Quantitative Mineralbestimmung in der Schlufffraktion von Böden auf der Grundlage der chemischen Analyse und unter Anwendung der Karl-Fischer-Titration. II. Ergebnisse bei Böden aus Geschiebedecksand,Geschiebemergel und Löß

Quantitative estimation of the mineralogical composition from silt-fractions of soils on the basis of the chemical analysis and by application of the Karl-Fischer-titration. II. Results obtained with soils from glacial sand, boulder marl and loess The contents of micas and feldspars were quantified in the silt-fractions from horizons of a podsolic brown earth developed on glacial sand and of lessives on loess as well as on boulder marl by using a method that has been described in detail in part I. Three components each of micas and of feldspars, namely muscovite (Ms), phlogopite (Phl), annite (Ann), orthoclase (Or), albite (Ab) and anorthite (An) were determined. The silt fractions of the three investigated soils are similar in their mineralogical composition. Feldspars are composed of equally high amounts of Or and Ab. Micas are dominated by the Ms-component. Apparently the mica content of the silt fractions is reduced during soil development, whereas no significant changes can be found for feldspars. The loss of micas is responsible for the decreasing potassium content of the silt fractions.     

Einfluß der Stickstoffdüngung auf Ertrag,Ertragsstruktur und N-Verwertung von Winterweizen - Möglichkeiten und Grenzen der Bestandesführung

Influence of nitrogen level on yield, yield structure and N utilization of winter wheat - Possibilities and limits of crop management In pot experiments the influence of number of plants per pot (10 or 20), nitrogen level (1,2 - 2,4 - 3,6 g N/pot) and application date (DC 21-29-32/37-51) on yield components, grain yield and nitrogen uptake was investigated. Number of stalks per plant were influenced by removing all tillers except one or two compared to untreated. In pots with 10 and 20 plants, yield was uneffected by the number of tillers removed. Similarly, small differences were observed in the number of earbearing stalks, grain per ear and weight of 1000 seeds. Yield components were not influenced by N-application at 2,4 g N/pot. Removal of tillers to one or two per plant resulted in high 1000 seed weight (58 g) and great number of seeds per ear (55) but not in high yields. The importance of a compensatory relation between the number of earbearing shoots, number of seeds per ear and 1000 seed weight for yield formation and N uptake is discussed.     

Morphologie und Alter von Böden der Südlichen Frankenalb und der nichtkarbonatische Mineralbestand der Kalksteine

Morphology and age of soils in the ‘Südliche Frankenalb’ and the noncarbonate mineral composition of the limestones Soils in the ‘Südliche Frankenalb’ are described according to their local particle size and color characteristics, and their typical situation in the landscape. ‘Solifluction’ (mixing of limestone fragments with terra fusca solum) and sedimentation of aeolian material were the important processes which complicate the reconstruction of soil formation. The quantities of carbonate-free residues of limestones vary in a wide range between 0.7 and 25.4%. With this property, a grain size- and a mineralogical property, the limestone samples are separated by discriminant analysis in three groups. In contrast, the clay mineral composition of all the limestone residues is very homogeneous. In the fine clay fraction (< 0.2 μm) and coarse clay fraction (2-0.2 μm) illite and illite/smectite mixed layer minerals are the predominant minerals with proportions of 90% and 80–85%, respectively. The time necessary for soil formation is calculated to be 1.6 (20 cm depth, IIT-horizon) and 2.7 million years (36 cm depth, IIT + Bv₂-horizon), respectively. This calculation is based on a Malm Delta limestone (0.7% residue). The carbonate output is calculated from CaCO₃ solution rates in the CO₂-H₂O system and actual leaching rates derived from local climate data. The period of soil formation from other limestones was not as long.     

Zur Ermittlung der Schwermetallverfügbarkeit lithogen und anthropogen belasteter Standorte. 1. Cd und Cu

Investigations about the availability of heavy metals in soils with lithogen and anthropogen enrichment. 1. Cd and Cu First results obtained from field experiments on two locations with high natural content of heavy metals (Cd and Cu) are described. It became evident that an anthropogen enrichment by addition of Cd oxides had a stronger effect on the Cd contents of plants (oats) than the higher lithogen soil content. In respect of the Cu it is indicated that contrary to the prevailing knowledge of high lithogen contents it seems that it leads to increased contents of the plants (barley). The CaCl₂-extraction of the soil has proved to be suitable to identify the plant available Cu contents, but it is restricted to determine the available Cd fraction. The DTPA-extractable fractions showed poorer relations to the metal contents of the plants.