ALLEGED REASONS FOR SHADING. i 



it be washed away by the next rain, and the application of commercial 

 fertilizers is for the same reason more or less impracticable. The use 

 of leguminous annuals would also be attended with the difficulties of 

 frequent replanting and the disposal of vegetable debris which often 

 invites the danger of plantation fires. Leguminous trees, however, 

 hold the soil in place, and seldom require replanting or other care; 

 their shade discourages the growth of weeds, diminishes the cost of 

 cultivation, and lessens the bad effects of drought. Rational shade cul- 

 ture thus renders it possible to utilize and maintain the fertility of 

 extensive regions favorably located climatically, but too broken to be 

 amenable to agriculture as practiced in temperate regions. In addi- 

 tion it has a most important bearing on coffee and many other tropical 

 industries throughout their present extent and future expansion. 



It could not have been expected that experimental investigation of 

 the value of leguminous trees in coffee culture would have been made 

 while all the benefits of their use were ascribed merely to the shade; 

 indeed the popularity of Erythrina is commonly explained by refer- 

 ence to its rapid growth and to the belief that it furnishes water to the 

 roots of the cacao trees, while Inga is said to have been selected for its 

 umbrella-like top which is supposed to jdeld shade of a qualit}^ and 

 quantity particularly grateful to the coffee. Moreover, experimental 

 decision on the subject would have been obscured by the fact that 

 shade, if ever directly beneficial, is seldom necessary for coffee, its 

 good effects being generally limited to the protection of the soil and 

 the superficial roots of the coffee. This consideration and others 

 to be noted later have furnished the partisans of shade with real 

 though insufficient arguments, while the generalty obvious deterio- 

 ration of coffee grown in heavily shaded situations has undoubtedly 

 strengthened the conviction of the advocates of open culture. To 

 determine experimentally the nature and extent of the injuries due to 

 shade has naturally seemed superfluous to those who believed that its 

 use was merely an ignorant superstition, while those who profited by 

 the planting of leguminous trees have persisted in defiance of all 

 assertions that shade is worthless or harmful, though they continued 

 to plant leguminous trees, not because leguminous, but because they 

 yielded a supposedly desirable kind of shade. 



Admitting that sustained fertility of the soil and not perennial shade 

 is the basis of the successful coffee culture of Central America and the 

 northern countries of South America, it is possible to appreciate in new 

 light niaiw facts and opinions which were previously meaningless or 

 quite contradictory. Shade may be detrimental, but leguminous trees 

 may be advantageous; to adjust the balance to the profit of the 

 planter is the problem to which experimental attention should now 

 be addressed. To maintain the maximum of fertility with a mini- 

 mum of shade, to lessen the labor of culture without decreasing the 



