ALBERT

Description: Einfluss der Witterung auf den Zuckerrübenertrag KATASTER-BESCHREIBUNG: Monaten April, Mai und Juli von Bedeutung KATASTER-DETAIL:

Description: Verfahren der multiplen Regressionsgleichungen zur Vorhersage von Ernteerträgen aus Witterungsdaten KATASTER-BESCHREIBUNG: Abhängigkeit des Ertrags von der Witterung (Temperatur, Sonnenscheindauer, Niederschläge, Windgeschwindigkeit, Relative Luftfeuchte, Regentage) KATASTER-DETAIL: -

Description: Monatsmittelwerte der Witterungsfaktoren zur Abschätzung der Erträge mit multiplen Regressionsansätzen KATASTER-BESCHREIBUNG: KATASTER-DETAIL:

Description: Induction of necrotic cell death by oxidative stress in retinal pigment epithelial cells Cell Death and Disease 4, e965 (December 2013). doi:10.1038/cddis.2013.478 Authors: J Hanus, H Zhang, Z Wang, Q Liu, Q Zhou & S Wang

Description: Nitrogen (N) fertilizer not used by the crop can increase the risk of nitrate leaching into the groundwater. In two growing seasons, 1990/91 and 1991/92, the relationships between N fertilization and yield, N uptake by the grain and the N leaching in the subsequent percolation period were investigated in a multifactorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape – winter wheat – winter barley, and effects of soil tillage (minimum tillage without ploughing, conventional tillage), application of pig slurry (none, application in autumn, application in autumn and in spring), mineral N fertilization (none, 80 or 200 kg N ha−1 to oilseed rape and 120 or 240 kg N ha−1 to cereals) and application of fungicides (none, intensive) were all tested. In each year, the rotation and the treatments were located on the same plots. Mineral N fertilization and fungicide application increased yield and N uptake by grain or seed in all crops. In contrast, the application of slurry, especially in autumn, had only small effects on yield and N uptake. Nitrogen losses by leaching (measured using porous ceramic cups) were affected mainly by the year and the crop. In 1992/93, averaged over all factors, 80 kg N ha−1 was leached compared with 28 kg N ha−1 the previous year. Oilseed rape reduced N losses, whereas under winter wheat up to 160 kg N ha−1 was leached. Due to a lower N-use efficiency, autumn applications of slurry increased N leaching, and mineral N fertilization of the preceding crop also led to higher N losses.Since the amount of leached N depends both on the nitrogen left by the preceding crop (unused fertilizer N as well as N in residues) and on N uptake by the subsequent crop, it is not possible to apportion the N losses to any particular crop in the rotation. The cropping sequence, together with its previous and subsequent crops, must also be considered.To minimize leaching, N fertilization must meet the needs of the growing crop. In order to improve the efficiency further, investigations must be conducted in order to understand the dynamics of N in the plant–soil system in conjunction with the weather and crop management practices.

Description: Soil sampling in autumn gives important information on the soil N dynamic. In the growing seasons 1991/92 to 1995/96, the effects of different crop management systems on soil mineral N (NO3-N plus NH4-N:Nmin) were investigated in a factorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape – winter wheat – winter barley, and soil tillage (conservation tillage without ploughing, conventional tillage), application of pig slurry (none, autumn, autumn+spring), mineral N fertilization (0, 120 and 240 kg N ha−1) and fungicide application (none, three applications) were all varied. Each year, the treatments occurred in all three crops of the rotation and were located on the same plots. Nmin was determined on four dates (‘After drilling’, ‘End of autumn growth’ before winter, ‘Beginning of spring growth’ before N fertilizer application, and ‘After harvest’) to 90 cm in 30 cm horizons.Under all crops, Nmin showed a large year to year variation. Highest values of 132 kg N ha−1 were observed ‘After drilling’, which decreased until ‘End of growth’. The increase of autumn Nmin (‘After drilling’, ‘End of autumn growth’) was mainly due to autumn slurry, whereas mineral N fertilizer mainly affected Nmin ‘After harvest’. Soil tillage and fungicide application only slightly modified Nmin at all dates.The relationship between N leaching and Nmin measured either ‘After drilling’ or at the ‘End of autumn growth’ in 1991/92–1994/95 remained too poor to be used to estimate N leaching. N net mineralization during autumn and winter varied with crops, as estimated by the Nmin changes between ‘After drilling’ minus ‘Start of spring growth’ plus N uptake by the crop at ‘Start of spring growth’ plus N leaching during winter. On average over the years, 39 kg N ha−1 were mineralized under oilseed rape and 42 kg N ha−1 under wheat compared with 31 kg N ha−1 under barley. However, a large year-to-year variation occurred. In addition, the ranking of the years differed with the crops. Slurry application led to different amounts of mineralized N. Under barley only 25 kg N ha−1 were calculated for the autumn slurry, but 42 kg N ha−1 for the autumn plus spring slurry treatment. In contrast, under oilseed rape the highest value of 41 kg N ha−1 occurred in the autumn slurry plots. Under wheat, slurry application only slightly affected N mineralization. Increased mineral N fertilization decreased N release under oilseed rape, but significantly increased it under cereals. Application of fungicides did not affect N mineralization during winter.

Description: In NW Europe, autumn-grown oilseed rape normally receives nitrogen (N) in autumn as seedbed N and in the spring as a split application at the beginning of growth and at stem elongation. In the growing seasons 1990/91 to 1992/93, the effects of slurry and mineral N fertilization on yield, N uptake by the seed and apparent N-use efficiency (NUE) by oilseed rape (Brassica napus) were investigated in a factorial field experiment at Hohenschulen Experimental Station near Kiel, NW Germany. The crop rotation was oilseed rape–winter wheat–winter barley, and soil tillage (conservation tillage without ploughing, conventional tillage), application of pig slurry (none, autumn, spring, autumn+spring) and mineral N fertilization (0 to 200 kg N ha−1) were all varied. Each year, the treatments were applied to all three crops of the rotation and were located on the same plots.Between the years, average seed yield ranged from 3·04 to 3·78 t ha−1, while the corresponding N uptake by the seed varied from 107 to 131 kg N ha−1. Slurry application in spring increased the seed yield and N uptake by the seed in all years, whereas the effect of autumn slurry alone or in combination with spring slurry was negligible. Mineral N fertilizer increased seed yield and N uptake by the seeds except in 1991/92, when N amounts exceeded 160 kg N ha−1. No significant slurry×mineral N interaction occurred. Apparent NUE of mineral N was larger than that of slurry N, but decreased with increasing mineral fertilizer N rates. Only 5% of the autumn slurry N was apparently utilized by the seeds, compared with 24% of the spring slurry N.Despite its ability to take up substantial quantities of N before the winter, oilseed rape utilized very little autumn slurry N for seed production. To minimize environmental impacts, slurry should be applied in the spring, when plants are more able to use N for yield formation, even if NUE of slurry N is lower than that of mineral N. However, since NUE changes with the amount of applied N, it is difficult to find the best combination of slurry and mineral N fertilization to avoid negative environmental effects.

Description: Increasing the efficiency with which crops use supplied nitrogen (N) can minimize the impact on the environment. In the growing seasons 1990/91 to 1992/93, the effects of different cropping systems on yield, N uptake by the grain and apparent N-use efficiency (NUE) of the grain of winter wheat and winter barley were investigated in a factorial field experiment at Hohenschulen Experimental Station near Kiel in NW Germany. The crop rotation was oilseed rape–winter wheat–winter barley, and soil tillage (conservation tillage without ploughing, conventional tillage), application of pig slurry (none, autumn, spring, autumn+spring), mineral N fertilization (0–240 kg N ha−1) and application of fungicides (none, applications against pathogens of the stems, leaves and ears) were all varied. Each year, the treatments were applied to all three crops of the rotation and were located on the same plots.Averaged over all factors, wheat yield was 〉7 t ha−1 dry matter in all years and N uptake of the harvested grain varied between 140 and 168 kg N ha−1. Pig slurry application in autumn increased grain yield and N uptake more than spring slurry in two out of three years. Mineral N unfertilized wheat yielded only 5·3–6·3 t ha−1 depending on the year, mineral N fertilization increased wheat yield up to 8 t ha−1. Barley yield was lower than wheat yield, ranging from 4·5 t ha−1 in 1993 to 6·3 t ha−1 in 1992. Unlike wheat, spring slurry N affected barley yield and N uptake more than autumn slurry.Wheat apparently utilized 12–21% and barley up to 13% of the applied slurry N for its grain development. In 1991, the highest apparent slurry N-use efficiency (SNUE) of wheat and barley occurred after the late spring slurry application. However, in the following years, autumn SNUE of wheat was similar to (1992) or higher than (1993) spring SNUE, presumably because of vigorous tiller growth before winter. Additionally applied mineral fertilizer N decreased SNUE.Apparent mineral fertilizer N-use efficiency (FNUE) was higher than SNUE and ranged in wheat from 40 to 59% and in barley between 19 and 37% of the applied mineral fertilizer N. FNUE decreased with increasing N fertilization.To improve the N-use efficiency of both slurry N and mineral fertilizer N, more information is needed about the combined use of both N sources, with special emphasis on split applications of slurry as is common practice for mineral N fertilizer.