SUMMARY ON FERTILIZATION 321 



decreased the weeds and increased the useful plants, 

 grasses and clovers; that basic slag increased the clovers 

 about 20 per cent and some years up to 35 per cent, 

 while weeds were much reduced, and that the plot having 

 1,500 pounds of slag resulted in the cleanest pasture 

 fullest of grasses and with most clovers. Lime added 

 to superphosphate resulted in the most clovers of any 

 plot and here also weeds were most effectually repressed. 

 Lime alone slightly increased the clovers but had little 

 effect on weeds. The feeding of cake increased the 

 grasses and repressed the weeds. It was found that 

 orchard grass was increased where basic slag was used 

 and to a less extent by bonemeal and superphosphate. 

 Sheep fescue was increased by ground lime and super- 

 phosphate and by cake feeding. As the sheep were 

 taken off at the end of summer there was left grass to 

 be grazed by cattle. Calling the keep of a cow worth 

 24 cents, the plots produced yearly revenues varying 

 from 64 cents on the untreated plot to $1.36 on Plot 3, 

 $1.20 on Plots 4 and 9, $1.02 on Plot 10, $i on Plot 

 i , $1.08 on Plot 8, 86 cents on Plot 2, 96 cents on Plot 

 5, $1.02 on Plot 7. 



SUMMARY OF FERTILIZATION. 



Grasses take from the soil available nitrogen, thrive 

 especially well in soils rich in nitrogen, and need also 

 phosphorus, potassium and lime. Most American soils 

 contain enough potassium, so the need comes down to 

 lime, phosphorus and nitrogen. Grasses can not get 

 nitrogen from the air, while clovers can. When the 

 conditions are right for clovers and they are well estab- 



