshwater depressional wetlands. Soil Science Society of America Journal 76(4): 1482-1495. doi:10.2136/sssaj2011.0362
Ballantine, K.A., P.M. Groffman, J. Lehmann, and R.L. Schneider. 2014. Stimulating nitrate removal processes of restored wetlands. Environmental Science and Technology 48(13): 7365-7373. DOI: 10.1021/es500799v
Ballantine, K.A., J. Lehmann, R.L Schneider, and P.M. Groffman. 2015. Trade-offs between soil-based functions in wetlands restored with soil amendments of differing lability. Ecological Applications 25(1): 215-225. DOI: 10.1890/13-1409.1
webpage – last update 6 February 2021