Description: ABSTRACT Impact assessments on river systems of the combined effect of bed and suspended sediment loads emitted from quarries are difficult to find. In this study, bed and suspended loads were measured to determine the impact of a 20 ha limestone quarry on the river system of its 5,000 ha steep, diverse Land Use/ Land Cover but mostly forested catchment. A network of hydrologic and sediment monitoring instruments was deployed over the catchment during two separate study periods when sediment loadings were measured from captured storms. Results showed that the quarry stood to make a disproportionately large contribution to the catchment's estimated 2.1 Mg ha -1  yr -1 suspended sediment load. Large storm events contributed most of the loadings with five events supplying 92% of total loadings at the outlet. A paired method approach to compare suspended sediment loads between two subcatchments showed that during 8 storm events, the quarry yielded between 2 and 49.2 Mg ha -1 per event while the forest never yielded more than 0.1 Mg ha -1 . Furthermore, the contribution of sediments from the quarry to bed load was more than 75% at a section 1.2 km downstream. Future management activities to reduce sediment and bed loads, not only from this catchment but all others with similar Land Use/ Land Covers, should focus on improving quarry operations. This article is protected by copyright. All rights reserved.

Description: ABSTRACT Elucidating the links between catchment and channel geomorphic processes helps the understanding of landscape evolution and the geomorphic development of river basins, and then the land degradation processes. In this study we analyse suspended sediment dynamics and its relationship with rainfall, discharge and in-channel sediment storage in a highly dynamic Mediterranean montane catchment (the River Isáben, Southern Pyrenees, NE Iberian Peninsula). The aim is to assess hydrological controls on and temporal patterns of the suspended sediment load. High loads in this basin occur as a consequence of intense erosion in badlands located in the middle of the catchment. This study focuses on a reach located downstream from the main badland areas, where rainfall, discharge ( Q ), sediment transport ( SSC ), and in-channel sediment storage were monitored for a one year period. Marked seasonality in water and sediment load was observed; while most of the discharge occurred in winter and spring, most of the sediment was transported during summer and autumn. Q-SSC hysteretic loops revealed the importance of sediment availability (whether stored in the channel or originating from wider catchment source areas) in the river's sedimentary response. Clockwise loops dominated during winter and spring, while counter-clockwise loops occurred mostly in summer and autumn, when in-channel storage reached its maximum. There were significant correlations between rainfall intensity in the sediment source areas, in-channel sediment storage and sediment yield. These correlations emphasize the importance of understanding sediment availability when analysing the temporal dynamics of sediment transport, especially in catchments where different source areas (slopes, riverbed) may contribute to the load to differing degrees and at different times of the year. This article is protected by copyright. All rights reserved.

Description: ABSTRACT Fighting land and soil degradation is in the mandate of the United Nations Convention to Combat Desertification (UNCCD). However, it is often suggested that a lack of scientific guidance has resulted from inadequate institutional mechanisms to channel science into UNCCD decision making, rather than from a lack of research on UNCCD related issues. To explore this issue in more depth, this study explores the corpus of international publications dealing with land and/or with soil degradation. We extracted information from the " Web of Science" . By applying bibliometric methods and data mining we mapped the key actors (laboratories, teams, institutions) involved in research on land and on soils. Several filters were applied to the databases in combination with the word 'desertification'. The further use of text mining software (Tetralogie®) allowed the analyses of similarities and differences between keywords, disciplines, authors and regions and identifies obvious clusters. Understanding interconnections between these clusters ultimately allowed a first diagnosis of some of the strengths and weaknesses of the scientific community dealing with desertification. This type of detailed analyses can contribute to clarify the scientific landscape at large and further in depth studies could lead to improvements in the way scientific advice is channeled into the UNCCD. This article is protected by copyright. All rights reserved.

Description: ABSTRACT High N fertilizer and flooding irrigation applied to rice in anthropogenic-alluvial soil often result in N leaching and low use efficiency of applied fertilizer N from the rice field in Ningxia irrigation region in the upper reaches of the Yellow River. Sound N management practices need to be established to improve N use efficiency while sustaining high grain yield levels and minimize fertilizer N loss to the environment. We investigated the effects of Nursery Box Total Fertilization technology (NBTF) on N leaching at different rice growing stages, N use efficiency and rice yield in 2010 and 2011.The four fertilizer N treatments were 300 kg N · ha -1 (CU, Conventional treatment of urea at 300 kg N · ha -1 ), 120 kg N · ha -1 (NBTF120, NBTF treatment of controlled-release N fertilizer at 120 kg N · ha -1 ), 80 kgN · ha -1 (NBTF80, NBTF treatment of controlled-release N fertilizer at 80 kg N · ha -1 ) and no N fertilizer application treatment (CK). The results showed that the NBTF120 treatment increased N use efficiency, maintained crop yields and substantially reduced N losses to the environment. Under the CU treatment, the rice yield was 9634 and 7098 kg · ha -1 ; the N use efficiency was 31.6% and 34.8%; and the leaching losses of TN was 44.51 and 39.89 kg · ha -1 ,NH 4 + -N was 5.26 and 5.49 kg · ha -1 ,NO 3 - -N was 27.94 and 26.22 kg · ha -1 during the rice whole growing period in 2010 and 2011, respectively. Compared with CU, NBTF120 significantly increased the N use efficiency and decreased the N losses from the paddy field. Under NBTF120, the N use efficiency was 56.3% and 51.4%, which was 24.7% and 16.6% higher than that of CU, and the conventional fertilizer application rate could be reduced by 60% without lowering the rice yield while decreasing the leaching losses of TN by 16.27 and 14.36 kg · ha -1 , NH 4 + -N by 0.90 and 1.84 kg · ha -1 , NO 3 - -N by 110.6 and 10.14 kg · ha -1 in 2010 and 2011, respectively. Our results indicate that the CU treatment resulted in relatively high N leaching losses, and that alternative practice of NBTF which synchronized fertilizer application with crop demand substantially reduced these losses. We therefore suggest the NBTF120 be a fertilizer application alternative which leads to high food production but low environmental impact. This article is protected by copyright. All rights reserved.

Description: ABSTRACT Depth distribution of soil organic carbon (SOC) fractions depends on the efficiency of agro-technical managements. Information on depth distribution of SOC fractions mostly confined to the plough layer and scant in dry lands of Punjab, Pakistan. Therefore, a field experiment was laid out with moldboard plough (MP) (control), tine cultivator (TC) and minimum tillage (MT) as main plots, and cropping sequences fallow–wheat ( Triticum aestivum L.) , (FW, control), mungbean ( Vigna radiata L.)–wheat (MW), sorghum ( Sorghum bicolor L.)–wheat (SW), green manure–wheat (GW) and mungbean-chickpea (MC) ( Cicer arietinum L.) as sub-plots. Treatment effects were assessed for microbial biomass carbon (MBC), potentially mineralizeable carbon (PMC), particulate organic carbon (POC), dissolved organic carbon (DOC), HCl insoluble carbon (HIC) and stratification ratio (SR) in Rawal series: Udic Haplustalf. Alfisols. The MBC concentration was the highest in MT system, at 15-30 cm depth under MW and PMC concentration was highest under SW with MT at 45-60 cm. MP had higher POC in FW sequence. The highest DOC was at 0-15 cm depth under MC with TC and stock of HIC was more under TC with FW sequence. The highest stratification ratio (SR) of PMC was under MT with FW at 0-15:15-30 and POC was under TC and MP with FW at depths of 0-15:45-60 cm. The highest SR for DOC was under MP with GW at 0-15:45-60 cm and HCl insoluble C was under MT with SW at 0-15:45-60. In broad-spectrum, labile organic fractions revealed differential sensitivity and, POC stocks are also a sensitive indicator to detect the short- management effects. This article is protected by copyright. All rights reserved.

Description: ABSTRACT This study intends to understand how desertification research is organised in Spain. We assume that a strong communication between scientific knowledge and stakeholders is needed to slow down and reverse the impacts of land degradation on drylands. With this purpose we conducted an in-depth study at a national level in Spain. The work focused on a sample of published references on desertification in scientific journals indexed in the Web of Science. The keywords were related to " desertification" , " drylands" , " land" , " soil" , " development" , and " Spain" . Multivariate analysis, bibliometric techniques and network analysis were used in order to: i) identify research categories and their temporal evolution throughout the period under consideration (1989-2012); ii) determine if there were different approaches amongst different regions affected by desertification in Spain; iii) establish the relationships between research categories; iv) characterize types of co-authorship; and v) map out the Spanish network on the science of desertification. Erosion-soil degradation and soil-analysis are the most important research categories, whilst climatic issues are subsidiary and quite isolated from the rest of topics. Very few articles consider " desertification" as the main theme. Socio-economic issues have scant links with the core of biophysical science. The Spanish network on the science of desertification shows a low density. Moreover, the relationships between universities/research centres with other stakeholders are marginal. This is not the best scenario for transforming scientific knowledge into practical tools for policy makers and land users. Knowledge transfer should be a priority for national desertification programmes. This article is protected by copyright. All rights reserved.

Description: ABSTRACT Combating land degradation in the semi-arid rangeland of sub-Saharan Africa is essential to ensure long-term productivity of these environments. In the Lake Baringo Basin in Kenya, communities and individual farmers restored indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study quantified the benefits of rangeland rehabilitation using yearly communal enclosures’ utilisation data compiled by Rehabilitation of Arid Environments (RAE) Trust over a 6 year period (2005–2010). Results showed that communal enclosures provide a source of income through the sale of fattened livestock, harvested grass seeds, hay, honey and charcoal, among other products. Regression analysis showed an increasing total enclosure income with time. The enclosures also provide grasses for thatching, livestock feed and dry season grazing. Indirect products like milk, blood and meat are essential for household nutrition and food security. These benefits reinforce the management through incentive to maintain existing enclosures and establishing new ones, and therefore, the increasing trend in rangeland enclosure. Increased soil and biomass carbon storage could come with other indirect environmental benefits including improvement in soil quality, land productivity for pasture production and food security, and prevention of land degradation, thus leading to economic, environmental and social benefit for the local agro-pastoralist communities. This article is protected by copyright. All rights reserved.

Description: ABSTRACT For many years, farmers across Italy have struggled to convert rocky landforms into farmlands. Recently, expensive, heavy machineries have been widely used for these activities, exaggerating costs on land preparation. Subsidized by the Italian authorities, nearly 40% of Puglia lands in southern Italy have been converted to farmland through these methods. Recent evidence shows that in the short term, rock grinding enriches the soil with nutrients and improves soil quality. However, over the long run, land degradation and ecosystem services deterioration become prominent, resulting in the abandonment of extensive lands. This Italian case study should be considered as an alarming example of the possible detrimental effects of the national subsidies policy which supports the conversion of natural landforms into agricultural lands. This article is protected by copyright. All rights reserved.

Description: ABSTRACT Following the decline of industrial manufacturing, many U.S. cities have experienced severe population reductions that have resulted in large areas of vacant land. Urban agriculture has emerged as a desirable land use for these spaces, but degraded soils are common. Therefore, we measured soil and plant responses to amendments and management in urban lots where vacant houses had recently been demolished in Youngstown, OH U.S.A. Soil degradation was observed following demolition activities in the form of compaction (bulk density of 1.5-1.8 Mg m −3 ) and low soil microbial biomass C (21 mg C kg −1 soil). Our split plot experiment measured the effects of organic matter (OM) amendments produced from yard wastes and the use of raised beds on soil properties and vegetable crop yields. Two years after their application, OM amendments resulted in significant improvement to a number of soil physical, chemical and biological properties. Vegetable crop yields were improved by OM amendments in 2011 and by both OM amendments and the use of raised beds in 2012. A soil quality index, developed using factor analysis and the soil management assessment framework (SMAF), produced values ranging from 0.60-0.85, which are comparable to those reported for rural agricultural soils. All results indicate that urban agriculture can be productive in vacant urban land and that amendments produced from urban yard wastes can improve soil quality at previously degraded sites and increase crop yields for urban agriculture. This article is protected by copyright. All rights reserved.

Description: ABSTRACT This paper explores incentives and challenges in community-based rangeland management. Results from three case studies indicate variability in herders’ motivation to contribute to the conservation and management of rangeland resources. The basic reason behind the failure to ensure sustained collective action largely lies in the little effort made by the intervening agencies in creating awareness on the long-term consequences of climate change and biodiversity loss. In some villages, observation of positive results maintained the motivation to conserve the range while in others the removal of external incentives seems to discourage continuity of management practices. Resource users put greater emphasis on short-term economic gains that undermines the prospect to see long-term impacts of the present action, refuting the theoretical argument that absence of alternative livelihoods would force individuals to place emphasis on the possibility to generate income streams from a resource in the longer term. This implies that designing institutions for rangeland management contributes to its sustainable use. This article is protected by copyright. All rights reserved.