DIRECT SOWING. 153 



allowing it to be broken up by swine ; or by a temporary 

 cultivation of field crops. Whether the one or other is prefer- 

 able depends on the method of sowing and the cost of the 

 operation. 



Too much moisture may prevent or retard germination, 

 may obstruct aeration of the soil, or render it cold and cause 

 the seed to rot. These inconveniences can be prevented either 

 by a better distribution of the water, or by draining. The 

 latter plan should be restricted to cases where the moisture is 

 really excessive, and where no injurious effect upon adjoining 

 areas is likely to be produced. In forestry it is better to 

 drain too little than too much ; in manj^ cases the forester 

 will do well to be satisfied with a species which will grow in 

 moist or wet soil, rather than endanger the proper develop:- 

 ment of valuable crops growing on adjoining lands. 



Irrigation may become necessary w^here the soil is ex- 

 cessively dry. It is an expensive operation, and the necessary 

 outlay will only be recouped in special cases. 



Manuring rarely occurs, except in nurseries, because it is 

 too expensive compared with the increase in the returns 

 which it is likely to secure. 



h. Time of Soicin;]. 



Nature sows in autumn in the case of most species growing 

 in temperate Europe, in some cases in summer, and in others 

 in winter or spring ; hence no absolute guide is given as to 

 the best time for sowing. Of the naturally sown seed a large 

 portion, while lying over winter, is eaten by animals, or 

 perishes through adverse influences of the weather, so that 

 only a small portion actually germinates in spring. In 

 artificial sowing the seed must be carefulh' husbanded, hence 

 it should be done at the most favourable season for germi- 

 nation, namely, wdien the soil is sufficiently moist and wheu 

 sufficient heat is available. The best time for sowing in 

 temperate Europe is during April and May, according to the 

 local climate. 



