Article Title:
NITROGEN CONTENTS OF COMPOSTS ENRICHED WITH ORGANIC NITROGEN SOURCES
Abstract: Information is scanty on the potentials of agricultural wastes to enrich composts whose low nitrogen (N) content limits their use in organic farming. This study involved enriching composts - cow dung + sawdust (CDSD) and poultry droppings + sawdust (PDSD) with N at 10, 20, 30 and 50 kg/ha from bone, blood, hoof and horn meals; and neem leaf and tithonia leaf meals and their incubation in soil for 16 weeks. Total N contents monitored at four-week intervals of incubation showed enrichment in 74.0 and 83.0% of CDSD and PDSD compared to the respective controls. N contents were highest in 21, 0, 1 and 28 composts incubated for 4, 8, 12 and 16 weeks respectively. At 4 weeks, CDSD enriched with 50 kg N/ha from blood meal (CDSDBM) and bone meal (CDSDBN) contained 10.5 and 9.2 g/kg total N while PDSD enriched with 50 kg N/ha from bone meal (PDSDBN) and tithonia leaf meal (PDSDTM) contained 9.3 and 8.6 g/kg total N. These are suitable for the cultivation of short-season leaf vegetables. N content reduced at 8 weeks of incubation and increased at 12 and 16 weeks. Only CDSD enriched with neem leaf meal (CDSDNM at all N rates) increased in N content with time of incubation. CDSDNM and PDSDBM at 50 kg N/ha contained the highest total N at 16 weeks of incubation and should be recommended for the cultivation of long-season vegetables. |
Keywords: Composts, agricultural wastes, enrichment, incubation, nitrogen content |
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