THE RELATIONSHIP BETWEEN SOIL AND AIR TEMPERATURE CONCERNING COTTONSEEDSCULTIVATION AT NORTH DELTA

There are 14 stations under the supervision of Extension Sector. Ministry of
Agriculture and Land Reclamation. Those stations are scattered all-round the country
and record the entire climate data daily or whatever it is needed. Agricultural climate
data were collected along the recorded period (FeO.1 51 to March 31. 2002). Data of the
. previous years was not used since the climate was significantly changed) from station
located at Sedi Salem, Kafr El-Sheikh Governorate to represent the North Delta
region.
It could be conclude' that the high temperature decline along the soil layer (0
- 20 em). _Tt:is led all the estimated statistics (max high, low high. min high, min low,
range high. range low, STDV high and STDV low) to be declined along the soil layer
(0 - 20 ern). Consequently. soil temperature change is affected in the upper layer
(Scm) and then decline sequentially in the sequenliallayers .
. The relationship between the lowest, highest clnd mean temperatures in the upper
soil layer (5 cm) and high air temperature is derived and represented by the equations
1· 3 below:
Soil low temperature (at 5.cm depth) =
                               . O:7783x(high. air temperature) ·3.0406          (1)
. 'R2::: 0.621
Soil high temperature (at 5-cm depth) ":; 0.9084x(high. air temperature) + 2.344               (2)
R2 '" 0.6779
Soil mean temperature (at s-cm depth) ::: O.8433x(high. air temperature) ·0.3483              (3)
R2::: 0.67'26
These equations provide whom it may be concerned (researchers, extension
workers and farmers) by a very simple method to get a quick prediction of soil
temperature just by knowing air temperature which is so easy and available to any
person. In order to cultivate cotton in the proper time as MALR recommend.