Soil quality assessment has been suggested as an effective tool for evaluating sustainability of soil and crop management practices.The objective of this study was to develop a sensitive soil quality index(SQI) based ...Soil quality assessment has been suggested as an effective tool for evaluating sustainability of soil and crop management practices.The objective of this study was to develop a sensitive soil quality index(SQI) based on bulk density(BD),water-holding capacity(WHC),water-stable aggregates(WSA),aggregate mean weight diameter(AMWD),total organic C(TOC) and C input to evaluate the important rice-wheat cropping system on an Inceptisol in India.A long-term experiment has been conducted for 18 years at the Indian Council of Agricultural Research-Indian Institute of Farming Systems Research,Modipuram,India.The treatments selected for this study were comprised of a no-fertilizer control and N,P and K fertilizers(NPK) combined with Zn and S fertilizers(NPK+ Zn+S),farmyard manure(NPK+FYM),green gram residues(NPK+GR) and cereal residues(NPK+CR),laid out in a randomized complete block design with three replications.Soil samples were collected and analyzed for BD,WHC,WSA and TOC.Correlation analysis revealed that both rice and wheat yields signi?cantly increased with the increases in AMWD,TOC and C input,but decreased with the increase in BD.The SQI values were then generated based on regression analysis of BD,WSA,AMWD,TOC and C input with rice and wheat yields for the 0–15 and 15–30 cm soil layers,respectively.Regression analyses between crop yields and SQI values showed a quadratic type of relation with the coeffcient of determination(R^2) varying from 0.78 to 0.89.With regard to soil sustainability,applying crop residues to both rice and wheat could maintain soil quality for a longer period,whereas the highest yields of both the crops were recorded in the NPK+Zn+S treatment.The regression equations developed in this study could be used to monitor soil quality in a subhumid tropical rice-wheat cropping system.展开更多
Aluminium and its alloys are widely used in the aerospace,automotive,and electronic industries due to their low density and good corrosion resistance,but their limited strength and wear resistance restrict performance...Aluminium and its alloys are widely used in the aerospace,automotive,and electronic industries due to their low density and good corrosion resistance,but their limited strength and wear resistance restrict performance under severe loading.We have introduced a binary hybrid reinforcement of multi-walled carbon nanotubes(MWCNTs)and hexagonal boron nitride(hBN)into a pure Al matrix by ultrasonic-assisted dispersion which was consolid-ated using spark plasma sintering(SPS)to exploit their combined ef-fects.MWCNTs formed a high-strength 1D framework and provided a better load transfer,while hBN provided solid lubrication through tribofilm formation.XRD confirmed the absence of harmful interfa-cial phases in the Al-M_(50)B_(50) nanocomposite.HRTEM showed that conventionally sintered Al-1%M_(50)B_(50) contained dislocation pile-ups and Al_(2)O_(3) pinning particles,whereas SPS Al-3%M_(50)B_(50) had uniformly dispersed reinforcements,strong interfacial bonding,and occasional Al4C3 nanocrystals,demonstrating the su-perior densification of SPS.Consistent with these observations,conventional sintering achieved its best properties at 1%M_(50)B_(50),yielding~92.02%relative density,~479.31 MPa hardness,~761.68 MPa compressive strength,and improved wear resistance compared to pure Al(~88.14%density,~322 MPa hardness,~422.60 MPa strength).However,higher nanofiller contents led to agglomeration and reduced performance.SPS enabled better densification and uniform filler distribution,with the Al-3%M_(50)B_(50) nanocomposite attaining~93.46%density,~638.63 MPa hardness,~1049.50 MPa strength,and~26%lower wear rate than pure Al.Overall,the dual reinforcement strategy combined with SPS processing overcomes the strength-wear trade-off,offering better microstructural stability,mechanical robustness,and tribological efficiency.展开更多
基金The financial assistance provided by the Indian Agricultural Research Institute,New Delhi,India
文摘Soil quality assessment has been suggested as an effective tool for evaluating sustainability of soil and crop management practices.The objective of this study was to develop a sensitive soil quality index(SQI) based on bulk density(BD),water-holding capacity(WHC),water-stable aggregates(WSA),aggregate mean weight diameter(AMWD),total organic C(TOC) and C input to evaluate the important rice-wheat cropping system on an Inceptisol in India.A long-term experiment has been conducted for 18 years at the Indian Council of Agricultural Research-Indian Institute of Farming Systems Research,Modipuram,India.The treatments selected for this study were comprised of a no-fertilizer control and N,P and K fertilizers(NPK) combined with Zn and S fertilizers(NPK+ Zn+S),farmyard manure(NPK+FYM),green gram residues(NPK+GR) and cereal residues(NPK+CR),laid out in a randomized complete block design with three replications.Soil samples were collected and analyzed for BD,WHC,WSA and TOC.Correlation analysis revealed that both rice and wheat yields signi?cantly increased with the increases in AMWD,TOC and C input,but decreased with the increase in BD.The SQI values were then generated based on regression analysis of BD,WSA,AMWD,TOC and C input with rice and wheat yields for the 0–15 and 15–30 cm soil layers,respectively.Regression analyses between crop yields and SQI values showed a quadratic type of relation with the coeffcient of determination(R^2) varying from 0.78 to 0.89.With regard to soil sustainability,applying crop residues to both rice and wheat could maintain soil quality for a longer period,whereas the highest yields of both the crops were recorded in the NPK+Zn+S treatment.The regression equations developed in this study could be used to monitor soil quality in a subhumid tropical rice-wheat cropping system.
文摘Aluminium and its alloys are widely used in the aerospace,automotive,and electronic industries due to their low density and good corrosion resistance,but their limited strength and wear resistance restrict performance under severe loading.We have introduced a binary hybrid reinforcement of multi-walled carbon nanotubes(MWCNTs)and hexagonal boron nitride(hBN)into a pure Al matrix by ultrasonic-assisted dispersion which was consolid-ated using spark plasma sintering(SPS)to exploit their combined ef-fects.MWCNTs formed a high-strength 1D framework and provided a better load transfer,while hBN provided solid lubrication through tribofilm formation.XRD confirmed the absence of harmful interfa-cial phases in the Al-M_(50)B_(50) nanocomposite.HRTEM showed that conventionally sintered Al-1%M_(50)B_(50) contained dislocation pile-ups and Al_(2)O_(3) pinning particles,whereas SPS Al-3%M_(50)B_(50) had uniformly dispersed reinforcements,strong interfacial bonding,and occasional Al4C3 nanocrystals,demonstrating the su-perior densification of SPS.Consistent with these observations,conventional sintering achieved its best properties at 1%M_(50)B_(50),yielding~92.02%relative density,~479.31 MPa hardness,~761.68 MPa compressive strength,and improved wear resistance compared to pure Al(~88.14%density,~322 MPa hardness,~422.60 MPa strength).However,higher nanofiller contents led to agglomeration and reduced performance.SPS enabled better densification and uniform filler distribution,with the Al-3%M_(50)B_(50) nanocomposite attaining~93.46%density,~638.63 MPa hardness,~1049.50 MPa strength,and~26%lower wear rate than pure Al.Overall,the dual reinforcement strategy combined with SPS processing overcomes the strength-wear trade-off,offering better microstructural stability,mechanical robustness,and tribological efficiency.
