Increasing Land Pressure Research Articles

Beijing Symbiotic Courtyard Model’s Post Evaluation from the Perspective of Stock Renewal

Stock renewal is one of the important methods of urban renewal, which focuses on optimizing and reusing existing urban spaces. With the increasing land pressure in present-day China and the need for land to be reclassified, the thinking mode of stock updating has become increasingly important. Beijing symbiotic courtyard is a representative urban renewal model that combines the characteristics of traditional quadrangle dwelling and modern architecture, aiming to achieve the symbiosis of history and modernity. After several years of implementation, the effectiveness of this model has become a matter of concern for all parties involved. Therefore, this paper takes stock renewal as the observation perspective, describing an evaluation for the Beijing symbiotic courtyard model, which contains different types of residents living in particular historical districts. It attempts to propose corresponding strategies, aiming to provide a more comprehensive thinking angle and planning method for the sustainability of stock renewal. In contrast to earlier studies, the proposed methods involve a specific mathematical statistical model called the IPA-KANO model, in addition to other traditional urban renewal methods. For a wide range of problems including historical district evaluation and renewal, the approach leads to potentially less errors than caused by manual operation. This comes from the fact that all the data are collected through survey questionnaires and big data, so the technical restriction of using mathematical model is to some extent ruled out in this new approach. Moreover, the approach offers new potential problems that cannot be handled using earlier techniques. After the calculation, although there are still defects, local residents are generally satisfied with the Beijing symbiotic courtyard model. The result suggests that it is of importance to reference this model for urban renewal so that can be widely promoted in historical district vitality regeneration.

The preservation of old forests in southwest China is closely linked to the presence of ethnic minorities

Sacred forests are increasingly disappearing due to increasing land pressure and a decline in cultural values. Protecting the remaining sacred forests plays a crucial role in preserving biodiversity. The existence of remaining old forests often related to local people and their culture, but this relationship has rarely been quantified at large regional scales. This study analyzes the relationship between old forest and ethnic minorities based on the location of the old forest at a high spatial resolution (2 m). We found a significantly positive correlation (p < 0.01) between the proportion of ethnic minority population and old forest patch number, area, aggregation, and maximum patch area. However, there was no correlation with the connectivity of the old forest (p = 0.14). We further show that both environmental and anthropogenic factors are important for the distribution of old forests. Hydrothermal conditions contribute to the growth of forests, and local ethnic customs and the corresponding ecological wisdom contributes to the preservation of old forest remnants (r = 0.12, p < 0.05). Our findings highlight the significance of social dimensions for the conservation of old forests. We encourage that forest management should consider the role of indigenous people and their cultural wisdom for a better conservation and restoration of degraded ecosystems.

Influence of Intercity Network on Land Comprehensive Carrying Capacity: A Perspective of Population Flow

The world is experiencing the largest wave of urban growth in history. Maintaining the rapid growth of cities without causing land and resource shortages is a severe problem that must be solved urgently. With the rapid development of globalization and information technology, the meaning of land comprehensive carrying capacity presents new changes. It is no longer entirely dependent on local resources and is likely to benefit from intercity connections beyond urban boundaries. However, can an inter-city network be a non-local solution to sustain urban growth without increasing land pressure? To address this question, this study adopted 287 cities in China as the research object to describe the spatial carrying characteristics of land at the national level by constructing an evaluation index system for land comprehensive carrying capacity. Furthermore, we constructed a population flow network model through social network analysis to explore the influence of intercity network on land comprehensive carrying capacity. Our findings are as follows: (1) The regional differentiation characteristics of land comprehensive carrying capacity at the national scale are evident, and reveal a spatial pattern significantly related to the urban economic development level. (2) The weighted in-degree, weighted degree centrality, and betweenness centrality in the intercity network positively impact the land comprehensive carrying capacity, and land use efficiency has a partial mediating effect. (3) Land comprehensive carrying capacity can be determined by non-local factors rather than local factors. As an effective non-local channel, strengthening intercity population flow and network integration can flexibly manage urban land scarcity.

Sahelian smallholders’ varietal mixtures reconcile yield and agrobiodiversity conservation

In the current setting, marked by the major challenges of growing food demand and climate change impacts, the ability of sub-Saharan agriculture to meet population needs depends on the resilience and adaptation capacity of this system. Using agrobiodiversity to promote agricultural sustainability is a strategy that has garnered much attention lately. Research suggests that mixing species or varieties within crop fields could increase the yield and/or stability. This mixing is also geared towards the conservation of crop diversity while ensuring that the various associated products and services will be available at the farm level.Few recent research studies have highlighted the benefits of varietal mixtures for Africa. This lack of research is a concern, given that this continent is considered to be highly vulnerable to climate change. This study was carried out to test whether plots with varietal mixtures would outperform monovarietal plots in terms of yield and pathogen regulation under smallholder farming conditions in Senegal. Together with farmers, we conducted 30 experiments in which mixtures of early- and late-flowering pearl millet landraces were grown in these farmers’ fields, while monitoring their low input management. We noted a significant positive effect of varietal mixtures on grain yield (mean gain of 63 ± 31.5 kg ha−1 for mixture plots, p = 0.046) with a relative yield total (RYT) averaging 1.87 ± 0.94. Both early- and late-flowering landraces benefited from mixtures, with a greater impact on late-flowering landraces. Higher fertility in terms of the seed number, percentage of fertile tillers and number of panicles per tiller, was documented in mixture plots. We did not find a significant effect of mixture on fodder, striga or weed infestation.In water and nutrient resource limiting conditions, such as in Sahelian agroecosystems, growing mixtures of early- and late-flowering landraces appeared to be an efficient way to increase productivity while ensuring agrobiodiversity conservation. Perhaps even more importantly, mixtures allowed farmers to harvest multiple products with different uses in an agrosocioecosystem context with constantly increasing land pressure.

Effects of livestock and wildlife grazing intensity on soil carbon dioxide flux in the savanna grassland of Kenya

Although grazing is the primary land use in the savanna lowland of southern Kenya, the effects of grazing on soil carbon dioxide flux (RS) remain unclear. A 12-month study was conducted from January to December 2020 on the effects of six grazing intensities sites (overgrazed (OG), heavily grazed (HG), moderately grazed (MG), moderately to lightly grazed (M-LG), lightly grazed (LG) and no grazing (NG)) on RS on. A camera trap was used to monitor the total number of animals at each site, indicating the grazing intensity. Weekly measurements of RS were taken using static greenhouse gas chambers along with simultaneous measurements of soil temperature (TS) and volumetric soil water content (WS) (depth of 5 cm). Mean RS at HG, MG, M-LG and LG sites was approximately 15–25% higher than at NG and OG sites (p < 0.001). Mean WS increased with decrease in grazing especially in the dry season, while TS increased with increase in grazing. We observed bimodal temporal variation in RS and WS due to two wet seasons in the year. Thus, variation in RS across the study period followed the changes in WS rather than those in TS. Mean values of RS in the wet seasons were significantly higher (>45%) than those in the dry seasons, and WS accounted for 71% of the temporal variability in RS (p < 0.05). In addition, the enhanced vegetation index (EVI, interpreted as a proxy for vegetation cover) explained 60% of the variance of RS, and WS and EVI together explained 75%. EVI showed a negative relationship (p < 0.05) with animal intensity, indicating that more grazing reduced vegetation cover and, consequently, soil organic carbon and biomass. Soil bulk density was lower at less grazed sites. While RS variability was unaffected by total nitrogen content, pH, and texture, correspondence analysis demonstrated that the main factors influencing RS dynamics across the year under different grazing intensities were WS and vegetation cover. Our results contribute to closing the existing knowledge gap regarding the effects of grazing intensity on RS in East Africa savannas. Therefore, this information is of great importance in understanding carbon cycling in savanna grassland, as well as the identification of the potential consequences of increasing land pressure caused by rising livestock numbers, and will assist in the development of climate-smart livestock management in East Africa.

Volume estimation of soil stored in agricultural terrace systems: A geomorphometric approach

High-resolution topographic (HRT) techniques allow the mapping and characterization of geomorphological features with wide-ranging perspectives at multiple scales. We can exploit geomorphometric information in the study of the most extensive and common landforms that humans have ever produced: agricultural terraces. We can only develop an understanding of these historical landform through in-depth knowledge of their origin, evolution and current state in the landscape. These factors can ultimately assist in the future preservation of such landforms in a world increasingly affected by anthropogenic activities. From HRT surveys, it is possible to produce high-resolution Digital Terrain Models (DTMs) from which important geomorphometric parameters such as topographic curvature, to identify terrace edges can be extracted, even if abandoned or covered by uncontrolled vegetation. By using riser bases as well as terrace edges (riser tops) and through the computation of minimum curvature, it is possible to obtain environmentally useful information on these agricultural systems such as terrace soil thickness and volumes. The quantification of terrace volumes can provide new benchmarks for soil erosion models, new perspectives to stakeholders for terrace management in terms of natural hazard and offer a measure of the effect of these agricultural systems on soil organic carbon sequestration. This paper presents the realization and testing of an innovative and rapid methodological workflow to estimate the anthropogenic reworked and moved soil of terrace systems in different landscapes. We start with remote terrace mapping at large scale and then utilize more detailed HRT surveys to extract geomorphological features, from which the original theoretical slope-surface of terrace systems were derived. These last elements were compared with sub-surface information obtained from the excavations across the study sites that confirm the reliability of the methodology used. The results of this work have produced accurate DTMs of Difference (DoD) for three terrace sites in central Europe in Italy and Belgium. Differences between actual and theoretical terraces from DTM and excavation evidence have been used to estimate the soil volumes and masses used to remould slopes. The utilization of terrace and lynchet volumetric data, enriched by geomorphometric analysis through indices such as sediment conductivity provides a unique and efficient methodology for the greater understanding of these globally important landforms, in a period of increasing land pressure.

Land consolidation, specialization and household diets: Evidence from Rwanda

Despite rapid population growth, increasing land pressure and urbanization, farmers in Sub-Saharan Africa have not intensified their production in a sustainable manner and farming systems remain predominantly subsistence-oriented. In response, developing country governments increasingly implement programs that promote crop intensification and more commercially-oriented agricultural systems. Rwanda’s Crop Intensification Program (CIP), launched in 2007, is one such example. However, despite its apparent success in raising production of several priority crops, there are legitimate concerns about the food and nutrition security implications for households that are encouraged to consolidate their land, specialize in their production, and increasingly rely on markets for their food needs. Using recent household survey data and a propensity score matching difference-in-differences method, we find that participation in land consolidation activities had ambiguous consumption effects: it positively impacted on consumption of roots and tubers, but had a negative effect on meat, fish and fruits consumption and the potential availability of vitamin B12 in participants’ diets. This calls for a review of CIP implementation practices to enhance the program’s food and nutrition security outcomes, with improvements in market functioning and market access being potential starting points.

Cropping Intensity and Agricultural Efficiency Patterns in North-Eastern Region of Chhattisgarh: A Geographical Study

Agriculture is the basic function for economy, settlement, and socio-cultural activities in North Eastern Region of Chhattisgarh. From the ancient to the modern period, the dignity of agriculture has remained unchanged. The agriculture of the state is depends on monsoon for which the farmers have to suffer damage of crops due to irregular and uncertain rainfall pattern. Crop productivity is basically related to irrigation, despite all efforts, the pure irrigated area from all sources of total agricultural land is 11.3%, which is the cause of high land, pat region and plateau. Through analysis, it is known that the distribution of tehsil wise crop intensity and agricultural efficiency in the state is uneven. That is why it is necessary to increase the crop intensity due to increasing population and increasing land pressure. Since agricultural efficiency is a profound relationship with agricultural productivity. So in addition to the physical background, the crop intensity and agricultural efficiency of the state can be increased through the addition of HYV seeds, fertilizers, mechanization, farming training, mixed crop system, land improvement etc. At present it is possible to increase the area irrigated by canal, tube well, well, pond, reservoirs and rivers, but the study area is prevalent from dense forests and primitive tribes. Primitive tribes still adopt traditional farming methods so that production is relatively low.

Intensified sweetpotato production in Papua New Guinea drives plant nutrient decline over the last decade

Sweetpotato (Ipomoea batatas) is the staple food of the Papua New Guinea Highlands and is primarily grown in swidden-type production systems. Because of high population growth and limited available land to expand agricultural production, land use must be intensified to ensure food security. In this study, changes in sweetpotato production systems were assessed by comparing field surveys conducted in 2005 and 2014. During the nine years between surveys, the length of fallow period decreased by 48%, from an average length of 12.1 in 2005 to 6.3 years in 2014. This reduction coincided with a reduced growth period for sweetpotato production gardens from 13.1 to 9.6 month (27%). The time required to reach gardens from the family home increased by 60% from 2005 to 2014. This surrogate measure shows that increasing land pressure has forced farmers to use more remote sweetpotato gardens. The clear driver for increased production was increased demand for sweetpotato as a cash crop; 83% more sweetpotato was sold, rather than consumed by the producer. Despite the increase in production, the management of soil fertility remained unchanged, and farmers continued not to use mineral fertilisers for sweetpotato production. The intensification of land use reduced the occurrence of traditional bush/tree fallow species, such as Casuarina oligodon, which were traditionally used as fallow species in the sweetpotato system, but have been replaced by food legumes, e.g., beans and peanuts. As a consequence of land use intensification, there was a clear decline in soil fertility, particularly for soil N, P, Fe, and Zn, and plant tissue concentrations of N, S, Ca, Fe and B. Given the present rate of population growth and limited land area available to expand, land use intensification will continue. Comparison of the two surveys reported here, indicated that nutrient rundown of the system is occurring. To prevent further depletion of soil nutrients, especially as further intensification of the system is anticipated, nutrient inputs to the sweetpotato production system will need to be increased. In the short to medium-term, this may be through landscape nutrient redistribution strategies such as mulching with organic matter from outside the garden area in a cut and carry or cut and place method, but in the longer-term we anticipate that high levels of production can only be sustained through the addition of mineral fertilisers.

Colonization and changing social structure: Evidence from Kazakhstan

We study how Russian colonization of the Kazakh steppes in the late 19th century influenced the evolution of traditional institutions of Kazakhs. Using a rich dataset constructed from Russian colonial expedition materials, we find that during the transition from nomadic pastoralism to a semi-sedentary pastoralist-agricultural system, Kazakhs’ traditional communes shrank, property rights on land became more individualized, and households became less likely to pool labor for farming. We argue that two main forces behind this evolution were increasing land pressure and technological change. The speed and the magnitude of these adjustments were much larger than usually assumed in most of development economics literature on traditional institutions.

Quantifying ambivalence towards sustainable intensification: an exploration of the UK public’s values

Sustainable intensification (SI) has been proposed as a solution to meeting the challenge of feeding a growing global population under increasing land pressure. This paper explores the level of ambivalence felt towards SI and towards experts promoting SI based solutions to meet food security. A web-based experiment was conducted with 600 respondents who had varying degrees of knowledge about food security issues. We found a diversity of public ambivalence towards sustainable intensification and a high level of felt ambivalence towards experts promoting SI as a solution to global food security. High levels of ambivalence towards experts seemed to influence how messages on global food security were accepted. Moreover, within the respondents here sustainable consumption and greater equity ranked higher than production based sustainable intensification solutions. This paper represents the first application of the psychological construct of ambivalence applied to the topic of sustainable intensification and we argue this helps to localise the debate around SI as it offers the opportunity to capture or disentangle responses towards food security issues.

Clans and Ploughs: Traditional Institutions and Production Decisions of Kazakhs under Russian Colonial Settlement

This article investigates how, with increasing land pressure during Russian settlement in Kazakh steppes in the late nineteenth century, clan institutions affected the transition from nomadic pastoralism to settled agriculture. Using a novel dataset constructed from Russian colonial expedition materials matched with clan genealogies, we find that, controlling for geographic factors, clan identity strongly influenced the duration of transhumance period, the organization of production, and the acquisition of new agricultural tools. Information transmission within clans, external economies of scale in nomadic pastoralism, and clan-specific values and norms underlie the results.

Efficacy of indigenous arbuscular mycorrhizal fungi for promoting white yam ( Dioscorea rotundata) growth in West Africa

Tuber yields of yam ( Dioscorea spp.), a main staple food in West Africa, are steadily declining per unit area, an incidence for which decreasing soil fertility due to increasing land pressure is largely blamed. Recent studies demonstrated the association of a plethora of arbuscular mycorrhizal fungi (AMF) with yam, soil microorganisms crucial for natural soil fertility. Thus, inoculation of yam with AMF could help reverse declining yields, above all in soils with a strong loss of AMF diversity due to agricultural land use intensification. In a pot experiment, we studied the impact of indigenous and exotic AMF isolates on growth performance of micro-propagated white yam plantlets ( Dioscorea rotundata, cv.TDr89/02461). Pots were inoculated with single spore derived isolates of Glomus etunicatum, originating from tropical environments in West Africa, South America and Asia and, for comparison, also with three isolates of other AMF species from temperate Europe. In addition, isolates of nine AMF species originating from sub-Saharan West Africa and three commercial AMF were compared. Six of the 11 isolates of G. etunicatum from the tropics increased yam tuber growth compared with non-mycorrhizal controls, whereas the European AMF species tended to be less efficient but led to an increased tuber phosphorus concentration. The African isolates of G. mosseae, G. hoi, G. etunicatum, Acaulospora scrobiculata and A. spinosa generally led to increased tuber growth compared with non-mycorrhizal controls, while isolates of G. sinuosum and Kuklospora kentinensis did not. Our study indicates that inoculation of micro-propagated yam plantlets with selected indigenous AMF could potentially constitute a sustainable measure to boost yam productivity again in degraded African soils.

Increasing land pressure in East Africa: The changing role of cassava and consequences for sustainability of farming systems

Increasing land pressure during the past three to four decades has transformed farming systems in the mid-altitude zone of East Africa. Traditional millet-, cotton-, sugarcane- and/or banana-based farming systems with an important fallow and/or grazing component have evolved into continuously cultivated cassava or cassava/maize-based systems. Within three to four decades, cassava cultivation increased from 1–11 to 16–55% of cropped fields in our six study sites. Declining soil fertility, and not labour or food shortage, was apparently the primary trigger for this transformation. The land use changes have increased nutrient offtakes and reduced nutrient recycling rates. Cassava and maize now account for 50–90% of nutrient removal. Whereas single-season fallows were the most important source of nutrient recycling on cropped fields in the past, currently cassava litterfall and maize stover contribute roughly 70% of nutrient recycling, with 50–70% of N, P and K recycled in cassava litterfall. This may explain why many farmers reason that cassava ‘rests’ the soil. With increasing land use pressure farmers progressively use cassava as an ‘imitation fallow’ throughout their farm. Farmers increasingly target cassava to poor fertility fields characterized by low pH and available P. High cassava intensities are nonetheless maintained on more fertile fields, probably to guarantee regeneration of soil fertility on all fields. Once cassava is targeted to poor fertility soils, farmers have run out of low-input management options and need to intensify management to maintain system productivity. As cassava is now used by more farmers and on a larger acreage than fallowing in the studied farming systems, cassava cropping could perhaps serve as an excellent entry point to strengthen system sustainability.

Land pressure and customary tenure: Cropland allocations in Swaziland

Abstract This paper examines the effects of growing land pressure on the distribution and quality of cropland allocations on customary tenured land (CTL) in Swaziland. Within the wider Sub‐Saharan context, the reform of indigenous tenure systems is now generally seen as a process of adaptation rather than replacement. The legal recognition of (existing and future) user rights is considered a practical way forward. This essentially rights‐based approach may divert attention from technical inadequacies indigenous systems may have, particularly under conditions of increasing land pressure. The case of CTL substantiates such shortcomings. CTL has seen a marked growth in population and land allocations since Independence. This had led to concerns on the land distribution efficiency in view of the improved agricultural production required to sustain the increasing number of rural households. By analysing historical changes in the number, size and quality of cropland allocations in selected rural communities, this paper demonstrates the occurrence of a high degree of inconsistency in cropland distribution at the community level, as well as inefficient land distribution at higher levels of scale. These shortcomings threaten the sustainability of the local agricultural production systems, and will need to be addressed in any meaningful reform process.

Increasing the relevance of scientific information in hillside environments through understanding of local soil management in a small watershed of the Colombian Andes

Abstract. This article explores the question of how scientific information can improve local agronomic management using concepts of uncertainty classification and uncertainty management. Information and data on local management of soil fertility based on a local classification system of soil quality were collected from a small watershed in Cauca (Colombia). The analyses suggest that farmers hold local knowledge about soils at two levels. The first is based on empirical observations and refers to local knowledge about soils and landscape, which shows that the classes identified in the local soil quality classification are consistent with results obtained using measured soil parameters. At the second level, farmers have some awareness of ecological processes and the appropriate use of relationships between key soil characteristics and management options. It is argued that local knowledge is not sufficient to cope with uncertainty introduced by a rapidly changing agriculture, including, for example, increasing land pressure, unpredictable market forces and climate change. We have suggested how scientific knowledge can contribute to the solution, based on an analysis that relates Cohen's (Heuristic reasoning about uncertainty: an artificial intelligence approach. Pitman London, 1985) and Rowe's (Risk Analysis 14, 743–750, 1994) uncertainty concepts to local knowledge.

Assessment of tillage erosion rates on steep slopes in northern Thailand

The switch from shifting cultivation to more permanent highland cropping systems in northern Thailand. led to an increase in soil tillage intensity. In order to quantify soil losses by tillage erosion, a tillage experiment was set up and an on-farm survey was conducted. Soil fluxes due to manual tillage on five slopes (32–82%) were measured by monitoring tracers, by measuring tillage step characteristics and by collecting soil material in a trench. The trench method yielded soil flux. values that were significantly smaller than those obtained by the tracer or the step method. Soil fluxes resulting from one manual tillage pass ranged between 39 and 87 kg/m on the tested slopes. On slopes up to 60%, there were no significant differences in soil fluxes. However, on slopes steeper than 70%, soil fluxes increased significantly because the angle of repose for soil clods was exceeded. The soil fluxes are used to construct a nomogram for estimating soil loss rates resulting from manual tillage erosion as a function of slope and plot length. Rates on a typical upland field (slope 30%–50%, slope length 30–50 m) range from 8 to 18 t/ha · tillage pass, so tillage erosion is a significant contributor to the total soil loss. It dominates on short fields and fields with buffer-strips, whereas water erosion is the more important form of soil loss on middle size and long fields. Increasing land pressure will result in increasing tillage erosion rates, and these need to be considered when assessing soil degradation rates or when studying hillslope evolution.