استخدام تقانات الجيومكانية في تقييم الحالة الخصوبية للعناصر الغذائية NPK في الوحدات الفيزيوغرافية الثانوية في مشروع الوحدة الزراعي

Abstract

This study has been conducted to evaluate the fertility status of common soil series within diagnosed physiographic units in the Al-Wahda agricultural project, depending on chemical methods by estamating soil content from Nitrogen, Phosphorus and Potassium, then classifying the project soils according to their content of these nutrients. The physiographical and topogrifical maps of the project have been analyzed, and according to their results five pedons locations were selected, which represents the most extensive soil series in the project for morphological description and estimating some physical, chemical and fertility proparties, plus 45 Auger hole locations have been identified by grid method in each hole soil samples were collected at depths 0-0.15, 0.15-0.30 and 0.30-0.45 m to estimate some chemical and fertility properties (SOM, pH, ECe, Total N and available P & K). The results of study showed that highly saline soils was formed 40.9%, while moderately saline soils formed 31.8% , while strong saline soils percentage reached 27.3%. The Spatial distribution of soil's organic matter content classes in the project showed the supremacy of the low class with 80.2% in comparison to the medium class which formed 19.8%. Two total nitrogen classes were diagnosed which are very low and low with percentages of 87.5% and 12.5% respectively. The highest weighted mean for total N 0.132% was recorded at the irrigation levee soil, while the lowest value 0.039 was recorded at the depression soil. The spatial distribution map for available phosphorus ranged between 6-27mgP. Kg-1 and in a classical manner it showed extension in the medium class's area followed by a less degree of the low class. The two classes formed 65.2% and 34.8% respectively. The highest content value 17.9mg P.kg-1was found within the irrigation levee soil, while the lowest content 8.9 mg P.kg-1was showed at the depression soil physiographic unit. The spatial distribution of the available potassium coexisted of two classes high and medium which forming 26.4% and 73.6% respectively. The highest mean of soil's content 358.6 mg K.kg-1 was recorded in the depression soil, while the lowest mean 188.0 mg K.kg-1 was recorded at the irrigation levee soil. The nutrients index showed that soil's total nitrogen content reached 1.00 which means that Al-Wahda agricultural project's soils have low total nitrogen, while phosphorus index reached 2.30, which means that the project has moderate soil content of this element, while the potassium index reached 3.00 which means that soils potassium content is high.