BULLETIN OF THE BUSSEY INSTITUTION. 65 
It will be seen at a glance that the various nitrates taken by themselves 
_ are here of very little use. Even the mixture of nitrate of potash and 
phosphate of potash in jar No. 9 fails from lack of lime. But the 
mixed solutions which contain all the elements needed for the growth 
of plants yield as good crops in the sterile sand as in the compara- 
tively speaking fertile sand of the other sets of experiments. 
The last set of experiments, Series D, Set 4, illustrates very clearly 
the fertilizing power of the New Jersey green sand, both as regards 
potash and phosphoric acid, as well as the importance of using a 
nitrogenized manure in conjunction with the green sand in order that 
the latter may produce its proper effect in actual field-practice. It is 
interesting to note in all the experiments how readily the comparatively 
speaking insoluble “rock-phosphates” of the sands are put to use by 
plants that are duly supplied with potash and nitrogen and the other 
kinds of plant-food, provided the sorl is kept morst. 
In the following table the results of the four sets of experiments of 
Comparative yield of dry substance ; 
the crop from Berkshire sand and water = 1. 
tes Chemicals employed. Ashes } 
containing mivcana| PGMS NT Tees 
nitrogen), 
1 | Sulphate of magnesia. . . 10.10 1.30 1.00 1.70 
2| Sulphate of lime ... . 13.60 1.00 1.40 0.90 
3 | Chloride of potassium. . . 3.60 1.15 0.90 1.00 
4-| Phosphate of potash .. . 11.70 0.90 0.75 0.85 
5 | Nitrate of potash . .. . 19.50 26.20 2.95 35.20 
Sammenreorime . ..°. . 18.00 25.10 4,20 30.80 
7 Nitrate of ammonia . . 9.20* | 21.90 3.70 16.90 
8 | Rain-water . 11.60 1.20 1.00 1.20 
Nitrate of potash and ron 
9 1 Bele de Sotach 22.00 | 24.30 | 6.35 | 30.60 
Nitrate of lime and phayohate 
10 aia ‘; 12.65*| 24.30 | 29.90 | 25.40 
Nitrate of potash, “sulphate 
is ae G4 14.00 | 29.00 | 2.00*| 25.80 
Phosphate of potash and sul- 
12 j eine zn 13.25 | 170 | 1.15 | 0.95% 
Phosphate of potash and sul- 
13 i Bor ciarncsin 4 13.70 | 0.70*| 145 | 0.65* 
Nitrate of lime, phosphate of 
14 potash, sulphate of Faane-| 21.65 30.05 21.85 23.65 
sia . 
Nitrate of lime, phosphate of 
15 } MT euiphate of ime. ‘} 16.35 | 29.65 | 19.85 | 26.40 
Nitrate of lime, chloride of ; . 
16 potassium, sulphate of mag- 25.80 26.65 21.95 14.50* 
nesia, phosphate of potash . 
* Only two plants. 
VOL. I. 9 
