The century experiment: the first twenty years of UC Davis' Mediterranean agroecological experiment

Abstract

Abstract. The Century Experiment at the Russell Ranch Sustainable Agriculture Facility at the University of California, Davis provides long-term agroecological data from row crop systems in California's Central Valley starting in 1993. The Century Experiment was initially designed to study the effects of a gradient of water and nitrogen availability on soil properties and crop performance in ten different cropping systems to measure tradeoffs and synergies between agricultural productivity and sustainability. Currently systems include 11 different cropping systems-consisting of four different crops and a cover crop mixture-and one native grass system. This paper describes the long-term core data from the Century Experiment from 1993-2014, including crop yields and biomass, crop elemental contents, aerial-photo-based Normalized Difference Vegetation Index data, soil properties, weather, chemical constituents in irrigation water, winter weed populations, and operational data including fertilizer and pesticide application amounts and dates, planting dates, planting quantity and crop variety, and harvest dates. This data set represents the only known long-term set of data characterizing food production and sustainability in irrigated and rainfed Mediterranean annual cropping systems. There are no copyright restrictions associated with the use of this dataset.

Deep soil inventories reveal that impacts of cover crops and compost on soil carbon sequestration differ in surface and subsurface soils

“…The Century Experiment (previously known as Long‐Term Research on Agricultural Systems, LTRAS) is located at the Russell Ranch Sustainable Agriculture Facility near the University of California, Davis (38°32′24″N, 121°52′12″W), with an elevation of 16 m. The site is located in California's northern Central Valley in an alluvial plain of the Putah Creek watershed, which contains soil deposited from what is now the Berryessa Reservoir and includes the Great Valley Complex, Sonoma Volcanics, and Quaternary surface deposits (Shlemon, Horner, & Florsheim, ; Wagner et al, ; Wolf et al, ). The area was originally oak savannah and perennial grassland; ecotypes which have been mostly replaced by annual row crop agriculture.…”

“…The site has two soil types: (a) Yolo silt loam (Fine‐silty, mixed, superactive, nonacid, thermic Mollic Xerofluvents) and (b) Rincon silty clay loam (fine, smectitic, thermic Mollic Haploxeralfs). Detailed soil horizon information (classification and depths) can be found in the Century Experiment published dataset in Wolf et al (). Prior to layout of the Century plots, the site was surveyed for soil characteristics and laid out in a randomized complete block design with three blocks.…”

“…We predicted that (a) intensive annual vegetable/grain systems with the highest organic C inputs-e.g., from WCC and/or compost-will show the greatest soil C gains; (b) low-intensity systems with fallow will lose soil C throughout the soil profile; and (c) the direction of soil C change will differ among soil layers throughout the 2 m profile, particularly between the disturbed cultivated layer (0-30 cm) and the undisturbed subsoil (60-200 cm). (Shlemon, Horner, & Florsheim, 2000;Wagner et al, 2011;Wolf et al, 2018). The area was originally oak savannah and perennial grassland; ecotypes which have been mostly replaced by annual row crop agriculture.…”

Organic management promotes natural pest control through enhanced plant resistance to insects

“…S1). Another reason we chose to 217 focus on Russel Ranch for the soil slurries experiments was because it consists of 3 218 replicated plots for each management regime (34). To remove effects of soil physical 219…”

“…Field studies took place during the 2017 growing season at the organic and conventional longterm treatments of the Century experiment established in 1993 at Russell Ranch (Davis, CA, USA) (34). Three additional field studies took place on commercial farms in Yolo county in 2017.…”