3 io 
Journal of Agricultural Research 
Vol. XIV, No. 8 
Cowpea Crop 
The rye roots were ground and mixed with the soil as with the preceding 
crops, and pots seeded with 15 seeds of Manetta variety of cowpeas on 
June 7, 1917. After germination, plantlets were reduced to six per pot. 
The crop was harvested on the following September 17, before the cow- 
peas had matured. This was done, as the plants had been injured by 
mildew. 
In Table IX will be found the results of this experiment. 
TabeE IX. —Weight of cowpea crop and potash removed from soil 
Dry matter (grams). 
Potash removed (grams). 
Treatment. 
Whole 
plant. 
Aver¬ 
age 
total. 
Rela¬ 
tive 
rank of 
aver¬ 
age. 
Whole 
plant. 
Average 
total. 
Aver¬ 
age gain 
over 
no 
potash. 
Potassium sulphate. 
30-4 
27. 0 
26. 1 
o -374 
• 35 ° 
• 346 
•465 
.476 
.468 
f -643 
.669 
l -672 
. 720 
. 694 
. 680 
Do.‘. 
27. 8 
63-3 
0.356 
0. 272 
Do. 
2 potassium sulphate.. 
31.0 
33 ' 0 
30.6 
40. 2 
44.6 
46. 7 
48. 0 
42. 0 
41. 6 
20. 0 
Do. 
31-5 
71.7 
.469 
• 385 
Do. 
2 potassium sulphate plus calcium 
carbonate. 
) 
■ Do. 
43.8 
99 - 7 
. 661 
•577 
Do. 
2 potassium sulphate plus 2 calcium 
carbonate. 
. 
Do. 
43-9 
100. 0 
.698 
. 612 
Do. 
Biotite. 
. 300 
. 326 
. 7 TA 
Do. 
17. 6 
19.7 
21. 4 
20. 6 
19. 1 
43-5 
•313 
. 229 
Do. 
2 biotite.. 
.306 
■ 3 12 
' . 200 
Do. 
20. 3 
46. 2 
. 306 
. 222 
Do. 
18.3 
24. 0 
26. 0 
2 biotite plus calcium carbonate. 
Do. 
24.9 
56-7 
•374 
.386 
• 37 ° 
• 3 ° 2 
• 294 
. • 3 12 
. 224 
.236 
. 224 
. 270 
. 264 
• 2 <6 
. 302 
. JTO 
■ -376 
Do. 
24. 8 
23.0 
22. 0 
* 
2 biotite plus 2 calcium carbonate. . . 
Do... 
■24. 0 
54-6 
• 3°3 
. 219 
Do. ... 
27. 0 
14. 0 
16. 8 
Muscovite. 
Do. 
15-0 
T 
. 228 
TA A 
Do. 
143 
15 * 0 
13 -0 
20. 0 
22. 6 
OT" A 
• A 44 
2 muscovite.. 
Do. 
14-3 
32.5 
. 263 
TTn 
Do. 
• A /y 
2 muscovite plus calcium carbonate.. 
Do. 
21. 5 
48.9 
.310 
. 226 
Do. 
22. 0 
.318 
. 326 
. 3l6 
. 7 TA 
2 muscovite plus 2 calcium carbonate. 
Do. 
2K. O 
23.O 
24. 2 
TO. O 
24. 1 
54 - 8 
.318 
• 2 34 
Do. 
Orthoclase. 
. ISO 
, T26 
Do. 
8.4 
8.0 . 
■ 8. 1 
18. 4 
.138 
•°54 
Do. 
• 13 ° 
