Where We Work

Our work focuses on the following three case studies:

  • Diversified crop and beef systems in California, US
  • Sheep and viticulture systems in California, US
  • Corn, soy, and beef cattle systems in Mato Grosso, Brazil
  • Viticulture and sheep systems in Marlborough, New Zealand
  • Dairy systems in Canterbury, New Zealand

Brazil, the US, and New Zealand are among the largest global producers of ruminant livestock in the world, accounting for a combined 371 million head of cattle, buffalo, and sheep (1). Due to the sheer magnitude of crop and animal production in these countries, agriculture contributes greatly to their overall GHG emissions, as well as regional water and air pollution challenges (2–7). Brazil and the US are the 2nd and 4th largest emitters (respectively) of carbon dioxide equivalents (CO2e) from enteric fermentation in the world, and 3rd and 7th largest emitters of CO2e from synthetic fertilizer (8). However, New Zealand emits five times more CO2e per capita than Brazil and the US from agricultural sources (2–7).


Brazil is the second largest producer of beef cattle products and second largest producer of soy in the world. These two products account for >35% of national agricultural export value (1). The state of Mato Grosso has the largest soybean area in the country (8.6 million hectares (Mha) in 2013/14), pasture area (26 Mha), and cattle herd (28 million animals)(9, 10). It has witnessed higher rates of agricultural expansion than in any other region in Brazil with crop farming expanding from 2.4 to 11 Mha from 1990-2012 (11). This crop expansion resulted in direct conversion of forest and the displacement of cattle ranching into forests (12, 13). Cattle stocking rates are very low, only 0.5 animals per hectare in some regions and there are more than 2 Mha of degraded pasture (9).

The key challenge in this region is how to increase the productivity of cattle ranching and avoid the displacement of pastures into forest areas by integrating crops into pastures. A recent study estimates that the adoption of ICLS could more than double the stocking rates of degraded pastures by improving improve soil quality where organic matter has been lost after years of monoculture (14). However, ICLS currently occupy only ~80,000 hectares in the state of Mato Grosso (14).

United States

The US is the largest producer of cow’s milk in the world, as well as the largest producers of corn and alfalfa (1). Within the US, California is the largest producer of milk, sweet corn, and alfalfa (15). Much of the dairy production in the state comes from intensive confined systems (>500 heads), where cows are kept in a fairly small, non-pastured area, fed mainly grains, and treated frequently with antibiotics (16). Continuous corn and alfalfa production for dairy feed requires high levels of synthetic fertilizers and is a major source of water extraction and water pollution in the state (17). Thus, both intensive crop and dairy production contribute to the high level of water nitrate pollution in the state; roughly 10% of the public drinking water supply is contaminated (18, 19). From a public health perspective this social problem is aggravated by the fact that many of the inhabitants of rural areas in California are among the poorest in the country, living in towns with inadequate water filtration systems and health services. Meanwhile, dairy producers are struggling to keep their business afloat as they see their profit margins shrinking; prices of livestock feed have increased rapidly, while milk prices have not kept pace, sending many smaller dairies into bankruptcy (20). In California feed costs as a portion of gross value of production in California rose from 57% to 72% from 2010 to 2013.

The key challenge in this region is how to increase the profitability of dairy farming, while reducing the nutrient load per hectare and reducing surface and groundwater demand. One potential option to achieve this goal is by allowing cows have access to pastureland and/or cropland for at least part of the year. This would spread the manure generated by cattle over a larger area and help reduce the amount of synthetic fertilizers applied on the pastures and cropland. It would also reduce dairies’ dependency on expensive purchased feeds- the highest input cost- and could result in higher milk prices for producers if consumers are willing to pay more for pastured dairy (as they have repeatedly demonstrated in California)(20).

New Zealand

New Zealand has become a global player in the international wine market in the past several decades. In 2015, New Zealand wine exports totaled $1.42 billion, representing a 3-fold increase in the past 10 years. Marlborough, New Zealand – at the top of the South Island – is home to 65% of the nation’s total area in viticulture, 75% of its total grape tonnage, and 70% of all winegrape growers in 2015 (21). The predominant varietal is Sauvignon Blanc, which makes up 86.5% of the export market (22). This region was previously occupied by pasture-based sheep and beef cattle production, which has been greatly reduced as wine acreage increased. In 1995 Marlborough had 930,216 sheep in the region. By 2014, this number had dropped to 544,578. Similarly, beef cattle in 1994 numbered 80,354 but decreased to 59,967 in 2014. As winegrapes took over the flat land areas located close to rivers and the sea in Marlborough, sheep and beef farmers moved further up into the hill country of Marlborough, where grass growth is more seasonal (highly limited during the winter). This shift significantly changed water use in the region as there was a exponential increase in irrigation infrastructure in the region. Between 1999 and 2010 irrigation in the region grew from 6,300 to 55,000 ha – an increase of more than 700% (23). The region is now fully allocated for water resource consents.

The key challenge in this region is to identify economically viable forms of integration between the sheep and viticulture systems that can improve feed availability for sheep during winter months without reducing the productivity of vineyards or requiring additional use of irrigation.


  1. FAO (2014) Food and Agriculture Organization Online Statistical Service: Production and Trade Statistics (Rome, Italy) Available at: faostat.fao.org.
  2. USDA (2007) Grassland pasture and range, 1945-2007 Available at: http://www.ers.usda.gov/data-products/major-land-uses.aspx#25970.
  3. IBGE (2006) Agriculture and Livestock Census. Brazilian Inst Geogr Stat. Available at: http://sidra.ibge.gov.br.
  4. MfE (2010) Environmental Report Card: Land Use Environmental Snapshot Available at: http://www.mfe.govt.nz/environmental-reporting/land/land-use-indicator/land-use-environmental-snapshot.html.
  5. US EPA (2014) Inventory of U.S. Greenhouse Gas Emissions and Sinks.
  6. MCTI (2013) Estimativas anuais de emissões de gases de efeito estufa no Brasil Available at: http://gvces.com.br/arquivos/177/EstimativasClima.pdf.
  7. MfE (2014) Greenhouse Gas Inventory Available at: http://www.mfe.govt.nz/publications/climate/greenhouse-gas-inventory-2014/greenhouse-gas-inventory-2014-year.pdf.
  8. FAO (2014) Food and Agriculture Organization Online Statistical Service: Agriculture Emissions, Enteric Fermentation Available at: http://faostat.fao.org.
  9. IMEA (2010) Bovinocultura Mato-Grossense – Caracterização da bovinocultura no estado de Mato Grosso (Cuiabá).
  10. CONAB (2014) Séries históricas relativas às safras. Cia Nac Abast Área Plantada, Prod e Produção.
  11. IBGE (2013) Municipal Agricultural Production Survey. Brazilian Inst Geogr Stat. Available at: http://sidra.ibge.gov.br.
  12. Morton DC, et al. (2006) Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon. Proc Natl Acad Sci 103(39):14637–14641.
  13. Barona E, Ramankutty N, Hyman G, Coomes OT (2010) The role of pasture and soybean in deforestation of the Brazilian Amazon. Environ Res Lett 5(24002):1–9.
  14. Observatório de ABC (2014) Análise dos Recursos do Programa ABC – Visão Regional (São Paulo).
  15. USDA (2013) California Agricultural Statistics. Annu Bull. Available at: http://www.nass.usda.gov/Statistics_by_State/California/Publications/California_Ag_Statistics/2013cas-all.pdf.
  16. USDA ARMS Farm Financial and Crop Production Practices. Available at: http://www.ers.usda.gov/.
  17. Rosenstock T, Liptzin D, Six J, Tomich T (2013) Nitrogen fertilizer use in California: Assessing the data, trends and a way forward. Calif Agric 67(1):68–79.
  18. Harter T, et al. (2011) Groundwater Nitrate in the Tulare Lake Basin and Salinas Valley. American Society of Agronomy Conference Proceedings (Fresno, CA). Available at: http://calasa.ucdavis.edu/files/73479.pdf#page=162 [Accessed November 23, 2013].
  19. Powell JM, Russel MP, Martin NP (2010) Trends in the dairy industry and their implications for producers and the environment. Livestock in a Changing Landscape: Experiences and Regional Perspectives, eds Gerber P, Mooney HA, Dijkman J, Tarawali S, de Haan C (Island Press, Washington, D.C.), pp 115–139.
  20. Ellerby J (2010) Challenges and Opportunities for California’s Dairy Economy. Calif Cent Coop Dev Davis, CA p 5.
  21. New Zealand Wine Growers New Zealand Winegrowers Annual Report 2015. NZwine.com. Available at: http://www.nzwine.com/assets/sm/upload/bh/ph/9b/95/NZW Annual Report 2015.pdf.
  22. New Zealand Wine Growers New Zealand Winegrowers Annual Report 2015. NZwine.com.
  23. New Zealand Ministry for the Environment (2010) Consented irrigated area (thousand hectares) for each region in 1999, 2006, 2010 in 2010.