IRRIGATION IN FLORIDA. 25 



terns in Florida, but in such cases it is possible that the water plane 

 stood above the tiling for long periods, thus preventing the entrance 

 of tree roots, as the roots of most cultivated trees will not penetrate 

 below the level of the usual water plane. 



There are several groves near Terra Ceia that are subirrigated 

 and at least one grove near Palatka. At the present time these sys- 

 tems are working well, and are especially valuable from a drainage 

 standpoint. As these installations are new it can not be determined 

 how long they will withstand clogging by the tree roots. The sub- 

 soil surrounding the tile may be of such character as to keep roots 

 away from the tile or the ground water may be high enough to dis- 

 courage deep rooting. Still there is considerable danger of clogging 

 if the ground water should be lowered by protracted drought or by 

 artificial drainage on a large scale. 



A common rotation of crops in the Sanford trucking district is as 

 follows: first, lettuce is planted about September 1 and harvested 

 about the middle of October. This is followed by celery, which 

 should be harvested by February. Cucumbers may follow immedi- 

 ately and should be off the ground by the first week in May. Corn 

 then can be planted and harvested in August. There still remains 

 enough time to grow a crop of native hay before the time to plant 

 lettuce again. 



Many of the farmers follow an entirely different schedule, al- 

 though most of them plant celery. Some plant celery in October and 

 get two crops, the last crop being harvested in July. Others plant 

 beans, cabbage, cauliflower, and various other vegetable crops, while 

 still others plant a considerable acreage of potatoes. The winter 

 truck crops are shipped to the northern markets, while the corn and 

 hay crops usually are consumed at home. 



It has been stated that the cost of tiling averages $100 to $125 per 

 acre. This would be a heavy outlay for many crops, but when the 

 total cost of equipping land and the annual expense of growing a 

 celery crop is considered, the cost of irrigation does not seem ex- 

 orbitant since the cost of equipment, outside of irrigation, is about 

 $450 per acre. 



It should be emphasized that the Sanford subirrigation method 

 serves also for drainage — entirely, in fact, for some crops. This is 

 true especially for the summer cropping during the rainy season and 

 frequently during heavy rains in the winter season. There are some 

 disadvantages in having subirrigation and drainage systems com- 

 bined, one being the large loss resulting from the draining away of 

 expensive fertilizers; and another, the need of saturating the soil in 

 order to get enough moisture at the surface. Even if other methods 

 of irrigation were used, however, it would be necessary to have 

 drainage systems installed to take care of excess water, and when it 

 61867°— Bull, 462—17 i 



