Enhancing Soil Water Content for Increased Food Production in Semi-Arid Areas of Kenya Results From an On-Farm Trial in Mwala District, Kenya

Soil water conservation through tillage is one of the appropriate ways of addressing soil moisture deficit in rainfed agriculture. This study evaluated the effects of tillage practices on soil moisture conservation and crop yields in Mwala District, Eastern Kenya during the long rains (LR) and short rains (SR) of 2012/13. Six tillage systems: Disc plough (MB), Disc plough and harrowing (MBH), Ox-ploughing (OX), Subsoiling – ripping (SR), Hand hoe and Tied Ridges (HTR) and Hand hoe only (H) and, three cropping systems namely, sole maize, sole bean and maize - bean intercrop, were investigated in a split-plot design with four replicates. Data on soil water content was monitored at different weeks after planting and the crop yields at end of each growing season. A three-season average shows that soil water content and crop yields were higher in conventional tillage methods compared to the conservation tillage methods. Long term tillage experiments are thus required at different locations, under various environmental and soil conditions to validate the study findings.

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Spatial Analysis of Soil Water Content in Newly Implemented Agricultural Bench Terraces in the Ethiopian Plateau

10.5194/egusphere-egu2020-1127 ◽

2020 ◽

Author(s):

Giulio Castelli ◽

Shimbahri Mesfin ◽

Lucas Allan Almeida Olivera ◽

Elena Bresci ◽

Eyasu Yazew

Keyword(s):

Soil Moisture ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Water Conservation ◽

Soil Aggregates ◽

Soil Disturbance ◽

Northern Ethiopia ◽

Ethiopian Plateau ◽

The World

<p>In arid areas prone to desertification and soil erosion, the effectiveness of agricultural bench terraces in increasing soil moisture is dependent on their correct implementation. However, despite its relevance for securing food production in many areas of the world, the relationship between proper terracing implementation and the landscape capacity of holding soil moisture is still not understood. Moreover, spatial patterns of Soil Water Content (SWC) within the same terraced hillslope are weakly studied. The present work analyses SWC variations in four newly implemented terraced sites in Tigray Region, Ethiopia: Teshi, Ruba Feleg, Michael Emba and Enda Chena. Field SWC data were collected for the dry season of 2017 (February, March and April) from the upper, middle and lower part of each terraced site, including a non-terraced benchmark area. In all sites, terraced areas show SWC significantly higher than non-terraced ones (p < 0.05), with the lower part of the terraced hillslope more humid than the others for the whole period analyzed. A Multiple Linear Regression (MLR) analysis of SWC was conducted in order to highlight possible dependencies of SWC values. MLR highlighted significant dependency of SWC from the date of analysis, the position of the sample in the terraced slope, as well as a significant positive correlation of SWC with the percent of Water Stable Aggregates (WSA) analyzed at the study sites. Since high soil disturbance induces low soil aggregates stability, this result shows how measures to reduce soil disturbance during implementation can significantly increase SWC of radical terraces. Overall, the results of the present paper testify the good performances of bench terraces in Northern Ethiopia in terms of water conservation, and this first benchmark study can inform future terracing implementation in some arid and semi-arid agricultural areas of the world.</p><p>The abstract is based on Mesfin, S.; Almeida Oliveira, L.A.; Yazew, E.; Bresci, E.; Castelli, G. Spatial Variability of Soil Moisture in Newly Implemented Agricultural Bench Terraces in the Ethiopian Plateau. Water 2019, 11, 2134.</p>

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Effects of Superabsorbent Polymer on Soil Water Content and Sugarcane Germination and Early Growth in Sandy Soil Conditions

Sugar Tech ◽

10.1007/s12355-018-0672-5 ◽

2018 ◽

Vol 21 (3) ◽

pp. 444-450 ◽

Cited By ~ 3

Author(s):

Kenta Watanabe ◽

Samran Saensupo ◽

Yanischa Na-iam ◽

Peeraya Klomsa-ard ◽

Klanarong Sriroth

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Sandy Soil ◽

Early Growth ◽

Soil Conditions ◽

Superabsorbent Polymer

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Multimodel assessment of climate change-induced hydrologic impacts for a Mediterranean catchment

Hydrology and Earth System Sciences ◽

10.5194/hess-22-4125-2018 ◽

2018 ◽

Vol 22 (7) ◽

pp. 4125-4143 ◽

Cited By ~ 9

Author(s):

Enrica Perra ◽

Monica Piras ◽

Roberto Deidda ◽

Claudio Paniconi ◽

Giuseppe Mascaro ◽

...

Keyword(s):

Climate Change ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Climate Models ◽

Actual Evapotranspiration ◽

Soil Conditions ◽

Hydrologic Models ◽

The Future ◽

The Mediterranean

Abstract. This work addresses the impact of climate change on the hydrology of a catchment in the Mediterranean, a region that is highly susceptible to variations in rainfall and other components of the water budget. The assessment is based on a comparison of responses obtained from five hydrologic models implemented for the Rio Mannu catchment in southern Sardinia (Italy). The examined models – CATchment HYdrology (CATHY), Soil and Water Assessment Tool (SWAT), TOPographic Kinematic APproximation and Integration (TOPKAPI), TIN-based Real time Integrated Basin Simulator (tRIBS), and WAter balance SImulation Model (WASIM) – are all distributed hydrologic models but differ greatly in their representation of terrain features and physical processes and in their numerical complexity. After calibration and validation, the models were forced with bias-corrected, downscaled outputs of four combinations of global and regional climate models in a reference (1971–2000) and future (2041–2070) period under a single emission scenario. Climate forcing variations and the structure of the hydrologic models influence the different components of the catchment response. Three water availability response variables – discharge, soil water content, and actual evapotranspiration – are analyzed. Simulation results from all five hydrologic models show for the future period decreasing mean annual streamflow and soil water content at 1 m depth. Actual evapotranspiration in the future will diminish according to four of the five models due to drier soil conditions. Despite their significant differences, the five hydrologic models responded similarly to the reduced precipitation and increased temperatures predicted by the climate models, and lend strong support to a future scenario of increased water shortages for this region of the Mediterranean basin. The multimodel framework adopted for this study allows estimation of the agreement between the five hydrologic models and between the four climate models. Pairwise comparison of the climate and hydrologic models is shown for the reference and future periods using a recently proposed metric that scales the Pearson correlation coefficient with a factor that accounts for systematic differences between datasets. The results from this analysis reflect the key structural differences between the hydrologic models, such as a representation of both vertical and lateral subsurface flow (CATHY, TOPKAPI, and tRIBS) and a detailed treatment of vegetation processes (SWAT and WASIM).

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Long Term Effects of Ploughing and Conservation Tillage Methods on Earthworm Abundance and Crumb Ratio

Agronomy ◽

10.3390/agronomy10101552 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1552 ◽

Cited By ~ 2

Author(s):

Igor Dekemati ◽

Barbara Simon ◽

Igor Bogunovic ◽

Ivica Kisic ◽

Katalin Kassai ◽

...

Keyword(s):

Water Content ◽

Water Conservation ◽

Conservation Tillage ◽

Soil Tillage ◽

Long Term Effects ◽

No Till ◽

Cover Ratio ◽

One Year ◽

Tillage Methods

In addition to the dry (D) and rainy (R) seasons, a combination of the two i.e., rainy-dry (RD) and dry-rainy (DR), can also be observed in one year. The effects of the dry (D) and rainy (R) on soil are known, hence we hypothesized that the effects of the rainy-dry (RD) and dry-rainy (DR) periods on soil may differ from the former assessments. The aim of the study is to investigate the effect of six tillage treatments (ploughing—P, disk tillage—DT, loosening—L, tine tillage (a deeper—T and a shallower—ST) and no-till—NT) on earthworm abundance and crumb ratio during a long-term research (16 years) on Chernozems. The results related to the four year-groups (D, R, RD, and DR) with different residue cover. Seven degrees of cover ratio (between 12.5% and 62.5%) were selected on stubbles. Higher cover ratio (≥52.5%) improved water conservation, increased earthworm abundance (31 and 41 ind m–2) and crumb (78 and 82%) ratio (p < 0.01). R year came first in the rank of water content and earthworm abundance and DR proved to be more favorable for crumb formation. Considering the rank of soil tillage treatments, ST takes first place in evaluation of soil water content (SWC) and crumb ratio, and NT for earthworm abundance.

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Repeated geophysical measurements in dry and wet soil conditions to describe soil water content variability

Scientia Agricola ◽

10.1590/1678-992x-2018-0349 ◽

2020 ◽

Vol 77 (5) ◽

Author(s):

Daniela De Benedetto ◽

Francesco Montemurro ◽

Mariangela Diacono

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Soil Conditions ◽

Geophysical Measurements

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Relating surface backscatter response from TRMM Precipitation Radar to soil moisture: results over a semi-arid region

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-6-6425-2009 ◽

2009 ◽

Vol 6 (5) ◽

pp. 6425-6454

Author(s):

H. Stephen ◽

S. Ahmad ◽

T. C. Piechota ◽

C. Tang

Keyword(s):

Soil Moisture ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Arid Regions ◽

Vegetation Index ◽

Temporal Trends ◽

Model Parameters ◽

Precipitation Radar ◽

Semi Arid

Abstract. The Tropical Rainfall Measuring Mission (TRMM) carries aboard the Precipitation Radar (TRMMPR) that measures the backscatter (σ°) of the surface. σ° is sensitive to surface soil moisture and vegetation conditions. Due to sparse vegetation in arid and semi-arid regions, TRMMPR σ° primarily depends on the soil water content. In this study we relate TRMMPR σ° measurements to soil water content (ms) in Lower Colorado River Basin (LCRB). σ° dependence on ms is studied for different vegetation greenness values determined through Normalized Difference Vegetation Index (NDVI). A new model of σ° that couples incidence angle, ms, and NDVI is used to derive parameters and retrieve soil water content. The calibration and validation of this model are performed using simulated and measured ms data. Simulated ms is estimated using Variable Infiltration Capacity (VIC) model whereas measured ms is acquired from ground measuring stations in Walnut Gulch Experimental Watershed (WGEW). σ° model is calibrated using VIC and WGEW ms data during 1998 and the calibrated model is used to derive ms during later years. The temporal trends of derived ms are consistent with VIC and WGEW ms data with correlation coefficient (R) of 0.89 and 0.74, respectively. Derived ms is also consistent with the measured precipitation data with R=0.76. The gridded VIC data is used to calibrate the model at each grid point in LCRB and spatial maps of the model parameters are prepared. The model parameters are spatially coherent with the general regional topography in LCRB. TRMMPR σ° derived soil moisture maps during May (dry) and August (wet) 1999 are spatially similar to VIC estimates with correlation 0.67 and 0.76, respectively. This research provides new insights into Ku-band σ° dependence on soil water content in the arid regions.

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Root effects on soil water and hydraulic properties

Biologia ◽

10.2478/s11756-007-0110-8 ◽

2007 ◽

Vol 62 (5) ◽

Cited By ~ 8

Author(s):

Horst Gerke ◽

Rolf Kuchenbuch

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Water Content ◽

Bulk Density ◽

Soil Water ◽

Soil Water Content ◽

Hydraulic Properties ◽

Soil Hydraulic Properties ◽

Soil Hydraulic ◽

Root Effects

AbstractPlants can affect soil moisture and the soil hydraulic properties both directly by root water uptake and indirectly by modifying the soil structure. Furthermore, water in plant roots is mostly neglected when studying soil hydraulic properties. In this contribution, we analyze effects of the moisture content inside roots as compared to bulk soil moisture contents and speculate on implications of non-capillary-bound root water for determination of soil moisture and calibration of soil hydraulic properties.In a field crop of maize (Zea mays) of 75 cm row spacing, we sampled the total soil volumes of 0.7 m × 0.4 m and 0.3 m deep plots at the time of tasseling. For each of the 84 soil cubes of 10 cm edge length, root mass and length as well as moisture content and soil bulk density were determined. Roots were separated in 3 size classes for which a mean root porosity of 0.82 was obtained from the relation between root dry mass density and root bulk density using pycnometers. The spatially distributed fractions of root water contents were compared with those of the water in capillary pores of the soil matrix.Water inside roots was mostly below 2–5% of total soil water content; however, locally near the plant rows it was up to 20%. The results suggest that soil moisture in roots should be separately considered. Upon drying, the relation between the soil and root water may change towards water remaining in roots. Relations depend especially on soil water retention properties, growth stages, and root distributions. Gravimetric soil water content measurement could be misleading and TDR probes providing an integrated signal are difficult to interpret. Root effects should be more intensively studied for improved field soil water balance calculations.

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Effect of water on common lambsquarters (Chenopodium album L.) and barnyardgrass [Echinochloa crus-galli (L.) Beauv.] seedling emergence in corn

Canadian Journal of Plant Science ◽

10.4141/p01-195 ◽

2002 ◽

Vol 82 (4) ◽

pp. 855-859 ◽

Cited By ~ 5

Author(s):

M. L. Leblanc ◽

D. C. Cloutier ◽

C. Hamel

Keyword(s):

Soil Moisture ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Chenopodium Album ◽

Seedling Emergence ◽

Field Capacity ◽

Emergence Period ◽

Common Lambsquarters ◽

Weed Emergence

A 2-year field study was conducted in corn to determine the influence of rainfall, irrigation and soil water content on common lambsquarters and barnyardgrass emergence. Rainfall or irrigation had no influence on the final weed density and little on the pattern of weed emergence because the soil water content was at or greater than field capacity during the main weed emergence period. Irrigation may hasten the first weed emergence by warming the soil when temperature is limiting for germination. In southwestern Quebec, temperature appears to be the most important factor regulating germination in the spring since soil moisture is normally at field capacity for a long period, in part because of the melting of snow. Key words: Irrigation, weed emergence, soil moisture

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On the scaling characteristics of observed and simulated spatial soil moisture fields

Nonlinear Processes in Geophysics ◽

10.5194/npg-16-141-2009 ◽

2009 ◽

Vol 16 (1) ◽

pp. 141-150 ◽

Cited By ~ 20

Author(s):

M. Gebremichael ◽

R. Rigon ◽

G. Bertoldi ◽

T. M. Over

Keyword(s):

Soil Moisture ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Spatial Correlation ◽

Hydrologic Model ◽

Invariance Property ◽

Spatial Average ◽

Hydrologic Models ◽

Model Simulations

Abstract. By providing continuous high-resolution simulations of soil moisture fields, distributed hydrologic models could be powerful tools to advance the scientific community's understanding of the space-time variability and scaling characteristics of soil moisture fields. However, in order to use the soil moisture simulations from hydrologic models with confidence, it is important to understand whether the models are able to represent in a reliable way the processes regulating soil moisture variability. In this study, a comparison of the scaling characteristics of spatial soil moisture fields derived from a set of microwave radiometer observations from the Southern Great Plains 1997 experiment and corresponding simulations using the distributed hydrologic model GEOtop is performed through the use of generalized variograms. Microwave observations and model simulations are in agreement with respect to suggesting the existence of a scale-invariance property in the variograms of spatial soil moisture fields, and indicating that the scaling characteristics vary with changes in the spatial average soil water content. However, observations and simulations give contradictory results regarding the relationship between the scaling parameters (i.e. spatial organization) and average soil water content. The drying process increased the spatial correlation of the microwave observations at both short and long separation distances while increasing the rate of decay of correlation with distance. The effect of drying on the spatial correlation of the model simulations was more complex, depending on the storm and the simulation examined, but for the largest storm in the simulation most similar to the observations, drying increased the long-range correlation but decreased the short-range. This is an indication that model simulations, while reproducing correctly the total streamflow at the outlet of the watershed, may not accurately reproduce the runoff production mechanisms. Consideration of the scaling characteristics of spatial soil moisture fields can therefore serve as a more intensive means for validating distributed hydrologic models, compared to the traditional approach of only comparing the streamflow hydrographs.

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