Feb. 26,1917 
Effect of Water and Manure on Nitrates in Soils 
345 
therefore, shows a tendency for an inverse variation, the difference 
between the plots receiving no water and those receiving 40 inches 
being 90 parts per million. 
Table I. —Total soluble salts (in parts per million) in the fall at 'various depths in cropped 
and fallow soil receiving different quantities of manure and irrigation water . Average 
for three years 
CROPPED sou. 
Soluble salts (p. p. m.). 
Depth of soil. 
No water. 
5 inches of 
water. 
10 inches of 
water. 
20 inches of 
water. 
30 inches of 
water. 
40 inches of 
water. 
| 
Manure applied 
< 
(tons). 
0 
5 
15 
0 
5 
15 
0 
5 
15 
0 
5 
15 
0 
5 
IS 
0 
5 
15 
Feet. 
34 i 
304 
322 
372 
288 
404 
361 
372 
267 
335 
234 
393 
291 
3 °o 
389 
280 
314 
270 
324 
5 i 7 
325 
388 
436 
318 
385 
386 
337 
299 
347 
228 
360 
308 
402 
375 
274 
238 
228 
342 
506 
3^9 
35 i 
271 
283 
377 
412 
386 
302 
375 
298 
355 
284 
275 
436 
266 
356 
288 
341 
4 . 
435 
416 
380 
425 
259 
344 
344 
303 
363 
354 
3°9 
298 
317 
300 
235 
244 
271 
263 
326 
5 -. 
477 
283 
310 
261 
226 
299 
324 
287 
273 
358 
260 
252 
369 
282 
244 
223 
218 
205 
286 
6. 
374 
247 
304 
294 
260 
359 
256 
253 
237 
345 
300 
249 
386 
286 
338 
268 
278 
227 
292 
7 . 
514 
278 
343 
361 
238 
285 
287 
348 
211 
355 
232 
258 
325 
322 
358 
365 
277 
183 
308 
8. 
365 
353 
360 
487 
267 
359 
322 
342 
278 
296 
282 
296 
3x8 
284 
306 
3 i 4 
333 
238 
322 
9 . 
428 
294 
347 
318 
314 
3 U 
303 
357 
198 
335 
304 
273 
365 
361 
234 
299 
262 
255 
309 
10. 
348 
271 
301 
390 
247 
324 
249 
296 
252 
306 
279 
254 
302 
3 i 4 
269 
322 
290 
243 
292 
Average. 
431 
309 
340 
361 
270 
345 
324 
328 
268 
34 i 
273 
298 
326 
313 
322 
285 
284 
240 
3 H 
FALLOW SOIL 
In general, it will be noticed that the plots receiving no water con¬ 
tained more total salts in every foot, except the first, than the other 
treatments. When more than 10 inches of water were applied, the salt 
content of the top foot of the unirrigated soil was practically equal to 
or greater than the same foot of those receiving water. The top 2 and 
the lower 3 feet of the plots receiving 5 inches of water contain more 
salts than the corresponding feet of the other irrigated plots. When 
20 inches were applied, some of the salts seem to have moved below 10 
feet; the 30-inch irrigation shows this tendency still more, while the 
40-inch application seems to have driven much of the salts below the 
depths of sampling, since every foot of this treatment is somewhat below 
the others. Especially is this true for the first 5 feet. In general, the 
first 4 feet of the first four irrigation treatments are noticeably higher 
than the feet below, while for the last two irrigations the differences are 
somewhat more evenly distributed throughout for depth. 
