How management practices affect silicon uptake by Hordeum vulgare grown in a highly calcareous soil

2021 ◽  
Author(s):  
M.J. Sierra ◽  
T. Schmid ◽  
M. Guirado ◽  
O. Escolano ◽  
R. Millán
2020 ◽  
Vol 53 (1) ◽  
pp. 149
Author(s):  
Adel Ghoneim, et al.

<p>Understanding of P transformations following organic amendments addition to highly calcareous soils is necessary for developing better management practices that can help enhance P fertilizer use efficiency. Phosphorus solubility and availability for plant uptake under the conditions of arid calcareous soil is very low, making P nutrient supply a critical issue under these conditions. The aim of this study was to evaluate the impact of various types of organic amendments (chicken compost, cow compost and a mixture of humic-fulvic acid) applied alone at different rates of KH2PO4 fertilizer on P fractions in calcareous soil using the sequential chemical extraction method. Amended calcareous soil was incubated under laboratory conditions and soil samples were collected at 0, 4, 8 and 16 weeks of the incubation periods. Soil was sequentially extracted and analyzed for P different fractions. The results indicated that the addition of chicken and cow compost increased soluble and exchangeable-P and Ca-P fractions in calcareous soil and the increases depend on application rates. The results indicated that combination of chicken and cow compost with different KH2PO4 fertilizer application rates increased the concentration of soluble and exchangeable-P in the soil compared to organic amendments or KH2PO4 fertilizer applied alone. The P associated with Ca was the dominant P fractions in soil, ranging between 51 to 59% regardless of the different treatment and the period of incubations. The Al- and Fe-associated P fractions varied between 2 and 9%, with the maximum value being observed at the eighth week of incubation. The residual-P fraction ranged between 5 and 22% at different incubation periods.</p>


1992 ◽  
Vol 72 (4) ◽  
pp. 1121-1130 ◽  
Author(s):  
P. E. Jedel ◽  
J. H. Helm

Management practices such as the use of fertilizers and fungicides can have positive effects on grain yield and quality of cereals, especially where diseases are a concern. Six cultivars of six-row barley (Hordeum vulgare L.) were tested at two fertility levels (standard and high) with a late-season application of the foliar fungicide Tilt (propiconazole) to determine their agronomic responses to these management practices. In 1988, when yields were limited because of early season drought, only Leduc showed a positive yield response to the Tilt, even though it has the highest level of genetic resistance to scald and net blotch of the cultivars tested. In 1989, when yields were again limited by adverse environmental conditions, no response to Tilt was found. In 1990, when growing conditions during the season were excellent, Empress, Noble and Samson had positive responses to Tilt application. Tilt had no effect on grain protein, maturity, or harvest index; it slightly improved test weights and kernel weights and decreased percent thins; and it had variable effects on height, number of viable tillers m−2, and kernel number spike−1. Yield response to Tilt was not affected by fertility regime. High fertility (112 kg ha−1 N 37 kg ha−1 P) resulted in an overall increase in yield of 0.62 t ha−1 from the standard fertility treatment (84 kg ha−1 N 27 kg ha−1 P); decreased harvest index; delayed maturity in 1989 only; increased height, number of viable tillers m−2, and kernel number spike−1; increased protein content of the grain in 1988 only; and had no effect on test weight, kernel weight and percent thins. Because of the variability of response from year to year and cultivar to cultivar, the economic feasibility of Tilt application may be limited.Key words: Hordeum vulgare L., propiconazole, soil fertility, management


2021 ◽  
Vol 19 (4) ◽  
pp. e0304-e0304
Author(s):  
Vladimír Langraf ◽  

Aim of study: The study of epigeic arthropods provides information on how ecosystems respond to different management practices. Changes in the structure of epigeic groups reflect changes in the ecological status of habitats. We assessed the influence of semi-natural habitats and environmental variables on the dispersion of the epigeic groups. Area of study: Southwestern part of Slovakia Material and methods: Between 2018 and 2020, six barley (Hordeum vulgare L.) fields were selected each year. Five pitfall traps were placed on each field and environmental variables (soil pH and moisture, light conditions, soil N, P, K) were analysed. We collected 8,730 individuals belonging to 14 taxonomic groups. The variables of the study sites (habitat, locality name, cadastral area, altitude, coordinates of localities) were also analysed. Main results: We observed a decrease in the average number of individuals in the direction from pitfall traps 1 (semi-natural areas) to 5 (barley crop) between July and August. The number of individuals was similar in May and June. The dispersion of epigeic arthropods was affected by soil moisture, pH soil, phosphorus, potassium and nitrogen. In the beetles model group, which was represented by the highest number of individuals, we confirmed an increasing number of individuals with increasing values of K, P, N and soil moisture. The neutral pH of the soil was optimal for beetles. Research highlights: The ecotone rule does not apply during all months, so we have contributed new information about the ecotone rule. Agricultural intensification affects soil arthropods, a taxonomic group with an important role in the functioning of agricultural ecosystems.


Author(s):  
O. E. Bradfute ◽  
R. E. Whitmoyer ◽  
L. R. Nault

A pathogen transmitted by the eriophyid mite, Aceria tulipae, infects a number of Gramineae producing symptoms similar to wheat spot mosaic virus (1). An electron microscope study of leaf ultrastructure from systemically infected Zea mays, Hordeum vulgare, and Triticum aestivum showed the presence of ovoid, double membrane bodies (0.1 - 0.2 microns) in the cytoplasm of parenchyma, phloem and epidermis cells (Fig. 1 ).


Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.


1992 ◽  
Vol 86 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Steffen Reinbothe ◽  
Christiane Reinbothe ◽  
Jorg Lehmann ◽  
Benno Parthier

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