Interactive effects of elevated ozone and UV-B radiation on soil nematode diversity

Due to the uncertain future of the soil fumigants most commonly used in the EU, there is a need to develop new integrated pest management programmes to control crop diseases. Different nematode management practices, such as solarisation and the use of ecological nematicides, including nematophagous fungi, are used to control populations of plant-parasitic nematodes, one of the most common pests affecting crops. The objective of this study was to determine the effects of organic (neem seed paste and a mixture of nematophagous fungi) and conventional (oxamyl and fenamiphos) nematicides on soil physical chemical properties, soil biodiversity and plant biomass. Such effects were investigated in two types of habitats: low diversity soils from an agricultural farm and high diversity soils from a natural vegetation area. The greater effect was observed with the neem treatment, which induced a large boost of dauer juveniles in the nutrient-depleted soil, while the same treatment induced an increase of populations of less opportunistic, generalist bacterivore nematodes in the pine forest soil, rich in organic matter. We have studied the effects of different biological and chemical nematicides on the whole soil nematode community through ecological indices and their relationship with plant biomass, but further research is needed to improve understanding of the effect of these products on nematode assemblages.

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Interactive Effects of Elevated Ozone and Temperature on Growth and Yield of Soybean (Glycine max (L.) Merr.) under Field Conditions

Agronomy ◽

10.3390/agronomy10111803 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1803

Author(s):

Kent Burkey ◽

Ripley Tisdale ◽

Richard Zobel ◽

Samuel Ray ◽

Walter Pursley

Keyword(s):

Glycine Max ◽

Seed Yield ◽

Interactive Effects ◽

Growth And Yield ◽

Ozone Treatment ◽

Exposure System ◽

Elevated Ozone ◽

Glycine Max L ◽

The Individual ◽

Yield Responses

Elevated ozone and rising temperature are both factors in climate change, but they are difficult to study in combination due to exposure system requirements. We developed and deployed an air exclusion exposure system to treat soybean (Glycine max (L.) Merr.) cultivar “Jake” with season-long combinations of sub-ambient ozone (18 ppb, 12 h mean), elevated ozone (66 ppb, 12 h mean), and elevated temperature (+3.5 °C daytime, +2.4 °C nighttime) in irrigated field plots. Warming caused a shift in biomass partitioning from reproductive tissues into stems and petioles at mid-season that resulted in a significant 25% reduction in final seed yield and a significant reduction in harvest index. The elevated ozone treatment delayed mid-season biomass production, and final seed yield was reduced by a non-significant 2%. However, there were significant underlying effects of elevated ozone on seed production. The non-significant impact of ozone on seed yield of cultivar “Jake” resulted from significant increases in pod number (+16%) and seed number (+18%) that were offset by a significant reduction in seed size (−16%). No evidence of significant warming–ozone interactions was found in biomass or seed yield responses. In general, significant impacts of the individual warming or ozone treatments were found to be additive.

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Variation in soil nematode diversity under pasture with soil and year

Soil Biology and Biochemistry ◽

10.1016/0038-0717(84)90098-1 ◽

1984 ◽

Vol 16 (2) ◽

pp. 95-102 ◽

Cited By ~ 57

Author(s):

G.W. Yeates

Keyword(s):

Soil Nematode ◽

Nematode Diversity

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Assessment of soil nematode diversity based on different taxonomic levels and functional groups

Soil Ecology Letters ◽

10.1007/s42832-019-0019-5 ◽

2019 ◽

Vol 2 (1) ◽

pp. 33-39 ◽

Cited By ~ 1

Author(s):

Jiangnan Li ◽

Peiqin Peng ◽

Jie Zhao

Keyword(s):

Functional Groups ◽

Soil Nematode ◽

Nematode Diversity

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Soil nematode community response to fertilisation in the root-associated and bulk soils of a rice-wheat agroecosystem

Nematology ◽

10.1163/15685411-00002988 ◽

2016 ◽

Vol 18 (6) ◽

pp. 727-741 ◽

Cited By ~ 2

Author(s):

Ting Liu ◽

Yong Li ◽

Qirong Shen ◽

Huixin Li ◽

Joann K. Whalen

Keyword(s):

Agricultural Soils ◽

Community Response ◽

Paddy Rice ◽

Bulk Soil ◽

Rice Soil ◽

Soil Nematode ◽

Nematode Density ◽

Nematode Communities ◽

Nematode Diversity ◽

Growing Conditions

The practice of growing agricultural crops in rows results in larger soil nematode populations in the root-associated soil than in the bulk soil between the rows. Fertilisers applied to improve grain yield generally increase the abundance of nematode communities in agricultural soils. The objective of this study was to compare total nematode density and four dominant genera in the root-associated and bulk soils of paddy rice and upland wheat receiving organic and mineral fertilisers. Dominant nematode genera accounted for 80% of all nematodes and represented four trophic groups. There was greater total nematode density and a higher enrichment index (EI) but less nematode diversity (H′) and a lower structure index (SI) in the root-associated soil than bulk soil of upland wheat. By contrast, nematode abundance, diversity and ecological indices were similar in the root-associated and bulk soils of the paddy rice. Soil nematode communities were affected significantly and consistently by fertilisation in upland wheat and paddy rice phases. More herbivoreHirschmanniellawere present with mineral fertiliser than in the non-fertilised control. Straw-based organic fertilisers increased the abundance of bacterivoreEucephalobus. The lack of interaction between rhizosphere effect and fertilisation indicated that crop-growing conditions (different species and water regimes) were more influential on nematode communities and not consistently impacted by short-term organic and mineral fertilisation in the rice-wheat agroecosystem.

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Effects of Mowing Frequency on Soil Nematode Diversity and Community Structure in a Chinese Meadow Steppe

Sustainability ◽

10.3390/su13105555 ◽

2021 ◽

Vol 13 (10) ◽

pp. 5555

Author(s):

Jinling Zhao ◽

Jiale Chen ◽

Honghui Wu ◽

Linghao Li ◽

Fengjuan Pan

Keyword(s):

Community Structure ◽

Critical Factor ◽

Terrestrial Ecosystems ◽

Structure Stability ◽

Soil Nematode ◽

Soil Nematodes ◽

Grassland Ecosystems ◽

Management Measures ◽

Nematode Diversity ◽

The Stability

Soil nematodes are one of the most important components in terrestrial ecosystems and the critical factor driving the belowground process. The grasslands of Northeast China have been subject to mowing for ages, which theoretically should have had substantial effects on the processes associated with soil nematodes. However, relevant studies have barely been conducted to date. This study examined variations in soil nematode abundance, biomass, diversity, and community structure, with respect to varying mowing frequencies. The results showed that a higher mowing frequency significantly reduced the abundance of soil nematodes, biomass, diversity, and community structure stability in the ecosystem, while intermediate mowing frequency enhanced these parameters to different extents. Our findings indicate that the changing patterns of the nematode indices with mowing frequency conform to the intermediate disturbance theory. This study provides a theoretical basis for formulating grassland-related management measures and maintaining the stability of grassland ecosystems.

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