INSTITUTE, PUSA, FOR 1918-19 . 57 



from below and the appearance of this trouble. The lysi- 

 meters consisted of cemented tanks, ~j of an acre in area, 

 built above the ground level and provided with drainage 

 openings which could be closed or opened at will. Two 

 series of three lysimeters were constructed. One set was 

 filled with soil from the Kalianpur farm near Cawnpore, 

 the other with light Pusa soil. The Kalianpur soil is 

 exceedingly rich in available phosphate (0-318 per cent.) 



while Pusa soil, when analysed by Dyer's method, gives 

 very low figures for available phosphate (0-001 per cent.). 

 The results obtained were as follows : — 



(1) In both Pusa and Kalianpur soil, the indigo in the 



lysimeters with free drainage escaped wilt. 



(2) When the drainage openings were closed and 



waterlogging from below took place, all the 

 plants were wilted in both Kalianpur and Pusa 

 soil. 



(3) The wilt in the Kalianpur soil (rich in available 



phosphate) was much more pronounced than in 

 Pusa soil (said to be low in available phosphate). 



(4) The growth in Kalianpur soil was much slower 



than in Pusa soil. 



(5) The stoppage of drainage brought about an inter- 



esting change in the root system of the indigo 

 and caused the laterals to run near the surface. 

 Root development. The systematic examination of the 

 root system of this crop throughout the year, in various 

 soils and under different conditions of growth, continues 

 to yield interesting results. This work is still in progress 

 and is not likely to be completed for some time. The effect 

 of previous waterlogging on stiff soil on the root system is 

 very marked. Five months after sowing, equal areas on the 

 the waterlogged and control plots were taken and the 

 heights of the plants were measured. On the waterlogged 

 plot, the average height of 200 plants was 10-4 cm., on the 

 control the average height of an equal number of plants 

 was 28-0 cm. When the root system of the plants on these 

 plots was examined, it was found that the first effect of 



