602 FIELD AND GARDEN PRODUCTS 



fertilize. Plowing when done in the spring should be shallow. 

 Here the methods of irrigation and culture are different from those 

 employed elsewhere. 



Lands for Upland Rice. The lands which are, or may be, de- 

 voted to growing rice without irrigation are so varied in character 

 and location that no description can be given. In general it may be 

 said that rice can be grown on any soil adapted to wheat or cotton 

 provided climatic conditions are favorable. Rice is sometimes planted 

 between the rows of cotton. 



Irrigation. In rice culture the size of the fields depends on cir- 

 cumstances, chief among which are the slope of the land and the 

 character of the soil as regards drainage. Fields range in size from 

 60 to 80 acres on the level prairies of south\yestern Louisiana down 

 to 1 or 2 acres along the banks of the Mississippi River. In oriental 

 countries fields seldom contain more than a half acre. The entire 

 surface of each field should be nearly at the same level so that the 

 irrigation water will stand at about the same depth. Hence, where 

 the slope of the surface is considerable, the fields must be made small. 

 Fields must also be laid off in such a manner as to admit of effective 

 drainage. 



Canals and Levees. In coast-marsh and river-bottom culture 

 a canal is excavated on the outer rim of the tract selected, completely 

 inclosing it. The excavated dirt, is thrown upon the outer bank to 

 form a levee. The canal must be of sufficient capacity for irrigation 

 and drainage. The levee must be sufficient not only to inclose the 

 flooding water, but to protect the fields from the encroachment of 

 the river at all seasons. When practicable the rice lands are flooded 

 from the river, and find drainage by a canal or subsidiary stream 

 that enters the river at a lower level. The embankment must be 

 sufficient to protect the rice against freshets or salt water. Freshets 

 are injurious to growing rice, not only because of the volume of 

 water, but by reason of its temperature. A great body of water de- 

 scending rapidly from the mountains to the sea is several degrees 

 colder than water under the ordinary flow. Any large amount 

 of this cold water admitted to the field not only retards the growth, 

 but is a positive injury to the crop. In periods of continued drought 

 the salt water of the sea frequently ascends the river a considerable 

 distance. Slightly brackish water is not injurious to rice, but salt 

 water is destructive. 



The tract of land selected and inclosed is then cut up by smaller 

 canals into fields or subfields of suitable size, a small levee being 

 thrown up on the borders of each. The entire tract is usually level, 

 but if there should be any inequality care must be taken that the sur- 

 face of each subfield be level. The main canal is 10 to 30 feet wide, 

 about 4 feet deep, and connects with the river by flood gates. Through 

 these canals boats of considerable tonnage have ready access to the 

 entire circuit of the tract, while smaller boats can pass along the sub- 

 canals to the several fields. The subcanals are usually from 6 to 10 

 feet in width and should be nearly as deep as the main canal. Dur- 



