目的】探讨长期定位施磷条件下小麦产量、土壤有效磷水平及籽粒养分含量变化,为旱地小麦合理施用磷肥,提高产量、改善品质提供理论依据。【方法】基于2004年在黄土高原开始的长期定位试验,于2014—2015、2015—2016和2016—2017连续3年...目的】探讨长期定位施磷条件下小麦产量、土壤有效磷水平及籽粒养分含量变化,为旱地小麦合理施用磷肥,提高产量、改善品质提供理论依据。【方法】基于2004年在黄土高原开始的长期定位试验,于2014—2015、2015—2016和2016—2017连续3年取样,研究不同施磷量对小麦产量,生物量,产量构成,籽粒氮、磷、钾含量,土壤有效磷含量及磷吸收利用的影响。【结果】与不施磷相比,长期施磷使小麦产量平均提高67%,生物量提高58%,穗数和穗粒数分别增加64%和8%,而千粒重降低7%。施磷量与小麦产量、生物量呈抛物线关系,获得最高产量6 465 kg·hm^(-2)的施磷量为144 kg P_2O_5·hm^(-2)。籽粒氮含量随施磷量增加而降低,磷和钾含量随施磷量增加而提高。土壤有效磷含量与施磷量呈显著正相关,小麦获得最高产量时播前和成熟期有效磷含量分别为16.9和20.4 mg·kg^(-1)。磷吸收利用效率随施磷量增加而降低,施磷量提高50 kg P_2O_5·hm^(-2),需磷量增加0.4 g·kg^(-1),磷收获指数降低1.3%,生理效率降低45.1 kg·kg^(-1)。【结论】综合考虑小麦的籽粒产量和关键养分含量,研究区域旱地小麦应以95%的最高产量为实际生产目标,施磷量为94 kg P_2O_5·hm^(-2),播前土壤有效磷为12.0 mg·kg^(-1),成熟期为13.8 mg·kg^(-1)。展开更多
A two-year lysimeter study was conducted to study the effects of different fertilizers and soils on nitrogen leaching loss in a double rice cropping system by considering three major types of paddy soils from the Dong...A two-year lysimeter study was conducted to study the effects of different fertilizers and soils on nitrogen leaching loss in a double rice cropping system by considering three major types of paddy soils from the Dongting Lake area. The results showed that N concentration in the leachate did not differ significantly among the treatments of urea, controlled release N fertilizer and pig manure and that all these fertilizers produced higher total nitrogen （TN） concentrations in the leachate compared to the case where no fertilizer was applied. The TN leaching loss following urea treatment accounted for 2.28%, 0.66%, and 1.50% of the amount of N applied in the alluvial sandy loamy paddy soil （ASL）, purple calcareous clayey paddy soil （PCC）, and reddish-yellow loamy paddy soil （RYL）, respectively. Higher TN loss was found to be correlated with the increased leachate volume in ASL compared with RYL, and the lowest TN loss was observed in the PCC, in which the lowest leachate volume and TN concentration were observed. Organic N and NH＋-N were the major forms of N depleted through leachate, accounting for 56.8% and 39.7% of TN losses, respectively. Accordingly, soil-specific fertilization regimens are recommended; in particular, the maximum amount of fertilizer should be optimized for sandy soils with a high infiltration rate. To avoid a high N leaching loss from rice fields, organic N fertilizers such as urea or coated urea should primarily be used for surface topdressing or shallow-layer application and not for deep-layer application.展开更多
Soil erosion affects soil productivity and environmental quality.A laboratory research experiment under simulated heavy rainfall with tap water was conducted to investigate the effects of anionic polyacrylamide(PAM) a...Soil erosion affects soil productivity and environmental quality.A laboratory research experiment under simulated heavy rainfall with tap water was conducted to investigate the effects of anionic polyacrylamide(PAM) application rates(0,0.5,1.0,and 2.0 g m-2) and molecular weights(12 and 18 Mg mol-1) on runoff,soil erosion,and soil nutrient loss at a slope of 5°.The results showed the two lower rates of PAM application decreased runoff while the highest rate increased runoff as compared with the control.Sediment concentration and soil mass loss increased significantly with the increasing PAM application rate.Compared with the control,PAM application decreased K+,NH4+,and NO3-concentrations in sediment and K+ and NH+4 concentrations in runoff,but significantly increased the mass losses of K+,NH4+,and NO-3 over soil surface except for the NH4+ at PAM application rate lower than 1.0 g m-2.PAM application decreased the proportion of K+ loss with runoff to its total mass loss over soil surface from 60.1% to 16.4%.However,it did not affect the NH4+ and NO3-losses with runoff,and more than 86% of them were lost with runoff.A higher PAM molecular weight resulted in less soil erosion and K+ mass loss but had little effect on runoff and NH+4 and NO3-losses.PAM application did not prevent soil erosion and the mass losses of K+ and NO3-under experimental conditions.展开更多
探索黑糯玉米硒吸收利用和籽粒营养品质对叶面喷施有机硒肥的响应,对生产中合理施用硒肥,进而支撑山西“特”“优”农业高质量发展具有重要意义。本研究以品种晋鲜糯8号为试验材料,于2020—2021年连续2年在山西晋中黑糯玉米典型种植区...探索黑糯玉米硒吸收利用和籽粒营养品质对叶面喷施有机硒肥的响应,对生产中合理施用硒肥,进而支撑山西“特”“优”农业高质量发展具有重要意义。本研究以品种晋鲜糯8号为试验材料,于2020—2021年连续2年在山西晋中黑糯玉米典型种植区开展田间试验,设置一次喷施不同用量有机硒0、6和12 g Se hm^(-2),以及喷施量12 g Se hm^(-2)条件下分2次喷施,共4个处理,研究叶喷有机硒对黑糯玉米产量、硒吸收利用、籽粒花青素和铁锰铜锌含量的影响。结果表明,喷硒量和喷硒次数对黑糯玉米鲜食期籽粒产量和成熟期地上部各器官干物质量无影响。相比不喷硒,喷硒可提高鲜食期籽粒和成熟期地上部各器官硒含量、硒积累。喷硒12 g Se hm^(-2)时,籽粒硒含量达到满足人体硒营养需求的最低目标值100μg kg^(–1),增幅最大,介于110~181μg kg^(–1)。成熟期,植株各器官硒积累从高到低依次为叶片、籽粒、茎秆、苞叶、穗轴。喷硒12 g Se hm^(-2),分2次喷施的平均籽粒硒强化指数和籽粒硒回收率分别为6.95(μg kg^(–1))(g hm^(-2))^(–1)和2.4%,优于1次喷施。同时,鲜食期籽粒花青素和铁锰锌含量也最高, 2年平均值分别为209、27.9、15.9和22.8 mg kg^(–1),但各处理间籽粒铜含量无差异。因此,兼顾硒吸收利用和籽粒营养品质同步提升,该区黑糯玉米生产中叶喷有机硒肥用量至少应不低于12 g Se hm^(-2),且分2次喷施效果较优。展开更多
In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive ...In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/1, respectively.展开更多
Understanding bacterial transportation in unsaturated soil is helpful for reducing and avoiding pathogenic contamination that may be induced by irrigation with reclaimed waste water and for developing better irrigatio...Understanding bacterial transportation in unsaturated soil is helpful for reducing and avoiding pathogenic contamination that may be induced by irrigation with reclaimed waste water and for developing better irrigation management practic-es. Experiments were conducted to study the transport of a typical bacterium,Escherichia coli （E. coli）, in a sandy and a sandy loam soil under different application rates and input concentrations. A 30° wedge-shaped plexiglass container was used to represent one twelfth of the complete cylinder in the experiments. The apparent cylindrical application rate varied from 1.05 to 5.76 L h–1 and the input concentration ofE. coli from magnitude of 102 to 107 colony-forming unit （CFU） mL–1. For a given volume of water applied, an increase in application rate resulted in an increase in the wetted radius and a decrease in the wetted depth. In the sandy loam soil, the water spread out in a circular-arc shaped saturated zone on the surface, and the ultimate saturated entry radius increased with the application rate. An increasing application rate of water suspended bacteria alowed a more rapid transport of bacteria, thus acceleratingE. coli transport rate and resulting in a larger distributed volume ofE. coli for both soil types. For the sandy soil, more than 70% of theE. coli that was de-tected within the entire wetted volume concentrated in the range of 10 cm from the point source, and the concentration of E. colidecreased greatly as the distance from the point source increased. More than 98% of theE. coli was detected in a range of 5 cm around the saturated wetted zone for the sandy loam soil. For both soil types tested, an extremely high concentration ofE. coli was observed in the proximity of the point source, and the peak value increased with an increased input concentration. In principle, using an emitter with relative lower application rate would be effective to restrictE. coli transport. To reduce bacterial concentration in the sewage eflfuent during wastewater treatme展开更多
文摘目的】探讨长期定位施磷条件下小麦产量、土壤有效磷水平及籽粒养分含量变化,为旱地小麦合理施用磷肥,提高产量、改善品质提供理论依据。【方法】基于2004年在黄土高原开始的长期定位试验,于2014—2015、2015—2016和2016—2017连续3年取样,研究不同施磷量对小麦产量,生物量,产量构成,籽粒氮、磷、钾含量,土壤有效磷含量及磷吸收利用的影响。【结果】与不施磷相比,长期施磷使小麦产量平均提高67%,生物量提高58%,穗数和穗粒数分别增加64%和8%,而千粒重降低7%。施磷量与小麦产量、生物量呈抛物线关系,获得最高产量6 465 kg·hm^(-2)的施磷量为144 kg P_2O_5·hm^(-2)。籽粒氮含量随施磷量增加而降低,磷和钾含量随施磷量增加而提高。土壤有效磷含量与施磷量呈显著正相关,小麦获得最高产量时播前和成熟期有效磷含量分别为16.9和20.4 mg·kg^(-1)。磷吸收利用效率随施磷量增加而降低,施磷量提高50 kg P_2O_5·hm^(-2),需磷量增加0.4 g·kg^(-1),磷收获指数降低1.3%,生理效率降低45.1 kg·kg^(-1)。【结论】综合考虑小麦的籽粒产量和关键养分含量,研究区域旱地小麦应以95%的最高产量为实际生产目标,施磷量为94 kg P_2O_5·hm^(-2),播前土壤有效磷为12.0 mg·kg^(-1),成熟期为13.8 mg·kg^(-1)。
基金Supported by the National Natural Science Foundation of China (No.40771120)the National Key Technologies Research and Development Program of China during the 11th Five-Year Plan Period (No.2007BAD87B11)
文摘A two-year lysimeter study was conducted to study the effects of different fertilizers and soils on nitrogen leaching loss in a double rice cropping system by considering three major types of paddy soils from the Dongting Lake area. The results showed that N concentration in the leachate did not differ significantly among the treatments of urea, controlled release N fertilizer and pig manure and that all these fertilizers produced higher total nitrogen （TN） concentrations in the leachate compared to the case where no fertilizer was applied. The TN leaching loss following urea treatment accounted for 2.28%, 0.66%, and 1.50% of the amount of N applied in the alluvial sandy loamy paddy soil （ASL）, purple calcareous clayey paddy soil （PCC）, and reddish-yellow loamy paddy soil （RYL）, respectively. Higher TN loss was found to be correlated with the increased leachate volume in ASL compared with RYL, and the lowest TN loss was observed in the PCC, in which the lowest leachate volume and TN concentration were observed. Organic N and NH＋-N were the major forms of N depleted through leachate, accounting for 56.8% and 39.7% of TN losses, respectively. Accordingly, soil-specific fertilization regimens are recommended; in particular, the maximum amount of fertilizer should be optimized for sandy soils with a high infiltration rate. To avoid a high N leaching loss from rice fields, organic N fertilizers such as urea or coated urea should primarily be used for surface topdressing or shallow-layer application and not for deep-layer application.
基金Supported by the National Natural Science Foundation of China (No.40635027)the Fund of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,China (No.10501-169)
文摘Soil erosion affects soil productivity and environmental quality.A laboratory research experiment under simulated heavy rainfall with tap water was conducted to investigate the effects of anionic polyacrylamide(PAM) application rates(0,0.5,1.0,and 2.0 g m-2) and molecular weights(12 and 18 Mg mol-1) on runoff,soil erosion,and soil nutrient loss at a slope of 5°.The results showed the two lower rates of PAM application decreased runoff while the highest rate increased runoff as compared with the control.Sediment concentration and soil mass loss increased significantly with the increasing PAM application rate.Compared with the control,PAM application decreased K+,NH4+,and NO3-concentrations in sediment and K+ and NH+4 concentrations in runoff,but significantly increased the mass losses of K+,NH4+,and NO-3 over soil surface except for the NH4+ at PAM application rate lower than 1.0 g m-2.PAM application decreased the proportion of K+ loss with runoff to its total mass loss over soil surface from 60.1% to 16.4%.However,it did not affect the NH4+ and NO3-losses with runoff,and more than 86% of them were lost with runoff.A higher PAM molecular weight resulted in less soil erosion and K+ mass loss but had little effect on runoff and NH+4 and NO3-losses.PAM application did not prevent soil erosion and the mass losses of K+ and NO3-under experimental conditions.
文摘探索黑糯玉米硒吸收利用和籽粒营养品质对叶面喷施有机硒肥的响应,对生产中合理施用硒肥,进而支撑山西“特”“优”农业高质量发展具有重要意义。本研究以品种晋鲜糯8号为试验材料,于2020—2021年连续2年在山西晋中黑糯玉米典型种植区开展田间试验,设置一次喷施不同用量有机硒0、6和12 g Se hm^(-2),以及喷施量12 g Se hm^(-2)条件下分2次喷施,共4个处理,研究叶喷有机硒对黑糯玉米产量、硒吸收利用、籽粒花青素和铁锰铜锌含量的影响。结果表明,喷硒量和喷硒次数对黑糯玉米鲜食期籽粒产量和成熟期地上部各器官干物质量无影响。相比不喷硒,喷硒可提高鲜食期籽粒和成熟期地上部各器官硒含量、硒积累。喷硒12 g Se hm^(-2)时,籽粒硒含量达到满足人体硒营养需求的最低目标值100μg kg^(–1),增幅最大,介于110~181μg kg^(–1)。成熟期,植株各器官硒积累从高到低依次为叶片、籽粒、茎秆、苞叶、穗轴。喷硒12 g Se hm^(-2),分2次喷施的平均籽粒硒强化指数和籽粒硒回收率分别为6.95(μg kg^(–1))(g hm^(-2))^(–1)和2.4%,优于1次喷施。同时,鲜食期籽粒花青素和铁锰锌含量也最高, 2年平均值分别为209、27.9、15.9和22.8 mg kg^(–1),但各处理间籽粒铜含量无差异。因此,兼顾硒吸收利用和籽粒营养品质同步提升,该区黑糯玉米生产中叶喷有机硒肥用量至少应不低于12 g Se hm^(-2),且分2次喷施效果较优。
基金This work was supported by the National Natural Science Foundation of China (No. 30170261)the Natural Science Foundation of Tianjin (No. 023800411).
文摘In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/1, respectively.
基金financially supported by the National Natural Science Foundation of China(51339007)
文摘Understanding bacterial transportation in unsaturated soil is helpful for reducing and avoiding pathogenic contamination that may be induced by irrigation with reclaimed waste water and for developing better irrigation management practic-es. Experiments were conducted to study the transport of a typical bacterium,Escherichia coli （E. coli）, in a sandy and a sandy loam soil under different application rates and input concentrations. A 30° wedge-shaped plexiglass container was used to represent one twelfth of the complete cylinder in the experiments. The apparent cylindrical application rate varied from 1.05 to 5.76 L h–1 and the input concentration ofE. coli from magnitude of 102 to 107 colony-forming unit （CFU） mL–1. For a given volume of water applied, an increase in application rate resulted in an increase in the wetted radius and a decrease in the wetted depth. In the sandy loam soil, the water spread out in a circular-arc shaped saturated zone on the surface, and the ultimate saturated entry radius increased with the application rate. An increasing application rate of water suspended bacteria alowed a more rapid transport of bacteria, thus acceleratingE. coli transport rate and resulting in a larger distributed volume ofE. coli for both soil types. For the sandy soil, more than 70% of theE. coli that was de-tected within the entire wetted volume concentrated in the range of 10 cm from the point source, and the concentration of E. colidecreased greatly as the distance from the point source increased. More than 98% of theE. coli was detected in a range of 5 cm around the saturated wetted zone for the sandy loam soil. For both soil types tested, an extremely high concentration ofE. coli was observed in the proximity of the point source, and the peak value increased with an increased input concentration. In principle, using an emitter with relative lower application rate would be effective to restrictE. coli transport. To reduce bacterial concentration in the sewage eflfuent during wastewater treatme
