Effect of Different Amendments on Nitrogen Conservation During Simulated Composting

The objectives of this study were to evaluate the effects of different dosages of three amendments—peat, superphosphate, mixture of Mg(OH)2+H3PO4 ((Magnesium Hydroxide and Phosphorus Acid) on N (Nitrogen) conservation. The simulated composting experiment was carried out in a constant temperature water bath with pig manure and corn straw. The results showed that the ammonia volatilization could be inhibited to some extent under the treatments with fixing agents. Under the same simulated composting conditions, the nitrogen fixation effect of the three kinds of fixatives with the same proportion was as follows: Mg(OH)2+H3PO4 > superphosphate > peat. The fixation effect of N increased with the increase of the additives. The N fixation rate of Mg(OH)2+H3PO4 treatment was up to 66%. Compared with the CK (Control Group), the amount of cumulative ammonia emission decreased by 90.3% and the TN (Total Nitrogen) content increased by 39.31% in this treatment. Compared with other two kinds of fixing agents, Mg(OH)2+H3PO4 treatment could not only control N loss in composting process, improve the N nutrient content of compost products, but also could increase P (Phosphorus) and Mg (Magnesium) nutrients. Therefore, it had more popularization value and application prospect.