|
|
Nature of the nitrogen in the soil
|
124
|
|
|
Organic nitrogen in the soil
|
125
|
|
|
Differences of surface and subsoil nitrogen
|
126
|
|
|
Nitrogen as ammonia in soils
|
127
|
|
|
Amount of ammonia in soils
|
127
|
|
|
Nitrogen present as nitrates in the soil
|
128
|
|
|
Position of nitric nitrogen in soil
|
128
|
|
|
Amount of nitrates in the soil
|
120
|
|
|
Amount of nitrates in fallow soils
|
129
|
|
|
Amount of nitrates in cropped soils
|
130
|
|
|
Amount of nitrates in manured wheat-soils
|
131
|
|
|
The sources of soil-nitrogen
|
131
|
|
|
Accumulation of soil-nitrogen under natural conditions
|
133
|
|
|
Accumulation of nitrogen in pastures
|
134
|
|
|
Gain of nitrogen with leguminous crops
|
135
|
|
|
The fixation of "free" nitrogen
|
136
|
|
|
Influence of manures in increasing soil-nitrogen
|
136
|
|
|
Sources of loss of nitrogen
|
137
|
|
|
Loss of nitrates by drainage
|
137
|
|
|
Prevention of loss of nitrogen by permanent pasture and "catch-cropping"
|
138
|
|
|
Other conditions diminishing loss of nitrates
|
139
|
|
|
Amount of loss of nitrogen by drainage
|
140
|
|
|
Loss of nitrogen in form of "free" nitrogen
|
141
|
|
|
Total amount of loss of nitrogen
|
142
|
|
|
Loss of nitrogen by retrogression
|
142
|
|
|
Artificial sources of loss of nitrogen
|
144
|
|
|
Amount of nitrogen removed in crops
|
144
|
|
|
Losses of nitrogen incurred on the farm
|
146
|
|
|
Loss in treatment of farmyard manure
|
146
|
|
|
Nitrogen removed in milk
|
147
|
|
|
Economics of the nitrogen question
|
147
|
|
|
Loss of nitrogen-compounds in the arts
|
148
|
|
|
Loss due to use of gunpowder
|
148
|
|
|
Loss due to sewage disposal
|
149
|
|
|
Our artificial nitrogen supply
|
150
|
|
|
Nitrate of soda and sulphate of ammonia
|
150
|
|
|
Peruvian guano
|
151
|
|
|
Bones
|
151
|
|
|
Other nitrogenous manures
|
152
|
|
|
Oil-seeds and oilcakes
|
153
|
|
|
Other imported sources of nitrogen
|
153
|
|
|
Conclusion
|
153
|
|
|
|
APPENDIX TO CHAPTER III.
|
|
NOTE
|
|
|
I.
|
Determination of the quantity of nitrogen supplied by rain, as ammonia and nitric acid, to an acre of land during one year
|
155
|
|
II.
|
Nitrogen in soils at various depths
|
156
|
|
III
|
Nitrogen as nitrates in cropped soils receiving no nitrogenous manures, in lb. per acre (Rothamsted soils)
|
157
|
IV.
|
