Search results for "yield"

Effects of Plastic Mulching and Basal Nitrogen Application Depth on Nitrogen Use Efficiency and Yield in Maize

2018

The demand for increased grain production to support population and consumption growth has led to increased interest in field management approaches that incorporate plastic mulching and fertilization management. The purpose of this study was to investigate the effects of plastic mulching and basal nitrogen (N)-fertilizer application depth on N balance estimations, N use efficiency (NUE) and maize yield. The experiment was conducted in 2014 and 2015 with six treatments: no N fertilizer and no mulching (CK), traditional broadcast N fertilizer with mulching (T0), basal N-fertilizer application at a depth of 6 cm with no mulching (T1), basal N-fertilizer application at a depth of 6 cm with plas…

Shakedown theorems for elastic–plastic solids in the framework of gradient plasticity

2008

Abstract Static and kinematic shakedown theorems are given for a class of generalized standard materials endowed with a hardening saturation surface in the framework of strain gradient plasticity. The so-called residual-based gradient plasticity theory is employed. The hardening law admits a hardening potential, which is a C 1 -continuous function of a set of kinematic internal variables and of their spatial gradients, and is required to satisfy a global sign restriction (but not to be necessarily convex). The totally produced, the accumulated and the freely moving dislocations per unit volume, distinguished as statistically stored and geometrically necessary ones, are in this way accounted…

Olive yield as a function of soil moisture dynamics

2011

This study introduces a water-driven crop model aiming to quantitatively link olive yield to climate and soil moisture dynamics using an ecohydrological approach. A mathematical model describing soil moisture, evapotranspiration and assimilation dynamics of olive orchards is developed here. The model is able to explicitly reproduce two different hydroclimatic phases in Mediterranean areas: the well-watered conditions in which evapotranspiration and assimilation assume their maximum values and the real conditions where the limitations induced by soil moisture availability are taken into account. Annual olive yield is obtained by integrating the carbon assimilation during the growing season, …

Source shape and data analysis procedure effects on hydraulic conductivity of a sandy-loam soil determined by ponding infiltration runs

2017

Performing ponding infiltration runs with non-circular sources could represent a good means to sample completely an area of interest. Regardless of the shape of the source, predicting the expected reliability of the collected data by infiltrometers should facilitate soil hydraulic characterisation and also allow a more conscious use of the field data. The influence of the shape of the infiltration source (i.e., circular or square) and the analysis procedure of the steady-state infiltration data on the saturated hydraulic conductivity, Ks, of a sandy-loam soil was tested in this investigation. Circular and square surfaces sampled with the pressure infiltrometer (PI) yielded similar estimates…

Offsetting land degradation through nitrogen and water management during maize cultivation under arid conditions

2018

Morphological and agronomical characterisation of Sicilian bottle gourd Lagenaria siceraria (Mol.) Standley

2014

Local plant populations represent a valuable source of genetic variability. Lagenaria siceraria [Mol.] Standl. is a monoecious species of Cucurbitaceae grown in India and parts of the Mediterranean for its immature fruit and young leaves used as vegetables. The species is a high-value crop in Sicily where several landraces are grown in open field and in plastic greenhouse. The aim of this study was to characterise five Sicilian L. siceraria landraces (G1-G5), from a morphological and agronomical point of view. Genetic resource characterisation was carried out as a foundation for future conservation and breeding works. Fourteen qualitative and quantitative characters were assessed by using t…

SMAP Multi-Temporal vegetation optical depth retrieval as an indicator of crop yield trends and crop composition

2017

Vegetation Optical Depth (VOD) is related to Vegetation Water Content (VWC). This provides new and highly valuable information for ecological and agricultural studies. In this work, VOD from the Soil Moisture Active-Passive (SMAP) satellite has been retrieved with the new Multi-Temporal Dual-Channel Algorithm (MT-DCA). Then, it has been applied to the study of crop yield trends and crop composition. The increase on VOD (¿VOD) during crop development has been compared to yield data in two selected regions located in the United States. The first region presents a heterogeneous crop composition and weak ¿VOD-yield relationship (r2=0.21). The second region presents a highly homogenous cover and…

Efficient and Mild Ytterbium(III)-Catalyzed Tosylation of Alcohols.

2004

Ytterbium(III) trifluoromethanesulfonate efficiently catalyzes the reaction of primary and secondary alcohols with toluenesulfonic acid anhydride to yield the alkyl tosylates in high yields. The reactions were carried outunder neutral and mild conditions and product purification was easily achieved by means of short column chromatography.

Impact of lipid extraction on the dearomatisation of an Eisenia foetida protein powder

2010

www.elsevier.com/locate/foodchem ; FSTA:2010-Sp0197; International audience; Delipidation was studied as a way to dearomatise a non-conventional protein powder obtained from Eisenia foetida earthworms. In the first step, we studied the impact of several factors such as solvent type, extraction method and particle size on the yield of extracted lipids. Lipid extraction from samples was considerably improved using an ultrasound method with a chloroform/methanol mixture and small particle size. In the second step, the volatile compounds were extracted from the delipidated protein powder by the SAFE extraction method and by the HS-SPME method, and were further analysed by GC-MS. The chloroform/…

Reduced herbicide use does not increase crop yield loss if it is compensated by alternative preventive and curative measures

2018

Herbicide use must be reduced because of environmental and health issues. This raises the question of whether weeds and the resulting crop yield loss will increase. Previous studies analysing relationships between herbicide use intensity, weeds and yield loss suffer from methodological shortcomings in terms of weed flora and farm diversity as well as temporal scales. Here, we collected data on 272 arable cropping systems from one Spanish and six French regions, from farm surveys, the Biovigilance-Flore network, expert opinion, cropping system trials, crop advisors and scientists. Each system was simulated over 27 years and with 10 weather repetitions, using the virtual-field model FlorSys. …