| Vineyard pruning residues, as an organic by-product from the dormant pruning practice conducted annually will be inevitably generated with an amount of more than 2,100,000 tons on a fresh weight basis in China. In the past, most vineyard pruning residues were burned, causing either a waste of agricultural renewable resources or potential endangerment of human health and environment pollution.Vineyard pruning residues have a C:N ratio of about 60 and contain ca. 975 g kg-1 (dm) of organic matter, 7.2 g kg-1 (dm) of N, 1.1 g kg-1 (dm) of P, 5.0 g kg-1 (dm) of K and are rich in microelements required by crops. To recycle vineyard pruning residues onto agricultural land as organic fertilizer or conditioner can solve the environment pollution and potential traffic accident caused by open burning, as well as benefit developing organic fertilizer, maintaining and increasing soil fertility. Composting is considered as a suitable way of recycling organic wastes in agriculture compatible with the environment.Composting of vineyard pruning residues composted in open wooden composting boxes (V=250 L) at different initial C:N ratios (60, 52, 40 and 29) after addition of urea and co-composting at different mixing ratios of sheep manure (10, 20, 30 and 40 %), and co-composting of vineyard pruning residues with sheep manure in windrows (V=13.5 m3) under a covering with plastic foil and without covering were monitored by combinative means of physical, chemical, Inductively Coupled Plasma Atomic Emission Spectrometer (ICPAES) and FT-IR spectroscopy analyses. The objectives of this study were to determine: the characteristics of evolutions of main nutrients and organic matter transformation during composting process; to determine a proper initial C:N ratio range and sheep manure proportions, to establish some parameters related to vineyard pruning residues compost maturity, and to evaluated effects of covering with plastic foil on composting process in windrows. The results showed that:(1) Chopped vineyard pruning residue is a proper substrate for composting process after addition of a nitrogen source. The optimum of the initial C:N ratio is between 29 and 40 for achieving sanitation, maintaining a good biodegradation efficiency, at a N addition of 3.6-7.2 kg per ton of vineyard pruning residues (dry weight basis).(2) The maximum temperature values of 29, 40, 52 and 60 of initial C:N ratios reached were 76, 70, 68, and 65°C, respectively, after three to four days. The length of thermophilic phase (≥50°C) was 20 days for both of 29 and 40 of initial C:N ratios and 6 days for treatments of 52 and 60 of initial C:N ratios. The heat generation data was found to follow a linear correlation with the initial C:N ratio or corresponding initial C:N ratio.(3) Over 133 days of composting at different initial C:N ratios, the dry matter degradation was 39-59%. Total nitrogen mass losses were in the range of 23-37%.(4) A compost without phytotoxicity is available after 65 days of composting for vineyard pruning residues at different initial C:N ratios.(5) The water supplemented for per kilogram vineyard pruning residues (dm) was averaged out 2.5-4.1 kg during composting at different initial C:N ratios. The water addition after the first week of composting for all treatments accounted for 70% of total amount of...
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