الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The present work was carried out in the Desert Research Center, Maryout Research Station under calcareous soil conditions during the growing
seasons of 1997-1998 and 1998-1999. The aim of this investigation study the
effect of organic and mineral fertilizers on growth, yield and its components and chemical composition of Giza 20 onion cultivar .The experiment included
twenty treatments resulted from the interaction of 5 organic manures rates and 4 levels of compound fertilizer (NPK) As follows.
(A) Organic manure treatments were:
1- Control (without any addition)
2- FYM at rates of 10 and 20 ton per faddan added to the soil before
planting. 3- TR at rate of 10 and 20 ton per faddan added to the soil before
planting. (B) NPK fertilizers levels were : 1- Control (without any addition)
2- NPK1 (40N: 30 P20s: 50 K20)kg/fad.
3- NPK2 (60N: 45 P205: 75 K20)kg/fad.
4- NPK3 (80N: 60 P20S: 100 K20)kg/fad.
(C) The interaction treatments between organic manures arid chemical
fertilizers treatments.
Nitrogen, Phosphorus and Potassium were added in the ”orin of
ammonium sulphate (21.5%N), Calcium superphosphate (15% P20S) and
Potassium sulphate (48% K20), respectively.A split plot design with four replicates was adopted. The different rates of
organic manure were arranged in the main plots while the levels of compound
(N, P and K ) fertilizers were distributed randomly in the sub- plots
Obtained results could be illustrated as follows : 1- Vegetative growth characteristics :-
I~I-Organic manure treatments exhibited, significant increase in growth
parameters, during periodical samples of onion plants when compared
with control treatment. The highest values of growth characters obtained
from plants received town refuse treatments (10 and 20 t/fad.) The
treatments had no significant effect on neck diameter and bulbing ratio of
bulbs.
1-2-NPK treatments exhibited significant Increase In growth parameters
except neck diameter and bulbing ratio of bulbs when compared with
control treatment. The second and the third NPK treatments enhanced
growth characters of onion plants.
1-3-The interaction between organic and NPK fertilizers treatments exhibited
significant increase in plant length, fresh and dry weight of bulb.
1~4~Alit growth parameters, except bulbing ratio increased with age of plants.2. Yield and its components:-
2-1- Organic manure application had a positive effect on total yield, fresh and
dry weight of bulb in addition to bulb diameter when compared with
control treatment. Town refuse treatments (10-20 t/fad.) followed by FYM application at 20 t/fad surpassed than the other treatments.
2-2- NPK fertilizers application at different rates had a positive significant
effect on total yield, fresh and dry weight of bulb, as well as bulb
diameter.
- The highest values of total yield and its components obtained from onions
received the second and the third NPK treatments.
2-3- The interaction treatments between organic manures and NPK fertilizers
showed significant increase in total yield and fresh weight of bulbs.
the highest value of total yield obtained with onions received TR at 20 ton
Ifad + the second or the first NPK treatments.
3 . Chemical composition :-
3-1- Organic manures application exhibited significant increase in NPK content
in onions. Town refuse treatment at 20 ton Ifad enhanced than other
organic manures treatments.
- Applying organic manures (OM) to onion plants significantly increased
the percentage ofT.S.S in onion bulbs Also, heavy metals content increased in onions treated with OM but the
incearses were within allowed range of metals.
3-2-Applying the different levels of NPK fertilizers significantly increased
NPK contents in onion bulbs, and the NPK contents incearse with
increasing level ofNPK application.
- Regarding T.S.S percentage of onion bulbs, increased with increasing NPK
rates application to onion plants.
- Application of NPK at the second (NPK)2 and third (NPKh levels to onion
plants increased heavy metals content in onion bulbs significantly in the first
growing season only. But the incearses of heavy metals content in bulbs were
within allowed range.
3-3- The interaction between OM and NPK fertilizers enhanced N,K content in
onion bulbs when compared with the control treatment. TR at 20 t/fad +
(NPK)3 levels surpassed than other treatments in its effect on NPK content
in onion bulbs. The increase in phosphourus content in onion bulbs was not significant when compared with the control treatment.
- Heavy metals contents increased significantly in onion bulbs, but within
safty range as a results of the interaction between organic and NPK
fertilizers when compared with control treatment.6- Conclusion
Generally it could be concluded that under calcareous soil condition, The
addition of 20 t/fad of town refuse combined with second rate of NPK
fertilizers (60N+ 45 P20S+ 75K20) can be recommended for obtaining the best
vegetative growth, with highest total yield and best quality. It is worthy to
mention that using town refuse as organic manures at 20t/fad rates was safe
from the heavy metals nutritional point according to the appendix mentioned
and in materials and methods.