Project Number: 5310-61000-013-08
Project Type: Reimbursable

Start Date: May 24, 2007
End Date: Mar 31, 2009

Objective:
The objective of this cooperative research project is to test the assumption that a well designed and executed Comprehensive Nutrient Management Plan (CNMP) is protective of groundwater and to address potential weaknesses in the land application design and operation processes. The specific objectives are to assess the performance and sustainability of a CNMP for field-scale dairy lagoon water application by (i) characterizing the spatial variation of soil properties influencing the transport and fate of lagoon water contaminants using apparent soil electrical conductivity (ECa) to direct soil sampling and (ii) monitoring the spatio-temporal changes in transport-related soil properties through the root zone. This work is part of an overarching project entitled "An Integrated, Regional Approach to Dairy Management in the San Jacinto Watershed with Innovative Technologies Component", which has been funded by the State Water Quality Control Board's Agricultural Water Quality Grant Program.

Approach:
A 32-ha field located on the Scott Brothers Dairy in San Jacinto, California, has been selected as the on-farm, field-scale research site. An on-going plot-scale evaluation of the CNMP conducted at the research site will be used as a basis for the development of the field-scale CNMP and for determining field-scale lagoon water application amounts and timing. Intensive biennial ECa surveys will direct soil sampling using a response surface sample design. The ECa-directed soil sampling will characterize to a soil depth of 1.5 m the spatio-temporal variations in salts, trace elements (B, Mo, As, Se), and selected nutrients (NO3-N, NH4+, K, and P) and pathogens, as well as soil properties known to influence their fate and transport. A geographic information system (GIS) will be developed containing salt, trace element, and nutrient concentrations and soil properties influencing the fate and transport of solutes (e.g., sodium adsorption ratio, bulk density, water content, saturation percentage, texture, pH, organic carbon, major cations and anions, CaCO3, gypsum, and infiltration rate). Maps showing spatio-temporal changes in soil chemical properties due to management-induced change from dairy lagoon water reuse will be generated from the GIS. Documents Reimbursable with San Jacinto Basin Resources Conservation District. Log 29985.