30 MASS. EXPERIMENT STATION BULLETIN 380 



ITdl.^"^ During the latter part of the eighteenth century- the use of gypsum or 

 land plaster was initiated with much success and it was used extensively through- 

 out most of the nineteenth century. The use of limestone was common by 1820 

 in sections where it was abundant, but its general use was not extensive until 

 later on in the nineteenth century when processing and transportation facilities 

 were improved and costs had been lowered. In 1838 Colman reported that the 

 cost of lime in Massachusetts prevented its use to any considerable extent except 

 in the limestone regions. Many of the principal benefits of lime were recognized 

 by the same author when he spoke of its use as "neutralizing the acids which 

 render a soil sour and unproductive; in converting insoluble into soluble matter 

 and in thus preparing the vegetable matter in the soil for the food of the plants 

 and bringing it into condition by which it can be taken up by their roots. "'"^ 



Recent studies by Albrecht^"^ indicate that calcium is even more important in 

 the nutrition of plants than was formerly thought. Not only must calcium 

 be considered as a very essential element in itself, but plentiful supplies of calcium 

 in the soil are essential for the efficient utilization of other nutrient elements such 

 as potassium and phosphorus. These same studies have shown that available 

 calcium is the important consideration and that soil pH to a large extent is more 

 or less incidental. Therefore the use of materials which supply available calcium 

 in adequate quantities is of utmost importance. Limestone is probably the 

 cheapest and most effective source of calcium, and in Massachusetts where soils 

 are also deficient in magnesium, a dolomitic limestone is preferable. It must 

 also not be overlooked that man}' fertilizer materials carry calcium as an incidental 

 part of their composition and that calcium in this form may serve a very useful 

 purpose in supplying the needs of the crop. 



Potash and Phosphates. — The early and extensive use of wood ashes as a 

 "manure" indicates an early recognition of a deficiency of soil potassium in 

 Massachusetts. Jared Eliot in 1747 observed "Ashes is allowed on all hands to 

 be some of the best Dressing or Manure for Land; it enriches much and lasts long 

 but the misery is we can get but little."^"* A hundred years later Colonel Wilder 

 declared, "I have never used any manure on my soils that would produce such a 

 wonderful effect as ashes. ... I am of the opinion that there is no mineral manure 

 that we need so much upon our soils here in New England that have been long 

 under cultivation as potash. "^"^ Recent experimental results on the beneficial 

 effects of potash in stimulating the growth of white clover in permanent pastures, 

 in greatly benefiting stands of alfalfa and Ladino clover, and in increasing the 

 yields of hay mixtures, merely substantiate the keen observations of Colonel 

 Wilder. 



Historical references to the importance of phosphates are not nearly so fre- 

 quent as they are for potash and lime. However, the use of "bone manure" 

 before the middle of the nineteenth century is evidence that the addition of 

 phosphates was beneficial. More recently crop responses from phosphate fertili- 

 zation have not been so pronounced as they have from potash fertilization prob- 

 ably because of the comparatively light, or sandy nature of most Massachusetts 

 soils. Such soils invariably respond to potash fertilization before they do to 

 phosphate fertilization. Moreover, the phosphorus content of most commercial 

 fertilizers has been proportionately high ever since they came into extensive use 

 so that phosphorus needs in general have been met. It must not be construed, 



lOSpield Husbandry, p. 160. 



106Agriculture of Massachusetts, 2d Report (1838). p. 11. 



^"^Soil Science Society of America Proceedings V (1940), 1-16. 



lOSpield Husbandry, p. 43. 



l^^Mass. State Bd. Agric. 17th Annual Report (1869). Pt. I, p. 47. 



