History of Soil-Testing in South Carolina

Kathy Moore
July 22, 2011

T. E. Keitt, in 1914, initiated one of the earliest projects of the South Carolina Agricultural Experiment Station at the Pee Dee Station in Florence, SC.  Yield studies were done using varying rates of lime and nitrogen (N), phosphorus (P), and potassium(K) fertilizer.  This provided information concerning optimum soil pH values for various crops, rates of lime needed to attain the optimum pH levels, and rates of N, P, and K needed to maintain optimum yields.  However, the early work did not include soil test information.

Acid soils in South Carolina became a serious problem, and farmers abandoned some fields.  In 1928, Dr. W. R. Paden at Clemson College began testing soil from South Carolina cotton fields for pH using hydroquinone titrations.  His data indicated most South Carolina soils were too acidic to support good yields, but the yield problems could be remedied if farmers would lime their fields.  A study was done with over 2,150,000 soil samples indicating the acid problem.  The data was summarized, mimeographed, and distributed, but much of the data was not used and as a result comparatively small amounts of lime were consumed in South Carolina following the pH determinations.  Few farmers did however begin mailing samples to Clemson for pH testing.  The South's first public soil-testing program was established by 1938.  During the first year, the lab tested 1,983 soil samples.

During the early 50's the Clemson lab was using a sodium acetate (Morgan's) extractant for K and an HCl extractant for P (1).  Phosphorus was analyzed using a colorimetric method, and K was analyzed using a turbidimetric method.  Dr. H. Albritton headed up the lab, which was located in Long Hall, and wrote recommendations for each sample submitted.  The soil was collected in ice cream containers, about one-half pint, and mailed to the Soil Testing Laboratory, Agronomy Department, Agricultural Experiment Station, Clemson, South Carolina (3). 

Approximately 20,000 samples were analyzed in 1954. From 1950 to 1954, Dr. H. P. Cooper recruited funding to build the Poole Agricultural Center.  The lab moved to the new building in 1955. 

In 1956, South Carolina consumed only 133,651 tons of agricultural limestone.  Agronomists had estimated that South Carolina needed to consume over 1.5 million tons of limestone annually.  In 1957, the results from the pH determinations made two decades earlier were published.  Since relatively small amounts of lime had been consumed, the data still reflected the soil acidity problem in the state.  The published data was made available and county agents and other farm leaders encouraged farmers to follow suitable liming programs.  In 1959, the lab came under the direction of Dr. N. R. Page.  For lime recommendations, Dr. Page later started analyzing soil samples for buffer pH using a modified Adams Evans buffer method.  The Mehlich I extractant (2) was used for P, K, calcium (Ca) and magnesium (Mg).  P and Mg were analyzed using colorimetric methods and K and Ca were analyzed using turbidimetric methods.  Guidelines were prepared for the county agents to use to provide soil test recommendations.  The reports were sent to the agents to make the recommendations.

In July, 1965 the soil-testing laboratory was moved from the Agronomy Department to the Department of Agricultural Chemical Services.  The lab analyzed approximately 35,000 samples for farmers in 1970 - 1971.  Flamephotometry was introduced for analysis of K (4). Atomic absorption spectrophotometry was introduced for analyzing Ca and Mg (5).  Dr. C. L. Parks was hired by the University in 1969 as a soil fertility specialist and served as a liaison between the agents, public, and the University until he retired in 1992.  Dr. J. R.Woodruff joined the Agronomy Department in 1965 - 1987 and contributed with soil fertility research and teaching and used soil testing for interpretations.  Under Dr. L. P. Anderson's and Dr. G. R. Craddock's leadership in the 70's the soil-testing program was computerized and a new building was designed to house the lab.

In 1978, Hoke Hill from the Department of Experimental Statistics, working with Dr.Parks and John Wells, wrote the program to computerize the soil-testing recommendations.  Jeannie Currin worked on some of the SAS programming.  The reports now contained the recommendations needed based on the soil test results and hard copies were mailed to the county offices.  The number of soil samples analyzed reached over 90,000 annually. The H. P. Cooper Agricultural Service Laboratory, located on Old Cherry Road, was completed in 1980.  At that time, plant tissue, feed and forage, and nematode assay labs were added to the soil-testing service. 

Dr. A. K. Torrence was named Head of the Department of Agricultural Chemical Services.  Dr. Charles Mitchell was named director of The Agricultural Service Laboratory with a staff of 17 people and served for 4 years. October 1, 1984, Dr. Bob Lippert was appointed the new director of the lab.  Under Dr. Lippert's direction an irrigation water analysis laboratory was started in 1986 and an animal waste analysis laboratory was initiated in 1990. An Inductively Coupled Plasma (ICP) was purchased for the laboratory in 1992.  The ICP greatly reduced the labor needed to analyze the various agricultural samples.  The old Atomic Absorption and UV/Vis Spectrophotometers were given to different labs and through retirement the staff was reduced to 9. 

The soil test was no longer a free service.  A $5.00 per sample charge was implemented which included pH, P, K, Ca, Mg,Zn, Mn, lime and fertilizer recommendations.  When the fee was implemented, the total number of soil samples submitted decreased from 65,000 in 1991 to 28,600 in 1992. The Department of Agricultural Chemical Services dissolved in 1995 and the lab came under Agricultural and Natural Resources.  The Plant Problem Clinic moved in to the lab, and Mr. James H. Blake was appointed Director of the Diagnostic sections including the Plant Problem Clinic and the nematode assay laboratory.  Dr. Kathy Moore was appointed Director of the Analytical sections including soil-testing, plant tissue, feed and forage, irrigation water, and animal waste analyses. In 1996 the lab began sending hard copies of most soil test reports directly to the client with e-mail copies to the county offices.  B and Cu were added to the soil analyses along with calculations for CEC, Acidity, and % Base Saturation.  In 1998 the standard Adams-Evans buffer procedure was implemented and the lime recommendation tables were recalculated according to the standard procedure.

January 2, 2001 Na was added to the report and a new soil reporting system was implemented which allowed the user to access soil reports on the web.  The research lab on campus closed down in 2003 and two of the research laboratory technicians moved themselves and their equipment to the Ag Service Lab. During 2004 the nematode lab was shut down and a contract was signed with Mississippi State to handle the nematode samples.  Meg Williamson became manager of the Plant Problem Clinic.

A robotic pH analyser was purchased in 2004 and the day of reading soil pH's by hand had come to an end.  In July of 2005, the soil test fee was increased from $5.00 to $6.00.  A second analyser was put in place in January of 2006 which automatically dispensed the buffer solution.  With the recognition that a key ingredient in the Adams-Evans buffer was listed as a toxic waste, a new buffer solution was developed which duplicated the pH values obtained by the Adams-Evans buffer solution.  When the second analyser was put in place, the new Moore-Sikora buffer was put into the automatic buffer dispensing system.  In order to conserve solution, a 12 mL scoop (assumed 15 g) was put in place and the ratio became 15 g soil to 15 mL water to 15 mL buffer.  Compost analysis was also added in 2005.

In early 2007, the Plant Problem Clinic moved out of the Agricultural Service Laboratory and into the Clemson Applied Tech building in Pendleton.  The fertilizer lab took the place of the PPC and is now housed at the Ag Service Lab under the supervision of Alan Owens. In June of 2008, the lab was moved into the department of Plant Industry within Regulatory.

In 2008, a second ICP was purchased which enabled the analysis of many more elements - including certain heavy metals.  The number of research solutions and other type samples approached 7,000.

2009, the lab is back with Extension and analyzed 56,720 samples.

2011, Alan Owens retired from the fertilizer lab and Sarah Robinson assumed his role.  The Agricultural Service lab has a staff of 6.5 with 2 part time busy season employees and several year round students. 

(1)    Report of the Soil Test Work Group of the National Soil and Fertilizer ResearchCommittee.  1951.

(2)    A. Mehlich, determination of P, Ca, Mg, K, Na, and NH4 by North Carolina SoilTesting Laboratory.  (Mimeo 1953).

(3)    Lime for South Carolina Soils. Circular 378.  Clemson Agricultural College. September 1952.

(4)    Procedures Used by State Soil-Testing laboratories in the Southern Region of theUnited States.  1965.  Southern Cooperative Series Bulletin 102, 49 p.

(5)    Procedures Used by State Soil-Testing laboratories in the Southern Region of theUnited States.  1974.  Southern Cooperative Series Bulletin 190, 23 p.

Notes Regarding the Early History of SERA-6

     The Southern Regional Soil-Testing Work Group was formed in 1954 to provide a means of exchanging information regarding soil-testing.  The 13 Southeastern States included Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, NorthCarolina, Oklahoma, South Carolina, Tennessee, Texas, and Virginia.  As an example of some of the early work, the 1960 meeting was held at Oklahoma State University.  Lester W. Reed served as Chairman and R. D. Rouse served as secretary.  There were 9 active sub-committees:  pH, Lime Requirements, Methods,Calibration of Soil Test by Plant Analysis, Standard Soil Sample, Soil Test for Available Nitrogen, Phosphorus, Soil Test Calibration, Techniques and Instrumentation. It was agreed that the exchange of soil samples would be extremely important to ensure uniformity of soil test data across state lines.  In 1962 a regional project was initiated under the number S-52.  One of theactivities of the S-52 committee was to compile the soil-testing methods used by the states in the Southern Region (6).  The methods were revised by the Southern RegionalSoil-Testing Work Group in 1974 (7) and again in 1984 (8).

(6)    Procedures Used by State Soil-Testing Laboratories in the Southern Region of theUnited States.  1965.  Southern Cooperative Series Bulletin 102, 49 p.

(7)    Procedures Used by State Soil-Testing Laboratories in the Southern Region of theUnited States.  1974.  Southern Cooperative Series Bulletin 190, 23 p.

(8)    Procedures Used by State Soil-Testing Laboratories in the Southern Region of theUnited States.  1984.  Southern Cooperative Series Bulletin 190, 16 p.