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

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 pH > 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

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

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

Next prop to look at is pH Micronutrients These are plant micronutrients that may or may not be available

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 pH will eventually be nearly the same as the irrigation water pH 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 pH changes nutrient availability also changes (see pH chart) Hard water makes soft soil Soft water makes hard soil 3 of 3

Adjusting the soil pH changes more than just the pH ____________________________ 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 Fruit Growers Laboratory, Inc.