EXPEKLMENTS WITH PERMANENT PASTURES 27 



Finally, it should be emphasized that pasture improvement by top-dressing 

 is a long-time investment. Wry little improvement from lime, phosphorus, and 

 potassium, may be expected the first year after application. Nitrogenous fer- 

 tilizers will normally bring returns the first year of the application in accordance 

 with the quality of the vegetation when applied. 



SUMMARY AND CONCLUSIONS 



The result of four pasture experiments conducted in Massachusetts are sum- 

 marized as follows: 



1. In the first experiment, on an alluvial soil not typical of much of the per- 

 manent pasture land of Massachusetts, basic slag and low-grade sulfate 

 of potash changed a pasture flora consisting largely of bluets {Houstonia 

 caeridea L.) and poor grasses to one composed largely of white clover and 

 good grasses. 



2. The three other experiments were conducted on an upland glacial till soil 

 characteristic of much of the dairying section of Massachusetts. In these 

 experiments pasture flora consisting first, mainly of running cinquefoil 

 {Poteutilla canadensis L.); second, mainly of haircap moss {Polytrichnm 

 commune L. ); and third, of smaller proportions of these together with some 

 grasses and clovers, were transformed to flora consisting mainly of white 

 clover, bent grasses, and Kentucky blue grass. 



3. With the exception of a toxic effect of nitrate of soda for haircap moss, 

 lime was the most effective single material in producing desirable changes 

 in vegetation. Lime and potash were the most effective combination of 

 two materials; but a combination of lime, potash, and phosphate produced 

 the greatest change in vegetation. Nitrogen produced the greatest relative 

 and absolute increases in yield, and was more effective when used with 

 minerals than when used alone. 



4. The addition of nitrogen to the mineral treatments did not reduce the per- 

 centage of white clover in one experiment, but there was some indication 

 of a trend in that direction in another. In the presence of nitrogen, white 

 clover was maintained better with an abundant supply of minerals than 

 with a poor supply. Potash generally encouraged the presence of white 

 clover and thereby raised the protein content of the herbage. 



5. On plots having a vegetation largely of grass, applied nitrogen very gen- 

 erally caused an increase in yield of dry matter which varied from little to 

 several times that with minerals only. Generally, the added nitrogen caused 

 a relatively larger yield of protein than of dry matter. On plots having a 

 large percentage of clover, nitrogen had little or no effect. 



6. Plots which received fertilizer were more closely grazed than unfertilized 

 plots. This effect was noticed particularly on plots which received lime in 

 addition to the fertilizer. Chemical analysis of the clippings showed that 

 the addition of calcium (lime), nitrogen, and phosphorus caused an increase 

 of these elements in herbage. From this it appears that the composition of 

 the hcrl)age, as influenced by the fertilizers, is an important factor affecting 

 palatability. 



7. Botanical analysis was made of several of the crops of these experiments, 

 and the results brought out the importance of such work in the interpreta- 

 tion of results. Data obtained in white-clover years may lead to quite dif- 

 ferent conclusions from those drawn from results in off years. 



