Search results for "040103 agronomy & agriculture"

Organic Fertilization in Traditional Mediterranean Grapevine Orchards Mediates Changes in Soil Microbial Community Structure and Enhances Soil Fertil…

2016

Soil microbial populations and their functions related to nutrient cycling contribute substantially to the regulation of soil fertility and the sustainability of agroecosystems. A field experiment was performed to assess the medium-term effect of a mineral fertilizer and two organic fertilization systems with different nitrogen sources on the soil microbial community biomass, structure, and composition (phospholipid fatty acids, pattern, and abundance), microbial activity (basal respiration, dehydrogenase, protease, urease, β-glucosidase, and total amount of phosphomonoesterase activities), and physical (aggregate stability) and chemical (total organic C, total N, available P and water-solu…

Soil-Water Interactions Unveiled by Fast Field Cycling NMR Relaxometry

2017

Minor Losses and Best Manifold Position in the Optimal Design of Paired Sloped Drip Laterals

2018

Closure to “Simple Relationships for the Optimal Design of Paired Drip Laterals on Uniform Slopes” by Giorgio Baiamonte

2016

The author appreciates the interest of the discussers of the paper “Simple Relationships for the Optimal Design of Paired Drip Laterals on Uniform Slopes” and wants to express his gratitude to Joaquin Monserrat and Javier Barragan for the opportunity to discuss the issues they raised. In their discussion, they questioned the use of analytical relationships to derive the design variables that are required for the optimal design of paired sloped laterals. This paper detected the Best Manifold Position (BMP = 0.24) to design optimal paired laterals and, as the discussers mentioned, allows the methodology introduced by Baiamonte et al. (2015) to be applied. Thus, the issues they questioned and …

Simple Relationships for the Optimal Design of Paired Drip Laterals on Uniform Slopes

2016

Microirrigation plants, if properly designed, allow water use efficiency to be optimized and quite high values of emission uniformity to be obtained in the field. It is known that disposing paired laterals, in which two distribution pipes extend in opposite directions from a common manifold, contribute to increasing water use efficiency. Recently, an analytical procedure has been proposed to optimally design paired drip laterals on uniform slopes under the assumption of neglect: (1) the variations of the emitters’ flow rate along the lateral, and (2) the local losses due to the emitters’ insertions. However, this procedure is not readily usable for every geometric and hydraulic characterist…

Morphological characterisation of soil structure in tilled fields: from a diagnosis method to the modelling of structural changes over time

2004

Characterisation of soit structure within the tilled layer of cultivated fields is crucial because the importance of this soil characteristic on the biological, chemical and physical properties of the soil and its repercussions on water cycle, root growth and functioning. We present in this paper a method for field characterisation of soil structure. This method, practised since the 1970s, was designed for field diagnosis of the effects of cropping systems on soil structure. It is based on a stratification of the observation face of a pit dug perpendicular to the direction of tillage and traffic: spatial compartments are distinguished, according to the nature of the mechanical stresses they…

The role ofSphagnummosses in the methane cycling of a boreal mire

2010

Peatlands are a major natural source of atmospheric methane (CH4). Emissions from Sphagnum-dominated mires are lower than those measured from other mire types. This observation may partly be due to methanotrophic (i.e., methane-consuming) bacteria associated with Sphagnum. Twenty-three of the 41 Sphagnum species in Finland can be found in the peatland at Lakkasuo. To better understand the Sphagnum-methanotroph system, we tested the following hypotheses: (1) all these Sphagnum species support methanotrophic bacteria; (2) water level is the key environmental determinant for differences in methanotrophy across habitats; (3) under dry conditions, Sphagnum species will not host methanotrophic ba…

The impact of long-term water level draw-down on microbial biomass : A comparative study from two peatland sites with different nutrient status

2017

We examined the effects of long-term (51 years) drainage on peat microbial communities using phospholipid fatty acid (PLFA) analysis. We analysed the peat profiles of natural and adjacent drained fen and bog sites. Viable microbes (i.e. microbial PLFA) were present in relatively large amounts even in the deepest peat layers of both peatland sites, a finding that warrants further investigation. Microbial biomass was generally higher in the fen than in the bog. Microbial community structure (indexed from PLFA) differed between the fen and bog sites and among depths. Although we did not exclude other factors, the effect of drainage on the total microbial biomass and community structure was not…

Stable carbon isotopic composition of peat columns, subsoil and vegetation on natural and forestry-drained boreal peatlands.

2018

We studied natural and forestry-drained peatlands to examine the effect of over 34 years lowered water table on the δ13C values of vegetation, bulk peat and subsoil. In the seven studied sites, δ13C in the basal peat layer was 1.1 and 1.2 ‰ lower than that of the middle-layer and surface layer, respectively. Furthermore, there was a positive correlation between the δ13C values of the basal and surface peat layers, possibly due to carbon (C) recycling within the peat column. In the same mire complex, natural fen peat δ13C values were lower than those of the nearby bog, possibly due to the dominance of vascular plants on fen and the generally larger share of recycled C in the fens than in the…

Heterogeneity of carbon loss and its temperature sensitivity in East-European subarctic tundra soils

2016

Arctic peatlands store large stocks of organic carbon which are vulnerable to the climate change but their fate is uncertain. There is increasing evidence that a part of it will be lost as a result of faster microbial mineralization. We studied the vulnerability of 3500-5900 years old bare peat uplifted from permafrost layers by cryogenic processes to the surface of an arctic peat plateau. We aimed to find biotic and abiotic drivers of CLOSS from old peat and compare them with those of adjacent, young vegetated soils of the peat plateau and mineral tundra. The soils were incubated in laboratory at three temperatures (4°C, 12°C and 20°C) and two oxygen levels (aerobic, anaerobic). CLOSS was …