scholarly journals Land Degradation by Soil Erosion in Nepal: A Review

Soil Systems ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Devraj Chalise ◽  
Lalit Kumar ◽  
Paul Kristiansen

Land degradation, particularly soil erosion, is currently a major challenge for Nepal. With a high rate of population growth, subsistence-based rural economy, and increasingly intense rainfall events in the monsoon season, Nepal is prone to several forms of land degradation, such as floods, landslides, and soil erosion. To understand the causes, impacts, and possible management options for soil erosion, a review on the causal factors, status, and amelioration measures for land degradation in Nepal was conducted based on recent information available in national and international journals and grey literature. Intense rainfall and conventional tillage practices coupled with poor soil structure and steep slopes are the main drivers of soil erosion. Soil erosion leads to losses in soil and crop productivity, pollution of land and water resources, and a loss of farm income. Strategies to manage erosion include mulching, cover cropping, contour farming, strip cropping, and conservation agriculture practices, along with bioengineering techniques. Land degradation issues are a prime policy focus in Nepal, including national three- and five-year plans. However, these policies have been generally ineffective in reducing soil erosion, landslides, and floods in relation to the set targets. Realistic plans need to be formulated in Nepal focusing more on capacity enhancement and local participation to actively influence land-degradation processes.

2021 ◽  
Vol 14 (7) ◽  
pp. 19-31
Author(s):  
V.A. Chougule ◽  
J.B. Sapkale ◽  
V.S. Pawar-Patil

The phenomenon of accelerated soil erosion, the resulting of irresponsible land use practices and human interference bring considerable changes within the Achara basin. The high rate of soil erosion deteriorates the fertility of the soil and consequently reduces crop productivity. Accumulation of transported soil at the lower part of the basin creates a severe problem of sedimentation within the channel and affects the hydraulic characteristics. The estimated potential sediment yield has been derived by using an integrated RUSLE model accompanied remote sensing database in geospatial environment. The result reveals the estimated average annual soil loss for the watershed as 18.81 t ha-1 year-1 . Sediment Delivery Ratio (SDR) fluctuates from 0.01 to 0.627. It has shown remarkably low for almost all parts of the basin, except steep slope and lower part of the watershed depending on the channel gradient of the major river. The junctions of the main channels are more susceptible to accumulate the sediment (> 4 t ha-1 year-1 ) within the basin. The lowermost portion of the basin receives a massive amount of sediment which ranges between 0.01 to 127 t ha-1 year-1 causing sedimentation within the estuary. The attempted work focuses on assessment of the erosional risk and sedimentation issue of Achara basin. The applied model will be helpful in the disaster management planning of such kind of coastal basins in Maharashtra.


2020 ◽  
Author(s):  
Leigh Ann Winowiecki ◽  
Athanase Mukuralinda ◽  
Aida Bargués-Tobella ◽  
Providence Mujawamaria ◽  
Elisée Bahati Ntawuhiganayo ◽  
...  

Abstract. Land restoration is of critical importance in Rwanda, where land degradation negatively impacts crop productivity, water, food and nutrition security. We implemented the Land Degradation Surveillance Framework in Kayonza and Nyagatare districts in eastern Rwanda to assess baseline status of key soil and land health indicators, including soil organic carbon (SOC) and soil erosion prevalence. We collected 300 topsoil (0–20 cm) and 281 subsoil (20–50 cm) samples from two 100 km2 sites. We coupled the soil health indicators with vegetation structure, tree density and tree diversity assessments. Mean topsoil organic carbon was low overall, 20.9 g kg−1 in Kayonza and 17.3 g kg−1 in Nyagatare. Stable carbon isotope values (d13CV-PDB ) ranged from −15.35 to −21.34 ‰ indicating a wide range of plant communities with both C3 and C4 photosynthetic pathways. Soil carbon content decreased with increasing sand content across both sites and at both sampling depths and was lowest in croplands compared to shrubland, woodland and grasslands. Field-saturated hydraulic conductivity (Kfs) was estimated based on infiltration measurements, with a median of 76 mm h−1 in Kayonza and 62 mm h−1 in Nyagatare, respectively. Topsoil OC had a positive effect on Kfs, whereas pH, sand and compaction had negative effects. Soil erosion was highest in plots classified as woodland and shrubland. Maps of soil erosion and SOC at 30-m resolution were produced with high accuracy and showed high variability across the region. These data and analysis demonstrate the importance of systematically monitoring multiple indicators at multiple spatial scales to assess drivers of degradation and their impact on soil organic carbon dynamics.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Buddhadeb Roy ◽  
Shailja Dubey ◽  
Amalendu Ghosh ◽  
Shalu Misra Shukla ◽  
Bikash Mandal ◽  
...  

AbstractLeaf curl, a whitefly-borne begomovirus disease, is the cause of frequent epidemic in chili. In the present study, transmission parameters involved in tripartite interaction are estimated to simulate disease dynamics in a population dynamics model framework. Epidemic is characterized by a rapid conversion rate of healthy host population into infectious type. Infection rate as basic reproduction number, R0 = 13.54, has indicated a high rate of virus transmission. Equilibrium population of infectious host and viruliferous vector are observed to be sensitive to the immigration parameter. A small increase in immigration rate of viruliferous vector increased the population of both infectious host and viruliferous vector. Migrant viruliferous vectors, acquisition, and transmission rates as major parameters in the model indicate leaf curl epidemic is predominantly a vector -mediated process. Based on underlying principles of temperature influence on vector population abundance and transmission parameters, spatio-temporal pattern of disease risk predicted is noted to correspond with leaf curl distribution pattern in India. Temperature in the range of 15–35 °C plays an important role in epidemic as both vector population and virus transmission are influenced by temperature. Assessment of leaf curl dynamics would be a useful guide to crop planning and evolution of efficient management strategies.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 227
Author(s):  
Yang Yu ◽  
Jesús Rodrigo-Comino

Land degradation, especially soil erosion, is a societal issue that affects vineyards worldwide, but there are no current investigations that inform specifically about soil erosion rates in Chinese vineyards. In this review, we analyze this problem and the need to avoid irreversible damage to soil and their use from a regional point of view. Information about soil erosion in vineyards has often failed to reach farmers, and we can affirm that to this time, soil erosion in Chinese vineyards has been more of a scientific hypothesis than an agronomic or environmental concern. Two hypotheses can be presented to justify this review: (i) there are no official and scientific investigations on vineyard soil erosion in China as the main topic, and it may be understood that stakeholders do not care about this or (ii) there is a significant lack of information and motivation among farmers, policymakers and wineries concerning the consequences of soil erosion. Therefore, this review proposes a plan to study vineyard soil erosion processes for the first time in China and develop a structured scientific proposal considering different techniques and strategies. To achieve these goals, we present a plan considering previous research on other viticultural regions. We hypothesize that the results of a project from a regional geographic point of view would provide the necessary scientific support to facilitate deriving guidelines for sustainable vineyard development in China. We concluded that after completing this review, we cannot affirm why vine plantations have not received the same attention as other crops or land uses.


2021 ◽  
Vol 1 (1) ◽  
pp. 84-95
Author(s):  
Patience O. Obi ◽  
Jennifer E. Kent ◽  
Maya M. Jeyaraman ◽  
Nicole Askin ◽  
Taiana M. Pierdoná ◽  
...  

Asthma is the most common pediatric disease, characterized by chronic airway inflammation and airway hyperresponsiveness. There are several management options for asthma, but no specific treatment. Extracellular vesicles (EVs) are powerful cellular mediators of endocrine, autocrine and paracrine signalling, and can modulate biophysiological function in vitro and in vivo. A thorough investigation of therapeutic effects of EVs in asthma has not been conducted. Therefore, this systematic review is designed to synthesize recent literature on the therapeutic effects of EVs on physiological and biological outcomes of asthma in pre-clinical studies. An electronic search of Web of Science, EMBASE, MEDLINE, and Scopus will be conducted on manuscripts published in the last five years that adhere to standardized guidelines for EV research. Grey literature will also be included. Two reviewers will independently screen the selected studies for title and abstract, and full text based on the eligibility criteria. Data will be extracted, narratively synthesized and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This systematic review will summarize the current knowledge from preclinical studies investigating the therapeutic effects of EVs on asthma. The results will delineate whether EVs can mitigate biological hallmarks of asthma, and if so, describe the underlying mechanisms involved in the process. This insight is crucial for identifying key pathways that can be targeted to alleviate the burden of asthma. The data will also reveal the origin, dosage and biophysical characteristics of beneficial EVs. Overall, our results will provide a scaffold for future intervention and translational studies on asthma treatment.


2021 ◽  
Vol 189 ◽  
pp. 104502
Author(s):  
Gabriel del Barrio ◽  
Maria E. Sanjuán ◽  
Jaime Martínez-Valderrama ◽  
Alberto Ruiz ◽  
Juan Puigdefábregas

Author(s):  
D.H. Ranade ◽  
M.L. Jadav ◽  
Indu Swarup ◽  
O.P. Girothia ◽  
D.V. Bhagat ◽  
...  

Background: Rainwater harvesting is commonly practiced in areas, where the rainfall is insufficient for crop growing. Due to the intermittent nature of run-off events, it is necessary to store the maximum possible amount of rainwater during the rainy season so that it may be used as irrigation to enhance the crop productivity and farm income under soybean based cropping system.Methods: A study was carried out during 2018-2019 in Indore district of Malwa region. Rainwater harvesting tanks at on station (42´21´2.4m) and on farm (15´11´4m) were constructed for irrigation water availability. Provision of water harvesting tank increased the irrigation water availability (1781m3 and 630m3 respectively) and stored water was managed through various irrigation systems viz. rain gun, drip and flood.Result: It was resulted that the provision of water harvesting tanks enhanced the crop productivity and farm income under soybean based cropping system. Availability of irrigation encouraged the farmers to diversify the cropping pattern (soybean-chickpea, soybean -wheat). It is also clear from the study that even with smaller storage tank and through conjunctive use of ground (1164.2m3) and surface water (596m3), multiple crops (Soybean, potato, sweet corn, chickpea, onion, garlic etc.) can be grown. Soybean-Chickpea cropping system at station gave the net return of 70976 Rs/ha with B: C ratio of 3.15. Soybean-Wheat cropping system at farm gave the net return of 119000 Rs/ha with B:C ratio of 3.38. 


1970 ◽  
Vol 35 (2) ◽  
pp. 287-296
Author(s):  
M Akkas Ali ◽  
M Robiul Alam ◽  
MSH Molla ◽  
F Islam

The experiment was conducted at multilocation testing (MLT) site, Sujanagar, Pabna during the year of 2003-2004 to find out a soil test based economically viable fertilizer recommendation for the cropping pattern Boro-T. aman. Six treatments viz., moderate yield goal (MYG), high yield goal (HYG), integrated plant nutrient system (IPNS), recommended fertilizer of FRG' 97 (BARC) guide (RF), farmers' practice (FP), and absolute control were employed for the study. The grain yield of Boro and T. aman rice increased 18 and 14%, respectively, by IPNS compared to farmers' practice. Total grain yield of rice was increased by about 16% in the IPNS fertilizer package compared to farmers' practice. Fertilizer nutrients supplied both from organic and inorganic sources in adequate amount have a positive effect on productivity of soil. On an average it was found that highest grain yields of Boro rice (5.37 t/ha) and T. aman (4.49 t/ha) were obtained from integrated plant nutrient system (IPNS) where farmers’ practice gave yield of 4.55 and 3.94 t/ha. The highest average gross margin (70385 Tk./ha) and marginal benefit cost ratio (3.78) was also obtained from IPNS plots. Keywords: Crop productivity; fertilizer management; cropping pattern. DOI: 10.3329/bjar.v35i2.5892Bangladesh J. Agril. Res. 35(2) : 287-296, June 2010


2015 ◽  
Vol 7 (14) ◽  
pp. 8154 ◽  
Author(s):  
R. K. Sony ◽  
P. R. Arun

<p><strong> </strong>Anaikatty Hills of the Western Ghats in Tamil Nadu witness the annual spectacle of mass movement of lakhs of butterflies.  The present paper examines the impact of vehicular traffic on this ‘butterfly migration’ through a survey of butterfly mortality along a road stretch in Anaikatty Hills.  A high rate of mortality due to road traffic was observed during the mass movement of butterflies.  One-hundred-and-thirty-five butterfly road kills belonging to three families, nine genera and 12 species were recorded during the study.  The proportion of nymphalid butterflies among the road kills (70%) was very high compared to their respective share in the background population (39%), indicating a higher road mortality risk for nymphalids.  The conservation significance of the road traffic impact on butterfly assemblage and management options are discussed.</p><div> </div>


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