The effect of barnyard manure of different degradation levels on grass production

Abstract

Since degradation processes of dairy waste act in many ways in Hokkaido, the effects of barnyard manures of different degradation levels on grass production were estimated in pure timothy (Phleum pratense L.) grassland. Mean moisture content of barnyard manure was 80% for samples piled for 0 to 6 months. It decreased as the storage period increased. Mean N concentration of barnyard manure was 22 mg N kg-1 dry weights for samples stored for 0 to 6 months. It was 15 mg N kg-1 dry weights for the samples over 24 months. K concentration showed similar results. Mean K concentration of barnyard manure was 16 mg K kg-1 dry weights for the samples stored for 0 to 6 months. It was 5 mg K kg-1 dry weights for the samples over 24 months. P concentration of barnyard manure was stabler than that of other nutrients. The amount of N for the grass production based on the barnyard manure of different degradation levels was estimated as fresh barnyard manure > ripe barnyard manure. Utilization rate of K was higher than that of N, and the degradation level did not differ among the samples. However the amounts of K uptake were higher in fresh barnyard manure than in ripe barnyard manure.