Tectonic and geochemical controls on soil edaphic variability in the southern Kenya Rift, implications for early hominin land use

We have studied the importance of geological and soil edaphic factors for the location and duration of inhabitance of hominin sites in the southern Kenya Rift, East Africa. Using examples from the Lake Magadi-Olorgesailie region, we demonstrate that field mapping and analytical techniques derived from geology and soil science can provide important information for research in early hominin migration and land use.The Lake Magadi-Olorgesailie region is located in the center of the ~60-km wide rift floor and characterized by a complex network of sub-parallel, nearly vertical, fault escarpments. The largest area of the rift floor is covered by trachyte flows, while other volcanic rocks including basalts, phonolites and carbonatites are located around Mt. Olorgesailie, Mt. Esayeti, Mt. Suswa and Singaraini. The Mid Pleistocene Olorgesailie site is famous for an unusual abundance of hominin artefacts, fossil mammals and palaeoenvironmental indicators, preserved in sediments spanning ~1.2 to <0.4&#8201;Ma and has been the subject of wide-ranging and intensive studies on hominins and their archeology. Other important hominin sites in the region are located in the Koora Graben, and in the vicinity of Lake Magadi.&#160;We have analyzed the chemical composition of a large number of geological and soil samples in the southern Kenya Rift, in order to understand the control of geochemical and tectonic processes on the release and distribution of vital soil nutrients. &#160;&#160;&#160;Results show that in the study region volcanic, tectonic and related pedogenic processes created a complex suite of landscape features potentially advantageous for human habitation. Analysis of soil samples from the main volcanic and metamorphic rocks as well as from sedimentary deposits shows that soil edaphic properties are closely correlated with the chemical composition of the parent materials and that deficiencies of soil nutrients are reflected in the mineralogy of the volcanic rocks. Particularly, deficient levels of calcium are sourced in the lack of calcium-bearing minerals in soils developed on trachytic rocks. Further, we show that soil nutrient distributions correlate with the relief created by tectonic faulting. We observed a significant increase of the concentrations of Ca, Mg, P in soils, with proximity to active normal faults.&#160;We suggest that the combination of complex terrain and patchy nutrient distributions created narrow migration corridors potentially exploited by animals and the humans who hunted them. Our study implies that tectonics, geology and related soil edaphics have been important drivers for human habitation and strategic land use. Knowledge of these processes and their impact on past human-landscape interactions contributes to a broader understanding of how landscapes influenced hominin behavior and subsistence strategies in prehistoric time.

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Effect of Soil Orders and Land Uses on Available Soil Nutrients in Meghalaya, India

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2020/v32i330260 ◽

2020 ◽

pp. 62-71

Author(s):

Chandan Goswami ◽

Naorem Janaki Singh ◽

Bijoy Krishna Handique

Keyword(s):

Land Use ◽

Spatial Distribution ◽

Soil Nutrients ◽

Land Management ◽

Mean Value ◽

Soil Samples ◽

Land Uses ◽

Sustainable Land Management ◽

P2o5 Content ◽

Zn Content

Understanding of spatial distribution of available soil nutrients is important for sustainable land management. An attempt has been made to assess the spatial distribution of available soil nutrients under different soil orders and land uses of RiBhoi, Meghalaya, India using geo-statistical techniques. Seven Land Use Land Cover (LULC) classes were selected from LULC map on 1:50,000 scale prepared by National Remote Sensing Centre (NRSC) viz. Abandoned Jhum (AJ), Current Jhum (CJ), Deciduous Forest (DF), Double Crop (DC), Evergreen Forest (EF), Kharif Crop (KC) and Wastelands (WL). Again, three soil orders were identified by National Bureau of Soil Survey and Land Use Planning (NBSS&LUP) in RiBhoi district of Meghalaya, India viz. Alfisols, Inceptisols and Ultisols. 105 soil samples were collected, 5 replicated soil samples from 21 strata derived from 7 LULC and 3 soil orders. Soil samples were analyzed for available nitrogen (N), available phosphorus (P2O5), available potassium (K2O) and available zinc (Zn) using standard procedures. One way ANOVA was carried out using IBM SPSS Statistics 20.0 software. Significance levels were tested at p≤0.05. N content varied from low (215.50 kg/ha) to medium (414.30 kg/ha) with mean value of 291.50 kg/ha. On the other hand, P2O5 content varied from low (19.90 kg/ha) to high (68.30 kg/ha) with mean value of 43.52 kg/ha. Similarly, K2O content varied from low (112.09 kg/ha) to high (567.84 kg/ha) with mean value of 273.68 kg/ha. Again, Zn also varied from low (0.26 ppm) to high (1.46 ppm) with mean value of 0.64 ppm. In Alfisols, N was found to be higher in EF, AJ & CJ than DF, DC, KC and WL. KC has been found to have lower N than all other LULC classes. Higher P2O5 has been found under EF over KC and WL. AJ has been found to have higher K2O than all other LULC classes. K2O has also been found to be higher in CJ over DC, KC and WL. DF and EF have been found to have higher K2O than KC and WL. Zn has been found to be higher in EF over CJ, DC and WL. In Inceptisols, higher amount of N was observed under EF over all other LULC classes. Higher N has also been found under CJ over DF, DC, KC and WL. P2O5 content was found to be higher under DF over all other LULC classes. Higher P2O5 content was also found under AJ, CJ and DC than KC and WL. Higher amount of K2O has been found under AJ over all other LULC. K2O content of soil under DF was also higher than CJ, EF, KC and WL. Zn has been found to be higher under EF over all other LULC classes. Zn content under CJ has also been found to be higher than AJ, DF, KC and WL. In Ultsols, higher amount of N has been found under EF compared to all other LULC classes. Lowest N content was found under KC. P2O5 content was found to be higher under EF, DF and AJ over all other LULC. K2O content has been found to be higher under CJ in comparison to all other LULC classes. K2O content of EF and DF were also found to be higher than AJ, DC, KC and WL. Again, K2O content has been found to be higher under DC compared to AJ, KC and WL. Zn content under EF and AJ was found to be higher than all other LULC classes. CJ, DF, DC, KC and WL have been found to have lower Zn content. It has been observed that P2O5 content is significantly higher in inceptisols irrespective of LULC classes. The study has highlighted the spatial distribution of available soil nutrients as a function of soil orders and LULC. This will be a useful input in sustainable land management programmes.

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PETANI KUNINGAN DALAM PUSARAN KONFLIK KELAS

JURNAL PENELITIAN ◽

10.28918/jupe.v13i2.721 ◽

1970 ◽

Vol 13 (2) ◽

Author(s):

Nanang Susanto

Keyword(s):

Climate Change ◽

Land Use ◽

Action Research ◽

Participatory Action Research ◽

Soil Nutrients ◽

Qualitative Approach ◽

Participatory Action ◽

Cost Of Production ◽

Depth Interviews ◽

Participatory Observation

Penelitian ini menguji teori Marx yang mengatakan bahwa dalam proses kapitalisasi, petani lahan kecil akan tergusur oleh petani lahan besar. Penelitian ini menggunakan pendekatan kualitatif dengan metode Participatory Action Research (PAR). Menggunakan teknik observasi partisipasi di lapangan, studi ini melakukan wawancara mendalam terhadap petani. Analisis data yang digunakan bersifat induktif. Penelitian ini menghasilkan kesimpulan, bahwa teori Marx tidak terjadi di malar Aman. Adapun penyebab menurunnya pertanian disebabkan menurunnya unsur hara tanah, mahalnya biaya produksi, alih fungsi lahan dan perubahan cuaca. Sedangkan strategi petani lahan kecil untuk mempertahankan kehidupan yaitu melakukan pola tanam tumpang sari, melakukan pekerjaan tambahan, dan mengatur keuangan.This study examines Marx's theory which says that in the process of capitalization, small land farmers will be displaced by large land farmers. This study uses a qualitative approach with the method of Participatory Action Research (PAR). Using the techniques of participatory observation in the field, the study conducted in-depth interviews on farmers. Analysis of the data used is inductive. This study led to the conclusion that Marx's theory does not happen in Aman malar. The cause of the decline of agriculture due to declining soil nutrients, the high cost of production, land use and climate change. While the strategies of small land farmers to sustain life is to do the planting patterns of intercropping, do extra work, and manage finances.

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Effect of period of sugarcane cultivation on the abundance and distribution of weed seeds in the soil profile

Planta Daninha ◽

10.1590/s0100-83582014000300006 ◽

2014 ◽

Vol 32 (3) ◽

pp. 507-513

Author(s):

R.O. Adereti ◽

F.O Takim ◽

Y.A. Abayomi

Keyword(s):

Land Use ◽

Soil Depth ◽

Seed Banks ◽

Soil Samples ◽

Soil Tillage ◽

Fallow Period ◽

Tillage Practices ◽

Weed Seeds ◽

Seed Distribution ◽

Screen House

An experiment was laid down in a screen house to determine the distribution of weed seeds at different soil depths and periods of cultivation of sugarcane in Ilorin, Nigeria. Soil samples from different depth levels (0-10 cm, 11-20 cm and 21-30 cm) were collected after harvesting of canes from three different land use fields (continuous sugarcane cultivation for > 20 years, continuous sugarcane cultivation for < 10 years after long fallow period and continuous sugarcane cultivation for < 5 years after long fallow period) in November, 2012. One kilogram of the sieved composite soil samples was arranged in the screen house and watered at alternate days. Germinating weed seedlings were identified, counted and then pulled out for the period of 8 months. Land use and soil depth had a highly significant (p £ 0.05) effect on the total number of weeds that emerged from the soil samples. The 010 cm of the soil depth had the highest weed seedlings that emerged. There was an equal weed seed distribution at the 11-20 cm and 21-30 cm depths of the soil. Sugarcane fields which have been continuously cultivated for a long period of time with highly disturbing soil tillage practices tend to have larger seed banks in deeper soil layers (11-20 cm and 21-30 cm) while recently opened fields had significantly larger seed banks at the 0-10 cm soil sampling depth.

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Modeling Community-Scale Natural Resource Use in a Transboundary Southern African Landscape: Integrating Remote Sensing and Participatory Mapping

Remote Sensing ◽

10.3390/rs13040631 ◽

2021 ◽

Vol 13 (4) ◽

pp. 631

Author(s):

Kyle D. Woodward ◽

Narcisa G. Pricope ◽

Forrest R. Stevens ◽

Andrea E. Gaughan ◽

Nicholas E. Kolarik ◽

...

Keyword(s):

Remote Sensing ◽

Land Use ◽

Resource Use ◽

Training Data ◽

Systems Science ◽

Participatory Mapping ◽

Land Use Patterns ◽

Modeling Framework ◽

Use Patterns ◽

Human Habitation

Remote sensing analyses focused on non-timber forest product (NTFP) collection and grazing are current research priorities of land systems science. However, mapping these particular land use patterns in rural heterogeneous landscapes is challenging because their potential signatures on the landscape cannot be positively identified without fine-scale land use data for validation. Using field-mapped resource areas and household survey data from participatory mapping research, we combined various Landsat-derived indices with ancillary data associated with human habitation to model the intensity of grazing and NTFP collection activities at 100-m spatial resolution. The study area is situated centrally within a transboundary southern African landscape that encompasses community-based organization (CBO) areas across three countries. We conducted four iterations of pixel-based random forest models, modifying the variable set to determine which of the covariates are most informative, using the best fit predictions to summarize and compare resource use intensity by resource type and across communities. Pixels within georeferenced, field-mapped resource areas were used as training data. All models had overall accuracies above 60% but those using proxies for human habitation were more robust, with overall accuracies above 90%. The contribution of Landsat data as utilized in our modeling framework was negligible, and further research must be conducted to extract greater value from Landsat or other optical remote sensing platforms to map these land use patterns at moderate resolution. We conclude that similar population proxy covariates should be included in future studies attempting to characterize communal resource use when traditional spectral signatures do not adequately capture resource use intensity alone. This study provides insights into modeling resource use activity when leveraging both remotely sensed data and proxies for human habitation in heterogeneous, spectrally mixed rural land areas.

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Afforestation of Degraded Croplands as a Water-Saving Option in Irrigated Region of the Aral Sea Basin

Water ◽

10.3390/w13101433 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1433

Author(s):

Navneet Kumar ◽

Asia Khamzina ◽

Patrick Knöfel ◽

John P. A. Lamers ◽

Bernhard Tischbein

Keyword(s):

Land Use ◽

Water Balance ◽

Water Supply ◽

Water Availability ◽

Irrigation Water ◽

Water Saving ◽

Aral Sea ◽

Water Balance Components ◽

Study Region ◽

Trade Offs

Climate change is likely to decrease surface water availability in Central Asia, thereby necessitating land use adaptations in irrigated regions. The introduction of trees to marginally productive croplands with shallow groundwater was suggested for irrigation water-saving and improving the land’s productivity. Considering the possible trade-offs with water availability in large-scale afforestation, our study predicted the impacts on water balance components in the lower reaches of the Amudarya River to facilitate afforestation planning using the Soil and Water Assessment Tool (SWAT). The land-use scenarios used for modeling analysis considered the afforestation of 62% and 100% of marginally productive croplands under average and low irrigation water supply identified from historical land-use maps. The results indicate a dramatic decrease in the examined water balance components in all afforestation scenarios based largely on the reduced irrigation demand of trees compared to the main crops. Specifically, replacing current crops (mostly cotton) with trees on all marginal land (approximately 663 km2) in the study region with an average water availability would save 1037 mln m3 of gross irrigation input within the study region and lower the annual drainage discharge by 504 mln m3. These effects have a considerable potential to support irrigation water management and enhance drainage functions in adapting to future water supply limitations.

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Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using 137Cs techniques

Forest Ecosystems ◽

10.1186/s40663-021-00311-1 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Shamsollah Ayoubi ◽

Nafiseh Sadeghi ◽

Farideh Abbaszadeh Afshar ◽

Mohammad Reza Abdi ◽

Mojtaba Zeraatpisheh ◽

...

Keyword(s):

Land Use ◽

Magnetic Susceptibility ◽

Soil Erosion ◽

Erosion Rate ◽

Land Use Changes ◽

Soil Samples ◽

Natural Forest ◽

Oak Forests ◽

Erosion Rates ◽

Rainfed Farming

Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Results Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. Conclusions We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.

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Accumulation patterns of soil organic matter in forests as a legacy of historical charcoal burning

10.5194/egusphere-egu21-5161 ◽

2021 ◽

Author(s):

Anna Schneider ◽

Alexander Bonhage ◽

Florian Hirsch ◽

Alexandra Raab ◽

Thomas Raab

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Large Scale ◽

Soil Surface ◽

Landscape Scale ◽

Legacy Effects ◽

Charcoal Production ◽

Study Region ◽

Land Use Legacies

Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils.&#160;The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.

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DEGRADASI LAHAN PADA KEBUN CAMPURAN DAN TEGALAN DI KABUPATEN DHARMASRAYA

Jurnal Solum ◽

10.25077/js.4.1.5-9.2007 ◽

2007 ◽

Vol 4 (1) ◽

pp. 5

Author(s):

Syafrimen Yasin ◽

Gusnidar Gusnidar ◽

Dedy Iskandar

Keyword(s):

Land Use ◽

Soil Depth ◽

Soil Surface ◽

Soil Samples ◽

Imperata Cylindrica ◽

Undisturbed Soil ◽

Fertility Status ◽

Land Use Types ◽

Bulk Volume ◽

Soil Fertility Status

A research conducted in Sungai Rumbai, Dharmasraya Regency and in Soil Laboratory Andalas university was aimed to evaluate soil fertility status on the depth below 0-20 cm from several land use types , especially under Mixed Garden and annual cultivated dryland soil. Soil samples were taken on Ultisol at 0-8% slope (late-waving soil surface). Land use types evaluated were forest, annual cultivated dryland, bush land, rangeland covered by Imperata cylindrica and mixed garden. Composite soil samples for soil chemical analysis were taken on the 0-20 cm soil depth with four replications, and 5 drillings for each replication. Undisturbed soil samples by using sample ring were used to analyze sol bulk volume. The data resulted were compared to the criteria and were statistically tested using Analysis of Variance and then were continued by LSD at 5% level. From the results of analyses could be concluded that land use for mixed garden had the higher Organic Carbon (OC) content and the lower bulk volume (BV) than those for annual cultivated dryland soil.Key Words: Degradasi Lahan, Kebun Campuran, Tegalan

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Investigation of Climate and Land Use Change Impacts on Stream Flow of Guder Catchment, Ethiopia

10.21203/rs.3.rs-976225/v1 ◽

2021 ◽

Author(s):

Bekam Bekele Gulti ◽

Boja Mokonnen Manyazew ◽

Abdulkerim Bedewi Serur

Keyword(s):

Climate Change ◽

Land Use ◽

Stream Flow ◽

Open Space ◽

Smart Growth ◽

Assessment Model ◽

Study Region ◽

Climate Conditions ◽

Change Impact ◽

The Impact

Abstract Climate change (CC) and land use/cover change (LUCC) are the main drivers of streamflow change. In this paper, we investigate the impact of climate and LULC change impact on stream flow of Guder catchment by using Soil and Water Assessment model (SWAT). The scenarios were designed in a way that LULC was changed while climate conditions remain constant; LULC was then held constant under a changing climate and combined effect of both. The result shows that, the combined impacts of climate change and LULC dynamics can be rather different from the effects that follow-on from LULC or climate change alone. Streamflow would be more sensitive to climate change than to the LULC changes scenario, even though changes in LULC have far-reaching influences on streamflow in the study region. A comprehensive strategy of low impact developments, smart growth, and open space is critical to handle future changes to streamflow systems.

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Vertical distribution of soil nutrients under different land use systems in Bangladesh

Journal of Aridland Agriculture ◽

10.25081/jaa.2020.v6.6438 ◽

2020 ◽

pp. 6-12

Author(s):

Tahsina Sharmin Hoque ◽

Shafia Afrin ◽

Israt Jahan ◽

Md. Joinul Abedin Mian ◽

Mohammad Anwar Hossain

Keyword(s):

Electrical Conductivity ◽

Land Use ◽

Organic Matter ◽

Soil Ph ◽

Soil Depth ◽

Organic Matter Content ◽

Soil Samples ◽

Water Soluble ◽

Exchangeable K ◽

Land Use Systems

Soil depth can significantly influence the availability of nutrients in soil. An experiment was conducted with seven soil samples from seven land use types to observe the effect of soil depth on soil properties under various land use systems. Soil pH, electrical conductivity (EC), organic matter, available phosphorus (P), available sulphur (S) and different forms of potassium (K) such as water soluble, exchangeable and non-exchangeable were determined from the soil samples collected from four soil depths (viz. 0-10, 10-20, 20-30 and 30-40 cm). Soil pH varied from 6.30-7.39 irrespective of depths and land uses and it increased with increasing soil depth. Electrical conductivity of the soils ranged from 42-310 µS cm-1 and organic matter status of most of the soils was very low to medium in level. Both EC and organic matter content decreased with the increase of soil depth. Available P concentration showed no specific changing trend with soil depth whereas available S concentration under different land use systems decreased with increasing soil depth. The concentrations of water soluble, exchangeable and non-exchangeable K in soils varied from 12.30-39.60, 20.90-53.16 and 163.30-684.30 mg kg-1, respectively and showed no specific changing pattern with soil depth. Water soluble K content was higher in rice growing fertilizer and manure-treated soil but higher exchangeable and non-exchangeable K contents were observed in banana growing soil. In rice growing soils, nutrient concentration is mostly higher in nitrogen (N), P and K + farm yard manure (FYM) - treated plots compared to rice growing control plots.

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