AND COLLEGE, PUSA, FOR 1915-16 85 



parison of these principles with the practices in vogue in 

 the irrigated areas of Baluchistan cannot fail to show that 

 an enormous quantity of valuable water is now being 

 wasted. As the principles underlying water-saving are 

 not understood and little has been done in utilizing the 

 present supplies to the best advantage, it will not be out of 

 place briefly to refer to them here. Both experience and 

 experiment prove that if the maximum duty of irrigation 

 water in wheat-growing is to be obtained, special attention 

 must be paid to the following five principles : — 



1. The irrigation water available must be spread over 

 the largest possible area. 



2. Heavy waterings reduce the proportion of grain to 

 total crop. 



3. The growth period of wheat is increased by heavy 

 waterings. 



4. When the water supply is limited, the root develop- 

 ment of the wheat crop must be deep. 



5. The soil moisture must be preserved, as far as 

 possible, by a surface mulch of dry soil. 



Applying these principles to the conditions of the 

 Quetta valley, it was found that the highest duty of water 

 could be obtained by irrigating the land once a few days 

 before sowing and by breaking up, by means of the lever 

 harrow, the rain crusts formed during winter and spring. 

 The average yield on large scale trials on unmanured land 

 at the Experiment Station worked out at 17} maunds of 

 grain per acre. The zamindars, on the other hand, often 

 water their wheat six times after sowing and obtain an 

 average of 13^ maunds of grain. The same amount of 

 water spread over seven acres, if used according to the 

 method employed at the Experiment Station, would give 

 7 times 17} or 124J maunds of wheat. The difference in 

 favour of the experiments is therefore 110} maunds of 

 wheat. If the average irrigated acreage of wheat in the 

 Quetta valley is multiplied by 100, the result would indi- 

 cate, in maunds of wheat per annum, the present annual 

 waste of water on this crop alone. On every 200 acres of 



