Agricultural salinity problems facing Agricultural salinity problems facing CaliforniaCalifornia

Steve Grattan, Ph.D.Steve Grattan, Ph.D.Department of LAWRDepartment of LAWR

University of California, DavisUniversity of California, Davis

Central Valley of CaliforniaCentral Valley of California

San J

Sierra Nevada(Granite rock; low salts)

San Joaquin Valley

Sacramento Valley

Coastal Range(Sedimentary rock; high salts)

Sierra Nevada Mountains

Low EC irrigation water

High Saline Water TablesHigh Saline Water Tables

San J

Sierra Nevada(Granite rock; low salts)

San Joaquin Valley

Sacramento Valley

Coastal Range(Sedimentary rock; high salts)

Master DrainMaster Drain

Completed

Not completed

Low salinewater

Traditional crops(non-saline)

Salt-tolerant cropsAnd forages

Halophytes

Solar Evaporator

Increasing salinity

Sequential Reuse

Search for salt tolerant forages

High salt toleranceHigh biomass productionHigh forage quality

Forages in sand tanks at the US Salinity Lab irrigated with either 15 or 25 dS/m synthetic drainage water 2001-2002

Desirable characteristics:

‘Jose’ tall wheatgrass

Bermuda grass

Livestock performance on sites irrigated

with saline drainage water (high Se/Mo)

Cattle grazing on Bermuda grass at

Westlake site, (July 2002) 160 steers

on 62 acres

‘Jose’ Tall wheatgrass Red Rock Ranch (2008)

UC Davis, USDA-ARS, Fresno State

Rice damage from salinity Rice damage from salinity in Sacramento Valleyin Sacramento Valley

Scardaci et al., 2002

Upper Basin

Lower Basin

Evapo-concentration

Drained farm land Imperial and Coachella Drained farm land Imperial and Coachella ValleysValleys

NovemberNovember--March March Temperature: 20Temperature: 20--25 C25 C

R. Cummins photo

Salton SeaSalton SeaImperial Valley

Coachella ValleyR. Cummins photo

5 million tons of salt added 5 million tons of salt added each yeareach year……plus Seplus Se

Recreational uses include fishing, boating, swimming, camping

Sea water intrusionSea water intrusion

Threatens coastal agriculture such as Monterrey, Threatens coastal agriculture such as Monterrey, Santa Maria, Lompoc, Oxnard, Los Angeles Santa Maria, Lompoc, Oxnard, Los Angeles (vegetable crops, commercial nurseries, and tree (vegetable crops, commercial nurseries, and tree crops)crops)

Monterey County

Salt sensitive Salt sensitive crops grown in crops grown in CaliforniaCalifornia’’s s coastal valleyscoastal valleys

Salinity in CaliforniaSalinity in California’’s Sacramentos Sacramento--San Joaquin DeltaSan Joaquin Delta

Tides and river flows Influence salinityin Delta

Recycled municipal waste waterRecycled municipal waste water

CSIP (Castroville Sea Water Intrusion Project) CSIP (Castroville Sea Water Intrusion Project) Service AreaService Area

Suitability Study ofSuitability Study ofNapa Sanitation DistrictNapa Sanitation District(NSD) Recycled Water(NSD) Recycled Waterfor Vineyard Irrigationfor Vineyard Irrigation

100%100%

50%50%

Soil Salinity (Soil Salinity (ECeECe, , dS/mdS/m))0 2 4 6 8

1.51.5

0.8-1.3 dS/m

UCCE study, 2006

Yie

ld Grape yields in relation to salinity

Salt management guideSalt management guide(Ken (Ken TanjiTanji, editor; UCCE and USDA), editor; UCCE and USDA)

Interactive CD that provides

Basic information on salinity management, landscape plant salt-tolerance, design and re-design of landscape systems based on different soil types, plant-water demand, plants with different tolerances

Available: DWR, WateReuse, LADWP, City of Cerritos, So Cal Salinity Coalition, West basin MWD, Central basin MWD, National water Research Inst

CaliforniaCalifornia’’s futures future

Reduction in good quality irrigation waterReduction in good quality irrigation waterIncreased use of municipal wastewaterIncreased use of municipal wastewater

Increased degradation of coastal ground Increased degradation of coastal ground waterswaters

Increased threat to Increased threat to salinizationsalinization of deltaof deltaSalinity impacting high value, salt Salinity impacting high value, salt

sensitive cropssensitive cropsExpansion of desalinizationExpansion of desalinization