Your SlideShare is downloading. ×
0
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Third Presentation Structure Index
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Third Presentation Structure Index

550

Published on

Clayey Soil degradation is detected via a recent method (introduced by Monier, 1994, in France) for the calculation of a Structure Index using three fluids

Clayey Soil degradation is detected via a recent method (introduced by Monier, 1994, in France) for the calculation of a Structure Index using three fluids

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
550
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
4
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Presentation by Prof. Dr. Mohamed Fahmy Hussein The 4 th Conference on Recent Technologies in Agriculture Challenges of Agricultural Modernization Faculty of Agriculture, Cairo University Tuesday, 4 November, 2009
  • 2. Mohamed Fahmy Hussein * , , Salah El-AMIR * and Essam RAMADAN ** Application of Structure-Index Technique to Detect Soil Degradation فحص تقنية دليل بناء لرصد تدهور الأراضى * Cairo Univ., Fac. of Agric., Soil & Water Dept., Egypt ** Ministry of Agriculture, Cairo, Egypt
  • 3. Location Map, Nile-Delta Apex, Bagour, Monofyah, Egypt
  • 4. Some Experimentral Data ESP = Exchangeable Sodium% ECaP = Exchangeable Calcium%, EMgP = Exchangeable Magnesium% EKP = Exchangeable Potassium% CEC = Cation Exchange Capacity, meq/100 gram soil K = Hydraulic Conductivity (Saturated) SI = Structure Index
  • 5. Prelude – page-1 <ul><li>Soil degradation is an environmental problem world-wide. </li></ul><ul><li>Under irrigated-agriculture, soil degradation is controlled by soil water-regime. </li></ul><ul><li>A principal change in soil-water regime started in the Nile alluvial-soils of Egypt about 150 years ago, through the replacement of the basin-irrigation by perennial-irrigation. </li></ul><ul><li>That change has resulted in humid soils with shallow water-table, almost everywhere in the Nile-delta and valley. </li></ul><ul><li>The over-recharge of the semi-confined (lower) and the unconfined (upper) aquifers was estimated by tritium data-series for GW, and construction of a tritium input-function for Nile water affected by thermo-nuclear bombs of the 1960’s. </li></ul>
  • 6. Prelude – page-2 <ul><li>Soil structure is extremely important soil property, expressing the stresses under which the irrigated-soils are cultivated . Unstable aggregates would be formed in clayey-soils under hydraulic and chemical problems (salinity/sodicity development) due to irrigation without field-drainage. </li></ul><ul><li>Elegant technique has recently been introduced for the evaluation of soil-structure status through estimation of the stable aggregates% under three treatments ( 1- Alcohol then Water, 2- Benzene then Water, and 3- Water alone.) </li></ul><ul><li>The Benzene will over-destruct the aggregates, while Alcohol protects the aggregates, and the Water alone treatment is somewhere in-between. </li></ul>
  • 7. Synopsis 1 <ul><li>Fourteen profiles were sampled in the Nile-Delta Apex, Bagour Monofya Govr. for estimation of Structure-Index . </li></ul><ul><li>The samples were also analyzed for salinity level, the exchangeable cations, and the cation-exchange capacity . </li></ul><ul><li>The obtained results are discussed in this work and compared to older results for saline soils at the north of the Nile Delta. </li></ul><ul><li>The increase of the Structure-Index value indicates significant soil-structure degradation (more unstable aggregates.) </li></ul><ul><li>The rise of the piezometric level of the semi-confined aquifer, hydraulically-connected to the unconfined aquifer, during the last 120 years is about 10m (as estimated from tritium model.) </li></ul>
  • 8. Synopsis 2 <ul><li>The chemical change of soil-water chemistry and the rise of the water-table is believed to be behind the observed soil-structure degradation in the study area. </li></ul><ul><li>The value of the Structure-Index, SI, of the studied samples was in the range of about 2-12. </li></ul><ul><li>The linear relationships obtained between the Structure-Index with salinity (EC) and sodicity (ESP) has a high scatter due the contribution of other factors. </li></ul><ul><li>The Structure-Index method seems more sensitive than the classic Structure-Factor method </li></ul>
  • 9. Tritium Prediction Model for Nile Water
  • 10. Stable Aggregates and the Structure-Index Values
  • 11. Structure-Index Values in Fourteen Profiles
  • 12. Structure-Factor Values in Five Profiles
  • 13. Structure-Index and Structure-Factor versus ESP
  • 14. SI versus EC, and ln ESP versus ln EC
  • 15. Exchangeable Cations versus ESP
  • 16. Log-transformation of K sat , ESP, and Structure-Index
  • 17. ملخص <ul><ul><li>أوضحت البيانات وجود تدهور ملحوظ بالبناء الأرضى فى نحو نصف عدد القطاعات محل الدراسة، حتى بالطبقات العليا لا السفلى فقط . وظهر أن ) دليل البناء ( structure-index, SI يمتاز بسهولته عند مقارنة عدد كبير من العينات ويعطى دلالة أوضح من ) مُعامل البناء structure-factor , SF( التقليدى، كما يمكننا ربطه بغيره من المتغيرات - كتملح وصودية التربة وتوصيلها الهيدروليكى المشبع - وهو أمر هام لما لتلك المتغيرات من علاقة بتدهور بناء التربة بفعل التغيرات المائية . </li></ul></ul><ul><ul><li>لاحظنا ارتباط قيم دليل البناء ( SI ) بتملح الترية ( EC ) والصودية ( ESP ) خطياً، وإن كانت نقاط البيانات فى العلاقتبن ( SI - EC ) و ( SI - ESP ) عالية التبعثر خصوصاً بالمراحل المتأخرة من تزايد التملح والصودية . وكان ميل الخط ( SI - EC ) أكبر من ميل الخط ( SI - ESP ) ، مما يعنى أن تدهور التربة يظهر بمجرد بدء تملحها وقبل تحولها لتربة صودية، ولاحظنا أن تزايد التملح عن dS/m 16 أدى لانخفاض رقم الدليل ( وهو تحسن وهمى سببه تزايد التماسك بفعل التملح المفرط ) مما جعل الخط المستقيم يلتوى لأسفل . تراوحت قيمة رقم الدليل بين حوالى 2 و 12 ، وظهرت علاقات خطية موجبة بين التملح ( EC ) والصودية ( ESP ) ، وانخفض التوصيل الهيدروليكى المشبع بنزايد رقم الدليل . ولحأنا لتحويل قيم التوصيل الهيدروليكى ودليل البناء والصودية ( ESP ) لوغاريتمياً لإيضاح الانحدارات الخطية . </li></ul></ul><ul><ul><li>لاحظنا نفع الدليل كمؤشر على حالة بناء التربة، ونعتقد أنه يفيد مشروعات صيانة الأراضى ثقيلة - القوام، خاصة المتأثرة بالأملاح، لأن التعرف على مدى التدهور هو أولى خطوات تحسين الأراضى . </li></ul></ul>
  • 18. شكراً Thank You

×