Effects of different soil management practices on soil free-living nematode community structure, Eastern China

Abstract

. 2008. Effects of different soil management practices on soil free-living nematode community structure, Eastern China. Can. J. Soil Sci. 88: 115Á127. An investigation was conducted in a Shouguang agroecosystem, Shandong Province, Eastern China, in order to determine the long-term (10Á15 yr) disturbances of three different agricultural management practices. In this study, the main focus was on free-living soil nematodes, as a tool which will help differentiate between treatments according to their sensitivity to physical, chemical, and biota composition. In this study, three treatments were implemented in each of a total of four investigated sites: greenhouses, conventional farmlands, and fallows. Diversity, maturity (MI) and weight indices were used to assess the nematode community. The results indicated that greenhouses have a lower richness (SR), diversity, modified maturity index (SMI), modified maturity index for all nematodes with c-p 02Á5 [SMI (2Á5)], plant parasite index (PPI), PPI/MI values, and fungi-feeding/bacteria-feeding (F/B) ratio, as well as lower basal index (BI) and channel index (CI) and higher dominance. These results elucidated the difference between the three treatments, where the greenhouses were an enriched disturbed system compared with the other treatments and were dominated by bacterivorous nematodes, the fallows were a relatively infertile and stable system dominated by plant parasites, and the conventional farmlands can be positioned between the above two treatments.

Effects of organic, low input, conventional management practices on soil nematode community under greenhouse conditions

“…Bacterivores were the most abundant trophic group in all three systems, which is in accordance with previous findings (Liu et al 2006;Chen et al 2008;Dong et al 2008) that bacterivores were dominant in greenhouse conditions. However, the proportion of bacterivores (more than 80%) was higher relative to the abovementioned studies.…”

“…Compared with other studies (Liu et al 2006;Chen et al 2008;Dong et al 2008;Li et al 2010) of greenhouse conditions, our findings revealed a higher proportion of omnivore-carnivores, and this proportion was close to that of another report (7.8%) in an open farmland environment (Hu & Qi 2010) near our study site. Forge et al (2005) noted that manure applied may enhance the availability of food resources for the nematodes of high-order trophic groups.…”

“…Our study revealed a higher nematode density (209-1180) higher than these two studies, which may mainly be related to land-use type and soil nutrition content. Dong et al (2008) also found the abundance of nematodes was higher in greenhouses than farmlands in most sampling sites but lower than that in fallow habitats. The finding of organic soils with higher nematode density compared with low input and conventional soils is generally in agreement with Liang et al (2009), who found that total nematode abundance responded positively to manure treatment.…”

“…Compared with the exposed environment, the greenhouse is often in a semiclosed state (Chen et al 2014) with excessive use of organic and synthetic fertilizers, intensive management, and high temperature and moisture content (Liu et al 2006). A high input level with intensive management may lead to a bacterial-dominated decomposition pathway (Dong et al 2008), and the soil food web tended Conventional management practices with synthetic fertilizers, pesticides, and herbicides induce serious environmental pollution and food safety problems. Organic and low input management aims to solve these problems by the addition of organic amendments and elimination or reduction of chemical inputs.…”

Sensitivity of Nematode Community Analysis to Agricultural Management Practices and Inoculation with Local Effective Microorganisms in the Southeastern United States

“…Because of the Tyelenchidae family's ambiguous position in the soil food web [62], it was interesting to find that, in both seasons, nematodes from the Tylenchidae family showed a similar trend in correlations with CO 2 , N min and yield as the FF nematodes. In nematode trophic analysis it is unclear whether to place Tylenchidae among the plant parasitic nematodes or the fungal-feeders [63][64][65][66][67]. These findings suggest that, in our case, Tylenchidae are more closely associated with fungal-feeders.…”