A Day in an Irrigated Plantation 279 



water is turned into each block for a depth of two feet for about 

 two days. The remainder of the year the trees go without water 

 except for the limited rainfall. Naturally it is difficult to find 

 species capable of thriving under such conditions. 



Where patches of alkali soil occur, the blocks are trenched 

 and irrigated several years before planting. The flooding re- 

 moves the alkali and renders the soil fit for planting. 



The rotation first fixed for the plantation was 15 years, suffi- 

 cient to furnish fuelwood 5 to 6 inches in diameter. When the 

 railways ceased taking wood for fuel, the rotation was raised 

 to 20 years in order that a larger proportion of workwood might 

 be secured. 



The system now followed is coppice under standards. From 

 8 to 15 Shisham standards are left when the coppice is cut at 

 20 years and are allowed to stand over through another rota- 

 tion for the production of logs. At 40 years the standards are 18 

 to 26 inches d.b.h. and 50 to 60 feet high, producing each one 

 good log 12 to 17 feet long and a quantity of smaller timber. 



Nearly all the plantation was originally pure Shisham. Birds 

 have distributed mulberry throughout the whole area, and its 

 superior coppicing ability, more rapid growth and constant re- 

 seeding have enabled it in two rotations or less to almost com- 

 pletely oust the Shisham. A root fungus, not known to seriously 

 affect the Shisham in its natural habitat, the flooded river lands 

 of the region, has developed throughout the flooded plantation, 

 and is hastening the disappearance of the species. Mulberry 

 forms 80 per cent of the outturn from the compartments now 

 being cut. It is already becoming difficult to find sufficient Shis- 

 ham standards for the next rotation, and those standards being 

 left over will largely disappear because of root fungus before 

 the next cutting period. 



A question has already arisen concerning the species to be 

 used for standards. Mulberry will not do, as it reaches the limit 

 of its profitable development in 20 years. It will be probably 

 necessary to plant for standards. 



Limited experiments have been made with eucalypts. Ordi- 

 narily, this species cannot be planted in the Punjab because of 

 white ants which devour the young trees. White ants have been 

 driven out of the existing plantations by half a century of yearly 



