VII.] 



PH YSICAL EFFECTS OF MANURE 



219 



the texture without getting the soil too open — a defect 

 which is now beginning to overtake the plot that has 

 been so continuously treated with large amounts of 

 farmyard manure. 



A soil which has been enriched in humus by 

 repeated applications of farmyard manure will resist 

 drought better than one in which the humus is low ; 

 the difference is seen, not so much in the greater amount 

 of moisture present in the soil containing humus, as 

 in the way it will absorb a large amount of water 



Table LXIX. — Percentages of Water in Rothamsted Soils. 



temporarily during heavy rainfall and then let it work 

 more slowly down into the soil, thus keeping it longer 

 within reach of the crop. Good examples are afforded 

 by the Rothamsted plots ; samples of soil were taken 

 from the wheat land on 13th September 1904; on 

 the previous day 0-262 inch of rain had fallen, but 

 for nine days before there had been little or no rain. 

 The portions of the plots from which the samples were 

 drawn had been fallowed through the summer, so that 

 the drying effect of the crop is eliminated. Samples 

 were also taken from the barley plots on 3rd October 

 of the same year; 0-456 inch of rain had fallen on the 

 30th September, before which there had been fifteen 

 days of fine weather. Table LXIX. shows the water 

 in the soil of the unmanured and the continuously 



