174 SYLVICULTURE IN THE TROPICS .n 



seedlings a better chance of obtaining the requisite 

 moisture at a lower level. The sides of the trench also 

 afford a certain amount of shade to young seedlings 

 when made in the proper direction. On flat land, 

 therefore, it will be preferable to give to the trenches 

 a direction which will give most shade during the hot, 

 dry weather, and which will vary slightly according to 

 the latitude north or south of the equator. On hilly 

 ground they should be made horizontal; and, both on hilly 

 and flat ground, should be interrupted at short intervals, 

 not only to collect water, but to prevent the trenches 

 being turned into drains. The seed can be sown at 

 the bottom of the trench either in furrows or dibbled 

 in from distance to distance. When there is an un- 

 certainty as to whether the dry season may not be 

 interrupted by some heavy downpours which might fill 

 the trenches and kill the germinating seed or the 

 seedlings, seed is sown, not only at the bottom of the 

 trench but also along its lip. If the season turns out 

 dry, the seeds at the bottom of the trench will have the 

 best chance of success ; but if rain fills the trenches, 

 those on the brims will obtain the necessary moisture from 

 them. 



On water-logged soils the seed can be sown on ridges, 

 and the young seedlings can be thus given a fair start. 



When sowing in patches these patches are usually 

 arranged in squares, rectangles, or equilateral triangles 

 as described in the preceding chapter, except perhaps on 

 rocky ground, or on soil of varying quality where they 

 may be made where the plants are most likely to succeed. 

 The patches may be made of varying size, from 30 

 to 90 cm. square (1 to 3 ft. square), or they may be 

 rectangular, like interrupted strips, in which case they 

 are destined to contain a larger number of seed. The 

 soil having been prepared the seed is dibbled in. It is 

 usual to put two or three seeds at least in the same 

 patch, but not in the same hole, in order to provide for 

 any failures. If more than one seed germinates, the 

 superfluous seedlings can afterwards be lifted out and 



