جداول لتوضيح محسنات التربة ومظاهر نقص العناصر ومخصبات التربة ؟

مافائدة الكالسيوم فى تربية شجرة بولونيا وأنواعة ؟

الكالسيوم Calcium ومفيد جدا جدا لشجر البولونيا 
الكالسيوم فى الأرض Calcium in Soil
يوجد الكالسيوم بتركيز مرتفع فى القشرة الأرضية بالمقارنة بباقى العناصر المغذية الأخرى باستثناء الأكسيجين والحديد حيث تكون نسبته حوالى 3.64% ، بينما تكون نسبته فى التربة الزراعية حوالى 1.5% . ويتواجد الكالسيوم فى التربة فى عدة صور تختلف درجة صلاحيتها بالنسبة للنبات وهذه الصور هى : 
- معادن حاملة للكالسيوم :
يدخل الكالسيوم فى تركيب العديد من المعادن السيليكاتية مثل : الفلسبارات Feldspars و Amphiboles ومركبات الفوسفات مثل : مجموعة الأباتيت ، وكربونات الكالسيوم المختلفة مثل: الكالسيت CaCO3 والدولوميت CaCO3 . MgCO3 ، وتعتبر المركبات الأخيرة ذات تأثير كبير فى الأراضى الجيرية ، حيث يرتفع تركيز الكالسيوم فى هذه الأراضى إلى نسبة تتراوح بين 10 - 70% كالسيوم .
وتختلف الأراضى فيما بينها اختلافاً كبيراً فى محتواها من الكالسيوم ، ويرجع ذلك إلى مادة الأصل الناشئة منها هذه الأرض كذلك على قابلية المعادن الحاوية للكالسيوم على التجوية والذوبان ومدى تعرض هذه الأراضى للأمطار . وتعتبر الأراضى الموجودة فى المناطق الجافة وشبه الجافة غنية فى الكالسيوم وذلك لوفرة المركبات المعدنية المترسبة والتى يدخل فى تركيبها الكالسيوم مثل الكالسيت ، والدولوميت ، والجبس ، والأباتيت وغيرها من المعادن الأولية والثانوية ، مع ملاحظة أن معدل تحرر الكالسيوم من هذه المركبات بطئ جداً وذلك لارتفاع رقم الـpH فى هذه المناطق ، وتعتبر الأراضى المصرية غنية فى الكالسيوم نظراً لزيادة محتواها من المعادن الحاملة له حيث تتراوح نسبة كربونات الكالسيوم فى أراضى الوادى والدلتا ما بين 2 - 3% ، بينما الأراضى الجيرية والتى توجد بمساحات واسعة فى الساحل الشمالى الغربى وبعض المناطق فى سيناء وأراضى الهضبة الشرقية المتاخمة لوادى النيل وأيضاً فى بعض مناطق الاستصلاح فى غرب النيل تكون نسبة كربونات الكالسوم بها من 10 - 60 % . فى حين نجد فى المناطق الرطبة والأراضى الحامضية يكون محتواها من الكالسيوم منخفض جداً بالمقارنة بأراضى المناطق الجافة وذلك لتعرض الأراضى فى الحالة الأولى للأمطار مما يؤدى إلى غسيل الكالسيوم من على أسطح التبادل للغرويات الأرضية ويحل محله أيون الأيدروجين مما يؤدى إلى زيادة حموضة هذه الأراضى . وتعتبر درجة ذوبان المركبات الحاوية للكالسيوم ومنها الكالسيت ذات أهمية من حيث تغذية النبات أومن حيث حموضة وقاعدية الأرض . فالكالسيت من المركبات القليلة الذوبان حيث إن درجة ذوبانه فى الماء قليلة (10 - 15 جزء فى المليون) . لكن بانخفاض رقم الـpH سواء بزيادة وجود غاز ثانى أكسيد الكربون CO2 أو إضافة الأسمدة ذات التأثير الحامضى مثل كبريتات الأمونيوم ( ينتج من عملية التأزوت للأمونيوم أيونات الأيدروجين ) كذلك إضافة المادة العضوية ، كل ذلك يساعد فى ذوبان الكالسيت كما فى المعادلة التالية :
CaCo3 + CO2 + H2O Ca( HCO3 )2 
بينما يكون تأثير أيون الأيدروجين كما يلى:
CaCO3 + 2H+ Ca2+ + H2O + CO2 
وبالتالى يمكن أن يتحرر أيون الكالسيوم نتيجة تأين البيكربونات ، أيضاً يمكن أن تتكون البيكربونات الناتجة من تأين حمض الكربونيك الناتج من العمليات الحيوية بالتربة مثل تنفس الجذور والكائنات الأرضية وأيضاً الناتج من تحلل المادة العضوية.
- الكالسيوم المدمص (المتبادل):
يوجد الكالسيوم مدمص على أسطح الغرويات الأرضية سواء المعدنية منها أو العضوية ، ويعتبر الكالسيوم المدمص ذو أهمية كبيرة فى المحافظة على بناء جيد للتربة حيث يشجع أيون الكالسيوم على تكوين التجمعات الأرضية مما يزيد من المسافات البينية بين الحبيبات خاصة فى الأراضى الطينية وبالتالى تزداد عمليات التهوية مما يؤثر إيجابياً على كفاءة امتصاص الجذور للأيونات . وتختلف كمية الكالسيوم المتبادل فى الأرض حسب نوع معادن الطين السائدة فى هذه الأرض ، فمثلاً نجد أن الأراضى الغنية فى معادن من نوع 1:2 يمثل الكالسيوم المتبادل منها حوالى 80% من السعة التبادلية الكاتيونية لهذه الأرض . فى حين نجد أن هذا الرقم ينخفض إلى 20% فى الأراضى الغنية بمعدن الكاؤلينيت وهو من المعادن من نوع 1:1 . ويعتبر الكالسيوم المتبادل رصيد للكالسيوم الذائب فى المحلول الأرضى لوجود حالة من الاتزان بينهما علماً بأنه لا يمكن القول بأن كل الكالسيوم المتبادل ميسر للنبات وذلك لأن قوة ربط أيون الكالسيوم على سطح الغروى هى التى تحدد ذلك .
- الكالسيوم الذائب: 
معظم الأراضى المعدنية يحتوى محلولها الأرضى على كمية كافية من الكالسيوم لسد حاجة المحاصيل المختلفة والنامية فيها. بينما قد تعانى الأراضى العضوية من نقصه نتيجة لادمصاص الكالسيوم على الدبال وتكوين معقدات عضوية للكالسيوم غير ذائبة . وفى الأراضى الحامضية نتيجة لإحلال الأيدروجين محل الكالسيوم على مواقع التبادل فإنه يحدث للكالسيوم غسيل من المحلول الأرضى . وتتأثر الكمية الذائبة فى المحلول الأرضى بعوامل مختلفة من أهمها : رقم الـpH حيث يحدث ترسيب للكالسيوم فى صورة مركبات عديدة بارتفاع هذا الرقم وعلى الرغم من ذلك تحتوى هذه الأراضى على كمية كافية من الكالسيوم صالحة لتغذية النبات . بينما فى الأراضى الحامضية يقل الكالسيوم الذائب وسبق تفسير سبب ذلك . أيضاً لنوع معدن الطين وكمية المادة العضوية تأثير كبير على الكمية الذائبة .
الكالسيوم فى النباتCalcium in Plant 
يوجد الكالسيوم فى معظم النباتات بكميات كبيرة وخاصة فى الأوراق . وتحتوى الأوراق المسنة على الكمية العظمى من الكالسيوم عكس الفوسفور والبوتاسيوم اللذين يوجد معظمهما فى الأوراق الحديثة ، ويُثبت معظم الكالسيوم فى جدر الخلايا على صورة بكتات الكالسيوم Calcium pactate والتى تكون الصفيحة الوسطى وهذا ضرورى فى الانقسام الميتوزى للخلية ، كما يعمل الكالسيوم على المساعدة فى ثبات الجدر الخلوية وكذلك فى الحفاظ على تركيب الكروموسومات . وفى كثير من الأنواع النباتية يوجد الكالسيوم على هيئة بلورات غير ذائبة من أكسلات الكالسيوم . وقد يكون الكالسيوم أملاحاً مع الأحماض العضوية الأخرى كما يحتمل دخوله فى التفاعلات الكيميائية مع جزيئات البروتين . ويمثل أيون الكالسيوم أحد المكونات الهامة للعصير الخلوى ، وأيضاً يعتبر هذا العنصر ضرورى لاستكمال واستمرار القمة المرستيمية ، حيث وجد أنه بغياب الكالسيوم يقل نشاط الانقسام المباشر وقد يقف تماماً . كذلك يساعد الكالسيوم فى نشاط كثير من الإنزيمات مثل Phospholipase, Argin, Kinase, Adenosine Triphosphates كما وجد أنه يعمل على معادلة الأحماض العضوية بالخلايا مما يقلل من سميتها .
أعراض نقص الكالسيوم على النبات: 
يعتبر الكالسيوم من العناصر الغير متحركة داخل النبات حيث قليلاً ما يعاد توزيعه داخل الخلايا النبات إذا ما قل تركيزه أو انعدم وجوده حول الجذور . فقد تحتوى الأوراق المسنة لنبات ما على كميات كبيرة من الكالسيوم المخزون ، فى حين تعانى الأوراق الحديثة لنفس النبات نقصاً فى هذا العنصر . وعموماً قلما تظهر أعراض نقص الكالسيوم على النباتات النامية فى الحقل وخاصة فى أراضى المناطق الجافة وشبه الجافة ومنها الأراضى المصرية ، بينما العكس يمكن حدوثه بظهور أعراض النقص على النباتات النامية فى الأراضى الحامضية . ويمكن إيجاز أهم الأعراض كما يلى :
1- تبدأ ظهور الأعراض على الأوراق الحديثة ، حيث تكون هذه الأوراق مشوهه وصغيرة ولونها الأخضر الداكن غير عادى .
2- الأوراق تصبح مجعدة ويحدث لها التفاف إلى أسفل وتظهر الحواف متموجة وغير منتظمة ، ويحدث أن تصبح الأوراق طرية نتيجة انحلال جدر الخلايا ويقف نمو البرعم الطرفى ، مع حدوث تكسير فى السويقات الصغيرة .
3- يحدث ضعف أو تلف ملحوظ فى الجذور ، ويمكن أن يحدث تعفن لها، كذلك يحدث ضعف عام للسيقان . 
4- تظهر نقط جافة على البراعم الطرفية ويحدث تساقط للأزهار .
5- يسبب نقص الكالسيوم ظهور مرض يسمى Btter pit على ثمار التفاح والذى يتميز بظهور بقع بنية صغيرة غائرة ومنتشرة على كافة سطح الثمرة . أما ثمار الطماطم فتصاب بمرض يسمى بعفن الطرف الزهرى للثمرة Blossom-end rot حيث تتهدم الخلايا وتتعفن فى الجهة السائبه من الثمرة .

الأسمدة المحتوية على الكالسيوم : 
يدخل الكالسيوم فى تركيب كثير من الأسمدة 
الأسمدة المحتوية على الكالسيوم
السماد الرمز الكيميائى
سوبر فوسفات عادى Ca (H2PO4)2. CaCO3
سوبر فوسفات ثلاثى Ca (H2PO4)2
نترات النشادر الجيرى NH4NO3. CaCO3

نترات الكالسيومCa (NO3)2

كيف نستخدم الكعوب فى إكثار شجرة بولونيا ؟

من طرق تكاثر الخضرى تكاثر بالكعوب 
1- يتم زراعة شتلات البولونيا بطريقة مكثفة وفى فصل الشتاء يتم قص الافرع الخضرية والابقاء على الكعب وجزء من الجذور
2- ويتم تقليع العقل من الارض ملش بدون جذور ويتم غسلها جيد بماء 
3- ويتم حفظها لحين الزراعة فى بداية فصل الربيع
4- يتم إحضار مبيد فطرى وعمل محلول منة ( 1جم لكل لتر ماء ) ويتم غمس العقل فى محلول مده 1 دقيقة
5- نخرج العقل من محلول وتترك لتجف ويتم عمل جور
6- تنبية عدم وضع اى سماد عضوى حتى لايكون بيئة مناسبة لنمو البكتريا وفطريات وموت الجذور 
وصور موضحة 

كيف نضيف العناصر الغذائية للشجرة بولونيا مثل تجربة البلغارية ؟

هذة المقالة مايفيد كيفية التسميد ل5 مواسم = 5سنوات وذلك من تجربة دولة بلغاريا ونستفيد منها بمصر ووطن عربى مع بعض التعديلات البسيطة 

بولونيا يحتاج الى الكثير من المواد المغذية إلى تطوير كامل لها محتمل!

عادة يتم تطبيق الأسمدة الحبيبية يدويا على السطح في زراعة الربيع. يتم خلط السماد مع التربة 1: 1 في حفرة

حيث كانت الزراعة هي. في وقت لاحق خلال الموسم لديك لاستخدام

إضافي 300 (طبقا لنوع التربة والمناخ والنمو المسجلة)

قبل تطبيقها على الشجرة باستخدام رش manure- (مع الجانب الإفراج) بحيث حبيبات ستسقط مباشرة في زرعت على

خط. (A صغير أربعة - مركبة "ATV" هو المناسب لهذا النشاط لسبب أنه لن تضر التربة مثل جرار الثقيلة سوف افعل).

هذا سوف تتكرر في الموسم المقبل ولكن من الضروري للحفاظ على النمو الأخضر السريع خلال المواسم الحارة

(عادة 2 تطبيقات في الموسم الواحد حتى السنة الثالثة، عندما يكون هناك هو التطبيق الكامل لل200G الأسمدة للنبات خلال فصل الربيع ويكفي للسنة).

نظام التسميد التالي توصية أساسية جدا

للمناخ دافئ مع التربة تنظيما جيدا ولكن سوء. عليك أن نعلم أن هناك العديد من الأماكن في بلغاريا حيث التربة غنية بما فيه الكفاية وتمتلك كميات مماثلة وهم المفرط

في الغالب من حيث مدة التطبيق هي.

* زراعة يتعين إنجازها في وقت أواخر الربيع أو أوائل الصيف.

الأسمدة الحبيبية

فترة الأسمدة / طريقة شجرة

1. وضع السماد 1: 1 مع التربة السطحية

 يوضع

السوبر فوسفات الثلاثي 500 باليد، على السطح

البوتاسيوم كبريتات 120 خطيا، منتشرة في

نترات الامونيوم 150 مركز من كل سطر

2. أواخر الشتاء قبل 300-500g 

الموسم الثاني الموحدين

الأسمدة

هذه المبالغ المقدرة تقريبية وإجراء

يوصى تحليل التربة لتصميمهم معين.خلال 

موسم الثالث التسميد ينبغي أن يكون بقدر ما فيالثاني

. يتم رش الأسمدة في 1.5 متر من

وقف، لأن الجذور الأكثر تقدما.

الموسم الرابع - 600 غرام روث / الخشب متناثرة بالتساوي في جميع أنحاء المزارع.

الموسم الخامس وبعد فقط إذا لزم الأمر.أفضل نوع التطبيقية الأسمدة ومبالغ فيها تختلف باختلاف

المناخ ونوع التربة. عندما المناخ الجاف جدا

قد يكون التسميد السائل الحل الوحيد الممكن لتقديم

المواد اللازمة. 

بعد بضعة مواسم دورة الاكتفاء الذاتي

المواد الغذائية بداية لبناء والأوراق المتساقطة تبدأ ل

تغذية جذور النظام.

 ?HOW TO ADD NUTRITIENTS

Paulownia needs a lot of nutrients to develop its full

potential!

Usually granular fertilizer is applied manually on the surface in

spring planting. Manure shall be mixed with soil 1:1 in the hole

where the planting is. Later during the season you have to use an

additional 300 (depending on soil, climate and observed growth)

by applying them to the tree using manure- spreaders (with side

release) so that the granules will fall directly at the planted on

line. (A small four - vehicle "ATV" is appropriate for this activity

for a reason that it will not damage the soil like a heavy tractor

will do). This will be repeated the next season but it is necessary

to maintain a rapid green growth during the warm seasons

(usually 2 applications per season until the third year, when there

is a full application of 200g fertilizer for a plant during the spring

is enough for the year).

The following fertilization scheme is a very basic recommendation

for warm climate with well-structured but poor soil. You have to

know that there are many places in Bulgaria where the soils are

rich enough and possess similar quantities and they are excessive

mostly in terms of duration of application are.

*Planting has to be accomplished at the time of late spring or

early summer.

Granular fertilizer

Period fertilizer / tree method

1. Planting manure 1:1 with a topsoil

1a. Planting

Triple superphosphate 500 by hand, at the surface

Potassium sulphate 120 linearly, scattered at the

Ammonium nitrate 150 center of each line

2. Late winter before the second season 300-500g combined

fertilizer

These estimated amounts are approximate and the conducting of

the soil analysis is recommended for their specific determination.

During the third season fertilization should be as much as in the

second. The fertilizer shall be sprayed at 1.5 meters from the

stem, since the roots are more developed.

Fourth season - 600 g manure/wood scattered evenly throughout

the plantation.

Fifth season and after only if needed.

The best applied type of fertilizer and its amounts vary according

the climate and the soil type. When the climate is very dry the

liquid fertilization may be the only possible solution for delivering

the necessary substances. After few seasons the cycle of selfsufficiency

nutrients beginning to build and fallen leaves starts to

feed the root system.

إحتياجات شجرة بولونيا بطريقة مبسطة ؟

Land

1. Ground water level: more than 1.5m.

2. Soil texture: permeablility or breathability good   loam and sand soil, avoid clay, harden, ventilation adverse soil.

3. PH of soil, 6-7.5 is the best, 5-8.9 is acceptable.

4. Good irrigation and drainage systerm will be better.

 Elevation up to 2000m is acceptable 

Water

1. Fecund and wet. No ponding and water saturation

2. Annual rainfull 400mm-1200mm.

3. In seedling period, keep the soil with good   moisture(20-40%), after grow up than 50cm drought resistant ability improve,then better and better.

attention please: water enough, no ponding, keep   soil breathing

Sunshine

1. Plant paulownia tree in sunny place and keep away   from heavy wind.

2. Try to prohibit paulownia tree under other bigger   trees

3. Density. For seedling using 0.8x1m or 1x1m distance,   for forestation 4x4m or bigger distance.

Plant with crop distance more than 3x15m

Temperature

Annual temperature 12-20celsius degree grow better; -20-+45celsius degree is ok, vulnerable to frost damage if absolute temperature less than -25celsius degree.

Fertilizer

At the first, for paulownia seed, paulownia root and   paulownia stump, and other paulownia planting, give little fertilizer, and in the future: less quantity fertilizer and 

much more times

.

تجربة عملية بمعدل نمو و إرتفاع شجرة بولونيا فى 6 شهور ؟

هذة تجربة تمت لقياس معدل النمو بالشهر والاسابيع لمشاهدة معدل النمو السريع والقوى ونلاحظ تبكير فى زراعة وهذا يختلف من بلد إلى أخر و فى الوطن العربى ومصر يفضل من بداية شهر 5 حتى أخر شهر 9 

زراعة يوم 16-3 الارتفاع 3 بوصة 

تاريخ 24-3 بعد 8 ايام الارتفاع 6 بوصة 

تاريخ 10-4 بعد 25 يوم الارتفاع 9 بوصة 

تاريخ 18-5 بعد شهرين الارتفاع 12 بوصة 

تاريخ 4-7 بعد 3شهور و3 اسابيع الارتفاع 2 قدم و7 بوصة

تاريخ 15-7 بعد 4 شهور الارتفاع 4 قدم و3 بوصة

تاريخ 1-8 بعد 4 شهور ونصف الارتفاع 7 قدم

تاريخ 16-8 بعد 5شهور الارتفاع 8 قدم و7 بوصة 

تاريخ 17-9 بعد 6 شهور الارتفاع 13 قدم 

مقالة بلغة الانجليزية عن شجرة بولونيا فيها كثير من معلومات الهامة ؟

هذة مقالات بالغة الانجليزية عن الرى - والتربة - التجفيف - القص - الامراض 

CONTENT
1.0 PRODUCTION OF PAULOWNIA FOR BIOMASS
1.1 Choosing a place
1.2 Reqirements of Paulownia for the soil, climate and agronomical
conditions.
1.3 Instructions for soil sampling for soil analysis.
1.4 Planting material
1.5 Planting and looking after – general conditions
1.5.1. Preparation of the land
1.5.2. Rain and wind
1.6 Planting
1.6.1 Pastures and lands covered with bushes
1.6.2 Bushes control after planting
1.6.3 Trench
1.6.4 Disking /leveling/
1.6.5 Furrowing and marking
1.6.6 Determination of the seeding scheme
1.6.7 Watering
1.6.8 Fertilising
1.6.9 Paring
1.6.10. Planting without complete treatment of the soil
1.7 Diseases and enemies
1.8 Yields
1.9 Harvest
1.9.1 Direct harvest of chips
1.9.2 Harvest of whole stems
1.9.3 Harvest of sticks
1.10 Drying and storage
1.11 Restoration of the land
2.0 ECONOMIC APPLICATION
2.1 Burning, Gazification and Pyrolysis
2.2 Bioremediation
2.3 Costs and economic evaluation
3.0 ENVIRONMENTAL IMPACTS FROM THE USES OF PAULOWNIA
3.1 Flora
3.2 Invertebrates

Introduction

World petrol and gas reserves are decreasing and their yield, deliveries and high

interest are making the final product too expencive. Bulgaria and central

Europe generally are having limited stocks of similar energy sources and they

are importing the bulk of their needs. When it is about petrol this is near 100 %,

in the cases about gas it is the same. If we make a conclusion this is going to be

an almost full dependence from external sources that could not be influenced.

Europe is facing the challenge of the climate change, the increasing dependence

of importing resources and energy and the rising energy costs.

In this condition the European aims for sustainable development are becoming

more difficult for achieving. The new European energy policy, in particular – and

the national, aim to overcome these challenges for the benefit of all European

citisens. The starting point of the European energy policy is at the tree priority

directions:

Mastering the negative climate changes;

limiting the external dependence of EU of imported energy

resources;

encouragement of the economi cal growth and

employement and thi s way i t wi l l as sur ing secure

and af fordable energy for the user s ;

Achieving these goals is impossible without the development and the use of a

wide range of renewable energy technologies – wind, solar, hydro, tidal and

thermal. The biomass from energy cultures that have a particular application in

Bulgaria are at the developpment stage where they are ready for commercial

application.

Renewable energy

The renewable energy sources are providing sustainable and carbon neutral

natural source of heat or energy, as well as improving the security and the

divercity of the deliveries of energy sources.

Some types of renewable energy are having the potential to create and sustain

significant employment in the economical regions. The main limitations with

the renewable energy sources are linked to the consumers confidence and

with the reliability and delivery (due to the nature of some of the sources for

example wind), as well as the costs for the construction that are

reflecting at the energy supply prices. The increasing interest into the

renewable energy and the forecasted potential is a result of multiple factors:

The world conviction that the levels of the carbon emissions needs

immediate decrease for reducting their effect over the global

warming;

This has led to the entry of many international binding instruments

under the Kyoto Protocol limiting the levels of carbon emissions to

certain levels up to 2012. In the European Union the binding norms

will continue to be valid even after Kyoto;

The decreasing reserves and the increasing prices of the fossil

energy sources, particularly gas, petrol and their sensibility to

political influences.

The need to reduce according to the energy import needs by

reliable supplies that the local sources can provide;

The extremely vulnerable position where the conventional

agricultural production is in at the overall economy of the country

and the press on her by multiple countries are urging to alternative

and sustainable possibilities for the use of the land such as the

growth of energy crops.

Big part of the potential that the biomass from energy cultures have in the

reduction of carbon emissions is coming from:

Displacement of the fossil fuel sources for heating as a beginning

and subsequently with the development of the technologies for

small and medium-sized power plants for electricity production.

The neutral status of the biomass from energy cultures regarding

to The C02 emissions, when the growing culture consumes as much

as atmosphere carbon dioxide that subsequently is being released

in the convertion and into the renewable energy as heat or

electricity.

The total carbon cost has been calculated for the production of

energy from biomass, gas and coals and shows the emissions of

CO2 from 60g, 400g и 1,000g for kW electricity respectively.

Biomass

All the the sustainable energy sources are entirely obtaining its energy from the

sun except the tidal and geothermal ones. In the case of energy cultures from

biomass the solar energy is transformed by the plant into a chemical energy

stored in the biomass through the natural process photosynthesis. This could

be oils or oilseed crops, the grass Miscanthus (elephant grass) or under the

shape of wooden biomass for the species with short rotation period such as

Paulownia, poplar or willow whose stems are going to be cutted. The wooden

species represents 60% of the total yield of biomass and Paulownia turns out to

be the most effective culture for our lattitudes comparing its year yield from

with the one from poplar, willow or Miscanthus.

The main advantage of Paulownia as an energy crops is the rapid growth in the

first 1-2 years of its development and the ability of its root system to maintain

the formation of new plants at the place of the trunk.

The material will be planted in the spring as at the end of the first vegetative

period it shall be cutted at ground level in order to provoke the next year

formation of multiple new stems. The growth in the next year is rapidly reaching

3-4 metres untill the end of the year and more than 6-7 metres in the second

year when it will be cutted for processing of the produced biomass. A similar

plantation can live 20-25 years and suggests 10-12 harvests, after that the land

could be reused for another application.The expected quantity of the yield per

acre is different according to few factors. At first comes choosing the kind,

place, climate factors, additional irrigation and all the others factors affecting

the traditional crops. The expected yields of Paulownia could vary within the

range of 30-40 tdm/ha/y or in two years rotational cycle up to 80 tdm/ha.

Measured in units of energy the dry mass from Paulownia has energy content

about 18MJ energy for a kilogram 42% from the energy in equivalent volume

of light fuel. This wat we can recalculate the yield per hectare per year

equivalent to 12 000- 17 000 l i t res fuel f rom hectar and f rom here

we can easi ly evaluate the yield f rom Paulownia in f inancial

equivalent .

At this background there is an expectation on the prices of the fuels that they

will gradually continue to grow and an investment in an energy crop like

Paulownia is really reasonable.

1. PRODUCTION OF PAULOWNIA FOR BIOMASS

1.1 Choosing the site

The downmentioned climatic, geographical and biological requrements of

Paulownia are intended to guide investors to the appropriate growing energy

crops on his choice for the plantation site.

Paulownia grows up to 2000м altitude and latitude 40оN и 40оS. For

husbandry with investment purposes is recommended the latitutde

do be less than750m – 800m.

The growth of the trees starts in the spring, when the temperature of the soil is

reaching 15оС -16оС. Opt imal temperatures for Paulownia’s growth are

in the range of 24оС -33оС.

Paulownia is highly adaptive to diverse soils and grows at a wide range, but the

best development could be seen with deep and well drained soils. The best

and preferred for raising Paulownia are the light aerated and sandy soils

without slope.

Unappropriate for ras ing Paulownia are the clay, rocky, podzolic and soaked

(swamped) soils. Soils that contain clay more than 25% and porosity under

50% are not appropriate for growing Paulownia.

Good growth of Paulownia is observed wi th soils having a рН from 5.0

to 8.9. Paulownia can not tolerate soil salinity more than 1%.

1.2 Requirements of Paulownia for the climatic and agronomic conditions.

Paulownia is highly adaptive tree species, but in order to ensure the

economical effect of the plantation and a hight yield if quality timber you have

to provide the following: appropriate soil, climate and agrotechnical conditions.

parameter Limits

 Mechanical composition, cont. of physical clay up to 30 %

 рН 5,00 – 8,50

 Content of water-soluble salts under 1 %

 Power of the profile above 90 сm

Power of the humus horizon above 40 сm

 Total porosity under 50 сm

 Soil density about 1,3 g/сm3

 Height of groundwaters under 2,00 m

 Altitude up to 800m

 Average year temperature 13 – 25 0C

 Max Т С0

+40,0 0C

 Min Т С0

-24,0 0C

 Rain, mm/month above 150 mm/month

 Wind speed up to 28 кm/h

 Light norm 20000 – 30000 lu

1.3 I n s t r u c t i o n s for soil sampling for soil analysis from areas intended

for Paulownia cultivation.

Basic requirement

The soil sample should be representative for the area where it was taken. For

this purpose it is necessary to take an average sample of each area, regardless

its size. If the size is more than 10 ha, an average soil sample has to be taken on

every 10 ha – so called elementary section. At slopes there are formations of

elementary sections in the upper, middle and down part of the field.

Collecting the first average samples has to be performed during normal

meteorological conditions.

1.4 Planting material

Choosing the planting material has a key role for ensuring the economic

impact of a plantation for biomass. The main criterias are the temperature

regime and the rainfalls. Theese are the two main requirements for the

choice of planting material. BIO Tree company suggests the hybrid kinds

expressly selected for biomass yield. The hybrid varieties selected in Bio

Tree company are appropriate for: yield of high quality timber – kind

Bellissia and for biomass production – kind Oxi.

1.5. Planting and growing – general conditions

1.5.1. Site preparation

Usually Paulownia is planted during spring and mid-summer in

dependence of the development stage of the planting material /one year

old saplings or young planting material/ and prefers horizontal or south

orientated slopes. As all young trees, Paulownia plants should be well

protected from herbivorous animals.

1.5.2. Sun

Paulownia requires a lot of sunlight for its best growth.

1.5.3 Rain

Irrigation is necessary if during the first vegetative period the rain is less

than 150 mm per month. In comparison 10mm of rain delivers 10 liters of

water. Watering is needed in the following years if the monthly rainfall is

under 50mm. Insufficient watering slows the growth but does not kill the

plant.

1.5.4 Wind

Plantation is good to be placed in areas without strong winds reaching

over 28km/h. When there are powerful winds at the place of planting

stabilizing post has to be put during the first year of development until

they form strong wooden stem. The speed of the wind is dangerous for

the young plants over 45km/h and such areas have to be avoided.

1.6.1. Pastures and lands covered with bushes

When selecting a pastures and meadows for plantation with Paulownia,

the terrain has to be pre-treated with herbicide at least 4-5 weeks before

planting. The adherence of thit period is required by the necessity of the

full degradation of the traces from the herbicide in the soil and not to

harm the young and fragile plants. The Herbicide must be choosen to be

able for removal after and to provide long – lasting control for at least 9

months.

The terrain shall be cleaned before the planting and any re-growth of the

weeds must be strictly controlled.

1.6.2. Control on the weeds after planting

Control over the weeds is helping the growth and the virality of the plant.

A circle with diameter 1.5 m around every single tree shall be maintained

without any weeds at least for the next 2 years. Springtime you have to

spray just before the beginning of the growth (waking up), but you should

escape a contact with the stem of the tree. If young rooting cuttings

appears around the tree they must be removed by hand and not by

herbicide.

1.6.3. Trench

Before planting it is recommended plowing the land /minimum at 40 – 60

cm/ aiming to crush the soil and to remove the roots of the perennial

weeds and bushes. If the soil is heavy and clay the trenching shall be at

the depth of 70сm - 80 сm.

1.6.4. Disking /leveling/

After trenching it is necessary to level the land two times. After that it

could be considered that the land is prepared for furrowing, marking,

planting.

1.6.5. Furrowing and marking

The furrowing is performed at the depth of 20 cm. After that you have to

mark the planting spots. In every single planting spot you have to put

additional fertilizer or manure that is mixed with soil in advance. The tree

is planted in a way that the connection between the stem and the root to

be of moisture saturation of the soil during the winter it is recommended

to build a mound (pile), so the level of the soi l wi l l increase at

the plant ing spot . It is appropriate the mound to be 25сm -30 сm

higher than its surrounding soil.

1.6.6. Determining the planting scheme

Paulownia for timber production – When creating a plantation for

timber we recommend the planting scheme with 4х4, 5х5 meters or 5х4

meters between the trees which means 500 or 600 trees per hectare.

Larger density leads to competition for area between the trees and slower

their growth after the first 3-4 years. Lower density leads to faster initial

growth which lowers the timber quality. Higher density does not lead to

commercial effect, the necessity of elimination of plants is connected with

expenses for eradication and herbicide treatment to stop the regeneration

from the roots and in the end the 3-4 years old stems does not possess

enough volume to be used for timber.

Paulownia for biomass – For effective yields we recommend the trees to

be planted with higher density than the one used for timber production.

The density should be between 3500 and 10 000 plants per hectare which

depends on the rotation cycles of for the biomass collection strongly

linked with the purposes of the biomass (pellets, chips, bioethanol,

fodder) and the harvest machines.

1.6.7. Irrigation

It is recommended before planting to irrigate well the terrain. The

saplings shall be irrigated at the day of their planting and after that, until

they develop a strong root system (about 2 years). The second

irrigation shall be 2-4 days after their planting. Irrigation after planting

shall be regular and amply, especially in a dry season. Irrigation is

necessary if the rain during the first vegetative season is not

less than 150 mm per month. It is also necessary in the following

years if the monthly precipitations are less than 50 mm.

The regular development of Paulownia requires :

or rains with with relatively equal alignment - minimum 120 - 150

mm per month irrigation /drip /and/or subsoil moisture at

the depth of 11.5 m.

The main requirement for maximum growth is the regular and amply

irrigation at a time of the vegetational period.

1.6.8. Fertilising

Paulownia is tolerant to poor soils and could reach acceptable dimentions

for the stem diameter. Paulownia thought, grows much better in fertile

soils. The experiments shows that the best is to apply the fertiliser under

the form of nitrogen, phosphorus and potassium at the time of planting.

Nitrogen is more effective, when it is applied as an independent element.

Sometimes it is necessary to fertilise the soil at the time of planting, but it

is strictly in accordance with the results of the soil analysis.

If preliminary soil analysis has not been performed you can do feeding up

by the following materials and start up nutrients:

- soil: organic fertiliser - 1 : 1

- triple superphosphate /TSP/ - 200gr

- potassium phosphate - 120gr

- ammonium nitrate - 150gr

During the exploitation of the plantation the soil is getting poorer and you

have to keep that in mind. Because of that it is necessary to use an

additional fertilisers during certain periods. The duration of the periods

depends on the basic position of the soil and also on the growth rate and

the rotation cycles of the plantations. It is recommended after the first

rotation cycles to monitor the amount of nitrogen, potassium and

phosphorus in the soil, after a scheme for alternate loading has been

issued.

1.6.9. Pruning

The goal of raising Paulownia is to produce a good crop of trees possessing

a good shape and in a good condition. This could be achieved by

for stimulation of the development of maximal quantity timber witout

wooden knots on the tree trunk. This could be achieved by removing the

branches, that are not having big importance in the maintenance of and

optimal leaves number needed for the photosyntetic activity.

1.6.10. Plant ing wi thout complete t reatment of the soi l

/it is allowed only in the cases when the complete treatment of the soil, forestation in a

forestry fund, decoration of parcs and gardens are not possible/

If for any reason you have to plant Paulownia without any treatment in

advance it is necessary to plant the plants into holes, previously

excavated.

Firstly the planting spots shall be marked, after the holes shall be

excavated. If the land is not loose, the holes shall be as wider as they can

be /for heavy soils it is obligatory/- at least 60х60х60 сm. The top soil

shall be separated from the bottom soil in the process of

digging. After that the hole shall be half filled with topsoil (it is

recommended to mix with organic fertiliser).

The plant shall be planted in a way that the connection between the

stem and the root will be about 1 cm below the ground level. The left soil

is superimposed and rammed. At a flat land, especially if there is a risk

of saturation of the soil during the winter is recommended to build a

mound (hillock), so the soil at the hole will be 30 cm above the ground

level. According to the depth of the holes and theirs dimentions an

excavation technic will be choosen.The size of the hole will be choosen

depending to the pre-treatment of the soil starting from 30Х30Х30 сm and

reaching up to 60Х60Х60cm.

Key Factors:

Soil analysis for determining the content clay and microelements and

for estimate how much the soil is suitable for Paulownia growth;

Soil preparation is fundamental for the satisfactory growth;

The weeds control is the most important aspect in the preparation of

the place and the tree growth during the first and the second year;

Irrigation is necessary if the summer rain is insufficient;

1.7 Diseases and enemies

Paulownia plantations do not suffer the typical diseases for the region. A

problem could be the sensitivity of the stem of stem and root decay in a

young age. Preparations against the grey decay and others is used for avoiding

it. The fight is not hard, but the disease depends on the iggiration

manner of the planting material during the first months and the

drainage of the soil. The presence of competitive vegetation in 50 cm zone

around the root system deteriorates significally the growth in height and

diameter. The constant cleaning around the stems is real ly

important because i t can af fect considerably the yield.

1.8 Yields

According the conditions, the choosen genotype /hybride kind/, the keeping

and the rest of the factors normally affecting the traditional crops, the yields of

Paulownia could vary into serious limits from 30-40 tdm/ha/y (tons dry matter

per hectar per year) or at biennial rotation cycle to 70-80 tdm/ha.

1.9 Harvest the production

The harvest of Paulownia produc t ion happens f rom late autumn

unt i l ear ly spr ing . At normal conditions this gives a period of 3 months

from December to the beginning of March. This time troubles the machines

entry and must be considered. If the conditions suggest earlier development

the buds cutting shall be withdrawed back in time. In general this means

harvest of the production before the juices of the plant begins their

movement in the stem and that way the stored in the roots reserves to assure

the development of new ones.

There are three manners for harvesting the crops. Direct harvest like wooden

chips, harvest of entire stems and harvest of cutted sticks with certain lenth

and each of them possess its advantages and disadvantages.

In most of the cases the harvest of the production is a process of cooperation

between different owners due to the specific of the process and the price of

the engines used. The separately purchase and the use of such machine is a

right choice only in few cases. Here the necessity of drying places shall be added

as well as the requirements of the chain with providers and the final users of

the production. All of that aggregate determines the choice for harvesting and

the following activities with the production.

1.9.1 Direct collection of chips

In that case the culture will be harvested and processed in chips at the cutting

of the stems. In that case the material might need artificial drying in

order to escape decay. Most of the machines for this type harvesting are

constructed to gather double rows by one turn possessing significantly changes

picking heads, that will be installed into the standart machines for foraging. The

machine cuts the stem and turns it after into chips and throw it in a trailer. In

this case the already used trailers for collecting a silage could be applied. If the

production is harvested while it is fresh, the quality of the chips is much better

and the fuel costs and amortization of the machine will minimize. This is the

most effective operation to harvest the production but also requires special

drying places. The chips starts to rot as like composting, that leads to energy

loss. Dryiers with ventilated floors used for the cereals are successfully applied

in this operation. In addition the chips is collected and dryied after the cereal

harvest has been already dryied and by this way the expensive equipment is

used additionaly. This type harvesting machines have the capacity of 5-6

hectares per day. In the case for Bulgaria where the lands are more compact

and scattered the capacity could be esteemed as 3-4 hectares per day.

1.9.2 Harvest of whole stems

In this case the culture will be hatvested on whole stems. Multiple conditions

must be considered while choosing the harvest method.

The machines mostly chop and release the stems, that are important for

harvesting, removing and storage like a separate operations.

There are still no effective machines that could tie the chopped stems and it

might be difficult to work with 6-10m rods. The collected stems shall be

transferred for second time for slicing before they turn into use. The collected

stems are being grouped straight in a formation similar like haystack. Thus

they are going to have good enough natural air ventilation for the necessary

period of about 2 months for wood drying without decompose. In this case it

means that the special needful dryers in the direct chips collecting are

necessary. The quality of the chips obtained by this method is lower than in a

case of direct collecting. Slicing the chips is more energy intensive operation

because the chopped wood has been dried. The machines used for cutting the

stems have the capacity of 4-6 hectares per day, thought they remains at the

places of cutting and needs to be collected and transported. Even that this is

more expensive havest method in terms of operating costs in Bulgaria in the

presence of small plantations, scattered plantations and the lack of expensive

dryers and picker machines, this method might turn out more applicable and

practiced.

1.9.3 Harvest rods.

This method takes an average place between the direct collecting of chips and

the cutting of whole stems. This type picker machines has been developped for

sugar cane and forms small pieces from the whole stem of length about 5-10

сm in a way similar of the chips collecting. The machine throws the pieces in a

trailer for removal from the plantation. In this case the bigger size of the

pieces and the ameliorated air circulation between them the natural drying is

possible in a way similar to the collecting of whole stems. This pieces also

needs additional cutting before use in order to maximize the combustion

efficiency, but unlike the whole stems they could be easily manipulated. Here

again the quality of the chips is worse than the one obtained directly, because

the material that has been cutted is relatively dry.

1.10. Drying and storage

Regarding the fact that the need of fuel supplement is amost constantly

throughout the whole year and depends on the final user it will requires a

specific type drying and storage. The part of the providers chain is not enough

clarified and requires work on the problems and theirs addressees. The fresh

harvested crops are having moisture around 21.3% (for comparison another

energy crop is having natural moisture around 50%) and the need of drying is

determined by the choosen harvest method. Generally this is only the directly

collected chips that might need artificial drying. The whole cutted stems are

not abe to reheat by themselves and to provoke decay and because of that will

get dry naturally. The artificial drying is an expensive operation and requires a

precise quantity of energy for decreasing the humidity to 20% so the chips

could stay stable for a longterm and for that reason the cutting shall be

pursuant in order to escape the necessity of artificial drying.

The drying is necessary because when the humidity is increased the cellulose is

easier digested by the fungi and bacteria and the tree starts to decay. This

causes loss of calorific value and generally loss of its fuel quality. The percent of

chips drying depends on the combustion chambers. The big furnaces are

accepting 30% moisture chips when the smaller ones are working more

effectively with dry material. Completely dry material is having the energy value

of 19 MJ/kg and the one with 22% humidity is having 17MJ/kg for a reason that

part of its energy is used for the drying process.

1.11. Recovery at a place

When the Paulownia plantations reaches the end of their living cycle, the area

shall be transformed into a grass land or infield. The root system of Paulownia

is significant and its mechanical removal could cause a substantially damage

of the soil.

After the last harvest gives new sprouts, when they are at the height of 30-50

сm), Paulownia is exclusively sensitive to herbicides, so the one time use of

herbicide (5l/ha glyphosate) is enough for destructing the actively growing

culture. The culture shall be left at least two weeks after the spraying in order

to ensure the full absorption and penetration of the herbicide.

By using a cultivator from the sprouts and the soil surface layer a shallow

tillable layer appears, where a cereal will be planted.

Furthermore the bigger part of the root system is in the soil without harming its

structure. A recovery like that of the lands for growing cereals could last whole

season. The conversion of the land into a complete tillable land could last

longer time so the roots can decay. Otherwise there is going to be a need of

a much complicated and expensinve mechanical removal of the sprouts

and the roots.

2.0. ECONOMIC APPLICATION

The final bruto energy consumption in Bulgaria could be summarized into three

general groups; for heating and cooling needs (44,1%), electroenergy

consumption (30,3%) and transport energy (25,6 %). Therefor it is difficult to

understand why most of the initiatives for energy production from renewable

sources is directed to production of electricity. In addition, the technologies

for heat generating are the most developed than all the others. For that reason

there is a great interest in them and into their development as a renewable

sources for energy, that are most applicable for the agriculture in Bulgaria. The

logistics for supply of very large megawatt plant composite by multiple small

producers will represent a serious logistic problem. The supply of relatively

small central (less than 1 MW) from small cooperative is the most sustainable

development way.

In this way the possibilities for delivery of heating to the final user are increasing,

threw one company for energy deliveries, having this way the for selling product

with additional costs and not a raw material (wooden chips).

2.1. Burning, Gazification and Pyrolysis

There are three thermodynamical processes that could be used for converting

the energy from the wooden chips into a usable energy – heat or electrical;

Burning, gasification and pyrolysis. In small dimentions, as it would be practical

for the conditions in Bulgaria the technologies for direct burning already exists

and they are applied, the technologies for gasification in small dimentions are

still developing and their commercialization is just about to happen, the

pyrolysis is still in the stadium of research and development.

2.1.1. Burning

Generally this is the most effective way to obtain heat from the wooden chips.

The process includes burning of the wooden chips with a sufficient amount of

2.1.2. Gazification

This is a shape of partlial combustion where the included in the chips energy is

being released under the shape of flammable gases, water vapors and

carbon monoxide. This will be achieved by heating up the fuel up to hight

temperatures (over 700 oC) at controlled deficiency of oxygen interfering the

full combustion up to water and carbon dioxide. This is relatively simple

chemical process and could be implemented in multiple systems (updraft,

downdraft, fluidised bed) depending on the place where the oxygen is being

saled or its direction of transit in the gazificated container.

The obtained gazes are being cooled and purificated and the combustion ends

in a standart internal combustion engine. Moslty used is the compression

ignition engine (diesel) as the most tolerant to the gas with a different nature.

The small amount diesel fuel (10%) is being used for improving the gas

combustion. This is having the additional advantage, in the abscence of gas

from wood the eingine could run entirely on diesel fuel.

By the use of gas obtained of wood for fuel in the eingine it produces 75-80%

by the power than if it works entirely on diesel fuel. Small systems from the

range of 100-250KW generated electricity are being developed but non

commercialized. The adaptation of wood to gas is relatively seamless but its

purification from particles and soots in order to allow the seamless

combustion in the eingine is a serious problem.

The efficacy evidences for the energy convertion by the use of eingine and

generator shows that it is in the range of 25-30%. But if the generated extra

heat is being used for electricity generation the efficacy could be increased up

to 75-80%. The gas obtained in the process is with low calorific value between

4 and 5 MJ/m3 and it is not economically viable for storage, so it is used at the

time of its formation.

This is the technology that is still in a process of research and development. It

is including heating up of the chips to temperatures from 4300C - to 7000C

with a full lack of air, whereat an energy is being released as a pyrolytic fuel,

dense carbon and inflammable gases. The relative parts of these products

depends on the used temperatures and from the residence time of the chips in

the reactor. The main advantage in this process is that it can produce liquid

fuel that can be stored and transported relatively easy. It has calorific

equivalent of 16MJ/kg, but it is acid and has a significant water content, i.e. it

is corrosive and appears unstable.

2.2 Bioremediation

Using Paulownia as a renewable energy culture with short rotation cycles is an

economically justified investition not just because of the high energy cost at

the moment. In this context we also should add the ability to extract

compounds from the contaminated soil and water, that further increases the

stability of the investment. This process called bioremediation is especially

applicable in the contemporains climate changes, where shall be taken

actions for the management of the waste from farms and sewage.

For many reasons Paulownia is very good kind for recycling (bioremediation)

of wastes. Paulownia uses significant quantities of water compared to other

wooden species. The huge root system of Paulownia and its descenging into

depth of about 2 me t r e s , cont r ib u t e s e x t r a c t i o n o f c omp o u n d s

n o t j u s t f r om t h e t o p s o i l b u t a l s o f r om d e e p e r

h o r i s o n s . T h i s c h a r a c t e r i s t i c o f t h e t y p e r e p r e s e n t s

e x c e l l e n t s k i l l s f o r ame l i o r a t i o n o f h i g h l y c o n t ami n a t e d

s o i l s , b u t a l s o t h e a p p l i c a t i o n o f wa s t e wa t e r s f o r i t s

i r r i g a t i o n . T h e h u g e l e a v e s , t h e f a s t g r owt h , t h e t o l e r a n c e

t o p o l l u t i o n a n d t h e s i g n i f i c a n t e v a p o t r a n s p i r a t i o n

contributes the extraction of destructive compounds from the soil and

water.

Precisely these characteristics are making Paulownia and engine for sustainable

bioremediation. Guiding principle f o r a l l t h e s y s t e m s f o r

b i o r e m e d i a t i o n i s t h a t t h e s u b s t a n c e s i n c l u d e d i n

t h e s y s t e m t h r o u g h t h e c o n t a m i n a t e d s o i l a n d

w a t e r a r e b e i n g e x t r a c t e d a f t e r t h e h a r v e s t a n d

t h u s t h e s y s t e m i s s t a b l e .

In a personal research (Zhu, 1991) f i n d s o u t t h a t 8 y e a r s o l d

P a u l o w n i a a r e a b l e t o t a k e a w a y N with a speed of 930 kg/ha

per year estimated according to the average nitrogen content in the leaves of

2,6%. World Institute for Paulownia describes the type as owner of the

exceptional ability to take away nitrates, heavy metals, pollutants and other

elements from the shallow and the deep part of the soil. With the loss of the

leaves the plant enriches the soil after once it has recycled many destructive

ingredients.

3.0 ENVIRONMENTAL IMPACT OF THE USE OF PAULOWNIA

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The use of Paulownia at short rotation cycles as regards to the environment

and the biodivercity differs in several general characteristics from the crops

grown for food.

With the crops c o m m o n l y m o s t u s e d i s a s m a l l p a r t

f r o m t h e w h o l e p l a n t e v e n w h e n t h e r e a r e m i n i m a l

c o s m e t i c d a m a g e s o f t h e c r o p y i e l d s a r e

s i g n i f i c a n t l y r e d u c e d .

With Paulownia when the whole plant is in use similar cosmetic damages are

having minimal impact and the step, where significant economical losses starts

is considerably high, that leads to savings from pests combat and diseases

control.

Paulownia forms relatively stable habitat comparing to the annual crops,

althought the harvesting invades it in a way. However, if Paulownia’s blocks

are at different ages (one and two years) the natural enemies of the pests can

settle and survive in neigborhood by naturally controlling the pests. Similar

cases are observed with serious pests as leaf beattles and rust. Any change in

the use of the land from one with annual plowing and cereals in Paulownia

plantations inevitably leads towards changes in the ecology/biodivercity.

Plantations of Paulownia could also be buffers in terms of limiting the diseases

transfer between the different agricultural. A full assessment could be made

only after long use of Paulownia plantations operated at the same location

combined with the relevant scientific assessments. Theese changes will be

affected by the use of herbicides, pesticides, inorganic and organic fertil isers,

wastewaters and cyclicality of cutting. In general the overall effect at the

places where Paulownia is replacing the intensive agricultural crops

cultivation will be positive, but where it replaces improved pastures it will

have minimal effect.

3.1.Flora

The change in land use from one for pastures and annual crops to another for

multiple year tree type with regular harvest will change the ground flora. The

species divercity in the plants community under Paulownia will firstly grow very

fast and subsequently slow as the species are changing until reaching and

establishing a poorer species community. Starting point of these changes and

the rate of change depends on the soil type and the factors: treatment with

herbicides, the use of fertilisers and the crop collecting periods.

The dencity of the plants in the Paulownia p l a n t a t i o n s i s h i g h .

With other similar crops it has been found that initially there are many

germinating seeds and subsequently shortly living many years (often

aggressive trees and bushes) and at the end with perennial types with

conservational values.

Plantations established at pastures are developping richer multi flora

plantations than plantations build up on pastures with annual plowing

and treated with herbicides.

Harvesting the production prevents the creation of completely stable

ground vegetation. Instant harvesting of the biomass has a dramatical

impact over the microclimate, sunlight, use of the water resulting as

instant increase in the species composition. During the next year it will

be less again.

Herbicides – Paulownia requires the use of herbicides for its stable

establishment in the place and the cultivation at least during the first

two exploatation seasons. Subsequently the tolerance to weeds is much

higher and this increases the level for uptaking pre care for control over

the weeds. In time gradually the invasive weed species are reduced and

it is only observed less competitive multi year shadow resistant

vegetation.

3.2. Invertebrates

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The richness of insects with Paulownia is considerably less than with other

fast growing species. There are also some leaves flies and aphids.

This causes an decrease in the necessity for insecticides use.

Species with conservational importance are not observed with

Paulownia.

Research on the condition of the earth worms under Paulownia

plantations has not been made. During research on other fast growing

cultures has been observed their decrease. In multi year established

willow plantations in Germany they are showing an increase.

The divercity of invertebrates at the ground floor is mostly according to

the nature of the ground vegetation. Intensivly cultivated plantations are

unlikely to provide rich habitats.

After cutting the biomass a short term peaks could be expected in the

number and the divercity of the invertebrates.

The invertebrate fauna is considerably poorer than the fauna found at

the annual crops despite the significantly greater divercity of the conditions

for existence.