The crude protein production of grassland and the utilization by milking cows.

An attempt was made with experimental data of various origins to quantify the intake of N from pasture grass by milking cows during the grazing period. It was also demonstrated how much of this N was removed by secretion in the milk as well as the conc. of N in the faeces and in the urine remaining on the pasture after grazing. From a fertilizer application to the pasture of 450 kg N/ha yr an equal conc. was taken up by the herbage. Of this herbage N about 75-80% remained on the pasture after grazing. The conc. remaining on the grassland increased sharply with increasing N rates and this went parallel with an increasing intensity in the N circulation in the system soil-plant-animal-soil and a rising NO3 content in the surface layer of ground water. (Abstract retrieved from CAB Abstracts by CABI’s permission

Effects of applications of sewage sludge and fertilizer nitrogen on cadmium and lead contents of grass.

During 5 successive years, 0, 6, 12 or 18 t/ha yr metal-bearing sewage sludge on a DM basis was applied to permanent grassland. Each sludge application was combined with various N treatments. Cd content of the grass increased considerably with increasing amounts of sewage sludge and fertilizer N; Cd content was higher in young than in old grass. The latter also applied to Pb but the increase in Pb content was less and the relation between the supply of Pb and the Pb content of the grass was poor. During the late autumn and winter the increase in Pb content was striking and was probably caused by pollution from the atmosphere. (Abstract retrieved from CAB Abstracts by CABI’s permission

Accumulation of heavy metals in the soil due to annual dressings with sewage sludge.

In a long term field experiment 0, 6, 12 or 18 tonnes/ha/yr of sewage sludge (dry matter basis) were applied to permanent grassland. Sludge application markedly increased the contents of Cd, Pb, Zn, Cu, Ni, Cr, Mo, to a depth of 15-25 cm, but Co, Mn and Fe contents were increased only in the surface 5 cm of soil. (Abstract retrieved from CAB Abstracts by CABI’s permission

Einfluss jaehrlicher Duengung von Gras mit Klaerschlamm auf den Gehalt an Schwermetallen und auf den Trockensubstanzertrag

Dit rapport behandelt een onderzoek naar de invloed van een jaarlijkse bemesting met zuiveringsslib op het gehalte aan zware metalen van gras en op de drogestofopbrengst. Het blijkt dat het gehalte aan zware metalen toeneemt bij toenemende slibbemesting, waarbij de toepassing van zuiveringsslib een geringe opbrengstverhoging tot gevolg heef