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Table 1   Plant Parts and Number LSU AgCenter Soil Testing and Pl

Procedures Used at the Laboratory

LSU AgCenter Soil Testing and Plant Analysis Laboratory (STPAL)

Please select a test procedure from the links provided below:

 

Soil Test
Analysis Sample Size Procedure
pH 10 g Add 10 ml deionized water, equilibrate 2 hr, read on pH meter.
Lime req. 10 g Add 25 ml deionized water and 2.5 ml saturated Ca(OH)2 for each ton of lime, shake 15 min every 3 hr for 16 hr, read on pH meter.
Sulfur req. 10g Add 25 ml deionized water and 3.125 ml of 0.1 N H2SO4 for each 1000 pounds of Sulfur, shake 15 min every 3 hr for 16 hr, read on pH meter.
Routine Includes: Phosphorus, Potassium,
Calcium, Magnesium,
Sodium, Sulfur, Copper, Zinc		 2 g Add 20 ml of Mehlich 3 extractant solution, shake 5 min on fast speed, read on ICP.
Organic matter 1 g Add 10 ml 1 N K2Cr2O7 and 20 ml concentrated sulfuric acid (wait 2 hr) then add 90 ml water, equilibrate 16 hr, read on colorimeter.
Boron 10 g Add 20 ml deionized water, reflux on 100 degrees Celius hot plate, read on ICP.
DTPA                                  Copper, Iron, Manganese,
Zinc 		10 g Add 20 ml pH 7.3 0.005 M DTPA solution, shake 2 hrs, read on ICP.
HCL                                    Arsenic, Lead, Cadmium,
Nickel, Zinc 		2 g Add 20 ml 0.1 M HCl solution, shake15 min, read on ICP.
Soluble Salts 20 g Add 40 ml deionized water, shake 30 min, equilibrate 16 hr, read on conductivity meter.
Sulfur 10 g Add 25 ml 0.5 M NH4OAc and 0.25 M HOAc,
shake 30 min, read on ICP.
Aluminum 2 g Add 20 ml of 0.1 M BaCl2 and NH4Cl solution, shake 15 min, read on ICP.
Oil 50 g Add 125 ml petroleum ether, shake 30 min, weigh and calculate.
Nitrogen 0.4 g Dry combustion by Leco CN analyzer.
Carbon 0.4 g Dry combustion by Leco CN analyzer.
Texture 5 g Add water and empirically determine.
Storm                                                                    Calcium, Chloride, Soluble Salts, Magnesium, Sodium, Sulfur, SAR 20 g Add 40 ml deionized water, shake 30 min, equilibrate 16 hr, read on conductivity meter, read on ICP.

Plant Tissue Test
Analysis Sample
Size		 Procedure
Phosphorus, Potassium,
Calcium, Magnesium,
Sulfur, Boron, Copper,
Iron, Zinc, Molybdenum,
Aluminum, Sodium, Lead,
Cadmium, Arsenic, Nickel,
Chromium, Cobalt, Selenium		 0.5 g Add 5 ml concentrated HNO3 (wait 50 min then 3 ml H2O2, digest for 2.75 hr on heat block, cool, dilute and read on ICP.
Nitrogen 0.15 g Dry combustion by Leco CN analyzer.
Carbon 0.15 g Dry combustion by Leco CN analyzer.

Water Test
Analysis Sample
Size		 Procedure
pH 25 ml Direct read on pH meter.
Alkalinity 25 ml Titrate to pH 4.5 using HCI and calculate.
Conductivity 25 ml Direct read on conductivity meter.
Sodium, Calcium,
Magnesium, Potassium, Iron, Maganese, Sulfate, Chloride		 15 ml Direct read on ICP.
Nitrate 20 ml Direct read on pH meter with ion-selective electrode (after ISA adjustment).