FIELD EXPERIMENTS WITH FERTILIZERS. PFA 

seen that the largest yield, 10.4 tons per acre, was obtained 
where only 25 pounds of nitrogen were added. Both in 1895 
and 1896 the larger quantities of sulphate of ammonia seemed 
to depress the yields. The hypothesis has been suggested 
that the repeated use of sulphate of ammonia through quite a 
period of years may have induced an acid condition of the soil. 
This might be unfavorable to the growth and development of 
bacteria and to the formation of tubercles. It has been noticed 
that the proportion of tubercles on the roots of the plants on 
these plots was much less than on corresponding plots where 
nitrate of soda was employed. As to the correctness of the 
hypothesis and the advantage of using slaked lime to correct 
the acidity, we have no experimental data to warrant any 
conclusions. 
TABLE 66. 
SPECIAL NITROGEN EXPERIMENT ON COW PEA FODDER. 
Weight and cost of fertilizers per acre, total crop, and tncrease of 
crop over that of the nothing plots. 














: ; Cow Pea FoppEr. g 
; ne Ae SM ee 2 
% FERTILIZERS. 2S 62 s oe Yield ee 
= ty mae on per Acre. o 
6 3 JP ES) (og Water.) | 8 
oe ° 
ae Lbs. g "Lbs. | Lbs. Tons. | Lbs. 
O Nothing, - - — —_— 450 | 10295 Gol ah waa 
§ Mixed Minerals, as s No. rea! - | 480? | | g 
1 Nitrate of Soda (25 lbs. N. ie - oH 12.00 938 | POs LUA et ee 
{| Mixed Minerals, as No. 6a, - | 480/ | | Rete 
) Nitrate of Soda (50 Ibs. N.), - | 320 § 2:5 °907).925) HIGT7O" 10-01. Oe 
Mixed Minerals, as No. 6a, - | 480? ts ey 
1 Nitrate of Soda (75 Ibs. N.), : PE Ae CRON A SenE aye TA er | 97 
Dis. Bone-black, | Mixed { a Ne 6856 
oe ae ata Minerals). |e1604 |. oc 97> here 8.7 5 
( Mixed Minerals, as No. 6a, - | 480 / 66 Hae ao hear 
a ( Sulph. of Am. (25 lbs. N.), - oa mere ; | TL 2) 4 
§ Mixed Minerals, as No. 6a, - | 480 Sans! 601 Brel eines 
a ( Sulph. of Am. (50 Ibs. N. : - ae Oe fk | ate ea ae 
Mixed Minerals, as No. 6a, - | 480 MoT Gah reper: 
a 1 Saleh. of Am. (75 lbs. N.), - | 3605 A hele bitkho ee a 
oo} Nothing, - - - — — ATA TOSTS ie. 54 — 
64) Mixed Minerals, as No. 6a, - | 480 8.00 | 828 | 17655| 8.8 7104 




