Effect of long-term soil management practices on nematode population in an Alfisol under continuous

A field study was carried out at Samaru throughout 2006 and 2007 seasons by using some organic and inorganic treatments on nematode community dynamics under a long-term continuous maize trial established in 1997. The experiment was laid out in a randomized complete block design and the treatments involved were urea fertilizer, animal manure, and legumes. Results showed that the population of fungivorous nematodes; Aphelenchoides spp. was greater in plots amended with legumes and urea than plots amended with animal manure in two seasons. Populations of nematodes in this trophic group significantly (p<0.05) increased in 2007 season compared to 2006 season. Populations of plant parasitic nematodes were reduced by using animal manure treatment compared to urea and legumes especially with Helicotylenchus spp. having the highest population followed by Hoplolaimus spp., Pratylenchus spp. and Scutellonema spp. in that order. Plant parasitic nematodes were the most abundant group irrespective of soil amendment. They ranged from 91.9 to 98.9% in 2006 and 93.8 to 97.8% in 2007 of the total nematode community and had a colonizerpersister (c-p) value of 3. This suggests that they have slower reproductive ability compared to the fungivorus nematodes with a c-p value of 2 and can survive longer under low nutrient requirements and environmental stress. Also, it suggests that the plant parasitic nematodes were more responsive to host plant than to soil amendments.