ABSTRACT
A filed experiment was conducted at Bahtim agricultural research
station, Kalubia Governorate, Egypt, during two successive seasons,
summer 2019 and winter 2019/2020 to study the effect of acid and base
compost pretreatment on some soil physical properties and sorghum
(Sorghum bicolor, cv. Giza 15) productivity and barley (Hordeum
vulgare L., cv. Giza 123), productivity. Two separated incubation
experiments were established, the first one was rice straw and corn straw
pretreated by 5 % sulphuric acid then incubated for three weeks, whereas
the second experiment was the rice straw and corn straw pretreated by 2
% potassium hydroxide then incubated for four weeks. At the end of
incubation period, the first experiment was neutralized by both calcium
carbonate and ammonium hydroxide to produce four different types of
composted materials; composted rice straw neutralized by calcium
carbonate 1B, composted rice straw neutralized by ammonium hydroxide
2B, composted corn straw neutralized by calcium carbonate 3B and
composted corn straw neutralized by ammonium hydroxide 4B. In
contrast, the second experiment was neutralized by both sulphuric acid
and citric acid to produce another four types of compost; composted rice
straw neutralized by sulphuric acid 1C, composted rice straw neutralized
by citric acid 2C, composted corn straw neutralized by sulphuric acid 3C
and composted corn straw neutralized by citric acid 4C. The eight pretreated
types of composts in addition to untreated rice straw 1A and
untreated corn straw 2A were incorporated with soil by 0.5 kg m-2 to
study their effects on soil physical properties and sorghum and barley
productivity compared to control (soil without compost addition).
The results indicated that all treatments increased dry and water
stable aggregates as compared to control. The treatment 2B (rice straw
treated by sulphuric acid and neutralized by ammonium hydroxide) was
the best treatment in increasing dry and water stable aggregates. Also, the
values of hydraulic conductivity and total porosity were significantly
Egypt. J. of Appl. Sci., 36 (1) 2021 1-16
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increased in all treatments compared to control. The highest values of
hydraulic conductivity and total porosity were recorded in the treatment
2B followed by 4B. Also, the added treatments significantly decreased
values of bulk density compared to control. The least value of bulk
density was recorded in the treatment 2B. The addition of composted
amendments had a significant impact on soil moisture constants (field
capacity, wilting point and available water) when compared to control
values. The best addition that increased field capacity and available water
was 2B, followed by 2C then 4B. Also, all of the treatments led to a
significant increase in sorghum and barley yields as compared to control.
The treatment 2B was the best treatment in increasing sorghum and
barley yield compared to control. The increase in sorghum and barley
yields may be attributed to that using of acid base pre-treated compost
enhanced improvement of soil physical properties that led to increase in
sorghum and barley yields.