EFFECT OF ORGANIC MANURES ON YIELD PROD CTION, AVAILABILITY OF SOME MICRONUTRIENTS ANO THEIR UPTAKE p.Y ONION PLANTS.

A field experiment was conducted during two successive winter
seasons of 2000/2001 and 2001/2002 on onion plant at Wa~y ~I- Moullak,
Ismailia Governorate to study the effect of two sources of organic manures on
yield production, availability of some micrcnutrients and t~6ir llpta~e b;: ;:'::!r:t.
The results revealed that increasing the application rates of urea fertilizer
increased the yield production of onion. It was noticed that farmy",rd manure
(FYM) resulted in a reduction of onion yield particularly in the firlst season.
However, in the second season, yield production of onion wa gradually
increased. Application of chicken manure (ChM) at different rates increased
the onion yield in both two seasons as compared with farmya{d manure.
Results also showed that application of farmyard manure combined with
chicken manure at different rates gradually increased the yield. It was
concluded that chicken manure combined with farmyard manure may correct
the final C/N ratio of the mixture and could create a preferable c9ndition for
enhancing the mineralization of the organic-No High percentas,e of yield
production were noticed at ratio of (1 :2) (FYM:ChM). The mean values of the
yield production can be arranged in the descending order (FY~ .,. ChM) >
ChM > urea> FYM. Results also clarified that the effectiveness of the organic
materials occurred in the second season than in the first one. Application of
farmyard manure, chicken manure and their combination influenc'3d the
uptake of Fe, Mn, Zn and Cu by onion plant, and also increased the
extractable fraction of the investigated elements particularly at 5 • 10cm depth
as compared with other treatments. It was evident that organic fertilizers in all
cases improved cropping, with the highest average yiRld of onion, being
obtained froill plots receiving farmyard or chicken manur or their
combinations.