Soil Degradation in Argan Woodlands, South Morocco

Author(s):  
Mario Kirchhoff ◽  
Lars Engelmann ◽  
Lutz Leroy Zimmermann ◽  
Irene Marzolff ◽  
Manuel Seeger ◽  
...  

<p>The argan tree (Argania spinosa) populations, endemic to South Morocco, have been highly degraded. Although the argan tree is the source of the valuable argan oil and is protected by law, overbrowsing and -grazing as well as the intensification and expansion of agricultural land lead to tree and soil degradation. Young stands cannot establish themselves; undergrowth is scarce due to the semiarid/arid climate and thus, goats, sheep and dromedaries continually browse the trees. Canopy-covered areas decrease and are degraded while areas without vegetation cover between the argan trees increase.</p><p>On 30 test sites, 60 soil samples of tree and intertree areas were studied on their soil physical and chemical properties. 36 rainfall simulations and 60 single-ring infiltration measurements were conducted to measure potential differences between tree/intertree areas in their runoff/erosion and infiltration properties. Significant differences using a t-test were found for the studied parameters saturated hydraulic conductivity, pH, electric conductivity, percolation stability, total C-content, total N-content, K-content, Na-content and Mg-content. Surface runoff and soil erosion were not statistically significant, but showed similar trends due to the higher complexity of runoff formation. The soil covered by argan trees generally showed less signs of degradation than intertree areas. With ever-expanding intertree areas due to the lack of rejuvenation of argan trees a further degradation of the soil can be assumed.</p>

2019 ◽  
pp. 68-73

The decline in soil organic matter, nutrient depletion, and loss of soil fertility due to soil degradation contribute to low agricultural productivity. Organic amend- ments (OAs) have the potentials to reverse soil degradation processes by improv- ing the soil's physical and chemical properties and consequently improve crop growth and yield performance. At Cranfield University, United Kingdom, a greenhouse study investigated the effects of Mushroom Compost, Anaerobic Di- gestate Waste, and Poultry Manure amendments applied at 10 t ha-1 and 30 t ha-1 equivalent rates on the physical and chemical properties of degraded soil. The treatments were laid out in the greenhouse in a completely randomized design replicated four times. The results showed that all the OA treatments significantly increased the soil water holding capacity, total porosity, and significantly reduced bulk density when compared with the un-amended control treatment. Further, the OA treatments showed significant increases in the soil Total-P, Olsen-P, Total-N, total oxides of N, ammonium-N, Available-K, and Available-Mg, relative to the control treatment. The results demonstrate the effectiveness of these OAs in im- proving soils’ physical and chemical properties, and so enhancing soil health and overall ecosystem functioning. The study demonstrated that these OAs improve the physicochemical properties of degraded so


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


2012 ◽  
Vol 524-527 ◽  
pp. 2139-2142
Author(s):  
Shu Li Wang ◽  
Chao Ma ◽  
Wei Bin Yuan

The soil physical and chemical properties of four densities (A:2500/hm2,B:3300/hm2,C:4400/hm2,D:6600/hm2) of hybrid Larch plantations, Larix olgensis plantation(E) and Quercus mandsurica forest(F) were studied in Jiangshanjiao forest farm of Heilongjiang province of China. Soil bulk density, soil porosity, total N, total P, available N and available P were affected significantly by plantation density in hybrid Larch plantations. The lowest surface soil bulk density was in density 2500/hm2. Soil porosity of density 2500/hm2and 3300/hm2was bigger than that of density 4400/hm2and density 6600/hm2. Total N, total P and available N of density 4400/hm2and 3300/hm2were higher than that of density 6600/hm2and density 2500/hm2. Total N, total P, available N and available P of hybrid Larch plantations were not lower than that of Larix olgensis plantation. The results of the soil physical and chemical properties under different densities of hybrid Larch plantations and different types of forest seems to confirm that hybrid Larch plantation did not decreased the soil fertility, and the hybrid Larch plantation with densities of 3300/hm2and 4400/hm2could be conductive to improving the soil quality. The results would provide the theories basis for manage the hybrid Larch plantations.


Author(s):  
Landing Biaye ◽  
Fary Diome ◽  
Seybatou Diop ◽  
Modou Mbaye ◽  
Djibril Tine ◽  
...  

The locality of Nioro du Rip is facing intense erosion, loss of agricultural land, soil pollution and soil degradation. Today, there is limited information about the soil physical and chemical properties in the locality. In this work, we describe the main essential factors or mechanism that control the evolution of the soil in the study area. The physical and chemical properties of soils encountered along a NE-SW transect in are analyzed in this paper. The statistical analysis results revealed low structural stability of soils in general, due to their low organic matter content and exchangeable bases and their predominantly silty texture. A net trend towards acidification, which is more pronounced in the lower-bottom and terrace soils, provides information on the conditions that are increasingly unfavorable to agricultural development. The multivariate principal component analysis (PCA) identified the preponderance of two factors among the four primarily involved in soil geochemical composition. These include a mineralization process (expressed through the first principal component (PC1), which causes soils to be rich in elements (Ca2+, K+,C, N, MO) controlling their structure and fertility level;  The PC2 axis expresses the spatial differentiation phenomenon of the soil granulometric composition: soils forming cluster poles according to their textural affinity in the projection of the plane formed by these two components , with on one side the sandy-dominated soils of the shallows and terraces and on the other the clay-dominated soils of the plateau and the slope. A clear reversal of textural polarity in the studied topo sequence that must be blamed on the strong water erosion in this area.


2019 ◽  
Vol 11 (12) ◽  
pp. 3369 ◽  
Author(s):  
Shuyue Feng ◽  
Hui Wen ◽  
Shimin Ni ◽  
Junguang Wang ◽  
Chongfa Cai

In the subtropical hilly areas of China, a collapsing gully, a particular type of permanent gully, poses a great threat to the productivity and sustainability of the local ecological and agricultural systems. However, few studies have been performed regarding the effects of collapsing gully erosion on soil degradation. The aim of this study was to evaluate the effects of collapsing gully erosion on soil-quality-related physical and chemical properties. The collapsing gullies that were severely affected by erosion processes were considered at three stages (initial, active and stable stages) and corresponding soil samples were collected to analyze the spatial variation of the soil physical and chemical quality at each stage. The changes in the properties were assumed to be considerable in the regions affected by the erosion process compared with those unaffected by this process. Soil physical properties were more susceptible than soil nutrients to collapsing gully erosion in different spatial locations. The soil quality index (SQI) system consists of total nitrogen (TN), total phosphorus (TP), pH, capillary porosity (CP), sand content (SA), soil cohesion (SC) and root density (RD). Collapsing gully erosion was found to affect the soil physical and chemical properties by progressively reducing the SQI. The mean SQI value was the lowest in the active stage of the collapsing gully, with a higher soil degradation. For the different spatial positions in the collapsing gullies, the scour channel showed the lowest SQI value. The limiting indicators varied in the different stages or spatial sites in the collapsing gullies.


2020 ◽  
pp. 9-23
Author(s):  
A. T. Gani ◽  
T. Bako ◽  
A. Christopher

The aim of this study was to examine the effects of seasonal flooding on the properties of floodplain soils of Wukari Area of Taraba state. The treatments consisted of five different locations of Gidan-Idi, Gindin-Dorowa, Tsokundi, Rafin-Kada and Nwuko and three different soil sample depths of 0-20 cm, 20-40 cm, and 40-60 cm laid out in a completely randomized design (CRD) and replicated three times. Soil samples were collected from each plot in 2016 and 2017. All soil samples were analyzed for physical and chemical properties. The results obtained were subjected to analysis of variance and means separated using F-LSD test at p≤.05. The results of the soil properties analysis showed that some of the determined parameters were significantly different at the different sample locations at p≤.05. The soils of Wukari Floodplains are mostly clay loam in texture having very slightly acid to neutral soil reaction, moderate organic matter, low total N, moderate available P, low exchangeable bases and CEC. The flood plain soils were moderate in soil fertility, a confirmation of the general characteristic of Savanna soils. The soils were not deficient in micronutrients. Seasonal flooding had significant (positive) influence on some physical and chemical properties of the flood plains most particularly at Rafin-Kada.


2019 ◽  
Vol 11 (17) ◽  
pp. 4755
Author(s):  
Juan Wang ◽  
Rui Wang

Straw checkerboards, as a mechanical sand barrier, are one of the most important engineering measures for sand control and vegetation restoration. In this study, we characterized the physical and chemical properties of soil crust treated with straw checkerboard in the Mu Us Sandland, Northern China, and investigated the mechanism of sand stabilization and revegetation in the arid area. We collected soil crust from 1.0 × 1.0 m straw checkerboards after revegetation intermittently over 10 years, and then measured properties such as soil particle size composition, bulk density, soil nutrients, pH, and other indicators in the laboratory. During the progress of straw checkerboard treatment, the results showed a significant decrease in percentage of soil crusts sand and a corresponding increase in the portion of silt and clay with straw checkerboard treatment years. The age of straw checkerboard treatment was positively correlated with soil nutrients, such as organic matter, total N, total P, total K, available N, available P, and available K. While pH showed a slightly rising trend, electrical conductivity (EC) was negatively correlated with crust life. The number of plant species has significantly changed, herbaceous vegetation succession being replaced by shrubs over 10 years, and vegetation coverage peaked at the sixth year. This study can represent a successful example of restoration in arid desert regions, thereby supplying more theoretical basis for sand fixation and dessert restoration.


2019 ◽  
Vol 8 (1) ◽  
pp. 114-119
Author(s):  
Olufemi Gabriel Dayo-Olagbende ◽  
Oluwawemimo Omowumi Akingbola ◽  
Gbolahan Saheed Afolabi ◽  
Babatunde Sunday Ewulo

Towards a more sustainable soil management through recycling of readily available weeds in Akure, Nigeria, different rates of Tithonia diversifolia (tithonia) were compared on a field trial to evaluate its effect on soil properties. The experiment was sited at two locations in South gate of the Federal University of Technology, Akure. Prior to the field establishment, a composite soil sample was collected and analyzed for physico-chemical properties. The sites were cleared and tilled. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replicates. The treatments consisted of three levels of tithonia application which are 0, 3 and 6 t ha-1. Each experimental unit size was 2 m x 2 m with 1 m alleyway. Maize (Zea mays L. var.TZB-SR) seeds were sown at a spacing of 75 cm by 25 cm and 10 were randomly sampled per plot for growth and yield parameters. Data were collected on maize yield and soil physical and chemical properties after harvest to ascertain sustainability of the mulch material after cropping. Application of tithonia mulch improved growth, and yield indices of maize as well as soil physical and chemical properties. The contents of soil total N, exchangeable cations, , CEC, Organic matter content, total porosity, moisture content and infiltration rate were found to significantly (p>0.05)  increase in treatments with tithonia mulch. The best result was from the application rate 6 tha-1 because it improved and left the soil conserved after harvesting maize. Similar trends were observed at the two sites despite variation in inherent soil properties.


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