Interactive Effect of Nitrogen Derived from both Mineral and Organic Sources on Yield and Quality of Onion Bulbs Grown on Two Different Soil Types of El-Fayoum Area, Egypt

摘要

TWO FIELD experiments were conducted during winter growing seasons for the two successive years of 2007 and 2008 on two soil sites of newly reclaimed and ancient agricultural areas of El-Fayoum Governorate. Such two soils having different soil characteristics, mainly due to they are derived and developed on two various soil origins, i.e., Eocene limestone for a newly reclaimed sandy loam soil that is calcareous in nature at Kasr Rash wan village (Tamia district) and the Nile alluvium for an ancient agricultural clayey one at Biyahmo village (Sinnuris district). The main objective of the current study represented by evaluating the response of vegetative growth of onion plants {Allium cepa L., var. Giza 6) as well as yield, its quality and storabilityof onion bulbs to a partial N-mineral substitution by an alternative N-source supplied from some local organic manures (i.e., a composted straw mixture of wheat and broad bean residues) at the rates of 20, 25 and 30 nrVfed as compared with applying 100% of the recommended N-mineral fertilizer as ammonium nitrate (33.5 % N), hopping an alleviation of the possible fears of chemical pollution for such a edible vegetable plant and environmental risks.The obtained fieldwork show that the studied soils are developed on two geomorphic units of fluvio-aeolian plain (i.e., sandy loam soil at Kasr Rashwan village) and El-Fayoum alluvial plain (i.e., clayey soil at Biyahmo village), which are occupied the eastern and middle parts of El-Fayoum Governorate, respectively. Also, the corresponding taxonomic units at the family level are "Typic Haplocalcids, loamy skeletal, mixed, hyperthermic" and "Typic Haplotorrerts, fine clayey, smcctitic, hyperthermic", respectively. By using a parametric system of soil evaluation for irrigated agriculture land, the results reveal that soil texture (s_1), CaCO_3 (s_3), and gypsum (s_4), with an intensity degree of moderate-slight, are represented the main soil limitationsfor productivity. Moreover, the suitability conditions in either current or potential classes of the two studied soils could be categorized as moderately suitable for irrigated agriculture land (S2), with a suitability index rating (Ci) ranged 51.07-72.68 %.