Scientific Agriculture. 



[June, 1909. 



tion and frequent irrigation, some delay- 

 in bearing would .have been amply- 

 compensated for by loss of current 

 outlay for fertilizers, and less liability 

 to injury from frequently unavoidable 

 delay, or from inadequacy of irrigation. 



Conservation of Soil Moisture. —Along- 

 side of economy in the use of irrigation 

 water, the conservation of the moisture 

 imparted to the soil either by rains or 

 irrigation is most important; critically 

 so where irrigation is unavailable. 



Utilization of Winter Rains and 

 Winter Irrigation.— However strong is 

 the popular demand for storage of the 

 winter rainfall and flood waters, too 

 many do not appreciate the importance 

 of the storage they can command with- 

 out the use of reservoirs within their 

 own soil mass. While there is a well- 

 grounded objection to subjecting plough- 

 ed land to the leaching action of the 

 abundant rains in the humid region, no 

 such objections hold in the case of 

 lands lying within the limits of 20 to 

 25 inches of annual rainfall. Here the 

 absorption of the winter rains should be 

 favoured to the utmost, for the run-off 

 is mostly a dead loss. Fall ploughing 

 wherever the land is not naturally 

 adequately absorbent, and is not there- 

 by rendered liable to washing away, is a 

 very effectual mode of utilizing the 

 winter's moisture to the utmost, so as to 

 brine: about the junction of the season's 

 moisture with that of the previous 

 season, which is generally considered as 

 being a condition precedent for crop 

 production in dry years. The same of 

 course holds true of winter irrigation ; 

 the frequent omission of which in 

 presence of a plentiful water supply at 

 that season is a prolific cause of avoid- 

 able crop failures. Moistening the ground 

 to a considerable depth by winter irri- 

 gation is a very effective mode of pro- 

 moting deep rooting, and will thus stand 

 in lieu of later irrigations, which being 

 more scant, tend to keep the roots near 

 the surface. 



Knowledge of the Subsoil— It cannot 

 be too strongly insisted upon that in 

 our arid climate farmers should make 

 themselves most thoroughly acquainted 

 with their subsoil down the depth of 

 at least four, but preferably six or 

 eight feet. This knowledge, import- 

 ant enough in the Bast, is doubly 

 so here, since all root functions are and 

 must be carried on at much greater 

 depths. It is hardly excusable that a 

 business man calling himself a farmer 

 should omit the most elementary pre- 

 caution of examining his subsoil before 

 planting orchard or vineyard, and 

 should at the end of five years find his 

 trees a dead loss in consequence of an 



unsuitable subsoil. Similarly, no irri- 

 gator should be ignorant of the time 

 or amount of water it takes to wet 

 his soil to a certain depth. We have 

 lately seen a whole community suffering 

 from the visible decline of thift of its 

 fruit trees, which occurred despite what 

 was considered abundant irrigation ; 

 i.e., allowing the water to run for a 

 given length of time, deemed to be suffi- 

 cient. Yet on being called in to investi- 

 gate the causes of the trouble, the 

 station staff found that the irrigation 

 water had failed to penetrate during 

 the allotted time to any beneficial 

 extent, so that the trees were, in the 

 main, suffering from lack of mois- 

 ture — a fact that could have been 

 verified by any one of the owners con- 

 cerned, by simply boring or digging a 

 hole or two. But no one had thought 

 of doing so, and all kinds of myste- 

 rious causes were conjectured to be at 

 work in the suffering orchards. A defi- 

 nite knowledge of the rapidity with 

 which irrigation water penetrates 

 downward and sideways in his soil 

 should form a part of the mental equip- 

 ment of every irrigator, particularly 

 in arranging his head ditches. For in 

 sandy lands it may easily happen that 

 when these are too far apart, the 

 Avater near the head ditch is already 

 wasting into the country drainage at 

 the depth of ten or twelve feet before 

 any has reached the end of the furrows, 

 or has wetted the lower half adequ- 

 ately. Many such cases come under 

 our observation, and such ignorance 

 of the conditions governing one of the 

 most important factors of success is 

 hardly excusable in any one. Nor is the 

 quality of the water used indifferent in 

 this connection ; for waters containing 

 alkali will fail to penetrate the soil as 

 quickly as would ordinary steam waters. 



Preventing Evaporation.— But suppos- 

 ing the moisture to have reached the 

 depths of the soil, whether from rains 

 or from irrigation, it is essential that 

 proper means be employed for retaining 

 it in the land, and especially to pre- 

 vent evaporation. That this is best ac- 

 complished by a mulch on the surface, 

 and that the best mulch for the purpose, 

 which need not be hauled on or off and 

 is always ready, is a surface layer of 

 loose, well-tilled soil, is pretty well 

 understood by all. But the extent to 

 which the presence or absence of such 

 a non-evaporating layer influences plant 

 growth and fruit production in a criti- 

 cal time, is not so fully appreciated. In 

 the present case the cultivation was 

 omitted in principle by one owner, who 

 considered cultivation superfluous on 

 the loose, generous soil on Alameda 



