Soil Resources Potentialities of Some Areas Adjacent to Bani Mazar-El-Boiety Road, West of El-Minia, Egypt

INTRODUCTION

Egypt has experienced a rise and the prevalence of combined food insecurity and income poverty to 17.2% (an estimated 13.7 million people) in 2011, up from 14% of the population in 2009. The increasing population and limited cultivated land, combined with land degradation and desertification pose significant challenges for production. Between 2010 and 2011the total cultivated area in Egypt decreased by about 1 percent, associated with encroachment of aeolion sand on agricultural land (World Food Program, 2013), which necessitates the need for exploring the desert land around the old cultivated area in Egypt to find out the suitable soils for agriculture and reasonable sustainable way. Agricultural expansion, on scientific basis, is considered the mainstay of Egypt’s national economy to take up and cope with the current economic chalenges.

The full understanding of the geological, geomorphological and pedological, as well as chemical and physical properties of soils is considered as the fundamental base for a successful reclamation plan in Egypt. Land evaluation is the process of estimating the potentials of land for alternative kind of use. According to Dent and Young (1981), it includes productive uses, such as arable farming, livestock production and forestry, together with the uses that provide services or other benefits, such as water catchment’s area, recreation, and tourism and wildlife conservation.

Remote sensing techniques have been utilized in soil science for many years as a tool for soil surveyors, reducing the time and expense for sampling (Palacios-Orueta and Ustin, 1998). Geographic information system plays a major role in spatial decision-making. The collected information for the suitability analysis for crop production should present both opportunities and constraints for the decision maker (Ghafari et al., 2000). The ultimate aim of GIS is to provide support for spatial decision making process (Foote and Lynch, 1996). Spatial analysis can be defined as the analytical technique associated with the study of geographic phenomena locations together with their spatial dimensions and their associated attributes (ESRI, 2010).

The present investigation deals mainly with the geomorphologic setting, soil condition and its classification in order to evaluate the potentialities of some soil resources adjacent to Bani Mazar-El-Boiety Road, West of El-Minia in terms of land capability and land suitability for the horizontal agricultural expansion and their optimum agricultural use based on remote sensing data, GIS facilities, selected soil-sites characteristics and physical and chemical characteristics of the different soil units.

The area under investigation is located in the west of El-Minia Governorate, adjacent to Bani Mazar-El-Boiety Road with about 33.5 km in length. It is bounded by longitudes 30^о 09` and 30<sup>о</sup> 30` E and latitudes 28^о30` and 28<sup>о</sup> 35` N, covering an area of approximately 82,883 acres, (Map 1). Said (1993) mentioned that in the western side of the Nile valley, the middle Eocene formations are covered by Oligocene gravel and cobbles. The Eocene limestone may crop to the surface locally. The main geological deposits in the study area are Nile deposits, sand dunes, aeolian deposits, gravel and basalt, (EGPC - Conco Coral Staff, (1987). According to Abu El-Izz (2000) the investigated area is built of recent alluvium sediments belong to Pleistocene, and Pliocene periods. The area is characterized by arid climate as the total rainfall is 7.8 mm/year. The dryness is prevailing most of the year and the wet periods are comparatively short. Based on the Egyptian Meteorological Authority data (2009) and Soil Taxonomy System (USDA Soil Survey Staff, 2014a), the soil temperature regime of the studied area is defined as Thermic, and the soil moisture regime as Torric. Ground water is considered the main source of irrigation water in the study area.

Map (1). Location of the investigated area at the west of El-Minia.

MATERIALS AND METHODS

A Landsat-8 Operational Land Imager (OLI) data covering the investigated area acquired in 2016 (path 177 / row 40) was employed in this study. It was merged and processed with Digital Elevation Model (DEM), (Fig. 1), which has been generated from the vector contour lines, and prepared in ERDAS Imagine 9.3 software (2010) to identify the different landforms of the study area. The OLI data were classified using the ISO-DATA classification technique (Map. 2) to produce unsupervised soil map for the resultant landforms (Lillesand and Kiefer, 2000).

A rapid reconnaissance survey was made throughout the investigated area in order to identify and verify landforms and to gain an appreciation of the broad soil patterns and landscape characteristics of the investigated area. The primary mapping units were verified based on the field interpretation and the information gained during the field work. Twenty two soil profiles were dug (note: soil profiles No. 1 & 16 not represented on the soil profile location map) to represent unsupervised soil mapping unit within the resultant landforms and to fulfill the requirements of the digital soil maps, in addition to some testing auger observations for the purpose of recognizing the boundaries among the different mapping units. A detailed morphological description of soil profiles was recorded on the basis of guidelines for soil description, FAO (2006).

The collected soil samples from genetic horizons/layers of the profile pits were subjected to some physical and chemical analyses using soil survey laboratory methods manual, USDA Soil Survey Staff (2014). Soil characteristics values were recalculated over a certain depth, some of them by using weighting factors for the different profile sections, Sys et al. (1991a). Soil classification was carried out according to the USDA Soil Taxonomy, USDA Soil Survey Staff (2014).

A land capability and suitability evaluation were applied using CERVATANA and ALMAGRA models constituent of MicroLEIS DSS respectively. These two models were designed by De la Rosa et al. (1992) and modified for computing purpose by De la Rosa et al. (2004). Following the generally accepted norms of land evaluation (Klingebiel and Montgmery, 1961; FAO, 1976; Dent and Young, 1981; ONERN, 1982; Verheye, 1986), the CERVATANA model forecasts the general land use capability or suitability for a broad series of possible agricultural uses. That model works interactively, comparing the values of the characteristics of the land-unit to be evaluated with the generalization levels established for each Use Capability Class. The prediction of general land use capability is the result of a qualitative evaluation process or overall interpretation of the following biophysical factors: relief, soil, climate, and current use or vegetation. Following the procedure of maximum limitation method, four capability classes are determined: Class S1-Excellent, Class S2-Good, Class S3-Moderate, and Class N-Marginal and Nule. Four subclasses are also defined according to the most limiting land qualifies.

While the second Model, ALMAGRA model, fits the types of biophysical evaluation that use as diagnostic criteria those soil characteristics or conditions favorable for crop development in function of productivity. The soil characteristics considered in this model are: limit of useful depth, useful depth, stoniness, texture, drainage, carbonates content, salinity, sodium saturation, and degree of development of the profile. For each soil characteristic, it was established a gradation matrix which relates the soil characteristic value with the corresponding soil crop requirements. Following the procedure of maximum limitation, five relative suitability classes are determined: Class S1-Highly suitable, Class S2- Suitable, Class S3-Moderately suitable, Class S4-Marginally suitable, and Class S5- Not suitable. The subclasses are indicated by the letters corresponding to the main limiting soil diagnostic criteria. Ten land uses were tested for their suitability in the investigated area, namely: traditionally crops wheat (T), maize (M), melon (Me), potato (P), sunflower (G) and sugar beet (R) as annuals; alfalfa (Af) as semiannual; and peach (Me), citrus fruits (C) and olive (O) as perennials. The requirements of each kind of land use are obtained according to Sys et al., (1993).

 The tested crops were chosen on basis that several problems are facing the decision makers which are: low quality soil resources, shortage of available irrigation water and low quality of the available water.

Geomorphologic, soil, land capability and land suitability maps were spatially generated by using Arc GIS software, ESRI (2010).

Fig. (1). 3D view of the investigated area showing the main landforms.

Map (2). Unsupervised classification of the investigated area.

RESULTS AND DISCUSSION

A- Geomorphology of the investigated area

The results showed that viewing a remotely sensed image merged with Digital Elevation Module (DEM) can often lead to get the better understanding of the patterns in the image and how they relate to the shape of the earth’s surface. And based on the visual and digital interpretation of merged Digital Elevation Module (DEM) with Landsat-8 OLI image together with knowledge drawn from the geological map (Egyptian General Petroleum Corporation Conco Coral Staff, 1987), topography map, ground truth data and soil survey of the study area, the geopedological approach (Zinck, 1989) is adopted to produce the physiographic map, (Map 3). The combination among landscape, lithology, morphology of the terrain surface, and the photo mapping units are shown in Table (1). Landforms map was considered a Geo- database map over which the representative soil profiles were spatially distributed.

Map (3). Main landforms of the investigated area represented by soil profiles.

Table (1). Physiographic legend, proportions of each landform and associated soil profiles of the study area.

1- The relief indicated by an Arabic number in sequence of decreasing slope gradient as follows:

1 Flat, 2 Almost flat, 3 Gently undulating, 4 Undulating, 5 Rolling, 6 Hilly, 7 Steeply dissected, and 8 Mountainous.

2- The lithology/ origin indicated by an Arabic number in sequence of old age to recent age.

B- Soils of the investigated area

The results showed that the area under investigation has different morphological, physical and chemical characteristics according to the studied soil profiles representing the different unsupervised soil mapping units of the resultant landforms. Tables (2 and 3) show values of soil attributes of some potential landform units which could be discussed and classified according to Soil Taxonomy (Map 4), (USDA Soil Survey Staff, 2014) as the following:

1- Soils of plateau foot slope (Pu 231)

Soils of this unit were formed at the down of a major rock escarpment of the limestone plateau landscape in the eastern part of the study area, formed from Wadi Rayan formation dated back to middle Eocene age. They occupy an area of about 5,011 acre covering 6.04 % of the total area and represented by soil profiles No. 8, 9 and 24. The surface is almost flat, sloping towards the east, and covered with many fine gravel. Surface runoff and associated hazard of water erosion are slight due to dominant very gentle slope. The data show that, because of the erosional and depositional process, soil profiles are either moderate (< 100 cm) or deep (> 100 cm) and lack any evidence of development. Characteristics of soils formed on it are mainly related to the local lithology.

Soil texture is sand throughout the different layers of representative soil profiles. Calcium carbonate content ranges between 10.7 and 29.92% with a general trend to increase in the profile bottoms reflecting the calcareous parent materials nature in the representative profile.  Gypsum content is recorded among the studied soil samples and ranges from 1.76 to 4.01%. Secondary formations of carbonates and gypsum in detectable amount were identified throughout the layers without any diagnostic horizons. Soil-pH is slightly alkaline (pH 7.4-7.7), ESP values indicate low sodium hazard (ESP 4.74-9.88%), and soil salinity varies from moderately to extremely saline (EC 9.03-50.2 dSm^-1). The vertical distribution of salts shows gradual homogenity with depth.  The soils of this unit are classified as Typic Torripsamments.

2- Soils of tableland having almost flat topography (Pu 232)

This unit is a part of the plateau landscape located between the major escarpment in the east and the minor escarpment in the west at the eastern part of the study area; formed from Wadi Rayan formation dated back to middle Eocene age. They occupy an area of about 5304 acre covering around 6.4 % of the total area and represented by profiles No. 7, 10, and 23. The surface is almost flat and covered with much fine gravel. The hazardous effect of water erosion is slight as surface runoff is very slow due to slight slope class. Because of the erosional and depositional process or due to limitation by a lithic contact, soil profiles are either shallow depth (< 50 cm) or moderately deep (50 - 100 cm) and lack any evidence of development. Characteristics of soils formed on it are mainly related to the local lithology.

            Data in Table (3) show that soils have coarse texture and are generally strongly to extremely calcareous (CaCO₃ % 18.93 – 66.34 %), moderate in gypsum content (1.71 – 4.5), and considerably varied salinity level are obtained (EC 3.88 – 29.17 dS/m). In representative profile No. 10, the salinity increases with depth reflecting the Eocene marine nature in the profile bottoms (Wadi Rayan formation). Values of pH (7.8 – 8.1) and ESP (16 -21%) show that the soils are saline-alkaline except soil profile-10 which has pH and ESP ranging from 7.4 – 7.9 and 8.5 – 10.5 %, respectively is saline. The soils of this unit are classified as Typic Torripsamments (profile-10) and Lithic Torriorthents (profiles-7 and 23).

3- Soils of depression (Pu 241)

Soils of this unit cover an area of about 10,871 acre, representing 13.11 % of the total area and are represented by soil profiles No. 2, 3, 14, and 15. They are formed in the low-lying lands existing in the Oligocene to Pleistocene plateau surface which is located at south west of the study area. The surface is almost flat, very gently sloped towards the center of this unit, and is covered with many varysized gravel. The hazardous effect of water erosion is slight as surface runoff is very slow due to slight slope class. Data in tables (2 and 3) show that soils represented by profiles 2, 3 and 14 are moderately deep while profile 15 is deep and all are characterized by sandy to gravelly sand texture, moderately well to excessively drainage and devoid of any sign of horizon development. Total carbonates are moderate (CaCO₃ % 4.49-10.51%), gypsum content is present as traces, soil-pH is slightly too moderately alkaline (pH 7.6-8.1), ESP values indicate low sodium hazard (ESP 5.11-13%), and soil salinity varies widely from very slightly to moderatley saline (EC 2.2-14.5 dSm^-1). Based on analytical data and field studied soils of depression are classified as Typic Torripsamments (profiles-3, 14, and 15) and Typic Torriorthents (profile- 2).

4- Soils of tableland having gently undulating topography (Pu 341)

These soils dominate the plateau surface of the study area occupying an area of about 28,103 acre representing 33.9% of the total area. They are developed from the formations dated back to Oligocene to Pleistocene ages. They are formed from sandy to gravelly sand soils. Surface is gently undulating and covered with gravel associated with desert varnish which minimizes surface runoff with slight hazard of water erosion. Soils of this landform were examined through profiles 4, 5, 12, 13, 17, 19, and 20. They are excessively and/or moderately well drained and characterized by deep to moderately deep profile. Very wide variation in total carbonate content are recorded among the representative soil profiles and ranging between 3.29 and 35.56 % due to the nature of parent material which consists essentially of sandy and gravelly sediments, while gypsum content is present as trace. Secondary formations of carbonates and gypsum in detectable amount were identified throughout the layers without any characteristics of diagnostic horizons. Soil reaction is slight tending to moderately alkaline range where pH values fluctuate between 7.4 and 8.4. Soils have wide range of salinity with EC values ranging between 4.07 and 27.25 dSm-¹. Values of ESP (from 6.5 to 14.5 %) indicate with values of EC and pH that those soils are saline. Hence, soils are classified as Typic Torriorthents (Profiles-4 and 5) and Typic Torripsamments (profiles-12, 13, 17, 19 and 20).

5- Soils of tableland having undulating topography (Pu 441)

Soils of table land having undulating topographycover an area of 1,3476 acre representing 16.25 % of the total area. The surface is undulating and covered with many varysized gravels. They are represented by soil profiles No. 6, 11, 18, 21 and 22. These soils are characterized by shallow or deep gravelly sand profile with excessively drained (profiles-11, 21 and 22) and poorly drained (profiles-6 and 18) status. Secondary formations of carbonates and gypsum in detectable amount were identified throughout the layers with no any characteristics of diagnostic horizons. The electrical conductivity values revealed that soil salinity varies widely from very slightly saline (EC ≈ 3.16 dS/m) to extremely saline (EC ≈ 20.6 dS/m). The higher figures of salinity are mostly concentrated in the middle  layers of profiles- 11, 21, and 22 as its EC values vary from moderately (EC ≈ 12.3 dS/m) to extremely saline (EC ≈ 20.6 dS/m). The soil-pH values vary from slightly (pH ≈ 7.6) to moderately alkaline (pH ≈ 8.3). ESP values (from 2.5 to 16.24 %) indicating with the other parameters (pH and EC) that these soils are mostly slightly saline – slightly alkaline. Hence, they are classified as Typic Torriorthents (Profile-11, 21and 22) and Lithic Torriorthents (profiles-6 and 18).

Map (4). Soil classification of the investigated area.

Table (2). The main morphological features of representative soil profiles in the investigated area.

* Consistency:   LO - Loose,   SO - Soft,   SHA - Slightly Hard,   HA - Hard

Table (2).  Cont.

Table (2).  Cont.

Table (3). Physical, and chemical soil properties in the investigated area.

*Texture: S - Sand,   LS - loamy sand,   GrS - Gravelly sand,   VGrS - Very gravelly sand,   VGrLS - Very gravelly loamy sand

Table (3). Cont.

Table (3). Cont.

C- Land capability of the investigated area

   Results of the agricultural land capability evaluation generated by CERVATANA model constituent of MicroLEIS DSS are presented in Table (4) and Map (5). They include land capability classes and associated limitations of the studied soils representing different landforms. Two land capability classes were recognized, "Moderate Capability, S3" and "Non-Productive, N". Lands of moderate capability have two subclasses abbreviated as "S3 r" referring to soils with slight constraint severity, and "S3 lr" including soils affected by severe soil constraints and erosion risk. S3 r subclass includes soils of most of the depression unit and partially the tableland having gently undulating topography, which has slight limitation regarding erosion factor. Meanwhile, S3 lr subclass has considerable limitations linked to topographic (slope), edaphic (shallow profile, poor drainage, and/or high gravel content), or climatic factors. It includes partially soils of the table-land having almost flat topography and depression units, whereas it includes most of the table-land having gently undulating or tableland having undulating topography. These substantially reduce the range of possible crops and the productive capability. Management techniques are more difficult to apply due to higher costs. Intensive practices are necessary - and sometimes special conservation practices to maintain a continued productivity. Non-productive land (N l) includes soils of plateau foot slope, most of the tableland having almost flat topography and partially of the tableland having undulating topography. They do not provide the ecological conditions necessary for agricultural crops, therefore they are recommended for pasture or forestry land utilization types. They may need very different management and conservation practices to overcome its topographic (slope), edaphic (high salinity and gravels), or climatic deficiencies.

Map (5). Land capability grades of the investigated area.

Table (4). Main land characteristics of representative soil profiles of the investigated area and its capability classes.

Table (4). Cont.

*Slope: NL-Nearly level,  GS- Gently sloping,  S- Sloping

**Capability classes: (S3r) Moderate capability soils with slight constraint severity due to erosion risk

– (S3lr) Moderate capability soils with sever soil constraints and erosion risk.

– (Nl) Non productive soils with sever topographic (slope), edaphic (high salinity and gravel)

D- Land suitability of the investigated area

The physical and chemical soil properties (soil suitability criteria) were further evaluated to define land suitability for ten land uses types which are; wheat, maize, melon, potatoes, sunflower, sugar beet, alfalfa, peach, citrus, and olive. For each land utilization type, matching soil characteristics with the crop requirements were performed to recognize the current suitability, and limiting factors. The land suitability evaluation results are shown in Tables (5 and 6) and Maps (6, 7, 8, and 9) for the selected land uses. The results showed that the soils under consideration were placed in classes S2, S3, S4, and S5 as follows;

1-  Suitable soils (S2)

Limited area is evaluated as suitable for some of the tested crops, namely; peach, citrus and olive (about 2,286 acre for each). This area is generally deep, sandy with almost flat topography. They are represented by profile 15. Agriculture limitations are mostly ascribed to the presence of slight salinity, and excessive drainage. Economically, under low input level, these soils will be highly suitable for these crops.

2-  Moderately suitable soils (S3)

 Wide areas are evaluated as moderately suitable for the tested crops as follow; 1- Sugar beet and alfalfa (26,549 acre for each), 2- Wheat, maize, watermelon, potato and sunflower (22,225 acre for each), 3- Olive (19,192 acre) and 4- Peach and citrus (12,884 acre for each).

These areas are represented by profiles 3, 10, 12, 13, 14, 15, 17, 18, and 19. Agriculture limitations for the tested crops generally include coarse texture and severe salinity in addition to excessive drainage in profiles 18, and moderately effective depth for fruit trees in profile 3. From economical point of view, these soils under moderate to high input level will be better to be utilized for the tested crops.

3-  Marginal suitable soils (S4)

The marginally suitable area for the tested crops ranges from 4,324 – 22,320 acre. They are represented by profiles 2, 4, 5, 7, 8, 9, 10, 12, 13 18, 20, 21, 22, 23, and 24. The main limitations of land are severe salinity, moderate to severe soil texture, poor drainage, effective depth, and gravel content.

4-  Not suitable soils (S5)

Most of the soils in the studied area are considered not suitable for the tested crops. These soils have severe problems due to the high salinity and alkalinity, severe soil texture, high gravel content, shallow rooting zone, and poor drainage.

Table (5). Main landform and representative soil profiles and its suitability classes* for the selected land use types in the investigated area.

Table (5). Cont.

* Suitability classes: (S1) highly suitable soils – (S2) suitable soils – (S3) moderately suitable soils - (S4) marginally suitable soils  – (S5) not suitable soils                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

** Soil limitations: (p) useful depth - (t) texture - (d) drainage condition - (c) carbonates content   - (s) salinity - (a) sodium saturation.

Table (6).  Suitability classes for the selected land uses and their areas (acre) in the investigated area.

         * Suitability classes: (S1) high suitable soils – (S2) suitabe soils – (S3) moderate suitable s – (S4) marginal suitable soils – (S5) not suitable soils