EFFECT OF DIFFERENT KINDS AND RATES OF SOLIDS ON SOME SOIL PROPERTIES AND PRODUCTIVITY

Field experiment was conducted at the f arm of S akha Agric. Res. S talion
during the two successive seasons (2001 and 2002). This investigation aimed to study
the effect and residual effect of treated sewage sludge (air-dried) (TSS) and farmyard
manure (FYM) application on some soils physical and chemical properties and its
productivity 0 f maize and sugar beet crops. Split plot design with 4 replicates was
implemented. Application rate occupied the main plots. Five rates: 0, 10, 15, 20 and
30 tons/fed were added one lime at the beginning of the experiment while TSS and
FYM were applied to the sub-plots. Results could be summarized as follows:
Application of ar.y of TSS or FYM had slightly decreased the soil pH, while
EC, soluble Na, Ca, Mg and SAR were obviously increased. Microelements (Cu, Zn
and Mn) were slightly increased. Meanwhile, the mean concentration of Fe was
obviously increased.
It is noticed that FYM increased EC, SAR values and Cu content more than
TSS especially at the low rates of application, while the inverse direction was noticed
for Zn, Fe and Mn.
Application of any of TSS or FYM had slightly decreased aggregation index
(AI). While mean weight diameter (MWD), optimum size, bulk density (BD), hydraulic
conductivity and total porosity were slightly increased at the low rates of TSS (10 - 15
tons/fed.) and then declined.
It is found that FYM surpassed TSS in its effect on the physical properties in the surface layer, while the inverse direction was induced (i. e, TSS surpassed FYM) in the subsurface layer.
The residual ef1ect of both TSS and FYM after sugarbeet was improving the
studied chemical and physical properties.
Grain yield of maize was increased at the low rate (10 tons/fed.) and then gradually decreased with increasing the rate of either TSS or FYM. But TSS surpassed FYM in reducing maize grain
Root weight of suqarbeet yield, sugar percentage (%) and total sugar content were increased as a result of the residual effect for increasing TSS and FYM application rates.            '