348 
Journal of Agricultural Research 
Vol. VIII, No. 9 
difference in nitrates was only about 6 p. p. m., in favor of the unmanured 
soil, all but the tenth foot in depth show a variation in the same direction. 
Manuring with 15 tons to the acre resulted in the formation of over 
1.6 p. p. m. more nitrates than where no manure was applied. On the 
average, the first and third feet in depth are the only ones that this 
manuring caused to differ noticeably in nitrates. 
Table II.—Effect of manure on the total soluble salts in cropped and fallow soil. 
Average of all moisture treatments for three years 
Soluble salts (p. p. m.). 
Depth of soil. 
No manure. 
S tons of manure. 
15 tons of manure. 
Average. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Feet. 
330 
426 
302 
495 
34 i 
362 
324 
428 
378 
418 
308 
428 
339 
35 i 
342 
399 
3 . 
352 
375 
319 
408 
351 
354 
34 i 
379 
4 . 
353 
403 
310 
383 
313 
370 
325 
385 
336 
358 
260 
399 
263 
384 
286 
380 
6 . 
321 
389 
271 
393 
286 
348 
292 
377 
7 . 
368 
362 
282 
335 
273 
339 
308 
- 345 
347 
344 
310 
353 
306 
326 
321 
342 
341 
354 
315 
327 
276 
328 
311 
336 
10. 
319 
343 
280 
314 
274 
312 
291 
323 
Average. 
345 
377 
296 
384 
302 
347 
314 
369 
Table III .—Effect of irrigation water on the total soluble salts in cropped and un¬ 
cropped soil. Average of all manure treatments for three years 
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! 
Average. 
d. 
Cropped. 
Fallow. 
J Cropped.; 
ft 
Cropped. 
Fallow. 
5 
Fallow. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Cropped. 
Fallow. 
Feet. 
322 
397 
355 
420 
334 
435 
321 
449 
327 
534 
288 
33 i 
325 
428 
410 
428 
380 
376 
341 
376 
312 
392 
362 
473 
247 
349 
342 
399 
3 . 
392 
369 
310 
424 
367 
386 ; 
342 
400 
332 
390 
303 
313 
34 i 
380 
4 . 
410 
447 
343 
405 
336 
437 
320 
370 
284 
395 
248 
258 
324 
38 s 
5 . 
356 
385 
262 
387 
294 
346 
290 
39 i 
298 
39 i 
216 
388 
285 
381 
308 
387 
305 
373 
249 
369 
298 
464 
337 
392 
258 
275 
293 
377 
7 . 
378 
349 
295 
333 
281 
342 
280 
390 
335 
390 
275 
267 
307 
345 
8. 
349 
347 
371 
309 
314 
357 
291 
355 
303 
362 
295 
314 
321 
34 X 
367 
370 
349 
357 
286 
299 
304 
298 
33 i 
374 
272 
317 
3x8 
336 
307 
302 
320 
330 
266 
310 
280 
339 
295 
375 
28s 
293 
292 
325 
Average. 
360 
378 
325 
371 
307 
363 
304 
385 
320 
407 
270 
3 ii 
3x4 
369 
Without consideration of the effect of the crop and comparison 
with the unmanured soil, the larger amount of manure affected the 
nitrates proportionately less than did the smaller. The difference between 
the two treatments favoring 15 tons of manure varied somewhat inversely 
