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18 
weighings. When the number of seeds per pound is high, it indicates that the seed is “a 
of less value than if the number of seeds per pound were less. , 
In the same way the weight per bushel may be taken as a measure of the value of seed, 
general, as this weight increases, the value of the seed also increases. 
Amount of seed to be sown per acre. The amount of perfectly pure and germinating se ed 
required to cover an acre of ground is always given under this head*). From this, the weight of ¢ om- 
mercial seed which is required, can readily be calculated, when its purity and germinalion are known, 
At the same time, the average amount of commercial seed of good quality which should be used, is ‘is 
also given. For example, the quantity of perfectly pure and germinating seed of Perennial rye-grass 
required to cover an acre of ground is 38'/2 Ibs. That is equivalent to 54 Ibs. of commercial seed, whose 
real value is 71 °/o (purity 95 °/o, germination 75 °/o**), ‘ 
If a mixture of seeds is to be made, the proportion of ground to be allotted to each kind of plant: is 
first fixed; the weight of each kind of seed can then be calculated from the tables in the appendix. Sup- 
pose that a mixture of perennial rye-grass and white clover has to be made, so that 50 %o of the ground 
is to be covered with perennial rye-grass, and 50 °/o with white clover. For this purpose 19 Ibs. — of 
perfeclly pure and germinating seed of perennial rye-grass = 27 lbs. of commercial seed having 
71°/o real value, and 3%/s Ibs, of pure and germinating white clover seed — 5'/s lbs. of commerc 5 
seed having 74 °/o value, should be used per acre. ; 
From grass land, the farmer wishes to obtain the maximum quantity of good animal nutriment. By 
sowing one kind of plant, the maximum produce is rarely obtained, either because the plant cannot 
cover the ground completely, or, if it does, only a small proportion of the produce is above ground 
since plants which can grow in this way are usually stoloniferous. The largest produce is in general I 
to be obtained by mixing, in proper proportions, those grasses and clovers which are most approp: iate 
to the soil. 
The plants most suitable for forming mixtures, which will cover the ground most completely, caw i 
readily be determined from the information given under the heading »Growth« in the special part of 
the work. It is very important that deep and shallow-rooted species are represented in such propor- 
tions that the roots fill up and utilize all the ground. The parts above ground form Top, M Middle. and 
Bottom grass; each of these kinds should have a due proportion of ground allotted to it. The a 
tion, rate of growth, as well as other special characters should also be taken into account. Space is 
too limited to explain further the principles on which the composition of plant-mixtures depends. F all 
details and numerous examples are given in Stebler’s special work on »The mixing of grass seeds«. 
When the proportion of ground to be assigned to each species of plant has been fixed, it is easy 
by means of the tables in the appendix, to calculate the weight of each kind of seed which should. se 
taken to form the mixture. 
On a surface of a given size, there is room for a greater number of plants of different SperiGars than 
when a single species is grown by itself. The number of plants required becomes greater, as the species 
composing the mixture become more numerous and diverse in character. That is why, in the tal 
the quantity of seed for a pure sowing is given in a separate column. For mixtures, additions varying 
from 10 to 80°/o are made (See the tables). | i 
When a mixture is to be laid down, the plants most suitable are first selected, then the ore or 
tion in which each kind is to be represented is fixed, and lastly, the additional percentage over a 
pure sowing is determined. Further detail is unnecessary here. | 
*) Data for these calculations are given by a great number of agricultural writers. 
38.5 < 100 
Sa 54. 
**) 
