scholarly journals Restoration of grazing land to increase biomass production and improve soil properties in the Blue Nile basin: effects of infiltration trenches and Chloris Gayana reseeding

Author(s):  
T. Erkossa ◽  
D. Geleti ◽  
T. O. Williams ◽  
F. Laekemariam ◽  
A. Haileslassie

Abstract Degradation of crop and grazing lands is a pervasive problem that negatively impacts agricultural productivity and livelihoods of crop-livestock farmers in the Blue Nile basin of Ethiopia. Area enclosure together with a cut and carry livestock feeding system is often advocated as an approach for the regeneration of degraded grazing lands. This paper reports the results of a two-year farmer participatory study conducted to assess the effects of infiltration trenches (ITs) and Chloris gayana Kunth (Rhodes grass; cultivar Masaba; tetraploid; C4 grass species) reseeding on restoration of degraded grazing lands. A split plot design was used with IT as the main plot and C. gayana reseeding as a sub-plot on 28 private grazing plots under enclosure. The results showed that IT alone increased soil moisture content and prolonged the growing period. IT and C. gayana reseeding together significantly (P ≤ 0.05) increased herbage dry matter yield and improved soil chemical properties. The highest mean herbage dry matter yield (21 Mg ha−1 per cut) was recorded for plots treated with IT and reseeded with C. gayana. The higher herbage dry matter yield was attributed to increased soil moisture and the resultant prolonged growing period induced by the trenches coupled with the ability of C. gayana to effectively utilize the retained water. The results suggest that an integrated land management approach involving enclosure, in-situ water conservation and C. gayana reseeding can rapidly increase biomass productivity on degraded grazing lands while also enhancing soil quality with concomitant livelihood benefits for farmers.

2021 ◽  
Vol 13 (9) ◽  
pp. 1835
Author(s):  
Yared Bayissa ◽  
Semu Moges ◽  
Assefa Melesse ◽  
Tsegaye Tadesse ◽  
Anteneh Z. Abiy ◽  
...  

Drought is one of the least understood and complex natural hazards often characterized by a significant decrease in water availability for a prolonged period. It can be manifested in one or more forms as meteorological, agricultural, hydrological, and/or socio-economic drought. The overarching objective of this study is to demonstrate and characterize the different forms of droughts and to assess the multidimensional nature of drought in the Abbay/ Upper Blue Nile River (UBN) basin and its national and regional scale implications. In this study, multiple drought indices derived from in situ and earth observation-based hydro-climatic variables were used. The meteorological drought was characterized using the Standardized Precipitation Index (SPI) computed from the earth observation-based gridded CHIRPS (Climate Hazards Group InfraRed Precipitation with Station) rainfall data. Agricultural and hydrological droughts were characterized by using the Soil Moisture Deficit Index (SMDI) and Standardized Runoff-discharge Index (SRI), respectively. The monthly time series of SMDI was derived from model-based gridded soil moisture and SRI from observed streamflow data from 1982 to 2019. The preliminary result illustrates the good performance of the drought indices in capturing the historic severe drought events (e.g., 1984 and 2002) and the spatial extents across the basin. The results further indicated that all forms of droughts (i.e., meteorological, agricultural, and hydrological) occurred concurrently in Abbay/Upper Blue Nile basin with a Pearson correlation coefficient ranges from 0.5 to 0.85 both Kiremt and annual aggregate periods. The concurrent nature of drought is leading to a multi-dimensional socio-economic crisis as indicated by rainfall, and soil moisture deficits, and drying of small streams. Multi-dimensional drought mitigation necessitates regional cooperation and watershed management to protect both the common water sources of the Abbay/Upper Blue Nile basin and the socio-economic activities of the society in the basin. This study also underlines the need for multi-scale drought monitoring and management practices in the basin.


2019 ◽  
Vol 11 (2) ◽  
pp. 125 ◽  
Author(s):  
Getachew Ayehu ◽  
Tsegaye Tadesse ◽  
Berhan Gessesse ◽  
Yibeltal Yigrem

In this study, a residual soil moisture prediction model was developed using the stepwise cluster analysis (SCA) and model prediction approach in the Upper Blue Nile basin. The SCA has the advantage of capturing the nonlinear relationships between remote sensing variables and volumetric soil moisture. The principle of SCA is to generate a set of prediction cluster trees based on a series of cutting and merging process according to a given statistical criterion. The proposed model incorporates the combinations of dual-polarized Sentinel-1 SAR data, normalized difference vegetation index (NDVI), and digital elevation model as input parameters. In this regard, two separate stepwise cluster models were developed using volumetric soil moisture obtained from automatic weather stations (AWS) and Noah model simulation as response variables. The performance of the SCA models have been verified for different significance levels (i.e., α = 0.01 , α = 0.05 , and α = 0.1 ). Thus, the AWS based SCA model with α = 0.05 was found to be an optimal model for predicting volumetric residual soil moisture, with correlation coefficient (r) values of 0. 95 and 0.87 and root mean square error (RMSE) of 0.032 and 0.097 m3/m3 during the training and testing periods, respectively. While in the case of the Noah SCA model an optimal prediction performance was observed when α value was set to 0.01, with r being 0.93 and 0.87 and RMSE of 0.043 and 0.058 m3/m3 using the training and testing datasets, respectively. In addition, our result indicated that the combined use of Sentinel-SAR data and ancillary remote sensing products such as NDVI could allow for better soil moisture prediction. Compared to the support vector regression (SVR) method, SCA shows better fitting and prediction accuracy of soil moisture. Generally, this study asserts that the SCA can be used as an alternative method for remote sensing based soil moisture predictions.


2020 ◽  
Vol 12 (13) ◽  
pp. 2138
Author(s):  
Getachew Ayehu ◽  
Tsegaye Tadesse ◽  
Berhan Gessesse

Monitoring soil moisture and its association with rainfall variability is important to comprehend the hydrological processes and to set proper agricultural water use management to maximize crop growth and productivity. In this study, the European Space Agency’s Climate Change Initiative (ESA CCI) soil moisture product was applied to assess the dynamics of residual soil moisture in autumn (September to November) and its response to the long-term variability of rainfall in the Upper Blue Nile Basin (UBNB) of Ethiopia from 1992 to 2017. The basin was found to have autumn soil moisture (ASM) ranging from 0.09–0.38 m3/m3, with an average of 0.26 m3/m3. The ASM time series resulted in the coefficient of variation (CV) ranging from 2.8%–28% and classified as low-to-medium variability. In general, the monotonic trend analysis for ASM revealed that the UBNB had experienced a wetting trend for the past 26 years (1992–2017) at a rate of 0.00024 m3/m3 per year. A significant wetting trend ranging from 0.001 to 0.006 m3/m3 per year for the autumn season was found. This trend was mainly showed across the northwest region of the basin and covers about 18% of the total basin area. The spatial patterns and variability of rainfall and ASM were also found to be similar, which implies the strong relationship between rainfall and soil moisture in autumn. The spring and autumn season rainfall explained a considerable portion of ASM in the basin. The analyses also signified that the rainfall amount and distribution impacted by the topography and land cover classes of the basin showed a significant influence on the characteristics of the ASM. Further, the result verified that the behavior of ASM could be controlled by the loss of soil moisture through evapotranspiration and the gain from rainfall, although changes in rainfall were found to be the primary driver of ASM variability over the UBNB.


2021 ◽  
Vol 41 (2) ◽  
pp. 165-173
Author(s):  
S. A. Ogedegbe ◽  
C. N. C. Nwaoguala

An experiment was conducted twice concurrently at Vom in Plateau State Nigeria in 2011 to evaluate the effects of three animal based organic fertilizers and three rates of application on the growth, seed and herbage yields of Rhodes grass (Chloris gayana var. Callide). This study involved three types (poultry, rabbit and sheep dung) of animal fertilizer and three rates (0, 25 and 50 t ha-1) of application in a 3 x 3 factorial arrangement fitted into randomized complete block design and replicated three times. Animal fertilizers significantly (p < 0.05) increased growth, seed, fresh herbage and dry matter yields of Rhodes grass. Generally, fertilizers from poultry and rabbit were similar and better (p < 0.05) than that of sheep in the enhancement of the measured variables. At 6 weeks after fertilizer application (WAF), fresh herbage yield was in the range of 14.6 – 48.3 t ha-1 whereas dry matter yield ranged from 4.7 – 13.9 t ha-1 while seed yield was 1.8 – 2.3 t ha-1. At 12 WAF, rabbit fertilizer produced significantly higher values than sheep fertilizer by 21.2 % for sward height, 70.1 % for fresh herbage yield and 61.4 % for dry matter yield. The correlation coefficients among the measured variables were positive and highly significant. The highest correlation recorded (0.937**) was between fresh herbage and dry matter yields. The study indicated that application of either rabbit or poultry fertilizer can suitably enhance Rhodes grass growth for higher herbage and seed yields. The study also showed that 25 and 50 t ha-1 of animal fertilizers on Rhodes grass yielded similar results. With adequate fertilizer application, Rhodes grass can produce sufficient herbage to meet the nutritional requirement of several ruminant livestock. It is not economical to apply more than 25 t ha-1 of animal fertilizers to Rhodes grass if they contain more than 1.21 % of nitrogen.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Mulisa Faji Dida ◽  
Alemeyehu Abebe Lemore ◽  
Kedija Ahmed Seid

Nitrogen is the most important macronutrient for forage and food crop production. Currently, cultivable lands in Ethiopia undergo a deficiency of this element. Thus, this study was conducted to find an appropriate rate of nitrogen (N) fertilizer for the better agronomic performance of Chloris gayana Masaba. The experiment was carried out at Assosa Agricultural Research Center. The experiment was conducted using a randomized complete block design with three replications, and the treatments were five levels of nitrogen fertilizer (0, 23, 46, 69, and 92 kg N/ha). The collected data were analyzed using the general linear model procedure of SAS, and the least significance difference was used for mean separation. Plant height at forage harvesting, dry matter yield, leaf to stem ratio, leaf height, number of leaves per plant, number of tillers, and seed yield were significantly ( p < 0.001 ) influenced by the year of planting while nonsignificantly ( p > 0.05 ) by nitrogen fertilizer rate and interaction of planting year and fertilizer rate. The mean leaf to stem ratio was significantly ( p < 0.001 ) higher in 2017 and 2018 than in the 2019 planting year. However, forage dry matter yield was significantly ( p < 0.001 ) higher in 2019, followed by 2018 and 2017 planting years. Mean seed yield was significantly ( p < 0.001 ) different among the establishment years and the peak seed yield productivity attained during the third year of harvesting (1st = 2nd < 3rd year of harvesting). Generally, all measured agronomic traits were not significantly responsive to the different fertilizer rates, and in the economic point of view, 0 kg of N/ha is recommended.


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