CHAPTER III 



PRELIMINARY WORKS- 



The area to be operated upon may not be in a fit condition to 

 be immediately sown or planted up, and some preliminary work 

 may, therefore, be called for to render it suitable for the purpose. 

 The soil may be either (1) swampy or too wet, or (2) entirely 

 wanting in cohesion, or (3) situated on a slope and liable to slip 

 or be eroded, or (4) too dry to give any hope of rapid success, or 

 even of success at all without irrigation. 



SECTION I. 

 Treatment of swampy or water-logged land. 



Even species that are naturally found in swampy situations grow 

 all the better for some slight correction of an excess of water. 

 Without a certain amount of root-aeration the absorbing organs 

 of plants cannot form the organic acids wherewith to dissolve, and 

 thereby utilise, the large proportion of essential, but not immedi- 

 ately soluble, matters present in the soil ; and without sufficient 

 oxygenatiou the decomposing organic substances in the soil would 

 yield an injurious quantity of humic and other acids hurtful to 

 plant-growth. It is evident that suilcient sub-surface aeration 

 must prove especially fatal to young seedlings, with their extreme- 

 ly delicate, tender and herbaceous constitution, their very limited 

 root-apparatus, their smill size, their restricted transpiring surface 

 so utterly disproportionate to- their functional activity, and their 

 slight recuperative power. Lastly, water-logged soils,, being very 

 cold, reduce still further the already diminished activity of the 

 roots. Hence, as already explained in Part I, the significant 

 scarcity of natural reproduction on water-logged or constantly 

 flooded land. The few seedlings that do ultimately survive are 

 unable to extend their roots into the deeper layers of the soil, and 

 hence suffer both in their growth and health and their stability.. 



