Scientific Agriculture. 



460 



[November, 1908. 



In carrying out this system in practice, 

 water is allowed to run do wa the trench 

 AB. to B, the furthest point from the 

 main distributing channels. The last 

 ring is then opened and allowed to fill. 

 As soon as this takes place, the main 

 trench is filled at C with a fillet of earth 

 and the connection at D is opened. The 

 second ring is now filled, and so on. In 

 this way there is no stoppage of work, 

 and the tree is not only supplied by the 

 water in the ring but also by that in the 

 section of the trench CB. 



With young trees the rings are filled 

 up after every monsoon and re-made on 

 a larger scale at the beginning of the 

 next hot weather after weathering and 

 manuring have been done. The longi- 

 tudinal trenches are left during the mon- 

 soon, as these serve as drainage channels 

 and prevent local water-logging. 



In planting new trees this system of 

 irrigation has been found most useful. 

 After the holes have been dug for the 

 trees and filled in, the rings are made 

 and the irrigation water run into these 

 before 'planting. By this means any 

 shrinkage and subsidence of the soil 

 takes place before planting, and can be 

 adjusted. Moreover, the young trees 



have the benefit of being planted in 

 a moist soil. February and March 

 are best months for planting young 

 trees in Behar, and by this means they 

 can be establised before the heavy rains 

 of the monsoon in July and August. 



In connection with the manuring of 

 trees this system of irrigation has 

 proved most useful. One of the difficul- 

 ties in applying manure to fruit trees 

 in India is the subsequent damage 

 done by white-ants {Termites), which 

 are attracted by the organic matter 

 of the manure and frequently turn 

 their attention to the tree and destroy it. 

 If the trees are manured just before 

 the rings are made, and if care is taken 

 to apply the manure only to the ring 

 of soil just underneath the outside 

 branches, the first watering not only 

 tends to rot the manure but also to 

 drive off the Termites. 



This ring method has great advatages 

 over the basin method of irrigating 

 fruit trees; which is practised by the 

 cultivators in India. In the basin 

 system (Fig. 2.), a shallow circular hole 

 is excavated round the base of the tree, 

 and these basins are connected up by 

 short trenches between the trees- 



In the first place, trees like Citrus plants 

 are not benefited by water lying round 

 the base of the stem and are then often 

 attacked by the "collar rot" disease. 

 Secondly, the water is not applied 

 directly to the young roots of older trees, 

 while in young trees they are apt to be 

 water-logged. Lastly, this method does 

 not facilitate manuring and drainage in 

 the monsoon. 



In the case of transplanted crops like 

 tobacco and ganja the system becomes 

 one of modified furrow irrigation. The 

 great danger in growing a crop like 

 tobacco, especially where the autumn 

 rains fail, is the loss of plants which 

 occurs on transplanting them in the 

 field and also from grasshoppers. The 

 usual method in India is to transplant iu 

 the evening, to water the young plants 

 and to cover them with nim leaves 

 during the heat of the day. Even when 

 every care is taken, many plants die. 

 In plant-breeding work, this loss is of 

 great importance owing to the danger of 

 a dead plant being replaced by one of a 

 wrong variety. In order to minimise 

 this loss, I have devised the following 



method :— After cultivation and manur- 

 ing are finished, furrows about one 

 foot wide and four inches deep are 

 laid off at the proper distance, so that 

 there will be a furrow between alternate 

 rows of tobacco. 



These furrows are then filled with water 

 sveral times, and the water is allowed to 

 percolate laterally until the soil is well 

 moistened between the furrows. Trans- 

 planting is now carried out in the soil 

 moistened by lateral seepage from the 

 trenches, and the young plants are 

 covered with nim leaves during the day 

 which are removed at night. When this 

 method is used, the loss of plants is not 

 more than one per cent., and there is 

 practically no danger of destruction by 

 grass-hoppers. During the last year when 

 the failure of the autumn rains almost 

 destroyed the tobacco crop of the 

 cultivators in the district, no difficulty 

 was experienced in growing good tobacco 

 at Pusa. Subsequent irrigation is done 

 by filling the trenches in the same 

 manner as that adopted before transplan- 

 ting.— Agricultural Journal of India, 

 Vol. III., Part III., July, 1908. 



