Search results for "N fertilization"
showing 10 items of 114 documents
Role of rotation and nitrogen fertilization on the productive and qualitative response of durum wheat (Triticum durum Desf.)
2012
Correct soil management can improve and/or sometimes restore the fertility of agricultural land. Crop rotations are important to maintain adequate soil organic matter content and to reduce chemical nutritional intake. Qualitative and productive durum wheat response is strongly influenced by soil nutrient availability, necessary for plant growth and development. Nitrogen availability, mainly during the first stage of growth, determines the uptake rate and total nitrogen uptake; later is also responsible of nitrogen translocation from vegetative to reproductive organs, determining yield and grain qualitative characteristics. The aim of the trial was to evaluate cropping system effects and nit…
Nitrogen efficiency component analysis in wheat under rainfed Mediterranean conditions: effects of crop rotation and nitrogen fertilization
2004
The research was carried out in 1999-01 in a typical Sicilian semi-arid area to evaluate the effect of crop rotation and N fertilization on the nitrogen use efficiency (NUE) in wheat. Crop rotation were: wheat-faba bean, wheat-chickpea, wheat-pea and continuous wheat; nitrogen fertilizer rates were: 0, 40, 80 and 120 kg N/ha. A split-plot design with three replications were used. Analysis of nitrogen efficiency components was performed according to the procedure of Higgins and Pan (1993) using grain yield, aboveground plant N, grain N and post-harvest inorganic soil N. Continuous wheat (WW) recorder the lowest grain yields while no differences were found in wheat grown after the three legum…
Wheat yield and grain quality as affected by tillage, sowing time and nitrogen fertilization under rainfed Mediterranean conditions
2004
The research was carried out in 9 sites (5 in 1999-00 and 4 in 2000-01) of inner area of Sicily different for soil type, slope, exposure and preceding crop. The following treatments were studied: (i) conventional tillage and sowing at conventional time (CT); (ii) no tillage and sowing at conventional time (NTc); and (iii) no tillage and early sowing (NTe). In 2000-01 the effect of three nitrogen fertilization treatment (single application at planting, P, and split dressing at two different rates, S and S+) were also evaluated. No tillage systems (NTc and NTe) significantly increased grain yield compared to CT treatment; no differences were observed between the two sowing dates. The producti…
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…
Differential Responses of Nitrate Reducer Community Size, Structure, and Activity to Tillage Systems
2009
ABSTRACT The main objective of this study was to determine how the size, structure, and activity of the nitrate reducer community were affected by adoption of a conservative tillage system as an alternative to conventional tillage. The experimental field, established in Madagascar in 1991, consists of plots subjected to conventional tillage or direct-seeding mulch-based cropping systems (DM), both amended with three different fertilization regimes. Comparisons of size, structure, and activity of the nitrate reducer community in samples collected from the top layer in 2005 and 2006 revealed that all characteristics of this functional community were affected by the tillage system, with increa…
Effects of tributyltin(IV) chloride on fertilization ofStyela plicata(Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy studies
2003
The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm–egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.
An Analysis of the Process of Fertilization and Activation of the Egg
1957
Publisher Summary Fertilization consists fundamentally in the release of a chain of metabolic reactions by virtue of which morphogenesis is started. The result of fertilization is the activation of the egg. This can be achieved also by several agents other than the spermatozoon and it is then spoken of as “artificial activation.” This chapter discusses the structural, physiological, and chemical changes that occur in the egg at fertilization that are significant in the understanding of the mechanisms of the activation. The chapter presents the hypothesis that in the cortex of the unfertilized sea urchin egg an inhibitor–enzyme complex is present. By reacting with some substance introduced b…
Cytochrome oxidase activity in the mitochondria of unfertilized and fertilized sea urchin eggs
1959
Abstract The cytochrome oxidase activity of isolated mitochondria of unfertilized and fertilized eggs of Paracentrotus lividus has been studied. It has been found that whereas in the mitochondria of unfertilized eggs saturation is reached at a cytochrome c concentration of 3.28 × 10−5 M, in those of fertilized eggs this occurs at a concentration of 5.74 × 10−5 M. It is shown that upon fertilization an increase of about 30 per cent of the activity of cytochrome oxidase takes place and no further changes appear to occur until blastula stage.
EFFECTS OF DIFFERENT FERTILIZATION LEVELS ON IBERIS SEMPERFLORENS POT CULTURE
2013
The genus Iberis (family Brassicaceae) includes 30 species of annual and perennial herbs and subshrubs that grow in a wide area from western and central Europe to the Mediterranean Basin. IberissemperflorensL. is a perennial evergreen subshrub (30-60 cm high) endemic to southern Italy and Sicily. Due to its abundance of white flowers and extensive flowering period occurring during the winter months, the species has good potential for pot cultivation and outdoor ornamental use in Mediterranean-type climates. Reliable and efficient propagation methods for I. semperflorens nursery production have been determined. However, there are limited information on cultural techniques of this winter flow…
Evidence for an intra- and extraplastidic pre-chorismate pathway.
1982
Pea plants grown under different conditions of cultivation, and eight different plant species with variegated leaves were used to study the intracellular localization of shikimate oxidoreductase (EC 1.1.1.25), the marker enzyme of the pre-chorismate pathway. The two series of experiments indicated an intra-and an extraplastidic compartimentalization of the enzyme, and both enzyme activities are regulated differentially. While the extraplastidic activity is permanently demonstrable, the intraplastidic activity is subject to the plants' developmental state and also depends on both illumination and fertilization.