Abstract:

Objective: This study aims to find the optimal compost mixtures for mulberry growth. The effects of different ratios of compost mixtures of municipal sludge and garden waste and their application amount on mulberry growth were investigated, in order to provide the scientific basis for the circulation of garden waste and municipal sludge. Method: A poting experiment was conducted with a design of four different compost products and different dosages. Municipal sludge and garden waste were mixed at four volume ratios (0:1, 1:3, 1:1, 1:0, marking as W01, W13, W11, W10), and each compost was put together with soil at different volume ratios (0:1, 1:3, 1:1, 1:3, 1:0, marking as CK, T1, T2, T3, T4). The germination, plant height in different growth periods and biomass were measured in the poting experiment. Result: The germination of mulberry seeds were inhibited by all four compost mixtures.The germination was most strongly inhibited by W10 ratio under the same fertilization, and the germination was most strongly inhibited by T4 in all of the four different compost mixtures. The growth of mulberry seedlings was inhibited to various degrees with the increase of fertilizer application at the early growth stage (30-60 d), and the inhibition was weakened at the subsequent growth phase, and even the growth promotion happened by some treatments.The maximum plant height appeared in T2 treatment with W11 ratio. The biomass accumulations of aboveground and underground were increased to various degrees by all the treatments except T4 of W10. Conclusion: Mixed compost products containing sludge can inhibit the germination and the early growth of mulberry seedlings, however the growth and biomass accumulation of mulberry seedlings can be promoted with the development of time, among which the best effect is to apply 25% mixed compost with 1:1 ratio of sludge and garden waste.

Key words: municipal sludge, garden waste, mixed compost, mulberry