Phosphorsäurewirkung in Komplexdüngern

In Inkubationsversuchen wurde das Mineralisierungsverhalten von Ernte‐und Wurzelrückständen (EWR) der auch als Industriepflanzen verwendeten Pflanzenarten Winterraps, Sonnenblume, Öllein, Miscanthus und Sachalinknöterich im Vergleich zu Winterweizen in Abhängigkeit vom Vegetationsstadium und der Bodentemperatur untersucht. Zwischen den Pflanzenarten, ihren Teilen und den Vegetationsstadien bestanden teilweise signifikante Unterschiede in der Mineralisierung. Von dem Pflanzenmaterial in der generativen Phase verblieben nach einer Inkubation von 70 Tagen unter optimalen Bedingungen (25°C, 60% WK_max) 55–70% der eingebrachten C‐Menge im Boden. Intermittierende Temperaturen (Wechsel 10 °C/25 °C) bewirkten eine geringere Mineralisierung, nur 28–34% des Pflanzenmaterials wurden umgesetzt.     

Foliar Iron Fertilization: A Critical Review

Application of foliar iron (Fe) sprays is a common means of correcting Fe deficiency of agricultural crops. However, variable plant responses to iron sprays, ranging from no effect to defoliation, have often been described in the Fe-fertilization literature. Knowledge is still limited concerning the mechanisms of penetration of a leaf-applied, Fe-containing solution and the role of Fe in the leaf. The complex and multi-disciplinary character of the factors determining the effects of Fe sprays hinder the development of suitable foliar fertilization strategies, applicable under variable local conditions and for different plant types. This review describes some key factors involved on the process of penetration of a leaf-applied, Fe-containing solution before briefly analyzing the available foliar Fe-fertilization literature. Iron chemistry, leaf penetration, and plant-nutrition principles will be merged with the aim of clarifying the constraints, opportunities, and future perspectives of foliar Fe sprays to cure plant Fe deficiency.     

Relationship between survival and yield related traits in Solanum pimpinellifolium under salt stress

A subset of the Solanum pimpinellifolium collection maintained by AVRDC—The World Vegetable Center, Taiwan was evaluated to assess effects of salt stress on physiological traits and yield-related traits with the aim of identifying potential S. pimpinellifolium accessions useful for salt tolerance breeding in tomato. We undertook a comparative analysis of yield and plant survival traits under normal and salt stress conditions to obtain a first indication of the crucial traits associated with salt tolerance in S. pimpinellifolium. Although most traits of S. pimpinellifolium accessions showed a similar percent decrease in mean under salt stress compared with the cultivated checks, the former exhibited a wide range for all traits, suggesting great genetic diversity that can be exploited for the identification of salt tolerant genotypes. Genetic variability for yield and survival traits under salt stress was quantitative with low to moderate heritability. Results of correlation and path coefficient analysis revealed no correlation between any of the physiological traits with yield-related traits indicating that the ability to survive and yield under salt stress are two independent sets of traits in S. pimpinellifolium. Results of the path analysis along with heritability and genetic advance showed that shoot dry weight and K/Na ratio are the two most critical component traits for survival, while fruit number is critical for yield per plant. The large S. pimpinellifolium panel evaluated in this study revealed five genotypes possessing better survival traits, seven genotypes with good yield traits, and two genotypes combining both superior survival and yield traits under salt stress.     

Is soot composed predominantly of carbon clusters?

Soot generated from diesel fuel in a combustion tube is characterized by microanalysis, x-ray diffraction, chemical reactivity, and nuclear magnetic resonance to address the recent proposal of the significance of carbon clusters in soot. The data support a traditional model of soot as polynuclear aromatic compounds rather than as clusters of carbon atoms with minimal edge site density. The amounts of noncarbon atoms in the soot (hydrogen, oxygen, nitrogen, and sulfur) are commensurate with the edge density of the crystallites (2 by 2 nanometers) inferred from diffraction. The chemistry of soot, in being reduced by potassium metal and alkylated by alkyl iodides, is that known for aromatic compounds and not that anticipated for materials such as graphite, with a small fraction of carbon atoms on edges.