38 BULLETIN 462, U. S. DEPARTMENT OF AGRICULTURE. 



however, that to erect an overhead S3^stem for the irrigation of most 

 of the field crops, where a yearly profit of $50 per acre is supposed 

 to be good, would be to lose money from the beginning. In any case, 

 the farmer should look into his conditions carefully before irrigating, 

 and be very sure that he can not get results from cheaper methods. 

 In many cases he will find that he can not, but there are many cases 

 where he can, and it should be his first duty to investigate. 



THE FUKROW METHOD AND OTHER SYSTEMS USED FOR IRRIGATING TRUCK. 



The two systems of subirrigation already described and the several 

 systems of overhead spray include 80 to 90 per cent of the area of 

 irrigated truck in the State. The remainder is covered by various 

 methods coming under the common designation of surface irrigation. 



The largest area of garden crops irrigated by surface methods is in 

 Manatee County, where it is estimated that 1,000 to 1,500 acres are 

 irrigated in this way. A small acreage of strawberries in Hillsboro 

 County is irrigated by surface methods. Other patches are scattered 

 through the State, probably totaling not more than 500 acres. 



The methods employed are very simple in most cases, many of the 

 farmers running water in open ditches and letting it flow down be- 

 tween the rows, regulating the flow by means of a shovelful of soil 

 at the head of the furrow. Some farmers use lengths of hose to aid 

 the flow in the furrows, while others use light-weight pipe to convey 

 water over the field. The objections to these systems are that they 

 are wasteful of water, and that there is a considerable amount of 

 labor attached to their operation. The possibilities in irrigation by 

 the furrow method are worthy of careful consideration and doubtless 

 it will become much more popular when better methods of distribu- 

 tion are emplo}^ed. 



IRRIGATION OF CITRUS GROVES. 



The need of moisture for citrus trees was taken up to some extent 

 under the discussion of soil tests. It was shown that the soil is com- 

 monly very dry for long periods, producing a harmful effect on the 

 trees. 



In order to determine the benefits accruing from the irrigation of 

 citrus groves, a portable pumping plant was procured which could be 

 taken from one grove to another. Such a plant will irrigate one or 

 two rows in an unirrigated grove; and the difference in yield and 

 quality of the fruit is observed later in the season. In this way exact 

 data may be obtained which will give the farmer some foundation on 

 which to estimate the allowable cost of applying water to the tree. 

 No definite data have yet been obtained. 



A great many orange and grapefruit groAvers claim that the benefits 

 from irrigation are not worth the expense of installing and maintain- 



