Functional Relationships Between Fertility and Some Soil Parameters

Abstract

The importance of empirical and theoretical model derivation

in agriculture has been increased due to presence of overwhelming

data obtained from researches in soil science and extensive usage

of computer in Agriculture. Mathematical definition of fertility is

significantly related to research of ecological fertility, usage of

maximum parameter values, management and prediction of fertility.

The derivation of mathematical models and their application after

execution of field and laboratory studies are important steps in

comprehending soil fertility. Some agroecological, agrophysical

and agrochemical characteristics of soils that constitute conceptual

soil model are taken into account in the field and laboratory

studies in order to obtain fertility model for irrigated gray-meadow

soils. These parameters were determined, evaluated and studied

based on the field experiments. The relationships between the

parameters and productivity of cotton were found out and static

models were derived by using the least square methods. The

correlation coefficients (average R = 0.90) of these models with

multiple parameters came out to be statistically significant. The

extreme points of function were calculated in order to obtain

maximum level of the product cultivation in theoretical way. The

evaluation of fertility level of experimental soils by these empirical

models seems to be possible as well.