Impacts of Rice Field Winter Planting on Soil Organic Carbon and Carbon Management Index

To tackle with the problem of prevailing farmland abandonment in winter,5 treatments includes Chinese milk vetch-double cropping rice(CRR),rape-double cropping rice(RRR),garlic-double cropping rice(GRR),winter crop multiple cropping rotation(ROT),winter fallow control(WRR)were set up.By measuring soil total organic carbon,active organic carbon and its components and calculating the soil carbon pool management index in 0~15 cm and 15~30 cm soil layers in the early and late rice ripening stage.The effects of different winter planting patterns on the changes of soil organic carbon and carbon pool management index were discussed.In order to provide theoretical basis for the optimization and adjustment of winter planting pattern of double cropping rice field in the middle reaches of Yangtze River.The results showed that soil total organic carbon,active organic carbon and its components in different winter cropping patterns were increased,and ROT and CRR treatments were more beneficial to the accumulation of soil total organic carbon,active organic carbon and its components as well as the improvement of soil carbon pool management index,which should be preferred in the adjustment of cropping patterns.

An evaluation of ureteral diameter ratio and vesicoureteral reflux index in the treatment of primary vesicoureteral reflux

Objective:Vesicoureteral reflux(VUR)index is a simple,validated tool that reliably predicts significant improvement and spontaneous resolution of primary reflux in children.The aim of this study was to evaluate and compare the ureter diameter ratio(UDR)and VUR index(VURx)of patients treated with endoscopic injection(EI)and ureteroneocystostomy(UNC)methods in the pediatric age group due to primary VUR.Methods:Patients under the age of 18 years old who underwent EI and UNC with the diagnosis of primary VUR between January 2011 and September 2021 were determined as the participants.The UDR was assessed using voiding cystourethrography,and the VURx score was determined prior to treatment based on hospital records included in the study.Results:A total of 255 patients,60(23.5%)boys and 195(76.5%)girls,with a mean age of 76.5(range 13.0e204.0)months,were included in the study.EI was applied to 130(51.0%)patients and UNC was applied to 125(49.0%)patients due to primary VUR.The optimum cut-off for the distal UDR was obtained as 0.17 with sensitivity and specificity of 73.0%and 63.0%,respectively.The positive and negative predictive values were 66.0%and 70.0%,respectively.Conclusion:When the UDR and VURx score are evaluated together for the surgical treatment of primary VUR in the pediatric age group,it is thought that it may be useful in predicting the clinical course of the disease and evaluating surgical treatment options.

Fertilization Affects Biomass Production of Suaeda salsa and Soil Organic Carbon Pool in East Coastal Region of China

Land use practice significantly affects soil properties. Soil is a major sink for atmospheric carbon, and soil organic carbon （SOC） is considered as an essential indicator of soil quality. The objective of this study was to assess the effects of N and P applied to Suaeda salsa on biomass production, SOC concentration, labile organic carbon （LOC） concentration, SOC pool and carbon management index （CMI） as well as the effect of the land use practice on soil quality of coastal tidal lands in east coastal region of China. The study provided relevant references for coastal exploitation, tidal land management and related study in other countries and regions. The field experiment was laid out in a randomized complete block design, consisting of four N-fertilization rates （0 （NO）, 60 （N1）, 120 （N2） and 180 kg ha-1 （N3））, three P-fertilization rates （0 （P0）, 70 （P1） and 105 kg ha-~ （P2）） and bare land without vegetation. N and P applied to S. salsa on coastal tidal lands significantly affected biomass production （above-ground biomass and roots）, bulk density （Pb）, available N and P, SOC, LOC, SOC pool and CMI. Using statistical analysis, significantly interactions in N and P were observed for biomass production and the dominant factor for S. salsa production was N in continuous 2-yr experiments. There were no significant interactions between N and P for SOC concentration, LOC concentration and SOC pool. However, significant interaction was obtained for CMI at the 0-20 cm depth and N played a dominant role in the variation of CMI. There were significant improvements for soil measured attributes and parameters, which suggested that increasing the rates of N and P significantly decreased Pb at the 0-20 cm depth and increased available N and P, SOC, LOC, SOC pool as well as CMI at both the 0-20 and 20-40 cm depth, respectively. By correlation analysis, there were significantly positive correlations between biomass （above- ground biomass and roots） and SOC as well as LOC in 2010 and 2011 across all soil depth, respectively. The treatment with N at 180 kg ha-~ and P at 105 kg ha-1 was superior to the other treatments. The results from the 2-yr continuous experiments indicated that, in short-term, there were a few accumulation of SOC and LOC concentrations by means of N and P application to S. salsa, whereas in the long run, S. salsa with N and P application was recommended for coastal tidal lands because of its great potential of carbon sequestration, improvements of soil nutrition status and promotion of soil quality.

Towards greener polymers:Trends in the German chemical industry

Global plastics production is expected to exceed 400 million tons and reach 600 million tons by 2060.Their synthesis currently accounts for approximately 3%of global greenhouse gas emissions.Approximately 60%of all polymers are produced for single-use.Examples include shopping bags,packaging materials,mulch films,and soluble polymers for cosmetics and other purposes.Currently,only a portion of single-use plastic is recycled or disposed of in incinerators or landfills.An estimated 20%is not disposed of properly and pollutes the global environment,especially the oceans.In response to these challenges,the United Nations,European Union,and many nation-states are developing regulatory frameworks that encourage the chemical industry to produce plastics with a smaller environmental footprint and often support this through research funding.Possible solutions include:(1)the use of green energy,green hydrogen,bio-based feedstocks,or CO_(2) in synthesis;(2)the reuse or recycling of plastics through conversion or pyrolysis;and(3)the production of biodegradable polymers.The German chemical industry contributes approximately one-third of polymer production in the EU.It is embedded in the EU regulatory and research landscape and anchored in the European Green Deal,which aims for carbon neutrality by 2050.In this paper,we describe how BASF and Evonik,two leading German chemical companies with strong but different polymer portfolios,respond to the call for greener polymers and how technologies are being developed to make polyurethanes,a particularly important and difficult-to-recycle family of elastomers and duromers,renewable and circular.Reducing the environmental footprint of plastics requires not only innovative materials but also proper governance,regulatory and collection systems,and public willingness to cooperate.In an international comparison of these competencies,expressed by the"polymer management index"(PMI),Germany achieved a top position.

Reduced tillage with residue retention improves soil labile carbon pools and carbon lability and management indices in a seven-year trial with wheat-mung bean-rice rotation

Soil total organic carbon(TOC)is a composite indicator of soil quality with implications for crop production and the regulation of soil ecosystem services.Research reports on the dynamics of TOC as a consequence of soil management practices in subtropical climatic conditions,where microbial carbon(C)loss is high,are very limited.The objective of our study was to evaluate the impact of seven years of continuous tillage and residue management on soil TOC dynamics(quantitative and qualitative)with respect to lability and stratification under an annual wheat-mung bean-rice cropping sequence.Composite soil samples were collected at 0-15 and 15-30 cm depths from a three-replicate split-plot experiment with tillage treatment as the main plots and crop residue levels as the sub-plots.The tillage treatments included conventional tillage(CT)and strip tillage(ST).Residue levels were high residue level(HR),30%of the plant height,and low residue level(LR),15%.In addition to TOC,soil samples were analyzed for particulate organic C(POC),permanganate oxidizable C(POXC),basal respiration(BR),specific maintenance respiration rate(qCO_(2)),microbial biomass C(MBC),potentially mineralizable C(PMC),and TOC lability and management indices.The ST treatment significantly increased the TOC and labile C pools at both depths compared with the CT treatment,with the effect being more pronounced in the surface layer.The HR treatment increased TOC and labile C pools compared with the LR treatment.The ST+HR treatment showed significant increases in MBC,metabolic quotient(qR),C pool index(CPI),C lability index(CL_(I)),and C management index(CMI),indicating improved and efficient soil biological activities in such systems compared with the CT treatment.Similarly,the stratification values,a measure of soil quality improvement,for POC and MBC were>2,indicating improved soil quality in the ST+HR treatment compared with the CT treatment.The ST+HR treatment not only significantly increased the contents of TOC pools,but also their stocks.The CMI was correlated with qCO_(2),BR,and MBC,suggesting that these are sensitive indicators of early changes in TOC.The qCO_(2) was significantly higher in the CT+LR treatment and negatively correlated with MBC and CMI,indicating a biologically stressed soil condition in this treatment.Our findings highlight that medium-term reduced tillage with HR management has profound consequences on soil TOC quality and dynamics as mediated by alterations in labile C pools.

Residue recycling options and their implications for sustainable nitrogen management in rice-wheat agroecosystems

Background In the Indo-Gangetic Plain,rice-wheat is the most extensively practiced crop rotation.The escalating issue of crop residue burning,particularly rice straw,and the necessity to lower the exorbitant expenses associated with fertilizer inputs stand out as significant challenges for farmers in the region.A well-suited integrated nutrient management(INM)strategy that focuses on recycling crop residues can serve as a solution to address these issues.Such a strategy not only mitigates air pollution resulting from residue burning but also helps combat water pollution due to nitrate losses from agroecosystems.Field experiments were used to evaluate the suitability of eight INM-modules that included various combinations of inorganic fertilizer rates(50%,100%,150%of recommended dose),crop residues(wheat and rice stubble retention at 30 cm standing stubble equivalent to 1/3 the straw yield),rice straw compost(RSC),farmyard manure(FYM),and green manuring(GM),compared to 100%recommended dose of fertilizers(F)and no fertilizer application.Results There was a considerable improvement in nitrogen mineralization,grain yields,and nitrogen use efficiency under GM+RSC-F50 and GM+FYM-F50.These INM modules would permit a 50%reduction in the use of chemical fertilizers.There was a little yield penalty with in situ rice residue incorporation at 100%F;however,this could be overcome with 150%F fertilizer application.In situ retention of wheat straw with a full application of fertilizer resulted in steadily rising crop yields over time.Changes in the redox potential,soil pH,and soil organic carbon best accounted for the observed trajectories in nitrogen use efficiency.Conclusion The most promising INM modules for adoption by farmers in the Indo-Gangetic Plain to judiciously use crop residues and curtail chemical fertilizer inputs are green manuring with Sesbania aculeata+rice straw compost at 5 t ha^(−1)+only 50%of recommended dose of fertilizers(GM+RSC-F50),and green manuring with Sesbania aculeata+farmyard manure at 5 t ha^(−1)+only 50%of recommended dose of fertilizers(GM+FYM-F50).Sole incorporation of crop residues without nitrogen augmentation from other sources might not help curtail chemical fertilizer use.Composting rice straw,which otherwise is widely burnt,proved a useful nitrogen source and a vital component of INM.Waste rice straw composting at the community scale and its application as a nutrient source can help achieve sustainable nitrogen management in the agroecosystems of Indo-Gangetic Plain.

Long-term fertilization and residue return affect soil stoichiometry characteristics and labile soil organic matter fractions

Ecological stoichiometry provides the possibility for linking microbial dynamics with soil carbon(C),nitrogen(N),and phosphorus(P)metabolisms in response to agricultural nutrient management.To determine the roles of fertilization and residue return with respect to ecological stoichiometry,we collected soil samples from a 30-year field experiment on residue return(maize straw)at rates of 0,2.5,and 5.0 Mg ha^-1 in combination with 8 fertilization treatments:no fertilizer(F0),N fertilizer,P fertilizer,potassium(K)fertilizer,N and P(NP)fertilizers,N and K(NK)fertilizers,P and K(PK)fertilizers,and N,P,and K(NPK)fertilizers.We measured soil organic C(SOC),total N and P,microbial biomass C,N,and P,water-soluble organic C and N,KMnO4-oxidizabIe C(KMnO4-C),and carbon management index(CMI).Compared with the control(F0 treatment without residue return),fertilization and residue return significantly increased the KMn〇4-C content and CMI.Furthermore,compared with the control,residue return significantly increased the SOC content.Moreover,the NPK treatment with residue return at 5.0 Mg ha^-1 significantly enhanced the C:N,C:P,and N:P ratios in the soil,whereas it significantly decreased the C:N and C:P ratios in soil microbial biomass.Therefore,NPK fertilizer application combined with residue return at 5.0 Mg ha^-1 could enhance the SOC content through the stoichiometric plasticity of microorganisms.Residue return and fertilization increased the soil C pools by directly modifying the microbial stoichiometry of the biomass that was C limited.

No-till and conservation agriculture in the United States:An example from the David Brandt farm,Carroll,Ohio

No-till(NT)farming(conservation agriculture)began in the US in the 1960s.The state of Ohio has a university research location that began no-till research in 1962.A few innovative Ohio farmers,including NT pioneers David Brandt and Bill Richards,were early adopters of the new conservation practice.Initially,no-till was most successful on sloping,well drained soils,then with improvements to the system,including cover crops,it became more widely adopted on all soil types.David Brandt was an enthusiastic learner and teacher of no-till practices,working with chemical company representatives and Cooperative Extension Specialists to demonstrate the system.David Brandt’s cooperation with Ohio State University researchers continues to provide a valuable site for studying the long term changes in soil health and ecosystem services.Results showed that total microbial biomass as one of the soil biological health indicators significantly increased with an associated decrease in carbon(C)loss under NT compared with conventional tilled soil(CT).Under NT,there was significantly higher total C and total N compared to CT.Active C,as a composite measure of soil health,significantly increased with NT.When cover crops,especially cover crop cocktail mixes,were used,NT substantially improved soil health.Long-term NT with cover crop cocktail mixes significantly increased the soil aggregate stability,compared with CT.The overall rate of C sequestration by NT suggested that the soils on the Brandt farm act as a consistent sink of atmospheric CO2 although this tends to level off after about 20 years.The Brandt farm showed that crop yields are increased under long-term NT with cover crops mixes.Results suggested that starting with a cover crop when switching from CT to NT,is more likely to ensure success and to maintain economic crop yields.Another early adopter,Bill Richards,from Circleville,Ohio,also became a national leader and promoter of no-till farming.He served as head of the United States Department of Agriculture’s Natural Resources Conservation Service in the early 1990s and instituted a program that led to rapid expansion of no-till.He advises that farmers who follow conservation agriculture principles need to be more proactive,from local level to national levels,to influence policy decisions that can lead to robust improvement in soil health.