The impact of long-term application of fertilizers in soybean fields on soil nematode community
structure was studied. The long-term application model of fertilizers lasted 13 years in a soybeane
wheatecorn rotation, and included three treatments: no fertilizer (NF), chemical fertilizer (urea and
ammonium phosphate, CF), and pig manure combined with chemical fertilizer (MCF). The soil nematode
community structures and ecological indices were determined from soil samples taken at five soybean
growth stages from May to October in the soybean phase of the rotation. Fertilizer application had
significant effects on abundance of plant parasites, bacterivores and fungivores (P < 0.05), but had no
significant effects on total nematodes and omnivores-predators. Abundance of plant parasites was higher
in NF than in MCF and CF, and abundance of bacterivores was highest in MCF. Fertilizer application
significantly affected Plant-parasitic Nematode Maturity Index (PPI) and Nematode Channel Ratio (NCR)
ecological indices (P < 0.05). ShannoneWeaver Index (H0) and Species Richness (SR) indices were higher
in MCF than in either NF or CF. The abundances of total nematode and plant parasites showed increasing
trend with soybean growth in all three treatments. This is probably due to soil environment being more
suitable for soil nematode survival with more food available for plant parasites as the soybean grows.
Soybean growth stage significantly affected the H0 , Free Living Nematode Maturity Index (MI) and PPI.
Bacterivores significantly correlated with soil nutrient status suggesting that they could be used as
a potential indicator of soil fertility.