The General Catalogue of the Massachusetts Agricultural College provides a list of 44 research articles published by faculty of the MAC between the years 1869 and 1886.   The following were the research publications attributed to Professor Stockbridge over this period.

1. Experiments with compound commercial fertilizers to test their comparative agricultural value and their value as compared with single elements. 1874.
2. Experiments to determine what elements will make practically a complete manure on our average soils.  1974.
3. To determine in feeding substances, the proportions of different elements of nutrition required to save needless expense, and to produce the most certain results.  1874.
4. Experiments on the continuous growth of crops on the same soil with chemical fertilizers alone.  1874.
5. Investigations on the temperature of soil and air, and on deposition of dew on the soil and plant.  1878.
6. Investigations in relation to evaporation and percolation of water from the soil. 1878.
7. The tilling of soils of different characteristics as affecting the loss of water by evaporation.  1878.
8. Investigations in relation to the comparative temperature of the soil and air by day and by night.  1878.
9. The determination of the elements of plant nutrition lost from the soil by leaching, and of those it retains.  1879.
10. Report on lysymetre.  1879.

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While Professor Stockbridge is best known as a beloved teacher and adviser, he also was a committed research scientist focused largely on plant nutrition and the development of  crop fertilizers.  According to a bulletin printed by W.H. Bowker & Co. titled “Stockbridge Fertilizers and Formulas”….

“the Stockbridge Fertilizers are compounded for different crops by formulas worked out by Hon. Levi Stockbridge, Professor of Agriculture in the Massachusetts Agricultural College.  They are the result of much patient investigation and experiment, and may be relied upon a being in theory and practice pretty nearly correct.” 

Professor Stockbridge had studied the writings of Justus von Liebig, the renowned German chemist who is considered the founder of modern chemistry.  Liebig’s famous “law of the minimum” reminded farmers that crop yield is not dependent as much on the total nutrients available as on the one essential element that is most scarce or limiting.

According to graduate of the pioneering class of 1871 W.H. Bowker, Professor Stockbridge, who never formally attended college, read Liebig on his own and also studied the research of Lawes and Gilbert who did long term fertilizer trials at the Rothamsted Experimental Station in England.  Stockbridge repeated some of this famous work in the U.S.  According to Bowker’s publication on the Stockbridge Fertilizers…

“All experiments which have thus far been tried with these fertilizers… have gone on to show that they did not exhaust the soil; but, on the contrary, left it richer, by actual test.

The experiment on potatoes… prove clearly that the soil was enriched rather than impoverished.  The experiments of Lawes and Gilbert, in England, are, however, more conclusive, inasmuch as they were conducted on the same land and extended over a period of twenty years.”

 The following report was published in Scientific Farmer in December of 1875.

Professor Stockbridge’s Experiments on Crop Feeding

The 1937 publication of the U.S.D.A. titled “A History of Agricultural Experimentation and Research in the United States: 1607 – 1925″ reports on his experimental methods…

“…in 1867 he began experiments with commercial fertilizers.  Soils from different parts of the college farm and adjoining farms were placed in pots in the plant house and in them were sown seeds of various crops.  The plants were fed from time to time with chemical elements which they were known to contain, and in an absolutely soluble condition. The elements were occasionally varied and sometimes compounded in such proportions as they had been found to exhibit in the several varieties.”

This early work continued until 1874 in cooperation with chemistry professor, Charles Goessmann.  It was determined that…

“the only substances the farmer must supply were nitrogen, potash and phosphoric acid; and second,that there was a marked relation between the quantity of the crop produced and the elements applied….”

Stockbridge developed the theory that fertilization should be based on the needs of specific crops, which could be determined its chemical composition.  While this is well understood today, this was new knowledge at the time.  Based on these experiments, Stockbridge developed a formula for each crop and which were published in bulletins and pamphlets of the day.  Here is the recommendation for fertilizing potatoes.

While the formulas were shared freely for all to use, the Stockbridge name was attached only to those fertilizers sold by W.H. Bowker and Co.  William Bowker himself claimed in his tribute to Professor Stockbridge that the first monetary royalties paid to Professor Stockbridge (in 1878) for use of his name…

“…was devoted to experimental work at Amherst, which practically laid the foundation for the first experiment station to be established in this country in connection with an agricultural college.”

The Massachusetts Agricultural Experiment Station was established in 1882, five years prior to the federal Hatch Act which provided federal funds for the creation of agricultural experiment stations in all states.  The commitment to scientific research by Stockbridge and the other 3 faculty of the MAC, when most U.S. colleges were focused on literature and the arts, made the Massachusetts Agricultural College unique at the time.

Other experiments by Professor Stockbridge focused on water availability from soil and water loss from plants and results were published by the Massachusetts Agricultural College Experiment Station.

Much of Levi Stockbridge’s research is published in the Annual of the Massachusetts Agricultural College, particularly in the Thirteenth Report (1876) and the Sixteenth Report (1879).

NOTE: a further explanation of the impact of Levi Stockbridge on research in the early days of Mass Aggie may be found here: Stockbridge and UMass.