AIR — WATER SOILS. 



729 



"When the third crop came to be planted in July a very heavy crop of oats had 

 been harvested from 4 oat cylinders, yielding over 12 tons of water-free matter per 

 acre, and a good crop of clover had been taken from the clover cylinders. The 4 oat 

 cylinders and 2 of those bearing clover were fitted for corn and planted with the 

 others. . . . 



"The corn on the oat stubble look decidedly as though it was nitrogen hungry, 

 but the oats had an extremely dark-green look and seemed to be overfed with nitro- 

 gen rather than underfed. The clover made a good fair growth for the first crop, 

 but it was not as large as the crop grown in the small cylinders on the upland soil, 

 while the second crop was decidedly poor for some reason. But a good crop of corn 

 followed the clover. 



"This much seems clear in regard to the treatment of these black marsh soils, they 

 respond well to farmyard manure, and even to coarse litter of any kind when well 

 worked in, while the commercial chemical fertilizers tried, other than potash, have 

 but little influence." 



Fertilizer experiments with Indian corn on marsh soils, 

 F. W. Woll (Wisconsin Sta. Bpt, 1897, pp. 264-271).— -This is au 

 account of chemical investigations made in connection with experiments 

 previously reported in part (E. S. R., 9, p. 536). In these experiments 

 it was assumed that the marsh soil was abundantly supplied with nitro- 

 gen. For this reason the fertilizers used included only different forms 

 of potash, phosphoric acid, and lime. The yield (grain and fodder) and 

 the dry matter and nitrogen in the crops grown were determined, and 

 the results are classified with reference to the degrees of fertility (poor, 

 medium, and good) of the soil on which the crop was grown, as shown 

 by chemical analysis. 



While it is not considered safe to draw conclusions from results of 

 one year's experiments, it is believed that the data obtained tend to 

 show that the fertility of these soils "is in direct proportion to the 

 content of potash, phosphoric acid, total nitrogen and active nitrogen 

 (nitrogen soluble in water, expressed in parts per million), and in inverse 

 proportion to the lime content of the soil." 



The composition of the different grades of soil was as follows: 



Composition of marsh soils from unfertilized plats. 



Constituents. 



Poor soil. 



First 

 foot. 



Second 

 foot. 



Medium soil. 



First 

 foot. 



Second 

 foot. 



Good soil. 



First 

 foot. 



Second 

 foot. 



Insoluble matter 



Volatile matter 



Potassium oxid 



Calcium oxid 



Phosphoric acid 



Nitrogen (total) 



Nitrogen soluble in water (parts per 

 million) 



Per cent. 



72.11 



12.30 



.26 



1.44 



.18 



.37 



36.2 



Per cent. 



81.48 



4.82 



.35 



1.49 



.13 



.05 



Per cent. 



74.49 



11.35 



.27 



1.35 



.20 



.32 



46.2 



Per cent. 



79.92 



5.80 



.34 



1.21 



.14 



.10 



Per cent. 



73.57 



11.73 



.30 



1.05 



.22 



.41 



50.1 



Per cent. 



79.49 



4.38 



.34 



1.32 



.15 



.12 



"The most plausible explanation of the different productive capacities of the 

 poor, medium, and good soil lies, it would seem, in their different contents of active 

 (nitric) nitrogen. For some reason or reasons as yet not understood, conditions in 

 the poor soils have been unfavorable to the process of nitrification or favorable to 

 denitrification. . . . 



