Control of sclerotium of sunflower through organic amendments of soil

Summary Out of six organic materials used to amend the infested soil for the control of Sclerotium wilt of sunflower, oat straw followed by oil cakes such as castor andneem cakes significantly reduced the incidence of the disease when compared with non-amended soil. Rice-husk and sawdust did not show any consistent and definite trend in influencing the disease incidence.Publication No. 2041 under the Journal Series of the Experiment Station, G.B. Pant Univ. of Agri.^±Techn., Pantnagar, Nainital (U.P.). India.     

Short-term dynamics of culturable bacteria in a soil amended with biotransformed dry olive residue

Dry olive residue (DOR) transformation by wood decomposing basidiomycetes (e.g. Coriolopsis floccosa) is a possible strategy for eliminating the liabilities related to the use of olive oil industry waste as an organic soil amendment. The effects of organic fertilization with DOR on the culturable soil microbiota are largely unknown. Therefore, the objectives of this study were to measure the short-term effects of DOR and C. floccosa-transformed DOR on the culturable bacterial soil community, while at the same time documenting the bacterial diversity of an agronomic soil in the southeastern Iberian Peninsula. The control soil was compared with the same soil treated with DOR and with C. floccosa-transformed DOR for 0, 30 and 60 days. Impact was measured from total viable cells and CFU counts, as well as the isolation and characterization of 900 strains by fatty acid methyl ester profiles and 16S rRNA partial sequencing. The bacterial diversity was distributed between Actinobacteria, Alphaproteobacteria, Gammaproteobacteria, Betaproteobacteria, Bacilli, Sphingobacteria and Cytophagia. Analysis of the treatments and controls demonstrated that soil amendment with untransformed DOR produced important changes in bacterial density and diversity. However, when C. floccosa-transformed DOR was applied, bacterial proliferation was observed but bacterial diversity was less affected, and the distribution of microorganisms was more similar to the unamended soil.     

Effects of incubation temperature on the organic amendment‐mediated control of Fusarium wilt of tomato

Organic soil amendments play important roles in the reduction of plant diseases caused by soil‐borne plant pathogens. This study examined the combined effects of concentrations of organic amendments, temperature and period of incubation in soil on the management of Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici (Fol). In an experiment with substrate mixture, Fol reduction was higher when the soils were incubated at 35°C than at 30°C. Disease severity was proportionally reduced as the volume of amendment added increased. Furthermore, disease was significantly lower in substrates incubated for 30 days at both temperatures, as compared to substrates incubated for only 15 days. The most effective control was achieved with pelletised poultry manure (PPM). In experiments with natural sandy soil, the effects of amendments on Fol populations, measured by real‐time quantitative PCR with TaqMan probes, were significant. The highest decreases in Fol DNA resulted when the soil was amended with 2% PPM and incubated at 35°C. The reductions in DNA concentrations was most likely related to the accumulations of high concentrations of NH₃ (27.3 mM) in soils treated with 2% PPM and incubated at room temperature (RT; 23 ± 2°C), or at 35°C. Severity of plants grown in soils incubated at RT decreased by over 40%, and more than 73% when incubated at 35°C, regardless of the rate of PPM. The results indicate that the management with PPM, when combined with heating or solarisation, is an effective control measure against Fusarium wilt of tomato.     

Lipid-enhanced Oilcane does not impact soil carbon dynamics compared with wild-type Sugarcane

The carbon neutral potential of bioenergy relies in part on the ability of feedstocks to sequester carbon (C) in the soil. Sugarcane is one of the most widely used bioenergy crops, yet there remain unknowns about how it impacts soil C dynamics. In addition, Oilcane, a genetically modified version of Sugarcane has been produced to accumulate more energy-dense oils and less soluble lignin, which enhances conversion efficiency but may also impact soil C cycling. Thus, our objectives were to examine the impact of Sugarcane litter decomposition on soil C formation and losses and determine if the genetic modifications to produce Oilcane alter these dynamics. To do this, we incubated bagasse (processed stem litter) and leaf litter from Sugarcane and Oilcane in microcosms with forest soil for 11 weeks. We used differences in natural abundance δ¹³C between C₃ forest soil and C₄ litter to trace the fate of the litter into respiratory losses as well as stable and unstable soil C pools. Our results show that genetic modifications to Oilcane did not substantially alter soil C dynamics. Sugarcane and Oilcane litter both led to net soil C gains dominated by an accumulation of the added litter as unstable, particulate organic C (POC). Oilcane litter led to small but significantly greater net soil C gains than Sugarcane litter due to greater POC formation, but the formation of stable, mineral associated organic matter (MAOC) did not differ between crop types. Sugarcane and Oilcane had opposing effects on tissue type where Sugarcane bagasse formed more MAOC, while Oilcane leaves preferentially remained as POC which may have important management implications. These results suggest that genetic modifications to Sugarcane will not significantly impact soil C dynamics; however, this may not be universal to other crops particularly if modifications lead to greater differences in litter chemistry.     

The role of organic amendments in wetland restorations

At the present rate of loss (since 1990), half of the remaining wetlands worldwide will be developed within ~140 years, underscoring the importance of improving the creation and restoration of wetlands. Organic amendments are sometimes used during wetland creation. To evaluate the effectiveness of adding organic amendments we used a combined numerical method to assign “scores” on five categories of evaluation metrics: plant growth, soil properties, carbon accrual, denitrification, and anaerobic processes (e.g. redox potential). We found that amendments identified as “topsoil” scored measurably higher and had consistently more positive values with fewer negative results compared to amendments identified as “allochthonous organic matter” (alOM). Organic amendments had about the same effect on soils with low soil organic carbon (<2.5%) compared to soils richer in organic carbon. Organic amendments are not uniformly effective, and in some cases may have negative side effects. For example, alOM often resulted in a loss of plant diversity. These outcomes along with site conditions should be evaluated before using organic amendments.     

Efficacy of dried seed powder of some plant species as soil amendment against Meloidogyne incognita (Tylenchida: Meloidogynidae) on tomato

The nematicidal activity of dried ground seeds of Ammi majus, Matricaria chamomilla, Ricinus communis, Brassica alba, B. oleracea, Peganum harmala, Solanum nigrum, Raphanus sativus and Eucalyptus sp. was assessed against the root-knot nematode, Meloidogyne incognita, infecting tomato in a glasshouse. The powdered seeds of the tested plants were incorporated into the soil at the rate of 5 g/kg and their nematicidal activity was compared with that of the synthetic nematicide carbofuran at the rate of 0.01 g a.i./kg. The effects of the treatments on the growth of tomato were also examined. The populations of M. incognita in the soil and root galling of tomato were significantly suppressed by the powdered seeds of all the plant species tested, with the greatest reduction occurring in soil amended with M. chamomilla, followed by soil treated with powdered seeds of A. majus, S. nigrum, R. communis and Eucalyptus sp. The efficacy of B. oleracea, B. alba, M. chamomilla and R. communis in reducing the number of J₂ in the soil was similar to that of carbofuran. All amendments, except powdered seeds of M. chamomilla and A. majus significantly increased shoot length compared to the untreated inoculated plants. Shoot weight was significantly increased in soil amended with powdered seeds of B. oleracea, B. alba, R. communis, P. harmala and S. nigrum, but not in soil amended with the other seed powders when compared with untreated inoculated soil. Significant increases in root length occurred in pots amended with seed powder of B. alba, R. communis and Eucalyptus and in root weight for P. harmala. None of the tested dried seeds was phytotoxic to tomato plants at the applied rate.     

The Use of Seedbed Modifications and Wood Chips to Accelerate Restoration of Well Pad Sites in Western Colorado,U.S.A.

Semiarid ecosystems of Western North America are experiencing a boom in natural gas development. However, these systems are slow to recover from the disturbances created. The purpose of this study was to develop improved restoration techniques on natural gas well pads in Western Colorado. This study examined effects and interactions of seedbed modifications, soil amendments, seed mixtures, and seeding methods. The experiment was conducted in pinyon‐juniper and semidesert shrub plant communities on five natural gas well pads beginning in 2006. Soil and plant cover data were collected to assess the effectiveness of 16 different treatment combinations. After two growing seasons, we found that patches of soil salinity (>4 dS/m) reduced plant cover to less than 20% on 55 of our 240 experimental plots. These patches of salinity, such as where reserve pits were buried, may need to be treated to completely restore cover on the total gas pad area, although causes of salinity patches needs further investigation. After removing the 55 saline plots from our data analyses, we found that wood chips (WC) as a soil amendment increased organic matter content and reduced non‐native species. Rough seedbed modifications increased the establishment of native species, especially during years of below average precipitation. Island broadcasting resulted in an increase of noxious plant cover during the second growing season. From these findings we recommend that disturbed well pads in a similar environment be restored by seeding native species on sites that are amended with WC and physically modified to create a roughened seedbed.     

Nutrient Profile of a Contaminated Soil Phytoremediated by Centrosema pubescen and Mucuna pruriens

Soil nutrients contribute to ecosystem-level processes and are important for productivity, community structure, and fertility in terrestrial ecosystems. Crude oil–stressed agricultural soil was subjected to phytoremediation for 12 weeks, and the nutrient status thereafter was characterized to investigate the inherent effects on such soils in relation to nutrient mineralization and community shifts. Manure additions significantly increased Mg, Na, NO₃-N, PO₄ ^?, and SO₄ ^2? contents along with pH values. Accumulated biomass and leaf area measurements were used to monitor nutrient cycles upon amendment addition. Experimental results indicate that after 90 days, the biotreatment had significantly higher levels of monitored nutrients (above 2500 mg/kg NO₃-N) than the unplanted control (<500 mg/kg NO₃-N), and compared well with the uncontaminated control. The results from this study highlighted inherent advantages of phytoremediation as a soil cleanup technique in terms of soil quality recovery and preservation.     

《野生动物保护法》再修订: 背景、争点与建议

《野生动物保护法》的修订已纳入全国人大2020年年度立法计划。现行《野生动物保护法》虽然经过多次修改, 但仍存在野生动物保护范围较窄、监管体制不顺、执法标准不科学、法律制度不完善等问题, 不能适应新时代“健康中国”、“美丽中国”战略协同规制的新需求。全国人大常委会通过的《关于全面禁止非法野生动物交易、革除滥食野生动物陋习、切实保障人民群众生命健康的决定》, 为修订《野生动物保护法》带来了良好机遇。目前各方面对于修订《野生动物保护法》既有共识, 也有争议, 呈现出不同利益诉求与立法思维的差异性, 以及立法过程中利益选择、利益表达、利益协调的复杂性。为此, 建议《野生动物保护法》的修订在完善立法目的、合理界定保护范围、健全“黑白”名单制度和许可证制度、优化野生动物保护监管体制、完善激励机制和法律责任制度等方面认真加以研究, 为促进环境治理体系和治理能力现代化“立良法”。