41 PASTURES AND PASTURE PLANTS chap. 



not of loo per real cent, value, the Alsike clover, White clover and Perennial 

 rye-grass possessing respectively only 90, 80 and 77 per cent, of pure and 

 germinating seeds ; but — 



If to produce 100 % of paslure with ico % value Alsike we sow 9'q lbs. — 

 Then ,, 1% ,, 1% .. ., --^ lbs.; 



9 '2 X 100 X 20 



And ,, 20% ., 90% ,, ,, — = 2-2lbs. 



" « ' ' '» " 100x90 



So the weight of any quality seed required per acre to produce a certain 

 percentage of the whole herbage of the pasture may be quickly calculated by 

 multiplying the weight of perfectly pure and germinating seeds (100 per cent, 

 real value) needed per acre (Column i. Table II.) for a pure sowing by the 

 percentage of the herbage to be formed with the particular plant under 

 consideration, and dividing the product by the real value of the seed to be 

 sown ; or 



the required quantity. / weight of pure and\ „tage of , 



(to form a certain I ^ germinating seed ^ J^^^^ \^ \ 



percen age of he required per acre Ure to be formed 



whole herbage) ; for a pure sowing. ) 



(real value of the seed to be sown.) 



Thus we ascertain that 6-19 lbs. of our White clover seed are required to 

 produce 60 per cent, of the plant of the entire pasture, while the requisite 

 20 per cent, of Perennial rye-grass may be obtained by sowing 1 1 lbs. of seed. 

 These deductions are conveniently tabulated thus : — 



^. c , I r> 1 1 Percentage of pasture Weight in lbs. 



Name of seed. Real value. to be occupied. , required per acre. 



Alsike clover 



White clover 



Perennial rye-grass 



90 20 2 '2 



i'O 60 \ 619 



77 20 no 



Temporary Pastures 



To last from i to t, years 



Introductory,— -As a general rule it is highly advantageous to alternate 

 the culture of grass leys of three years duration with cereals and roots, because 

 less labour and horses are needed than on a purely arable holding ; strong- 

 growing pasture grasses materially assist in cleaning the land by smothering 

 weeds ; leguminous plants enrich the soil by means of the nitrogen they 

 accumulate from the atmosphere, and the ramification and decay of their roots 

 leave the ground in an excellent condition for a corn crop ; the soil con- 

 stituents are utilised more economically ; the land can be kept in a higher 

 state of fertility ; and the farmer is insured sufficient roots and hay to keep 

 his stock during the winter. 



When a temporary pasture of three years duration is broken up, another 



