94 ENVIRONMENT AND MILLING QUALITIES. 



in wheat growing the best sample is produced under those condi- 

 tions which give the highest yield. This in reality clears up the 

 whole matter as will be obvious from the experiments described 

 below. These relate to hot weather cultivation and drainage — 

 two important factors in wheat production in the alluvium. 



A. Hot weather Cultivation. 

 In previous papers 1 attention has been drawn to the marked 

 effect of hot-weather cultivation in the production of wheat and 

 other crops, both kharif and rabi, in the alluvium of the Indo- 

 Gangetic plain. During the early period of the wheat experiments 

 at Pusa, when attention was being paid to the best methods of 

 growing the crop under Indian conditions, it was decided to try the 

 effect of opening up the stubbles immediately after harvest and so 

 exposing the soil to the hot dry winds which prevail at this period 

 of the year. The stubbles were ploughed several times and 

 thoroughly opened up resulting in the production of a deep dry 

 mulch of fine soil in which no growth of weeds was possible. This 

 enabled all the early monsoon rains to be absorbed, and the subse- 

 quent procedure consisted in sufficient cultivation to keep down 

 weeds and to break up the surface so as to allow of the percolation 

 of more water into the subsoil. In this manner sufficient moisture 

 was absorbed for a wheat crop of over forty bushels to the acre and 

 the fields rapidly became free of weeds. In the lighter lands, the 

 water holding capacity of the soil was increased by ploughing in 

 crops of san (Crotalaria juncea, L.) raised on the early monsoon 

 showers, but this has not yet been found necessary in the heavier 

 lands. 2 



1 See Nature, Feb. 17th, 1910 ; Memoirs of the Dej)t. of Agr. of India (Botanical Series) 

 Vol. Ill, No. 4, 1910, and Pusa Bulletin, No. 22, 1911. 



2 If green manuring with san is attempted on heavy wheat lands in Bihar, in years when 

 these soils are waterlogged after the green crop is ploughed in, the resulting wheat crop is 

 always less than if no manure had been added. The addition of the green crop seems to ac- 

 centuate anaerobic fermentation in the soil and to reducs the available nitrogen for the wheat 

 crop. Fortunately such heavy soils retain water well and are not in need of green manure for 

 this purpose. The fact that green manuring these heavy lands for wheat reduces the yield 

 seems to indicate that on rice lands in Bihar green manuring with san would increase the yield 

 considerably. 



