The effect of bedding amount on gas emissions from manure during storage
Research Institute of Agricultural Engineering, Drnovská 507, CZ161 01 Prague 6, Czech Republic
One of the major agricultural pollutants of environment is manure from livestock. We focused on dairy cows kept in the barns with straw bedding commonly used in the Czech Republic. We tested the hypothesis that the amount of bedding used daily relative to the number and size of animals kept has a significant effect on the emissions of gases from manure stored in a manure pile. In the experiment, a group of 10 dairy cows of Holstein and Czech Red Pied breed was housed in a stable bedded with various amounts of wheat straw (4–10 kg/livestock unit per day). The manure was removed from the stable after 48 h and mixed was stored in cubic containers with drain floor allowing measurement of manure leachate release. For 50 days we measured weight, volume, weight of manure leachate and manure temperature. Decreasing stored manure weight can be attributed to release of manure leachate and emissions of gases, primarily water vapor, as a result of microbial activity and increased temperature in the manure during storage. Using the calculated model, we found that daily production of emissions of water vapor and other gases was related to bedding amount in a statistically significant manner (P < 0.001). The cumulative amount of gas emissions grew rapidly in all treatments. Also total amount of emissions was related to bedding amount in a statistically significant manner (P = 0.004). We also found the relationship between internal manure temperature and the logarithm of the amount of emissions produced to be statistically significant (P < 0.001).