be done in autumn ii' possible. Strong liming with caustic lime inrnedlitely be Tore 

 stockinj is ver' dangerous. In the limin3 of water, 177 pcunds of burned lime per acre 

 may be given daily on numero-^s successive days, without hesitation. Care is advised 

 only v.lth water very poor in line and contairinr- ^^ut little carlonic acid. It is best 

 to cjntrol the pH value and keep it belo-.v 10. 



The quantities of line to be riven in bottom linin;^ against parasites siiould be at 

 least 2,200 to 3,300 pounds per hectare (B87 to 1,330 pounds per acre). These quantities 

 are to be strev;n on the wet congested flat bottom. With trout ponds, calciiin cj'anaraide 

 should be used in the proportion of about ^,^00 pounds per hectare (1,77^ poinds p^^r 

 acre). For regular yearly botto:a limings for fertilization, 220 to 380 po-jnds per 

 hectare (86.7 to 354.3 po'jnds per acre) of CaO is sufficient, if y:e a^e not dealing with 

 line poor or acid soil. Larger quantities of line generally do not ham ir. the pond, 

 Tfith acid ponds it is often well to provide a safety factor by ha'/in^ a reserve lining . 



Ilgures for calciun poor ponds must be decided in each inaividual case. The amount 

 of necessary line in such' cases depends quite obviously upon 2 factors: calcium content 

 of the Y/ater and calcium content of the bottom, in other words upon the pH rate. 



To increase the A.CV. of the vfater to 1 — desirable in most cases — a liming with ^0 

 pounds per hectare (177 pounds per acre) is usually sufficient. Experience shows, on the 

 other hand, that much larger quantities are necessary since the aciis, present in the 

 bottom, must also become neutralized. The pH rate of the upper layers of the bottom 

 soil must be raised to about 6, even to 6,5 if the A.CV. shall not fall off continuously. 

 iDnly proper determination of the line rsquirements of the bottom can lead to proper 

 estimation of the necessary amounts of lime. 



In agriculture, the calcium requirements of any kind of soil are approximately 

 calculated through the pH value. The figures, so obtained may need corrections, accord- 

 in;: to regional conditions, but I will give some of these figures as evaluated by Trenel , 



Table 23. 



pH value, measured 

 at the bottom. 



Lime requirements (dz. of CaO per hectare) 

 (1 dz. eq. 220./.6 lbs.) 



From this chart, the approxim.ite amount of IL-ne — necessarj' for the soil — can be 

 calculated, provided the pH rate of the soil is known. This amoiont has then to be added 

 to the amount, necessary for the water (approximntely 2 dz, equal A40.92 lbs. per hectare). 



Naturally the total lime requirements of a pond can also be determined simply by 

 lining the pond — after shutting o*'f the inflow--until the A.CV. rate reaches 0.5 to 1 

 cubic centimeter of nHCl per liter. If especially good returns are desired and fertili- 

 zation is intended, the A.CV. sho'old be raised to even 1 to 2 cubic centimeters nHCl per 

 liter. In case of very calciujTi poor v/ater and soil, the required amount of line ranges 

 betv/een 10 to 15 dz (837 to 1,330 poun-b per acre) of quick line per hectare during 

 summer. (1 dz equal 220.46 pounds),- according to Schaeperclaus and P.einecker. 



165 



