Severe resource shortage and waste of resource in agricultural production make it necessary to assess efficiency to increase productivity with high efficiency and ensure sustainable agricultural development. This pape...Severe resource shortage and waste of resource in agricultural production make it necessary to assess efficiency to increase productivity with high efficiency and ensure sustainable agricultural development. This paper adopted an input-oriented data envelopment analysis(DEA) method with the assumption of variable returns to scale to evaluate agricultural production efficiency of 100 major irrigation districts in Northwest China in 2010.Major findings of this paper were as follows: firstly, the average value of total technical efficiency, pure technical efficiency and scale efficiency of those irrigation districts in Northwest China were 0.770, 0.825 and 0.931,respectively; secondly, 30% of irrigation districts were technically efficient, while 42% and 32% of them showed pure technical and scale efficiency respectively. Among inefficient decision-making units, total technical efficiency score varied from 0.313 to 0.966, showing significant geographical differences, but geographical differences of pure technical efficiency was more consistent with that of total technical efficiency; thirdly, input redundancy was evident. Inputs of agricultural population, irrigation area,green water, blue water, consumption of fertilizer and agricultural machinery could be reduced by 34.88%,40.19%, 43.85%, 47.10%, 41.53% and 42.21% respectively without reducing agricultural outputs. Furthermore,irrigation area, green water and blue water had relatively high slack movement though Northwest China which is short of water resources. Based on these results, this paper drew the following conclusions: First, there is huge potential for Northwest China to improve its agricultural production efficiency, and agro-technology not input scale had greater influence on improvement. Second, farmers needed proper guidance in order to reduce agricultural inputs and it is time to centralize agricultural management for overall agricultural inputs regulation and control.展开更多
To investigate the environmental quality of the urban surface soil in Yinchuan City, the capital of Ningxia Hui Autonomous Region （Ningxia）, China, we sampled surface soil and measured the concentrations of 8 toxic ...To investigate the environmental quality of the urban surface soil in Yinchuan City, the capital of Ningxia Hui Autonomous Region （Ningxia）, China, we sampled surface soil and measured the concentrations of 8 toxic metals （Pb, Cr, Cu, Zn, Co, Bi, Ni and V） using X-ray fluorescence spectrometry. The enrichment characteristics and sources of these toxic metals in the soil were analyzed by the enrichment factor （EF） and multivariate statistical analysis. The results showed that the mean concentrations of these toxic metals in the soil samples were 25.0, 109.1, 16.8, 26.0, 37.2, 2.7, 25.3 and 59.9 mg/kg for Pb, Cr, Cu, Zn, Co, Bi, Ni and V, respectively, which were 1.2, 1.8, 0.8, 0.4, 3.2, 8.7, 0.7 and 0.8 times of the corresponding background values of Ningxia soil, respectively. The variations of Pb, Zn, Co, Bi and Ni concentrations in the surface soil of Yinchuan were larger than those of the other metals. Our results also showed that the toxic metals investigated in the soil had different enrichment levels. Both Co and Bi were significantly enriched, whereas Cr was only moderately enriched in the soil. There was a deficiency or minimal enrichment of the other toxic metals in the soil. Source analysis results based on the concentration, enrichment characteristics and multivariate statistical analysis indicated that Cr, V and Ni originated from a combination of fossil fuel combustion, traffic pollution and natural occurrence. Pb, Cu and Zn were predominantly derived from natural and traffic sources, while Co and Bi primarily originated from construction sources.展开更多
Research for changes of soil water and salt is an important content of land sciences and agriculture sciences in arid and semi arid regions. In this paper, sampling in actual agricultural fields, laboratory analysis o...Research for changes of soil water and salt is an important content of land sciences and agriculture sciences in arid and semi arid regions. In this paper, sampling in actual agricultural fields, laboratory analysis of soil samples and statistical analysis methods are used to quantitatively analyze soil salinity changes under different ir- rigation methods throughout the cotton growing season in Shihezi reclamation area. The results show that irrigation methods play an important role in soil salt content in the surface soil （0-20 cm） and sub-deep soil （40-60 cm）, fol- lowed by deep soil layer （60-100 cm） and root soil layer （20-40 cm）. Furrow irrigation yields the maximum soil salt content in deep layer （60-100 cm） or sub-deep layer （40-60 cm） and the maximum salinity occurs in the first half of the cotton growing season （June or earlier）. In contrast, drip irrigation yields the maximum soil salinity in the root layer （20-40 cm） or sub-deep （40-60 cm）, and this usually appears in the second half growing season （July or af- ter）. The ratio of chloride ion to sulfate ion （Cl-/SO2- 4） and its change in the soil are on the rise under furrow irrigation while the value first increased and then decreased with a peak point in June under drip irrigation. This suggests that furrow irrigation may shift the type of soil salinization to chloride ion type moreso than drip irrigation. Potassium and sodium ion contents of the soil show that soil sodium＋potassium content will drop after the first rise under furrow irrigation and the value is manifested by fluctuations under drip irrigation. Potassium＋sodium content change is relatively more stable in the whole cotton growth period under irrigation methods. The maximum of sodium and potassium content of the soil usually occur in deep soil layer （60-100 cm） or sub-deep soil layer （40-60 cm） in most sample points under furrow irrigation while it is inconsistent in different sample points under drip irrigation. A non- parametric test for paired samples is used to analyze differences of soil salt content under different irrigation methods. This analysis shows that the impact of irrigation on soil salinity is most significant in July, followed by August, June, May, and April in most sample points. The most significant impact of irrigation methods occurs in the surface soil layer （0-20 cm）, followed by deep layer （60-100 cm）, root layer （20-40 cm） and sub-deep （40-60 cm）. These conclusions will be benefitial for mitigation of soil salinization, irrigation and fertilization and sustainable land use.展开更多
基金supported by the National Key Research and Development Program (2016YFC0400201, 2016YFC0400 205)the ‘111’ Project from the Ministry of Education of China and the State Administration of Foreign Experts Affairs of China (B12007)the Science and Technology Planning Project of Yangling Demonstration Zone (2015NY-16)
文摘Severe resource shortage and waste of resource in agricultural production make it necessary to assess efficiency to increase productivity with high efficiency and ensure sustainable agricultural development. This paper adopted an input-oriented data envelopment analysis(DEA) method with the assumption of variable returns to scale to evaluate agricultural production efficiency of 100 major irrigation districts in Northwest China in 2010.Major findings of this paper were as follows: firstly, the average value of total technical efficiency, pure technical efficiency and scale efficiency of those irrigation districts in Northwest China were 0.770, 0.825 and 0.931,respectively; secondly, 30% of irrigation districts were technically efficient, while 42% and 32% of them showed pure technical and scale efficiency respectively. Among inefficient decision-making units, total technical efficiency score varied from 0.313 to 0.966, showing significant geographical differences, but geographical differences of pure technical efficiency was more consistent with that of total technical efficiency; thirdly, input redundancy was evident. Inputs of agricultural population, irrigation area,green water, blue water, consumption of fertilizer and agricultural machinery could be reduced by 34.88%,40.19%, 43.85%, 47.10%, 41.53% and 42.21% respectively without reducing agricultural outputs. Furthermore,irrigation area, green water and blue water had relatively high slack movement though Northwest China which is short of water resources. Based on these results, this paper drew the following conclusions: First, there is huge potential for Northwest China to improve its agricultural production efficiency, and agro-technology not input scale had greater influence on improvement. Second, farmers needed proper guidance in order to reduce agricultural inputs and it is time to centralize agricultural management for overall agricultural inputs regulation and control.
基金supported by the National Natural Science Foundation of China (41271510, 41461098)the Fundamental Research Funds for the Central Universities of China (GK201601009, 2017TS027)
文摘To investigate the environmental quality of the urban surface soil in Yinchuan City, the capital of Ningxia Hui Autonomous Region （Ningxia）, China, we sampled surface soil and measured the concentrations of 8 toxic metals （Pb, Cr, Cu, Zn, Co, Bi, Ni and V） using X-ray fluorescence spectrometry. The enrichment characteristics and sources of these toxic metals in the soil were analyzed by the enrichment factor （EF） and multivariate statistical analysis. The results showed that the mean concentrations of these toxic metals in the soil samples were 25.0, 109.1, 16.8, 26.0, 37.2, 2.7, 25.3 and 59.9 mg/kg for Pb, Cr, Cu, Zn, Co, Bi, Ni and V, respectively, which were 1.2, 1.8, 0.8, 0.4, 3.2, 8.7, 0.7 and 0.8 times of the corresponding background values of Ningxia soil, respectively. The variations of Pb, Zn, Co, Bi and Ni concentrations in the surface soil of Yinchuan were larger than those of the other metals. Our results also showed that the toxic metals investigated in the soil had different enrichment levels. Both Co and Bi were significantly enriched, whereas Cr was only moderately enriched in the soil. There was a deficiency or minimal enrichment of the other toxic metals in the soil. Source analysis results based on the concentration, enrichment characteristics and multivariate statistical analysis indicated that Cr, V and Ni originated from a combination of fossil fuel combustion, traffic pollution and natural occurrence. Pb, Cu and Zn were predominantly derived from natural and traffic sources, while Co and Bi primarily originated from construction sources.
基金National Natural Science Foundation of China(41171083/U1203181)
文摘Research for changes of soil water and salt is an important content of land sciences and agriculture sciences in arid and semi arid regions. In this paper, sampling in actual agricultural fields, laboratory analysis of soil samples and statistical analysis methods are used to quantitatively analyze soil salinity changes under different ir- rigation methods throughout the cotton growing season in Shihezi reclamation area. The results show that irrigation methods play an important role in soil salt content in the surface soil （0-20 cm） and sub-deep soil （40-60 cm）, fol- lowed by deep soil layer （60-100 cm） and root soil layer （20-40 cm）. Furrow irrigation yields the maximum soil salt content in deep layer （60-100 cm） or sub-deep layer （40-60 cm） and the maximum salinity occurs in the first half of the cotton growing season （June or earlier）. In contrast, drip irrigation yields the maximum soil salinity in the root layer （20-40 cm） or sub-deep （40-60 cm）, and this usually appears in the second half growing season （July or af- ter）. The ratio of chloride ion to sulfate ion （Cl-/SO2- 4） and its change in the soil are on the rise under furrow irrigation while the value first increased and then decreased with a peak point in June under drip irrigation. This suggests that furrow irrigation may shift the type of soil salinization to chloride ion type moreso than drip irrigation. Potassium and sodium ion contents of the soil show that soil sodium＋potassium content will drop after the first rise under furrow irrigation and the value is manifested by fluctuations under drip irrigation. Potassium＋sodium content change is relatively more stable in the whole cotton growth period under irrigation methods. The maximum of sodium and potassium content of the soil usually occur in deep soil layer （60-100 cm） or sub-deep soil layer （40-60 cm） in most sample points under furrow irrigation while it is inconsistent in different sample points under drip irrigation. A non- parametric test for paired samples is used to analyze differences of soil salt content under different irrigation methods. This analysis shows that the impact of irrigation on soil salinity is most significant in July, followed by August, June, May, and April in most sample points. The most significant impact of irrigation methods occurs in the surface soil layer （0-20 cm）, followed by deep layer （60-100 cm）, root layer （20-40 cm） and sub-deep （40-60 cm）. These conclusions will be benefitial for mitigation of soil salinization, irrigation and fertilization and sustainable land use.
