VARIATIONS OF N-P-K CONTENTS IN LIVESTOCK AND LIVESTOCK MANURE COMPOSTING

In this study, we used three kinds of fresh livestock manure as raw materials and 10% corn stalks as a leavening agent for aerobic static composting to investigate variations of total nitrogen (TN), ammonia nitrogen (AN), total phosphorus (TP), active phosphorus (AP), total potassium (TK), and active potassium (AK) during the three kinds of livestock and poultry manure composting in China.Results show that the percentage content of TN presented an increasing trend, and the fractions of AN in TN first rose and then declined as the composting proceeded in the compost heaps.The fraction of AN in TN for R1, R2, and R3 reached the peak of 7.38, 8.11, and 9.22%, respectively.The fraction of AP in TP for R1, R2, and R3 reached 24.15 ± 1.97, 29.33 ± 3.34, and 34.33 ± 1.58% with the increase of 31.89,18.26, and 35.53%, respectively, at the end of composting.The fraction of AK in TK for R1, R2, and R3 reached 49.44 ± 2.74, 58.37 ± 2.21, and 64.25 ± 3.56% with the increase of 32.44, 35.05, and 45.32%, respectively, at the end of composting.