Document Type : Research articles.
Authors
Soils, Water and Environ. Res. Institute, Agric. Res. Center, Giza, Egypt
Abstract
A field study was conducted on a sandy loam soil that is suffering from
salinity stress and Zn-deficient at a newly reclaimed area of Galbana Village
No. 7, Sahl El-Tina, North Sinai, Egypt during a growing summer season of
2009 to identify some scientific approaches for alleviating the negative effect of
soil salinity stress on the future projects in agricultural utilization. The applied
treatments were two solid N-mineral forms (i.e., urea of 46 N% and ammonium
sulfate of 20.6 N%) were added at the recommended dose of 120 kg N/fed as
soil application as well as three liquid mixtures of (1.0 g K-humate of 85 % +
0.5 g Zn SO4, which dissolved in 1 L water), (0.5 g Zn SO4 dissolved in 1 L of
soaking water extract of compost tea) and (0.75 g ZnSO4 dissolved in 1 L
water) were added at two equal doses of 300 L/fed for each one either as foliar
spray on plants or as soil application on the soil rows of growing plants. Maize
(Zea mais L., Three cross 321 cv.) was undertaken as plant indicator to identify
its possible response to grow under soil salinity stress of Sahl El-Tina area as
well as the relationship between either maize yield or grain quality and the
expected amelioration process in the experimental soil properties as a result of
the applied treatments.
The obtained results indicated that the experimental soil could be
classified as "Typic Torriorthents, loamy skeletal, mixed, thermic". Also,
wetness, soil texture, CaCO3, gypsum and salinity/alkalinity represent the main
limitations for soil productivity, with an intensity degree of moderate (65-75%),
for wetness, soil texture and salinity/alkalinity as well as slight (90-85 %) for
the other ones. The suitability classes for irrigated agriculture land in both
current and potential conditions could be belong the marginally (S3ws1n) and
moderately (S2s1) suitable classes, respectively. Moreover, the resultant
adaptations of soil suitability class for cultivating maize plants could be
considered as marginally suitable (S3s1n), and limiting factors of soil texture
and salinity/alkalinity in the current condition. Soil suitability becomes a
moderately suitable (S2s1) in the potential condition, and soil texture still
becomes a limiting factor.
The obtained results showed also that the studied maize plant parameters
such as growth characters (i.e., nutrient contents uptake by leaf tissues), ear
characters (i.e., length and diameter), biological yield (i.e., grain and stalk
yields fed-1), grain quality (i.e., weight of 100 kernels and crude protein %) and
grain nutritional status (i.e., N, P, K, Fe, Mn and Zn contents) were recorded the
best values at the applied rates of ammonium sulfate as a main source of Nmineral as compared to the same applied rats of urea. In addition, the liquid
fertilizer mixture of (0.5 g Zn SO4 dissolved in 1 L of soaking water extract of
compost tea) surpassed the other applied two mixtures for the previous plant
parameters. Moreover, the applied liquid fertilizer mixtures, in general, were
more effective on plant parameters when added as soil application on soil rows
of grown plants as compared with directly foliar spray on plants.
Thus, fertilizing maize plants with ammonium sulfate should be
enhanced soil availability of plant nutrient, due to the effective role of both
accompanied cationic (NH4+) and anionic (SO42-) forms. However, the applied
N- NH4+ causes a N-soil potentially safe over a wide range due to lower risks of
volatilization, leaching and de-nitrification losses as well as lowering soil pH
due to for the SO42- ions. Also, it was found that both soaking water extract of
compost tea and K-humate as a soil liquid fertilizer are not only considered as a
strategic storehouse for essential plant nutrients but also enhancing nutrients
uptake, reducing the uptake of some toxic elements and supporting Zn-deficient
as well as improving the nutrients balance in the soil solution and many of
the physiological processes in plants under soil salinity stress. Such
favourable conditions were positively reflected on ameliorating maize growth
parameters and grain yield with high quality of nutritional status.
Keywords
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