GENERAL PRINCIPLES. 43 



lands that are not hilly- If applied in the spring in the 

 fresh form it is not easy to avoid raking up more or less 

 of the manure in the hay at harvest time. Artificial 

 fertilizers may of course be used in lieu of farmyard 

 manure. The kinds that ought to be used and the quan- 

 tities to use will be determined largely by the needs of 

 the soil and of the plants. Fertilizers rich in nitrogen 

 are especially helpful in growing grasses. Potash is 

 equally helpful in growing clovers, but in a majority of 

 instances complete fertilizers are the most satisfactory. 

 It is usual to apply these fertilizers just after growth 

 has begun or after each cutting. 



The renewal of meadows through self-seeding is more 

 applicable to those in which medium red clover (Trifo* 

 Hum pratense) is one of the factors, than to those com- 

 posed entirely of grasses, since the former produces seed 

 in the autumn after one crop of hay has been harvested. 

 On certain light soils and in certain areas more or less 

 deficient in rainfall, meadows have thus been main- 

 tained for many years. But to maintain them thus it 

 was found necessary to graze them but little, or not at 

 all, according as moisture was present or absent. Mead- 

 ows composed entirely of grasses could not be renewed 

 thus, since after being mown they do not usually produce 

 seed again the same season. But it would be possible 

 to renew them thus by grazing for one season, but not so 

 closely as to preclude a part of the plants from maturing 

 and shedding seeds. 



Renovating Pastures. Pastures may be renovated 

 and improved by adding .seed directly or through the 

 medium of self -seeding, by dressing them with fertilizers 



