Professor Hezhong DONG, Cotton Research Centre, Shandong Academy of Agricultural Sciences, China;
Professor Zhiguo ZHOU, Nanjing Agricultural University, China
Journal of Cotton Research is hosting a thematic series on cotton physiology and pathology. The research community is encouraged to share original findings, methodology, results, databases, and/or software and opinions.
Scopes that may be covered in the submissions may include, but are not limited to the following:
1. growth and organ development;
2. plant and shoot architecture;
3. water, fertilizer, light, etc. use efficiency;
4. intelligent agriculture;
5. rhizosphere and other plant-environment interactions;
6. main disease and resistance.
Submission Deadline: 30 September 2019
Composting of cotton mill wastes may provide means for the production of a stable organic material, useful for soil improvement and as a substrate for plant growth. The aim of this work was to examine the composting process of cotton wastes and to evaluate the produced compost. Three composting piles were formed. In the first the ratio C/N was reduced to 28 with the addition of NH4NO3 , in the second cotton wastes were mixed with olive tree leaves at a ratio 2:1, respectively and in the third one a small amount of mature compost was added in order to trigger micro-organism activity. The results concerning the composting process, revealed that the reduction of the C/N ratio of the raw material is not a critical parameter for the composting of cotton mill wastes. The addition of olive tree leaves, as a bulking agent, enriched the final compost in nutrients and humic substances but delayed the overall process. The evolution of the composting process seems to be accelerated by the addition of a small amount of mature compost at the beginning. Decomposition of the materials lowered gradually the ratio C/N, due to carbon loss, reaching values between 9 and 10 while the nitrate content was increased significantly. The final produced composts were rich in nutrients and extractable humic substances. Tomato seedlings were superior in substrate with 30% (v/v) cotton mill wastes mature compost, compared to that in commercial substrates
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Despite measures taken to reduce reliance on chemicals (e.g. Ingard cotton), production of Australian cotton still involves significant inputs of pesticides, with the potential to contaminate other agricultural produce and riverine ecosystems. Since 1993, the environmental fate and transport of pesticides used in cotton growing have been extensively monitored to minimize their impact as chemical residues. This research has focused on endosulfan as the major insecticide applied on cotton farms, and as a model for other chemicals. Positive results of the research that can help provide more sustainable practices are:
Information on field dissipation of endosulfan, in farm soils, surface water and on nearby pasture. In summary, dissipation of endosulfan from cotton fields occurred mainly by volatilization in the first 2-3 weeks after application; endosulfan isomers on cotton plants and in soils are quickly metabolized, with half-lives of 3-4 days. Two weeks after application, only 2-3 % of the amount applied in one spraying remained in the foliage. Unfortunately, there is some persistence of the metabolic oxidation product endosulfan sulphate in the field, with a ‘half-life’ in soil of about 100 days. However, by the start of the new growing season only 1-2% of the endosulfan applied remained on field as endosulfan sulphate, so there is little or no long-term accumulation.
A study of the degradation of endosulfan on pasture showed that residues fell to acceptable levels within about 3-4 weeks, dependent on the distance from the line of spray application. Runoff waters contain 1-2% of total endosulfan transported or dissipated off field in one season, major storms accounting for 50% of this amount; the relative significance of lateral rather than vertical leaching of soluble chemicals in grey-cracking soils (Vertisols) is emphasized.
Immunoassays (ELISA) provide rapid, inexpensive, field tests for pesticide residues, providing more comprehensive data-sets that allow decisions on the release of contaminated water and the assessment of the progress in remediation.
Field research protocols needed to generate data for registration purposes have been developed.
Significant progress towards safer use of pesticides in cotton growing, resulting from the preparation of a database indicating risk factors with specific pesticides and herbicides and a better understanding transport mechanisms. The adoption of better management practices that reduce these risks is already contributing to more sustainable cotton production.
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Most row-cropped soils of the southern USA are low in organic matter and must be limed frequently to maintain an acceptable pH. Industry, municipalities and agriculture produce organic and other waste materials that can be used as soil amendments to increase both soil organic matter and pH. Field experiments were conducted on Gigger-Gilbert silt loam complex (fine-silty, mixed, thermic, typic fragiudalf-glossaqualf) to assess the effects of municipal biosolids, composted sewage sludge, paper mill sludge and paper mill boiler ash.
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