The Science of the Soil 129 



II. PLOT 2B; RECEIVING DUNG (14 TONS, CONTAINING 

 200 LB. NITROGEN A YEAR) 



Ife. per- Acre. 

 Nitrogen present in 1865 ('1752 per cent) ... ... 4,343 



Nitrogen supplied in manure, 1865-93 5,600 



Nitrogen supplied in rain, 1865-93 140 



Nitrogen supplied in seed, 1865-93 ... ... ... 56 



Total expected in 1893 10,139 



Nitrogen removed in crops, 1865-93 ... ... ... 1,484 



Nitrogen found in soil, 1893 (-2132 per cent) 4,976 



Total accounted for in 1893 6,460 



Leaving nitrogen unaccounted for 3,679 



10,139 



It would be difficult to find clearer examples of overdosing a soil with 

 food it did not require. In one case (Plot 7), leaving out the unavoidable 

 supplies from the rain and seed, 2408 Ib. of nitrogen were given to a 

 soil already containing 3034 Ib. Almost twice as much as the crop needed! 

 In the other case 5600 Ib. nitrogen were given to a soil still richer in the 

 same food (4343 Ib. per acre). But in this case, the greater the overdose 

 the smaller the quantity removed by nearly 500 Ib. 



That the loss of nitrogen was due mainly to overdosing seems to be 

 still further proved by the experiment on the unmanured plot, the figures 

 for which are as follows: 



PLOT 3; UNMANURED, 1865 TO 1893 



Ib. per Acre. 



Nitrogen originally present in 1865 (-1050 per cent), top 9 in. 2722 

 Nitrogen supplied in manure, 1865-93 ... ... ... 



Nitrogen supplied in rain, 1865-93 140 



Nitrogen supplied in seed, 1865-93 56 



Total expected in 1893 2918 



Nitrogen removed in crops, 1865-93 476 



Nitrogen found in soil, 1893 (-0940 per cent) 2437 



Total nitrogen accounted for, 1893 2913 

 Nitrogen not accounted for ... ... ... ... ... 5 



2918 



It would appear from these experiments that it is just as unwise to 

 give plants more food than they require in a given time as it is to gorge 

 animals with a certain diet. The system cannot absorb it, and the body 

 suffers in health in consequence. It would be interesting to have had 

 some information as to the cultural details carried out at Kothamsted, 

 the depth of culture, distance apart, and the yield per acre. 



VOL. I. 



