The Effective Role of Organic Manure and Ascorbic Acid for Inhibitory the Impact of Soil Salinity Stress under the Newly Reclaimed Soil Conditions

摘要

STUDYING the importance of using organic manure and ascorbic acid, as soil application and foliar spray respectively, to inhibitory the hazardous effects of soil salinity stress on vegetative growth, yield and its quality of onion plants (Allium copa L., var. Giza 6) under newly reclaimed soil conditions was the main objective of the current study. To achieve this target, a field experiment was carried out on a newly reclaimed soil at the Agriculture Experimental Farm of Demo, Fac. of Agric., Fayoum Univ., El Fayoung Governorate during two successive seasons of 2007-2008 and 2008-2009. Poultry manure as an organic manure was applied at the rates of 0, 10, 20 and 30 m(3) fed(-1), while the rates of ascorbic acid were 0, 100, 200, 300 and 400 mgL(-1), in form of few drops of Tween-20 added to an alleviation of the possible fears of chemical pollution for such as edible vegetable plant and environmental risks.The obtained data show that the experimental soil site is derived and developed on an origin calcareous in nature of Eocene limestone and it possesses a sandy clay loam texture with a moderate salinity The taxonomic unit at the family level is Typic Torriorthents, fine loamy, mixed, hyperthermic as well as the suitability conditions in either current or potential classes could be categorized as highly suitable for irrigated agriculture lands (S12), with a suitability index rating (Ci) 81.20 and 85.50 %, respectively, Concerning the response of onion growth characters to the applied treatments, data showed an obvious clearly response for either applied poultry manure of ascorbic acid as solely or combined ones, with a superiority towards the combined treatment of (20 m(3) poultry manure + 300 mg L-1 per feddan) from the economical point of view, under the conditions of such newly reclaimed desert sandy clay loam. Regardless of the, studied growth parameters, i.e., plant height number of leaves/plant, fresh or dry weights plant(-1), total chlorophyl and nutritional status of leaves recorded the greatest values by plants supplied with the aforementioned combined treatment. These favourable conditions positively reflected on maximizing total yield of union bulb/fed, with high quality parameters (i.e., fresh or dry weights bulb(-1) and their nutritional status). Such better characters of anion plants supplied with the applied treatments were more attributed to a direct role of poultry manure on improving: a) Soil hydro-physical and chemical properties, b) Soil power capacity, as a source of nutrients, for support root development among the different growth stages, c) Released organic constituents of active groups such as fulvic and humic acids which have the ability to retain the essential. plant nutrients in available chelate forms and d) Soil biologiaal conditions that enhancing mineralization of the released organic nutrients in available forms.From economical point of view, the relative increase percentages in total onion yield at the applied superior treatment of (20 m(3) poultry manure + 300 mg L-1 per feddan) reached about 50 % over the control, as an average for the two seasons, with high quality for the studied newly reclaimed soil. In addition, the periodical application of natural organic manure is considered the best option not only for maximizing onion yield and its quality, but also for sustaining soil fertility status and help to alleviate the possible risks of environmental pollution on human health. Moreover, the application of organic manure represents a solving for the problems of chemical residues in the export market commodities.