4 BULLETIN 3, U. S. DEPAKTMENT OF AGKICULTURE. 
Approximate seasonal factors having general application to the 
States of Nebraska, Iowa, Illinois, and Indiana are presented in 
Table I, being averages of the best judgment of practical farmers for 
the respective operations in the States named during the growing 
season from March to November, inclusive. 
Table I. — Approximate seasonal factors for farm work in four States of the Middle West. 
PERCENTAGE OF TOTAL DAYS AVAILABLE FOR WORK AT EACH SEASON. 
Operation, weather, etc. 
Indiana. 
Illinois. 
Iowa. | Nebraska. 
Spring plowing 
Spring harrowing 
Spring seeding 
Spring corn planting. 
Cultivating 
Haying 
Grain harvest 
Corn harvest 
Thrashing 
Potato harvest 
Fall plowing 
Fall harrowing 
Fall seeding 
Husking corn 
64.2 
60.7 
60.4 
62.5 
73.7 
67.8 
71.8 
74.3 
72.5 
64.6 
76.4 
73.9 
70.5 
73.3 
69.0 
63.8 
63.1 
68.9 
75.1 
68.0 
73.0 
73.0 
72.3 
67.0 
78.3 
73.8 
75.5 
79.5 
72.1 
70.5 
65.7 
71.1 
77.5 
70.1 
74.9 
75.1 
72.4 
68.4 
78.5 
77.2 
75.6 
82.3 
71.4 
67.5 
73.5 
79.7 
70.5 
76.5 
76.2 
74.9 
70.2 
79.2 
78.9 
76.2 
82.6 
State average. 
71.3 
75.2 
AVERAGE MONTHLY WEATHER CONDITIONS, MARCH TO NOVEMBER, INCLUSIVE. 
Normal temperature ° F . . 
Normal rainfall inches. . 
Rainy days in 1911 (0.01 inch and over) 
Entirely clear days in 1911 
Entirely cloudy days in 1911 
Partlv cloudy days in 1911 
59.0 
59.5 
55.2 
30.6 
29.7 
29.3 
9.5 
8.8 
7.8 
12.0 
' 13.9 
14.4 
8.9 
8.3 
7.3 
9.2 
8.2 
8.7 
57.5 
24.0 
5.7 
15.9 
5.5 
8.9 
It will be observed that, except in four instances, there is a regular 
increase in the percentage of available time for each operation from 
Indiana to Nebraska. It will also be seen that there is a regular 
decrease of rainy days and a regular increase of entirely clear days 
from Indiana westward, according to the weather records for the 
season of 1911. The normal rainfall also decreases regularly from 
Indiana westward for the 9-month period. In each percentage in 
the table from 50 to 100 estimates are submitted in terms of days 
From this we find that A equals 38.8 acres. 
Another problem. With the rates of work assumed here it is known that one man can plow, harrow 
three times, and drill 40 acres of wheat during the months of August and September. What is the per- 
centage of available time. For this problem we have — 
3 
40 
(m + iVs) = FX61 - 
This gives F equal to 65.3 per cent, or practically two days in three. 
In all cases where the area is known on which a man can perform certain operations within a given period— 
that is, when the seasonal duty of a man is known — the use of the above general formula enables us to deter- 
mine the average percentage of available time for the season and locality concerned. 
A very good way of determining the percentage of available time during the early summer is to ascertain 
the area of corn or other cultivated crop one man can till, the area he can till in a day, and how often the 
crop should be cultivated. Thus, in the corn-belt States one man can till 40 acres of corn. He can cultivate 
6 acres a dav, and the corn should be cultivated once every 10 days. From these facts it follows that 
40 
a) 
FxiO; whence, F=^, which means that two days in three are available.— W. J. Spillman. 
