ORANGES IN WESTERN ANDALUSIA. 573 



fifteen days, according to the greater or lesser porosity of the soil. The 

 first irrigation commonly takes place after the dropping of the blossoms, 

 though many practical growers recommend not to begin before July, 

 alleging that irrigation before that period is generally hurtful. It seems, 

 however, a fair presumption that the conditions of humidity prevailing 

 during the previous spring are a factor to be considered in this respect. 

 Irrigation is to be discontinued in October. The system most in vogue 

 is to have circular excavations surrounding each tree, said excavations 

 being connected by small gutters or canals, into which the water is al- 

 lowed to flow. This is the most economical method, and that is its strong 

 point in a country like this, where the rain-fall is light. Some of the 

 more careful orchardists are, however, opposed to this mode, urging that 

 the practice supplies an excess of water to the main roots (which leads to 

 asphyxia), whilst the eccentric rootlets are insufficiently, or rather, not 

 supplied at all. Where there is no scarcity of water it would certainly 

 be rational to experiment upon the effects of irrigation upon the entire 

 surface of the orchard, thus supplying the outlying rootlets with the 

 needful humidity. 



March is the month when plowing is first applied to the orchards, at 

 which time the irrigating ditches are restored or renewed. This is also 

 the proper time for putting on manure, which should be placed around 

 the trees, in zones of 1 to 2 meters in radius, this being done before 

 plowing has begun. Where the trees are planted in squares (marco 

 real) cross-plowing at right angles is in order; where the u diamond" 

 (ires bolilla) plan is adopted, the first furrows may be crossed and re- 

 crossed with advantage. The second plowing takes place at the end 

 of May. A plow making a furrow of from 20 to 30 centimeters in depth 

 is generally used. In August the soil should be hoed thoroughly ; this 

 process to be repeated in September or October. The best growers 

 affect the use of the harrow after each plowing, as it leaves the soil in 

 a mellower condition, breaks up the clods, and destroys the weeds. 



Before the orange trees have attained their full size (usually for five 

 or six years after placing them in the orchard) it is not uncommon to 

 raise some leguminous or root crop on the land, taking care, however, 

 to leave a circle of one meter in radius around each tree unoccupied. 



Fertilizers. The raising of successive orange crops year after year 

 must necessarily end in withdrawing from the soil all available mate- 

 rial for such culture, hence the attention of agronomists has been long 

 devoted to devising means for ascertaining the exact nature of the con- 

 stituents withdrawn, as well as the best mode of resupplying the soil 

 with such constituents or their equivalents in an assimilable form. The 

 following analyses taken from a recent treatise by a well-known Spanish 

 agronomist,* show what these constituents are and their relative quan- 

 titative proportions: 



*Don Luis Maria Utor, " La Agriciiltnra moderna." 



