Effects of tillage and organic management on some soil physical properties and wheat yield

الملخص EN

A field experiment was conducted on clayey soils having a subsurface soft pan at El Fayoum area to identify the impact of different tillage practices and organic application on some soil physical properties and yield of grown wheat plants.

Two tillage practices were employed (with and without subsoiling) as main treatments, then each one was treated with graded levels of surface tillage as subtreatments (zero, primary, secondary and conventional tillage).

All treatments under study were treated with sewage sludge as an organic soil amendment at rates of 0, 1, 2 and 4 ton/fed and mixed throughly with soil surface layer in three replicates.

Wheat seeds (Sakha 8) were planted during winter season of 2000/2001, and soil properties were examined at two periods of before ploughing and after four months from planting on three soil depths (0-20, 20-40 and 40-60 cm).

The main results can be summarized in: * Soil bulk density and total porosity values were proportionally decreased and increased, respectivelly, as a result of all applied tillage practices and sewage sludge rates, especially for the surface layers.

The effect of application sewage sludge at a rate of 4 ton/fed was almost similar or slight exceed that of resulted from surface ploughing in three runs.

* Soil strength, as measured by penetration resistance, was decreased coinciding with the applied tillage practices and sewage sludge rates, especially for the subsurface soft pan.

* Soil permeability and moisture constants were improved proportionally with applying tillage practices and increasing the rates of sewage sludge.

* All the used tillage and sewage sludge treatments led to a significant increase in both grain and straw yields of wheat.

So, the relative effects of negligible tillage management can be reduced by the addition of organic manure accompanied with or without tillage practices or their reduction.