food increase (food stock) can (without the utilization of the food becoming appreciably 

 poorer or that the natural nutrition portion of the total nutrition really sinks below 

 50 percent) be shown for the individual yield classes as follows t 



GLASS NATURAL INCREASE FOOD INCREASE 



I 5O.O5J 50.05? 



II 33.3 66.6 

 in 25.0 75.0 

 IV 20.0 80.0 



1 have accordingly compiled the yearly natural food, and total increase for the four 

 yield classes in Table 20, as was similarly done in Table 17 according to Walter's pro- 

 cedure. 



Table 20. 



Natural-, Food-, and Total-Increase in Carp Ponds of the 1st to IVth Yield Classes 

 (Compare with Table 17). 



CUSS I CLASS II CLASS III CLASS IV 



A Natural increase, kilogram/he ctar 

 B Food increase, kilogram/he ctar 

 C Total increase, kilogram/hectar 

 Normal basic piece increase, grams 



As examples and proofs for the basic correctness of this compilation, I am giving 

 in Table 21 the yield values from seven pond fisheries with varied, regionally conditionea, 

 but typical features. These figures correspond to the actually achieved natural and total 

 hectar yields and represent averages which are achieved in similar conditions of climate, 

 water and soil in the rest of Germany. 



Table 21. 



Total Hectar Increase and Natural Hectar Increase of Several North German Pond Fisheries. 



_ _ 



^°' ^°^"^ FISHKRY -j-oT-j^L INCREASE Kg/HA NATURAL INCREASE Kg/HA 



It is to be considered that Table 20 gives figures to be achieved. These values 

 naturally, can only be achieved by prescribed and faultless management of the ponds. 

 The calculation of the yearly total amount of food for a pond can be immediately obtained 

 by multiplying the food Increase per pond by the food quotient. The necessary yearly 

 amount of food for one hectar is calculated by multiplication of the food increase per 

 hectar by the food quotient of the distributed food: 



FOOD QUANTITY/Ha = FOOD DICREASE/Ha X Food Quotient . 



Example: — In a pond of 2 hectar size of the second j-ield class the feeding shall be 

 vdth lupine. The food increase can be estimated at about 300 Kg/Ha, or 600 Kg per pwid. 

 The yearly amount of food for the pond then ccmes to about 600 x ^ = 2^00 Kg. 



U5 



