EFFECT OF ALFALFA ON YIELDS OF FIELD CHOPS. 
potatoes from trie same plats excepting 1918, when this classification 
was not made, has averaged 192 bushels per acre, with a mean 
annual difference in favor of those following alfalfa of 101 ± 7. Again 
omitting the crop of 1918, the percentage of the total yield classed 
as marketable is 76^ while the mean annual difference in percentage 
marketable in favor of those following alfalfa is 12 ±1.3. 
Table I. — Effect of alfalfa on the yields of Irish potatoes at the Scottsbluff, Belle Fourche, 
and Huntley Field Stations, for the 6-year period from 1913 to 1918, inclusive. 
Station and rotation No. 
Yield of potatoes per acre (bushels). 
1913 
1914 
1915 
1916 
1917 
1918 
Mean. 
Scottsbluff: 
20 (no alfalfa) 
398 
403 
146 
280 
88 
206 
142 
285 
131 
273 
87 
179 
165+29 
40 (following alfalfa) 
271 + 20 
Difference 
+ 5 
+ 134 
+ 118 
+ 143 
+ 142 
+92 
+ 106+14 
24 (no alfalfa) 
235 
402 
146 
319 
109 
228 
217 
308 
134 
290 
150 
227 
165+15 
296± 18 
Difference 
+ 167 
+ 173 
+119 
+ 91 
+ 156 
+ 77 
+ 131 + 13 
30 (no alfalfa) 
329 
322 
216 
272 
146 
231 
226 
319 
167 
281 
79 
238 
194+24 
60 (following alfalfa) 
277+11 
Difference 
- 7 
+ 56 
+ 85 
+ 93 
+ 114 
+ 159 
+ 83+15 
31 (no alfalfa) 
353 
380 
243 
299 
175 
220 
244 
306 
211 
346 
81 
249 
218 + 23 
61 (following alfalfa) 
300+17 
Difference 
+ 27 
+ 56 
+ 45 
+ 62 
+ 135 
+ 168 
+ 82+17 
Belle Fourche: 
20 (no alfalfa) 
128 
88 
86 
96 
102 
94 
157 
129 
133 
124 
167 
203 
129+ 9 
40 (following alfalfa) 
122+11 
Difference 
- 40 
+ 10 
- 8 
- 28 
- 9 
+ 36 
-7+7 
24 (no alfalfa) 
109 
177 
112 
127 
111 
144 
151 
149 
120 
170 
191 
153 
132+10 
44 (following alfalfa) 
153± 5 
Difference ... . 
+ 68 
+ 15 
+ 33 
- 2 
+ 50 
- 38 
+ 21 + 11 
30 (no alfalfa) 
74 
97 
68~ 
105 
59~ 
105 
166~ 
119 
~139 
108 
168 
170 
112+17 
60 (following alfalfa) 
117+ 7 
Difference 
+ 23 
+ 37 
+ 46 
- 4? 
- 31 
+ 2 
+ 5+11 
31 (no alfalfa) 
90 
139 
140 
112 
137 
115 
188 
124 
205 
130 
231 
165 
165+16 
61 (following alfalfa) 
131+ 5 
Difference 
+ 49 
- 28 
- 22 
- 64 
- 75 
- 66 
- 34+13 
Huntlev: 
20 (no alfalfa) 
200 
250 
179 
156 
350 
350 
228 
247 
241 
224 
390 
445 
265+20 
40 (following alfalfa) 
279+30 
Difference 
+ 50 
- 23 

+ 19 
- 17 
+ 55 
+ 14+10 
24 (no alfalfa) 
316 
113 
171 
195 
_ 273 
190 
236 
166 
22<T 
182 
315~ 
373 
257+17 
44 (following alfalfa) 
203+21 
Difference 
-203 
+ 24 
- 83 
- 70 
- 47 
+ 58 
- 54+25 
30 (no alfalfa) 
188 
2S5 
156 
293 
228~ 
397 
22T 
292 
175 
238 
2S6 
345 
209+14 
60 (following alfalfa) . . . 
308+16 
Difference 
+ 97 
+ 137 
+ 169 
+ 68 
+ 63 
+ 59 
+ 99+14 
31 (no alfalfa)... 
160 
277 
140 
184 
273 
420 
212 
402 
91 
297 
324 
474 
200+26 
61 (following alfalfa) 
343 + 34 
Difference 
+ 117 
+ 44 
+ 147 
+ 190 
+206 
+ 150 
+ 143+15.5 
