Effects of cattle slurry manure management on grass yield

AbstractThe effects of application method, cattle slurry manure type and use of additives on grassland performance were studied in a 3-year field experiment on two farms on sandy soils in the northern part of the Netherlands. The objectives were to determine the effects on (1) nitrogen (N) utilization, (2) soil organic matter and soil N content, and (3) botanical composition of the sward. Cattle slurry manure from the two dairy farms was compared. Farm Harkema represented conventional management, while farm Drogeham used the additive Euromestmix® and reduced the N content of the dairy cow rations. In additional treatments, the slurry manure types were combined with the additives Effective Microbes® (EM) or FIR-naturel®. In all slurry manure type — additive combinations the slurry manure was either surface-applied or slit-injected. The resulting 12 treatments were applied without or with additional inorganic fertilizer N (165 kg ha−1). The annual apparent N recovery (ANR) of N fertilizer was 0.79 kg kg−1. The ANR of surface-applied slurry manure (0.30 kg kg−1) was consistently lower than that of slit-injected manure (0.44 kg kg−1), a difference that could be fully attributed to the manure applications during the growing season. No effect of application method was observed at the first application in March. Slurry manure type and additive use had no consistent effects on grass yield or N utilization. Statistically significant effects were only observed occasionally, mostly in interaction with other experimental factors. During the three experimental years, the changes in soil organic matter and soil N content were small. Application method had no effect on the measured soil characteristics. Slurry manure type and additive use had a small statistically significant effect at one site only. However, longer-term monitoring is necessary to draw firm conclusions. Application method, slurry manure type or additive use did not affect the botanical composition of the sward