FRUIT GROWERS LABORATORY INC Darrell H Nelson Horticulturalist

FRUIT GROWERS LABORATORY, INC. Darrell H. Nelson Horticulturalist

Did You Know? • California Farm Gate value in 2009 – ≈ 36 – 37 billion dollars – 90% comes from products produced on irrigated lands – California does not have a water problem, it has a salt problem

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Talking Points For Interpreting Irrigation Analysis Data • Why such a complete analysis? • Critical elements • Basic parts of an irrigation water analysis • Interpreting your irrigation analysis data • Water-born pathogens • Soil-Plant-Water interrelations • Units and conversions (see handout) First

Why Such A Complete Analysis? • To make sure the data is valid • To make sure every critical element is examined • To check cations and anions are in balance • To check that electrical conductivity and total dissolved solids correlate – TDS x 0. 7(conversion) = approximate E. C. Closer look at soil N avail

Irrigation Suitability Analysis

Plugging Hazards

Critical Elements • Chloride – Specific ion toxicity • Boron – Specific ion toxicity • Sodium – Should be less than 60 % of cations • Bicarbonate – High bicarbonate water seals the soil • Carbonate – Waters containing carbonate must have a p. H > 8. 3 and are usually very pure • E. C. – Should be less than 1200 umhos/cm for salt sensitive crops • SAR (Sodium Absorption Ratio) – Severe problems will persist above 9

The Basic Constituents of an Irrigation Analysis Report…A Break Down

Cations • These are the major positively charged ions in irrigation water Percent Base Sat

Anions • These are the predominately found negative ions in irrigation water • Meq of cations = Meq of anions Next prop to look at is p. H

Micronutrients • These are plant micronutrients that may or may not be available Next prop to look at is p. H

Crop Suitability and Amendments -

Water Pathogens • E. Coli 157 – Bacteria derived from fecal contamination • Salmonella – Primarily found in surface water • Listeria – Primarily found in refrigerated conditions

Soil-Water-Plant Interrelations • A sickly plant growing in a well drained and well fertilized soil is likely to be struggling with a pathogen or a physical disorder • High soil Potassium promotes Magnesium deficiencies in plants • High Magnesium soils usually have low infiltration rates • High soil Phosphorus levels promotes low plant uptake of Iron, Zinc, Manganese, and Copper 1 of 3

Soil-Water-Plant Interrelations • Soil p. H will eventually be nearly the same as the irrigation water p. H • Soil E. C. e should be 1. 5 to 2 times the water EC. If higher, check soil drainage and/or leaching conditions • At an E. C. e above 8, the soils osmotic pressure will be too high and plants will be stressed • At a higher E. C. e the soil solution may extract water from the plant or the fruit 2 of 3

Soil-Water-Plant Interrelations • As soil texture becomes heavier, water and nutrient holding capacity increases • As soil texture becomes heavier, the availability of water and nutrients decreases • As soil p. H changes nutrient availability also changes (see p. H chart) • Hard water makes soft soil • Soft water makes hard soil 3 of 3

Adjusting the soil p. H changes more than just the p. H ______________ Another ? on Micros

The Real Benefit of Water Data • Better crop selection • Better salinity management • Improved economic yields

Questions? For more info: Darrell H. Nelson www. fglinc. com Fruit Growers Laboratory, Inc.