32 MASS. EXPERIMENT STATION BULLETIN 380 



organic material itself to such an extent that the crop plants actually suffer from 

 an unbalance or a deficiency of one or more essential elements. A temporary 

 nitrogen deficiency is frequently induced when large quantities of carbonaceous 

 materials are plowed under without sufficient nitrogen to promote both the 

 decomposition of the organic matter and the satisfactory growth of the crop. 

 If available supplies of other elements are limited, deficiencies or perhaps an 

 unbalance of essential plant food nutrients may also be induced as a result of 

 the decomposition process. This is likely to be the situation in soils which had 

 been badly depleted of their available essential minerals before a quantity of 

 organic matter was plowed under. 



The need for supplementary nitrogen to promote the decomposition of certain 

 types of organic matter is generally recognized and steps are usually taken to 

 provide it; but the need for additional quantities of supplementary mineral 

 elements to promote decomposition is not generalK" recognized and this may 

 account for some of our now unexplainable difficulties in crop production. For a 

 number of years many farmers in Massachusetts have frequently had difficulty 

 in producing satisfactory tilled crops following immediately on land which has 

 lain for several years in hay or pasture. Since the common hay and pasture 

 species are capable of reducing fertility of a soil to a low level and since the general 

 practice has been to let such a condition develop, immediate difficulties in pro- 

 ducing crops on "run out" hay or pasture land might be expected. Unless the 

 needs of both the microorganisms and the crop can be satisfactorily met, the 

 crop will certainly suffer. The succeeding crop may be adequately fertilized, 

 but it may require a considerable period of time for the fertilizers to act and re- 

 establish satisfactory soil fertility relationships. 



The most satisfactory solution of this problem would be to prevent such a 

 condition from developing. If satisfactory levels of soil fertility are maintained 

 in hay and pasture lands, not only will greatly increased yields of better hay or 

 pasture herbage result but the succeeding crops in rotation will benefit from the 

 "positive" effects of decomposing organic matter instead of suffering from its 

 "negative" effects. In fact, one of the most satisfactory means of replenishing 

 the supply of organic matter in a cultivated soil is through the periodic produc- 

 tion of a well-fertilized sod crop. Stapledon has recently written that, "It is 

 an axiom to my mind to say that a ley [sod ] is a good preparation for any crop,"'!! 

 but this will only be true when the fertility levels maintained in sod lands are 

 comparable to those maintained in other crop lands. 



Tillage. — Over three hundred years ago Lord Bacon wrote that "Old ground, 

 that hath been long unbroken up, gathereth mosse; and therefore husbandmen 

 use to cure their pasture grounds, when they growe to mosse, by tilling them for a 

 yeare or two."'i2 Since the time of Bacon, much evidence has accumulated which 

 definitely indicates that grasslands, at least on soils similar to those in Massachu- 

 setts, must be periodically plowed and reseeded if high levels of productivity are 

 to be maintained. Jared Eliot, in describing grasslands in Connecticut, noted 

 that, "The Experienced Farmers say that their Grass Ground thus Ploughed 

 Once in Five Years mends the Land in this way."ii^ Bordley, writing about 

 grasslands in eastern Pennsylvania in 1801, said, "It is of great advantage to turn 

 up the ground, shift its surface, and bury the sods of grass. "i'^ This is in direct 

 contradiction to the idea now occasionally expressed, though not proved, that a 

 layer of organic matter at the surface of the ground is necessary for some of the 



!!!piough-Up Policy and Ley Farming (London, 1939), p. 75. 



I'^storer, Agriculture III, 612. 



!!*Fie!d Husbandry, p. 64. 



^'''Bordlcy's Husbandry (Philadelphia, 1801). p. 10. 



