The present investigation aims at studying the individual effect of soil
conditioning, i.e., bentonite, compost and biofertilizer on NPK availability, some sandy
physical properties, wheat and peanut, growth and yield. Therefore, a field experiment
was conducted out at Ismailia Agric. Res. st. The used conditioners were bentonite, compost, commercial biofertilizer and
their mixture. These conditioners were mixed and incorporated into the surface soil
layer (0-20cm) at different rates before cultivation of wheat. The soil availability of
macronutrients and NPK contents and the yield of wheat and peanut grains were
determined after two successive growth seasons (winter 2000/2001 and summer
2001). The obtained results indicated that the addition of compost (10 ton/fed.)
alone or mixed with biofertilizer gave the high values of organic matter content, while
applying bentonite (10 ton/fed.) followed by compost (10 ton/fed.) markedly decreased
the soil hydraulic conductivity. The maximum values of available N P were obtained by applying compost
(10 ton/fed.) as well as applying compost (10 ton/fed.) mixed with biofertilizer. While,
the highest value of available K was realized by applying either bentonite (10 ton/fed.)
or mixture of bentonite (10 ton/fed.) and biofertilizer. The best values of NPK concentrations and also the yield of wheat and
peanut were obtained by applying compost (10 ton/fed.) mixed with biofertilizer.