Search results for " Fertility."

Effects of soil compaction, rain exposure and their interaction on soil carbon dioxide emission

2012

Soils release more carbon, primarily as carbon dioxide (CO2), per annum than current global anthropogenic emissions. Soils emit CO2 through mineralization and decomposition of organic matter and respiration of roots and soil organisms. Given this, the evaluation of the effects of abiotic factors on microbial activity is of major importance when considering the mitigation of greenhouse gases emissions. Previous studies demonstrate that soil CO2 emission is significantly affected by temperature and soil water content. A limited number of studies have illustrated the importance of bulk density and soil surface characteristics as a result of exposure to rain on CO2 emission, however, none exami…

Reversing agriculture from intensive to sustainable improves soil quality in a semiarid South Italian soil

2010

Intensive agriculture (IA) is widespread in South Italy, although it requires frequent tillage, large amounts of fertilizers and irrigation water. We have assessed the efficacy of reversing IA to sustainable agriculture (SA) in recovering quality of a typical South Italy soil (Lithic Haploxeralf). This reversion, lasting from 2000 to 2007, replaced 75% of nutrients formerly supplied inorganically by farmyard manuring and reduced the tillage frequency. Several chemical and biochemical properties, functionally related to C and N mineralisation–immobilisation processes and to P and S nutrient cycles, were monitored annually from 2005 to 2007 in the spring. Reversing IA to SA decreased soil bul…

Early Effects of No-Till Use on Durum Wheat (Triticum durum Desf.): Productivity and Soil Functioning Vary between Two Contrasting Mediterranean Soils

2022

The diffusion of no-tillage (NT) is to be encouraged because of the benefits it can provide in terms of improving soil fertility and counteracting global warming and climate change as part of climate-smart agriculture practices. However, the introduction of this management can be difficult, especially in the first years of application, and can lead to unpredictable yield results depending on the soil type. Therefore, the aim of this experiment was to evaluate the early effect of NT use, compared to the conventional mouldboard ploughing (CT), on two different soils, a clay-loam (GAL) and a sandy-clay-loam soil (SMA), by monitoring a set of 43 different soil and plant variables that were expe…

Dental disease in a 17th–18th century German community in Jelgava, Latvia

2012

Aims: To determine the frequency and distribution of dental caries, periapical lesions, the periodontal disease, ante-mortem tooth loss and enamel hypoplasia in a high status, urban post-medieval population from the Duchy of Courland and Semigallia, and to compare these rates with those obtained from contemporary populations from urban and rural Latvian cemeteries. Materials: The sample analysed consisted of the dental remains of 108 individuals (39 male, 42 female and 27 non-adults) excavated from the Jelgava Holy Trinity Church cemetery in Latvia. A total of 1,233 teeth and 1,853 alveoli were examined. Results: The frequency of the observed conditions in this population was overall high b…

A Side-by-Side Single Sex Age-Structured Human Population Dynamic Model: Exact Solution and Model Validation

2008

A side-by-side single sex age-structured population dynamic model is presented in this paper. The model consists of two coupled von Foerster-McKendrick-type quasi-linear partial differential equations, two initial conditions, and two boundary conditions. The state variables of the model are male and female population densities. The solutions of these partial differential equations provide explicit time and age dependence of the variables. The initial conditions define the male and female population densities at the initial time, while the boundary conditions compute the male and female births at zero-age by using fertility rates. The assumptions of the nontime-dependence of the death and fe…

2018

Summary Background Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based t…

Reply of the Authors: Hysteroscopic resection of the uterine septum: is it always a necessity?

2009

[No abstract available]

Impact of climate, soil properties and grassland cover on soil water repellency

2021

Abstract Numerous soil water repellency (SWR) studies have investigated the possible causes of this temporal phenomenon, yet there remains a lack of knowledge on the order of importance of the main driving forces of SWR in the context of changing environmental conditions under grassland ecosystems. To study the separate and combined effects of soil texture, climate, and grassland cover type on inducing or altering SWR, four sites from different climatic and soil regions were selected: Ciavolo (CI, IT), Csolyospalos (CSP, HU), Pwllpeiran (PW, UK), Sekule (SE, SK). The investigated parameters were the extent (determined by repellency indices RI, RIc and RIm) and persistence (determined by wat…

Nutrient impoverishment and limitation of productivity after 20 years of conservation management in wet grasslands of north-western Germany

2009

Abstract European wet grasslands are characterized by high diversity of plant and animal species but are threatened by intensive land use. Although preservation or restoration of species-rich wet grasslands requires low nutrient availability that could be achieved by long-term management, studies monitoring nutrient removal are lacking. Our objective was to assess the long-term effect of management (mowing twice a year without or with PK fertilization for 20 years) on (i) productivity and nutrient removal with the harvest, (ii) the type of nutrient limitation, and (iii) plant species richness in wet grasslands in north-western Germany considering the differences between organic and mineral …

Sediment transport mechanisms and selective removal of soil particles under unsteady-state conditions in a sheet erosion system

2022

Abstract Selective removal of particles and nutrients by water erosion is a key factor in soil erosion studies. Most agricultural soils are located on gentle slopes where fertility is high; however, until now, the main attention on sediment transport mechanisms was paid to high-slope gradients, where soil erosion is intense, but soils are less productive. Despite the importance of sediment size distribution (SSD) and transport mechanisms under unsteady-state conditions, few studies have been done on this issue. Higher sediment concentrations in the early stages of the runoff indicate the need to deal with unsteady-state conditions. To address this issue, sheet erosion experiments were done …