Search results for "fertilization"

Quantitative importance of staminodes for female reproductive success inParnassia palustrisunder contrasting environmental conditions

2003

The five sterile stamens, or staminodes, in Parnassia palustris act both as false and as true nectaries. They attract pollinators with their conspicuous, but non-rewarding tips, and also produce nectar at the base. We removed staminodes experimentally and compared pollinator visitation rate and duration and seed set in flowers with and without staminodes in two different populations. We also examined the relative importance of the staminode size to other plant traits. Finally, we bagged, emasculated, and supplementary cross-pollinated flowers to determine the pollination strategy and whether reproduction was limited by pollen availability. Flowers in both populations were highly dependent o…

Vanadium perturbs the fertilization outcome and the metalloproteinase activity in sea urchin embryos

2021

Metal toxicology represents a current major topic due to the disper- sion of these elements in the environment. Metals are released from both natural sources and industrial activities. Some of them have also a clinical interest due to their application as metallodrugs (i.e., Pt, Cu, Au, Ru, and Y) or in medical diagnosis (Gd).1,2 Recently, V derivatives are considered as potential therapeutic factors in some diseases (e.g., obesity, diabetes, cancer, neurodegenerative and heart disorders). As a consequence, pharmaceutical residues could repre- sent emerging pollutants of aquatic environments, as wastewater treatment plants do not sufficiently remove these compounds3. Embryonic models repres…

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…

Impact of fertilization and direct seeding on activity and abundance of key denitrifier communities in a tropical soil

2007

Affiche, résumé; The aim of this work was to investigate to which extent different practices impacted on the bacterial communities involved in N2O emission.

Soil weed seedbank composition and structure in a long-term nutrient management experiment

2016

EAGESTAD; Weed communities can be influenced by nutrient availability, nutrient form (e.g. ammonium vs. nitrate), amendment timing, amendment type, and by immigration of seeds during amendment applications. New York ranks third in the United States in the number of dairy cows and thus dairy manure applications are prevalent throughout the state. The objective of this work was to compare the effect of dairy manure and inorganic fertilizer on soil weed seedbank composition and structure in a long-term nutrient management experiment. The field experiment was initiated in 2001 at the Cornell Musgrave Research Farm in Aurora, NY and compared ten treatments in a corn-alfalfa rotation using a rand…

Impact of fertilization, tillage and direct seeding on nitrate reducers in Madagascar

2007

Effect of fertilisation on the changes of soil pH and exchangeable aluminium content in soil

2015

W pracy oceniono stopień zakwaszenia gleby oraz zawartość glinu wymiennego w zależności od rodzaju zastosowanego nawozu mineralnego oraz jego dawki. Badania prowadzono w oparciu o doświadczenie wazonowe z jęczmieniem jarym odmiany browarniczej Propino. Uzyskane wyniki wskazują, że największe zakwaszenie oraz największe zawartości glinu wymiennego stwierdza się w warunkach stosowania nawożenia w kombinacji NPK wraz z saletrą amonową. Zastosowany w różnych dawkach siarczan wapnia dwuwodny nie wpłynął na zmianę odczynu gleby, a odnotowana zawartość glinu wymiennego była niższa niż w kombinacji NPK wraz z saletrą amonową.