Document Type : Research articles.
Author
Soils and Water Dept., Fac. of Agric., Fayoum University, Egypt.
Abstract
A green house pot experiment was carried out on a newly reclaimed
calcareous sandy loam soil (0-30 cm) having about 22 % CaCO3 at Demo
Experimental Farm of Agric. Fac., El Fayoum Univ. to study the hazardous
effects of the usage of different water salinity levels (i.e., 250, 600, 1200, 2400
and 4800 mg L-1) as well as the specific effect of anions (i.e., Cl-, CO32- and
SO42-) on some soil and plant characteristics. The response of the studied soil
and the plants grown thereon (elephant grass as a new summer green forage)
characteristics to organic manure (organic compost of plant residues) was a
matter of concern in this study.
The obtained results showed that there were pronounced adverse effects
on the studied soil physio-chemical properties as well as its fertility status (i.e.,
bulk density, soil strength, total porosity, hydraulic conductivity, available
water content, pore size distribution, organic matter content, pH, ESP and the
released available nutrients content in soil) with increasing water salinity
levels. In addition, these negative effects were not only associated with rising
water salinity levels but also with the specific effect of anions. However, the
hazardous effect of Na2CO3 salt surpassed both NaCl and Na2SO4 levels due to
its destroyer effect on soil aggregates, and consequently the other studied soil
properties. In this concern, the accompanied anions could be categorized
according their hazardous effects in an ascending order: CO32- > Cl- > SO42-.
The aforementioned hazardous effects of the applied water salinity levels
on soil characteristics were extended to the vegetative growth (germination
percentage and dry weight) and the nutrients uptake by the grown elephant
grass plants, which showed gradual decreases with increasing water salinity
levels. This may be attributed to the adverse effect of the higher soil solution
salinity on inhibiting uptake of plant roots for all nutrients. It was also evident
from the obtained data that applied organic compost at a rate 30 m3/fed led to
alleviate many of the adverse effects of the water salinity levels and their
specific effects on both the studied soil and plant characteristics. In general,
the applied organic manure increased active organic acids, and hence
enhanced the availability of both essential macro- and micronutrients (N, P, K,
Fe, Mn, Zn and Cu). The later case is considered more affective under
restrictive conditions of such calcareous soil media; moreover the applied
organic manure attained a relatively higher content of these essential nutrients.
Keywords
)
View on SCiNiTO