Contribution of Roots and Mycorrhizal Hyphae on Phosphorus Efficiency of Maize (Zea mays,L.) Genotypes Grown on Calcareous Soil—A Mechanistic Modeling Approach

ABSTRACT

This work was conducted to study phosphorus (P) efficiency of two maize genotypes (Zea mays, L.) in calcareous soil grown in potted soil with two levels of P in soil by adding 40 and 270 mg P/kg soil. Half of the pots were inoculated with arbuscular mycorrhizal fungi (AMF) (Rhizoglomus irregulare). The maize genotypes were harvested two times at 35 and 50 days after transplanting. The plant dry matter, root length and Plant P uptake of maize genotype Hagen 1 without mycorrhizal fungi (AMF) increased significantly compared with Hagen 9 at a low P level. In contrast, there was no significant difference between two maize genotypes inoculated with AMF under the same P level. The predicted value increased rapidly with increasing P levels from about 70% up to 97% in both maize genotypes with and without mycorrhizal fungi. At a low P level, the mycorrhizae hyphae contributed by about 31.6% and 30.2% of the predicted total P uptake in maize genotype Hagen 1 and Hagen 9, respectively. The results of this study suggested that the P-inefficient genotype Hagen 9 improved with inoculation with mycorrhizal fungi under a low P level at the same conditions of this experiment. Also, root growth system and mycorrhizal hyphae length would be a suitable plant parameter for studying P efficient maize genotypes, especially under limited P supply. The current study clearly pointed out that the mechanistic simulation model (NST 3.0) provides useful tools for studying the role of AMF in P uptake of plant.     

Evaluation of urea ammonium polyphosphate (UAPP) I. Effectiveness of banded and seed‐placed UAPP on irrigated corn (Zea mays L.)

Abstract

Field trials were established on an irrigated loamy sand using corn as a test crop. Row fertilizer was placed with the seed (seed‐placed) or in the conventional side placement position (side‐placed). The side‐placed treatments consisted of two carriers of UAPP (28–28–0 and 36–18–0), diammonium phosphate (DAP, 18–46–0) plus ammonium nitrate (AN, 33–0–0), and a control treatment. Two rates of application were used for each carrier. Seed‐placed treatments consisted of two carriers of UAPP (28–28–0 and 36–18–0), concentrated superphosphate (CSP, 0–45–0) plus AN, CSP, AN, and a control treatment. Two rates of application were used for each carrier, except AN, which was used at three rates.

High rates of side‐placed UAPP delayed emergence of corn and lowered the final population. Early season N concentration in corn seedlings was not affected by rate or carrier of side‐placed N. Early season P concentration in the corn seedlings was greater for AN + DAP than UAPP treatments at all rates of P, presumably due to toxic accumulation of free NH₃ in the UAPP band. High rates of side‐placed UAPP also reduced the yield of corn.

High rates of seed‐placed AN + CSP and UAPP reduced the germination of corn. However, low rates of UAPP also reduced germination, whereas low rates of AN + CSP did not affect germination. Since UAPP has a lower salt index than AN + CSP, the “salt effect”; of low rates of UAPP does not explain its effect on germination and emergence. The deleterious effects of UAPP were due apparently to either NH₃ or NO₂‐N toxicity.     

Characterization of “Mais delle Fiorine” (Zea mays L.) and nutritional,morphometric and genetic comparison with other maize landraces of Lombardy region (Northern Italy)

Genetic Resources and Crop Evolution - The loss of agrobiodiversity is a topic of global impact. On a local scale, Lombardy, in the Alpine macro-Region, has lost more than 78% of its plant...     

Response to comment by Dr. A.S. Kowalski on “The storage term in eddy flux calculations”

Kowalski correctly points out that the analysis in [Finnigan, J.J., 2006. The storage term in eddy flux calculations. Agric. Forest Meteorol., 136, 108–113] ignores the interplay between the storage terms and the WPL corrections. In this note we develop an expression for the vertical convective velocity that accounts for the effect of both the ‘steady state’ and unsteady ‘storage’ WPL terms on the flux of a trace gas like CO₂ measured with an open path sensor and sonic anemometer. The expression is derived using the mass density rather than the mixing ratio so that the eddy fluxes take the conventional covariance form that is commonly used in turbulence textbooks.     

Effects of K-Mg ratio on growth and cation nutrition of Vitis vinifera L. cv. “Dattier de Beiruth” grafted on SO4 rootstock

The area of planting of Vitis vinifera L. cv. “Dattier de Beiruth” (DB) grafted on the SO4 (Selection OPPENHEIM 4) rootstock is significant and constantly growing in Northern Algeria. A hydroponic culture was carried out with DB to investigate the effects of potassium-magnesium (K-Mg) ratio on plant growth and mineral nutrition. Four nutrient solutions were tested on which the K-Mg ratio is variable (nutritive solution (NS)1 = 0.3 K: 3.8 Mg, NS2 = 2.1 K: 2 Mg, NS3 = 2.6 K: 1.5 Mg and NS4 = 3.8 K: 0.3 Mg). The results showed that DB was characterized by a high capacity for K uptake. No significant differences among the treatments were detected in the leaf concentrations of calcium (Ca), however Mg uptake was inhibited by increase of K: Mg in the nutrient solution. Results showed that DB is sensitive to the variation of the cation composition in the nutrient solution. Antagonism between K-Mg was apparent.     

Reply to comments on: Mao et al. (2018) “Bibliometric analysis of insights into soil remediation” Journal of Soils and Sediments, 18(7):2520–2534

Journal of Soils and Sediments -     

Some comments on: Mao et al. (2018) “Bibliometric analysis of insights into soil remediation” Journal of Soils and Sediments, 18(7): 2520–2534

In order to improve the bias of using the Web of Science databases for bibliometric studies, the “front page” has been proposed by Ho’s group in 2012. Using the “front page” as the filter resulted in a huge difference compared to the method from the original paper of Mao et al. Furthermore, a cited reference plays an important role in a published paper. Readers are interested in the paper’s statements and might find useful information from the following researches. The reference section is an important part in a paper; however, it was easily ignored by the authors. This comment also offered information for citing the original idea of publication indicators used for the comparison of countries’ and institutions’ publication performances.

     

Retraction Note to: “Hassan W,David J (2014) Effect of lead pollution on soil microbiological index under spinach (Spinacia oleracea L.) cultivation. J Soils Sediments 14: 44–59

Journal of Soils and Sediments - This article has been retracted by the Editors-in-Chief.     

Guest Editors’ Introduction to the Special Issue on “Seismomatics: Space–Time Analysis of Natural or Anthropogenic Catastrophes”

Seismomatics is the fusion of mathematics, statistics, physics and data mining at the service of those scientific disciplines interested in the space–time analysis of natural or anthropogenic catastrophes. This special issue on seismomatics has been motivated by a conference of the same name, which took place in Valparaiso (Chile) from 5th to 9th of January 2015. The selection of papers comprises both new methodological proposals and a wide range of applications related to natural or anthropogenic catastrophes. We highlight statistical analysis of marine macroalgae, of annual minimum water levels of the Nile River, of massive data on chlorophyll, of temperature maxima recorded over a complex topography, and of airborne pollutants in relation to the spatial spread of human population across Europe.     

Expression of concern: “Hassan W,David J (2014) Effect of lead pollution on soil microbiological index under spinach (Spinacia oleracea L.) cultivation. J Soils Sediments 14: 44–59”

Journal of Soils and Sediments -