ECOLOGICAL REACTION OF CROP YIELDS 



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differs from the solution in which a larger number of factors are given a 

 place. For two growth factors the formula is of the third power and for 

 every growth factor added the power increases by one unit. In the formulae 

 I.I and 2.1 the expression for a factor is not changed if other factors are 

 taken up or left out. The formula implies that to solve an ecological problem, 

 every factor should be accounted for, and the result obtained with a 



Fig. 5. Shape of the growth curves according to the law of Hmiting factors. The 

 approach to the asymptotes is closer if more growth factors are taken into account. The 

 curves are all of a different shape with a bend sharper, the higher the maximum yield. 



Fig. 6. Second solution of the differential equations of the type of 3.1 a where the law 

 of Hmiting factors is assumed. Case of substituting, or antagonistic, factors. 



selection of the growth factors may not be considered equivalent to the 

 result for the full solution. 



The eqs. 3.4 and 3.5 are depicted in Figs. 5 and 6. The curves in Fig. 5 

 bear no simple relation to each other. The curves in Fig. 6 are shifted in a 

 horizontal direction. 



