306 NATURE AND PEOPERTIES OF SOILS 



lime. The two latter constituents are probably liberated by 

 basic exchange. The addition of any fertilizer seems espe- 

 cially to increase the lime in the drainage water. This is prob- 

 ably due to the development of acid fertilizer residues. In 

 general, it seems that the more productive the soil and the 

 heavier the fertilization, the higher the concentration of the 

 constituents in the drainage water. 



It is not always the case, however, that a manured soil 

 loses more nutrient material than an unfertilized one. Ger- 

 lach ^ reports experiments with soil tanks at the Bromberg 

 Institute of Agriculture, in which five soils rationally fertil- 

 ized yielded larger crops and lost in the main less nitrogen 

 and lime in the drainage water than the same soils unmanured. 

 The loss of potash was slightly greater from the manured than 

 from the unmanured soils. Apparently the stimulation that 

 the plants received from the fertilizer enabled them to make 

 such a good growth that they absorbed more soluble nitrogen 

 and lime in excess of the unfertilized plants than was added 

 in the fertilizer, and nearly as much potash. 



The most serious losses of plant nutrients in drainage are 

 those of the nitrogen and calcium, both of which losses are to 

 a certain extent unavoidable. These losses are also very 

 closely related, rising and falling together. Nitrogen is lost 

 as the nitrate while the calcium is leached out due to the 

 presence of the bicarbonate and nitrate radicals. "While loss 

 of lime goes on continually, it is of necessity particularly 

 large during periods of rapid nitrate accumulation. Nitrogen 

 is a high-priced fertilizer constituent, while a continued loss 

 of lime tends to produce soil acidity. About the only means 

 of conserving either of these constituents is to maintain a crop 

 on the soil, especially during the warmer seasons. 



* Gerlach, M., Pher die durch Sickermmser dem Boden Bnizogenen 

 Menge Wasser und Nahrstoffe; Illus, Landw. Zeitung, 30 Jahrgang, 

 Heft 95, Seite 871-881, 1910. Also^ Untersuchungen uber die Menge und 

 Zusammemetzung der Sicley wasser; Mitt K. W. Inst. f. Landw. in 

 Bromberg, Band 3, Seite 351-381, 1910, 



