FARMING IN THE LOWER RIO TiRANDE DISTRICT. 19 



ALKALI. 



Some of the low-lying soils contain alkali and, as is the case with 

 all irrigated regions in dry climates, the use of irrigation water 

 intensifies this condition. This is more particularly true near the 

 larger canals, where seepage water permeates the bordering land. 

 The use of drainage ditches and particularly opened " borrow pits " 

 helps materially to improve this condition. 1 Tile drainage is some- 

 times resorted to where proper outlets are available. Thorough 

 drainage will overcome these seeped and alkaline soil conditions. 



CLIMATE. 



The climate of the region is mild and healthful. The winters are 

 sufficiently warm for the production of the principal truck crops. 

 While the summers are comparatively long, they are not excessively 

 hot, temperature seldom being higher than 98° F. There are short 

 periods of disagreeable weather conditions in winter known as 

 " northers," which are the southern phase of blizzards of the north- 

 west and are accompanied generally by considerable wind and rain. 

 The temperature often falls to the freezing point during these 

 periods. 



The average date of the first killing frost in the fall is December 

 21 and of the last in the spring February 6. The earliest frost date 

 on record is November 15, and the latest in spring is March 5. It is 

 not uncommon for a winter to pass without a single frost. 



The average annual rainfall is approximately 27 inches, with the 

 greatest monthly rainfall occurring during June and September. 

 On account of the fact that many of the rains are torrential in char- 

 acter, the total precipitation is not so beneficial as is the case with 

 slower and well-distribute 1 rainfall. Not infrequently the annual 

 rainfall reaches a maximum of 40 inches, while it may be as low as 

 12 inches per year. 



There are occasional seasons when the rainfall is so well distributed 

 and in such quantity as to make irrigation unnecessary. Indeed, in 

 the vicinity of Lyford and Raymondville all crops are produced 

 under dry-farming conditions, though the strictest methods of mois- 

 ture conservation are necessary for successful farming. 



The region is generally healthful, the subtropical diseases being 

 very rare or nonexistent. Mosquitoes, fleas, and other insects are not 

 serious pests to the inhabitants. On account of the mild climate 

 there are a number of insect pests and plant diseases that attack 

 crops to some extent. 



1 A " borrow pit *' is an excavation or ditch bordering a canal from which earth has 

 been taken to form the banks of a canal. The pits are often irregular in size and depth, 

 but when opened from one to another successively, drainage of seepage water from the 

 canal may be effected. 



