148 



THE IRRIGATION AGE. 



IRRIGATION IN FRANCE. 



BY EDWARD CONNER. 



Though irrigation is much appreciated in France 

 it would be still more extensively practised were it not 

 trammeled by so many local impediments. The legal 

 complications to be removed before commencing to take 

 in hand the exploitation of a water meadow are as tortu- 

 ous as they are discouraging, while the difficulties are 

 still further increased by the minute division of landed 

 property. The laws of 1791 seem to be acted upon to- 

 day, at least as regards irrigating land. For instance, 

 the 'owner of the soil is only proprietor of the springs 

 thereon. To utilize a running stream that passes 

 through 3'our own or your neighbor's property, or to 

 dam it, to -turn its flows to your own benefit, or even 

 to tap the course of a canal, or of navigable or "float- 

 ing" river, are important matters to be arranged at the 

 outset, and which have frequently to be settled by re- 

 sorting to the Council of State. Then the state is chary 

 ,in according permission to utilize water that it has to 

 protect for all parties and for different purposes. In 

 the case of disagreeable neighbors, the difficulties and 

 worries in connection with the case will be found to be 

 numerous, while the cost of removing them will be 

 heavy. Nor is this all, for there are also important 

 preliminary matters to decide, such as the following: 

 Can a constant supply of water be obtained? Is that 

 water suitable ? Are the situation and the nature of the 

 soil satisfactory? Some water may contain highly in- 

 jurious substances to plant nutrition, the soil may be 

 naturally wet undrained, in a word having an im- 

 pervious subsoil. 



Irrigation, in the agricultural sense, implies the 

 employment of water in order to increase the yield of 

 crops; in another sense, it means the reclamation of 

 desert and arid countries. It is from rivers that irrigat- 

 ing water is generally obtained by placing the dam 

 across the river to secure a fall for the water over the 

 fields. One cubic foot of water supplied every second 

 during twenty-four hours will cover four acres of land 

 with a fraction less than a layer six inches deep. Given 

 suitable water and plenty of sunshine, good crops may 

 be obtained from nearly all soils. 



In France the water of the Durance river supplies 

 many canals that largely contribute to the prosperity of 

 Provence, while in Lombardy several canals feed irri- 

 gation, besides acting at the same time as navigable 

 ways. Important as it is to provide the soil with water, 

 it is equally as necessary to secure adequate means for 

 running the water off, in order to avoid stagnation and 

 the formation of marshes. This is why the flow ought 

 to be intermittent, so as to pass over one surface and 

 then over another alternately to water the soil by "frac- 

 tions" as it were. Plants, it should be well remembered, 

 are not unlike in their demand for water. Thus, where- 

 .as sainfoin, or trefoil thrives well on dry soil, lucerne 

 (or clover), another kind of grass needs a moist and 

 cool soil. The same remark equally applies to deep 

 rooted plants, which require less water than surface 

 rooted ones. 



There is both winter autumn to spring and sum- 

 mer irrigation; the water remains longer on the land 

 in the latter than in the former operation, and which 



also depends on the crops to be raised. It is alleged 

 that winter irrigation fertilizes the soil, while summer 

 irrigation only excites vegetation. However, it is not 

 easy to lay down any hard or fast rule as regards irriga- 

 tion, considering the many contradictions to which it is 

 subjected. It is evident that irrigation keeps the soil 

 a few degrees warmer in winter, while it must refresh 

 land in the summer. The great secret about the "art" 

 of irrigation is to properly carry it out. 



Sewage irrigation is a different question. Cultiva- 

 tors in the suburbs of Paris can command a uniform 

 supply of city sewage all the year round. French farm- 

 ers, when their holdings are small, are able to make 

 meadows gutters or channels, following the slope of the 

 ground, without any difficulty, and so distribute the 

 water to their satisfaction. If the operations are ex- 

 tensive, a local rural engineer is engaged for the pur- 

 pose of laying out the water furrows, etc., for the ad- 

 mission, distribution and carrying off of the surplus 

 flooding. The plan adopted depends on the lay of the 

 land, its area and the state of the water supply. Where 

 several neighbors associate in the work in common, all 

 will be found to work satisfactorily. 



In mountainous districts, such as the Vosges, the 

 peasants there have small reservoirs where the water 

 intended for irrigation purposes is stored, and let out, 

 as if out of a barrel, at fitting times. In less hilly 

 districts ponds are created in which the water is stored. 

 One hectare equals 2y 2 acres, and one metre is equal to 

 about 40 inches. Now, Belgrand, the great French en- 

 gineer, calculated that the quantity of water required 

 out of the basin of the Seine for the wants of cultiva- 

 tors in spring and summer is 1,583 cubic metres, equal 

 to a layer of water the 158th part of a metre, say 6 

 inches deep. He estimated that a clayey subsoil received 

 4,000 cubic metres of water by means of six waterings ; 

 but in the case of a permeable subsoil the waterings were 

 three times more numerous, while the total consump- 

 tion of water amounted to 9,600 metres per hectare. In 

 the south of France a concession for irrigation is based 

 upon, and corresponds to, a taking of a volume of water 

 of one libre (l 1 /^ pint) per second for one acre, pend- 

 ing six months, or a total of 15,350 cubic metres. But 

 it is only kitchen gardens that take such a quantity. 



Gasparin's rules were : For land containing 20 per 

 cent of sand, water every fifteen days, so as to give a 

 total layer of water equal to four inches deep; irrigate 

 every five days at the same rate if it contained 80 per 

 cent of sand. Arrange the supply for qualities of soil 

 between these two extremes. In the Vosges, after 

 mowing, a shallow sheet of water is laid on the field, 

 and the soil is allowed to dry every fifteen days, after 

 which the operation is renewed. In winter the water 

 is especially laid on, and particularly distributed over 

 any bald patches of the meadows, in order to get rid of 

 weeds and coarse grasses. As far as possible, watering 

 is stopped on the approach of frost, when it is resumed 

 cautionsuly in the spring and continued at intervals 

 till ten days before hay-making. There are intermittent 

 irrigations for the aftermath. In the Valley of the 

 Avre, in Normandy, the meadows there are watered 

 once a week during autumn and winter, and twice a 

 week during spring and summer. Night is preferred to- 

 day waterings whenever the air is dry. 



