Agronomic practices affect soil phosphorus(P) availability, P uptake by plants, and subsequently the efficiency of P use. A field experiment was carried out to investigate the effects of various agronomic practices(st...Agronomic practices affect soil phosphorus(P) availability, P uptake by plants, and subsequently the efficiency of P use. A field experiment was carried out to investigate the effects of various agronomic practices(straw incorporation, paddy water management, nitrogen(N) fertilizer dose, manure application,and biochar addition) on soil P availability(e.g., soil total P(STP), soil available P(SAP), soil microbial biomass P(SMBP), and rice P uptake as well as P use efficiency(PUE)) over four cropping seasons in a rice-rice cropping system, in subtropical central China. Compared to the non-straw treatment(control,using full dose of chemical N fertilizer), straw incorporation increased SAP and SMBP by 9.3%–18.5% and 15.5%–35.4%, respectively;substituting half the chemical N fertilizer dose with pig manure and the biochar application increased STP, SAP, and SMBP by 10.5%–48.3%, 30.2%–236.0%, and 19.8%–72.4%,respectively, mainly owing to increased soil P and organic carbon inputs;adding a half dose of N and no N input(reduced N treatments) increased STP and SAP by 2.6%–7.5% and 19.8%–33.7%, respectively, due to decreased soil P outputs. Thus, soil P availability was greatly affected by soil P input and use. The continuous flooding water regime without straw addition significantly decreased SMBP by 11.4% compared to corresponding treatments under a mid-season drainage water regime. Total P uptake by rice grains and straws at the harvest stage increased under straw incorporation and under pig manure application, but decreased under the reduced N treatments and under biochar application at a rate of 48 t ha-1, compared to the control. Rice P uptake was significantly positively correlated with rice biomass, and both were positively correlated with N fertilizer application rates, SAP, SMBP, and STP. Phosphorus use efficiency generally increased under straw incorporation but decreased under the reduced N treatments and under the manure application(with excessive P input), compared to the control. These results 展开更多
Condition assessment is one of the most significant techniques of the equipment’s health management.Also,in PHM methodology cycle,which is a developed form of CBM,condition assessment is the most important step of th...Condition assessment is one of the most significant techniques of the equipment’s health management.Also,in PHM methodology cycle,which is a developed form of CBM,condition assessment is the most important step of this cycle.In this paper,the remaining useful life of the equipment is calculated using the combination of sensor information,determination of degradation state and forecasting the proposed health index.The combination of sensor information has been carried out using a new approach to determining the probabilities in the Dempster-Shafer combination rules and fuzzy c-means clustering method.Using the simulation and forecasting of extracted vibration-based health index by autoregressive Markov regime switching(ARMRS)method,final health state is determined and the remaining useful life(RUL)is estimated.In order to evaluate the model,sensor data provided by FEMTO-ST Institute have been used.展开更多
Forests in Kenya are managed under different management regimes, including traditional community based forest management, command and control, participatory forest management, leasehold, concessions, and private. Asse...Forests in Kenya are managed under different management regimes, including traditional community based forest management, command and control, participatory forest management, leasehold, concessions, and private. Assessment of these regimes’ impact (positively or negatively) on forest conservation has not been done. The study was done to determine the impact on forest conservation of three management regimes traditional community based forest management, command and control, and participatory forest management. The survey was done through secondary data, focus group discussion, key informant interview, household survey, ecological survey, and land cover and land use analysis through GIS. The results indicate that the forest site under participatory forest management witnessed better forest management. In this site, the forest zone witnessing best management was the one near the forest station where the rangers are located and adjacent to the community that has been involved in forest management and benefited most from project intervention, an incentive for their participation in forest management. The forests under traditional community based forest management faced a high forest degradation rate. Forest under command and control regime witnessed the best forest condition improvement attributed to the management regime not allowing consumptive forest resource utilization. Each regime was best under its’ legislative framework and would facilitate better forest management and contribute to improved livelihoods without compromising forest quality. Participatory forest management was the most preferred management regime contributing to better forest management, improved community livelihoods, and formally involved communities and other stakeholders. Each regime’s appropriateness would be enhanced through stakeholder capacity building, institutional reform, adequate financial facilitation, and appropriate implementation. Therefore, adopting participatory forest management attributes to the other two management r展开更多
基金supported by the National Key Research and Development Program of China (Nos. 2016YFD0200307 and 2018YFC0213302)the Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2017418)。
文摘Agronomic practices affect soil phosphorus(P) availability, P uptake by plants, and subsequently the efficiency of P use. A field experiment was carried out to investigate the effects of various agronomic practices(straw incorporation, paddy water management, nitrogen(N) fertilizer dose, manure application,and biochar addition) on soil P availability(e.g., soil total P(STP), soil available P(SAP), soil microbial biomass P(SMBP), and rice P uptake as well as P use efficiency(PUE)) over four cropping seasons in a rice-rice cropping system, in subtropical central China. Compared to the non-straw treatment(control,using full dose of chemical N fertilizer), straw incorporation increased SAP and SMBP by 9.3%–18.5% and 15.5%–35.4%, respectively;substituting half the chemical N fertilizer dose with pig manure and the biochar application increased STP, SAP, and SMBP by 10.5%–48.3%, 30.2%–236.0%, and 19.8%–72.4%,respectively, mainly owing to increased soil P and organic carbon inputs;adding a half dose of N and no N input(reduced N treatments) increased STP and SAP by 2.6%–7.5% and 19.8%–33.7%, respectively, due to decreased soil P outputs. Thus, soil P availability was greatly affected by soil P input and use. The continuous flooding water regime without straw addition significantly decreased SMBP by 11.4% compared to corresponding treatments under a mid-season drainage water regime. Total P uptake by rice grains and straws at the harvest stage increased under straw incorporation and under pig manure application, but decreased under the reduced N treatments and under biochar application at a rate of 48 t ha-1, compared to the control. Rice P uptake was significantly positively correlated with rice biomass, and both were positively correlated with N fertilizer application rates, SAP, SMBP, and STP. Phosphorus use efficiency generally increased under straw incorporation but decreased under the reduced N treatments and under the manure application(with excessive P input), compared to the control. These results
文摘Condition assessment is one of the most significant techniques of the equipment’s health management.Also,in PHM methodology cycle,which is a developed form of CBM,condition assessment is the most important step of this cycle.In this paper,the remaining useful life of the equipment is calculated using the combination of sensor information,determination of degradation state and forecasting the proposed health index.The combination of sensor information has been carried out using a new approach to determining the probabilities in the Dempster-Shafer combination rules and fuzzy c-means clustering method.Using the simulation and forecasting of extracted vibration-based health index by autoregressive Markov regime switching(ARMRS)method,final health state is determined and the remaining useful life(RUL)is estimated.In order to evaluate the model,sensor data provided by FEMTO-ST Institute have been used.
文摘Forests in Kenya are managed under different management regimes, including traditional community based forest management, command and control, participatory forest management, leasehold, concessions, and private. Assessment of these regimes’ impact (positively or negatively) on forest conservation has not been done. The study was done to determine the impact on forest conservation of three management regimes traditional community based forest management, command and control, and participatory forest management. The survey was done through secondary data, focus group discussion, key informant interview, household survey, ecological survey, and land cover and land use analysis through GIS. The results indicate that the forest site under participatory forest management witnessed better forest management. In this site, the forest zone witnessing best management was the one near the forest station where the rangers are located and adjacent to the community that has been involved in forest management and benefited most from project intervention, an incentive for their participation in forest management. The forests under traditional community based forest management faced a high forest degradation rate. Forest under command and control regime witnessed the best forest condition improvement attributed to the management regime not allowing consumptive forest resource utilization. Each regime was best under its’ legislative framework and would facilitate better forest management and contribute to improved livelihoods without compromising forest quality. Participatory forest management was the most preferred management regime contributing to better forest management, improved community livelihoods, and formally involved communities and other stakeholders. Each regime’s appropriateness would be enhanced through stakeholder capacity building, institutional reform, adequate financial facilitation, and appropriate implementation. Therefore, adopting participatory forest management attributes to the other two management r
