28 KEPOUT OF THE AGlliCULTtJRAL RESEARCH 



pends on the season of the year. During the dry season 

 the general loss from this cause is much less than during 

 the monsoon ; hence the " protection " provided by a " rabi " 

 crop will be generally much less than that of a " rains " 

 crop; the former may be 2" or 3", the latter 7" or 8" of 

 water, {c) The amount of water which runs off the land 

 during heavy rain is known to vary within wide limits, and 

 although the gauges have yielded some information on the 

 subject, it relates to only one soil maintained perfectly 

 level. No very explicit deductions are therefore possible, 

 but the general conclusion has been drawn that perhaps 

 popular ideas have exaggerated its amount. 



The Amount of ISIitrate in Soils. — This subject is one 

 which has long been considered of great importance, and 

 the drainage water from the gauges, as also some field re- 

 cords, have added much to our knowledge of the subject in 

 so far as India is concerned. The total amount annuallv 

 formed in fallow land is very much greater — twice or three 

 times — than at Rothamsted. Then another feature has 

 appeared, namely, that nitrification is not active through- 

 out the dry weather, that is in fallow land — not irrigated; 

 absence of moisture in the surface soil during a part of 

 this period might be a controlling factor, but it is not a 

 complete explanation, because the sub-soil is always moist, 

 and here nitrification is similarly restricted to the monsoon. 

 Nor does the variation of temperature offer any better ex- 

 planation. With the advent of the monsoon, however, 

 nitrates form with astonishing rapidity, the occurrence 

 being most marked immediately after the first heavy ram. 

 This investigation promises to prove of great interest. 



The Water Requirernents of Crops. — Allusion has been 

 made in previous reports to this subject, and a second 

 memoir, No. 10, Chemical Series, has been published. In 

 continuation of what was published in Memoir No. 8, it 

 has been found that the nature of the soil has no effect on 

 the Transpiration Ratio; at the same time this factor has 

 a great influence on the rate of water movement, and hence 

 indirectly on the weight of crop produced. Field experi- 



