الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 184 |  |  |
| | | from | 184 | | |
Abstract
This work was carried out during 2011 and 2012 at the Nursery of Fac. Agric. Minia Univ. to investigate the effect of compost (200, 400 and 600 g / container) and nine treatments of bio. and / or minerals NPK fertilization, as well as, their interaction on Populus nigra plants.
Data showed that compost at the three used levels played a positive role in all vegetative and root growth traits, as well as, chemical constituents. Compost at high level resulted in the highest values.
All treatments of bio. and / or minerals NPK fertilization increased all vegetative and root growth parameters and chemical constituents. The highest values were obtained from the treatments of bio. + 75 % NPK dose or minerals NPK (full dose) alone.
The interaction among compost and bio. and / or minerals NPK fertilization treatments was significant in most cases for all studied parameters.
According to our results, it is expected that, compost3 in combination with bio. + 75 % NPK dose followed by minerals NPK (full dose) stimulated growth and some chemical composition of Populus nigra plants.
Vegetative growth parameters :
The interaction among compost levels and bio. and / or minerals NPK fertilization treatments had significant influence on all vegetative and root growth traits of Populus nigra plants in comparison with control treatment, except stem / root ratio had non significant differences during the two experimental seasons.
The highest values for all vegetative and root growth traits were obtained due to fertilizing Populus nigra plants with high level of compost (600 g / container) in combination with bio. + 75 % NPK (full dose) followed by minerals NPK (full dose) and, in some cases the highest values were obtained from adding compost at medium level (400 g / container) in combination with minerals NPK (full dose) or with bio. + 75 % NPK dose.
Chemical constituents :
The interaction among compost levels and bio. and / or minerals NPK fertilization treatments was significant for chlorophyll b only in the second season. Generally the best interaction treatments for the three tested photosynthetic pigments were compost (high level) in combination with minerals NPK (full dose) followed by bio. + 75 % NPK dose.
• The interaction among compost levels and bio. and / or minerals NPK fertilization treatments was significant for N, P and K % in both seasons.
• The highest N % was obtained due to compost3 in combination with either minerals NPK (full dose) followed by bio. + 75 % NPK dose without a significant difference in the second season.
• The highest P % was obtained due to compost3 in combination with either minerals NPK (full dose) or bio. + 75 % NPK dose.
• The best interaction treatment which gave the highest K % was compost3 in combination with minerals NPK (full dose).
In conclusion, it could be recommended, to apply the sandy soil of Populus nigra plants with compost at 600 g / container (filled with 20 kg sandy soil) and fertilized plants with mixture of biofertilizers (phosphorein, Minia Azotein and Effective microorganisms) + 75 % NPK (1.5 + 3 + 1.5 g / container) or only minerals NPK (full dose, 2: 4 : 2 g / container filled with 20 kg sandy soil) to improve the vegetative and root growth and some chemical composition of Populus nigra plants under the conditions of Minia Governorate.
.