DISCUSSION ON IRRIGATION AT A MEETING OF THE 

 PLANTERS AT FAJARDO ON AUGUST 15, 19 2. 



By W. W. SCHLECHT. 



Irrigation was first introduced in regions were the rainfall was 

 deficient for the growing of any crops, but it is now being rapidly 

 extended to regions where, although crops may be grown, the rainfall 

 at times, especially during the growing season, is too scant to produce 

 the best and largest yields. In order best to satisfy the conditions 

 of plant growth, the moisture should never fail from the time of plant- 

 ing until the crop is fully matured, and there are certain times when 

 the cessation of the supply will do more harm than at others. This 

 applies to sugar-cane, for which a drought during February or March 

 is not very harmful, but should a similar drought occur during the 

 growing season, from June to November, the yield is decreased by a 

 large percentage. Irrigation by supplementing the rainfall does away 

 with the element of chance, makes the crop larger and better and eli- 

 minates failures. 



In order to determine the extent to which this region (Fajardo) 

 requires irrigation, the same table of duty of water which was assumed 

 by the Porto Eico Irrigation Service has been used. It is assumed 

 that sugar-cane requires 72 inches of moisture during a year. This 

 may be rainfall or irrigation water. This gives an average of 6 inches 

 per month, but it is furthermore assumed that shortly after cutting 

 or planting and also while maturing and also during the 20 weeks of 

 harvesting the needs are not as great as during the growing season, 

 and based on these assumptions, a table of monthly requirements of 

 moisture or "duty of water" has been compiled. This it is assumed 

 will, in a general way, apply to this region. 



DUTY OF WATER. 



Total, 72.0 inches. 



Combining these requirements of moisture with the rainfall reci.rd 

 observed at the Station at Fajardo gives the amount of irrigation water 

 that should be applied to the land to obtain the best results. 



The table shows that during the past three months, from May 1,5th 

 to August 15th, which are in the growing season, there was a deficiency 

 of 12 inches of moisture. This, as can be seen by passing through the 



