30 BULLETIN 1481, U. S. DEPARTMENT OF AGRICULTURE 
An application of 400 pounds of acid phosphate at time of seeding 
and a spring application of 100 pounds of nitrate of soda or of 80 
pounds of ammonium sulphate as a top-dressing gave increased yields 
justifying the use of this combination for fall-sown oats on the Pied- 
mont Plateau. Unfortunately, unfertilized control plots were not 
used, and as a result the true value of the acid phosphate can not be 
determined by the data. The best results at Athens were obtained 
from applying the nitrogenous fertilizer around March 1. Applica- 
tions made as late as April 1 delay maturity and produce lower yields. 
The data from the three stations in the Coastal Plain section are 
less favorable to the use of nitrogenous fertilizer as a top-dressing 
than those from the Piedmont. Profitable increases were obtained at 
Tifton only, the best time of applying being around February 1. 
Applied as late as Mareh 15, the fertilizer resulted in a slight decrease 
in yield. The data from Ashburn and Quitman are too meager to be 
conclusive, but in general they agree with those from Tifton. 
In addition to the experiments reported in Table 18, another experi- 
ment was conducted at Athens in which nitrate of soda was used in 
two applications, 50 pounds on February 15 and 50 pounds on March 
15, or in one application of 100 pounds on February 15. Similar 
divided applications were made on March 15, and April 15. The 
data obtained are given in Table 19. 
TaBLE 19.—Yields obtained from divided applications of nitrate of soda to fall- 
sown oats at the Georgia State College of Agriculture, Athens, in 1915, 1916, 
and 1920 
; Quantity Acre yields (bushels) 
ae Le OE Single or divided applied S| = a 
ppiying (pounds) | 1915 1916 1920 | Average 
Feb 15 Cue application i ere eA Oot ae eek one oe es 100 19. 2 45.4 40. 8 35. 1 
0... | Dividedapplication2 22 ===. 2 puri eno oy 
Masala Ge elite: a ee Bees, Glo een of 100 24. 4 44.8 54. 6 41.3 
IDO = == One apy cation Rag Pe snes ae am Be ees ae 100 25. 8 46.1 48.7 40. 2 
Dol =| Divideduap plicatlomea ae ss= se) ues yee een al 
Apr is) woee ATES Rta Eh he a Be EON ek OF oink 50 100 25. 2 43.1 44, 4 37.6 
In this experiment fertilizer applied about March 15, either in a 
complete application or as part of a divided application, gave better 
results than when used earlier or later. The experiment where fer- 
tilizer was applied on various dates from January 15 to April 1 showed 
the best results from the March 1 application and slightly better re- 
sults from the March 15 than from the February 15 application. 
The data from this experiment agree with those of the other experi- 
ment. Except for the early dates in 1920, the data show no advantage 
in dividing the quantity of nitrate of soda to be used and applying 
it in two lots. The applications of nitrate of soda should be made 
at times when the plants are free from moisture. 
SUMMARY 
From 2,000,000 to 3,000,000 acres of fall-sown oats are grown 
annually in the South. In the Carolinas, Georgia, Alabama, Missis- 
sippi, and Louisiana considerably more than 50 per cent of the oat 
acreage is devoted to the fall-sown crop. 
Winter temperature is the limiting factor in fall-sown oat pro- 
duction, the northern limit being defined by the isotherm of 30° F. 
a ee 
