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Measurement, spatial spillover and influencing factors of agricultural carbon emissions efficiency in China
WU Haoyue, HUANG Hanjiao, HE Yu, CHEN Wenkuan
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Effects of tillage and straw returning method on the distribution of carbon and nitrogen in soil aggregates
ZHANG Yuming, HU Chunsheng, CHEN Suying, WANG Yuying, LI Xiaoxin, DONG Wenxu, LIU Xiuping, PEI Lin, ZHANG Hui
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Relationship between policy incentives, ecological cognition, and organic fertilizer application by farmers: Based on a moderated mediation model
SANG Xiance, LUO Xiaofeng, HUANG Yanzhong, TANG Lin
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Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models
YANG Jie, XIE Baopeng, ZHANG Degang
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Effects of straw returning and fertilization on soil bacterial and fungal community structures and diversities in rice-wheat rotation soil
ZHANG Hanlin, BAI Naling, ZHENG Xianqing, LI Shuangxi, ZHANG Juanqin, ZHANG Haiyun, ZHOU Sheng, SUN Huifeng, LYU Weiguang
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2014 Vol. 22, No. 7
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2014, 22(7): 749-756.
doi: 10.3724/SP.J.1011.2014.31232
Abstract:
Four tillage methods - conventional tillage without straw (CT), conventional tillage with straw incorporation (CTS), rotary tillage with straw incorporation (RTS) and no-tillage with straw mulch (NTS) - were used to study the effects of tillage on annual yield and water use efficiency in winter-wheat/summer-maize cultivation system in the North China Plain. Results showed that different tillage methods significantly influenced winter wheat yield and water use efficiency. Different tillage methods did not significantly influence yield and water use of summer maize, tillage with straw incorporation increased yield of summer maize. Although differences in winter wheat yield under RTS, CTS and CT were not significant, fewer effective panicles of winter wheat yield under NTS led to significantly lower yield, compared with other treatments. Compared with CT, NTS decreased annual yield by 5.13%, while RTS, CTS increased annual yield by 2.69% and 2.33%. The tillage methods had significant effects on soil water content in winter-wheat season, but had no impact on soil water content in summer-maize season. Also NTS improved soil water content and water storage in winter-wheat season. Compared with CT, NTS increased soil water storage by 39.07 mm and 26.65 mm in two consecutive years. In terms of crop water use, soil water accounted for the largest proportion of winter-wheat water use, followed by irrigation and precipitation. While precipitation accounted for the largest proportion of summer-maize water use, some precipitation contributed to soil water storage. NTS improved soil water storage in winter-wheat and also limited soil water use, implying that water use was lowest under NTS during winter-wheat season. Compared with CT, NTS saved 22.40 mm of soil water in winter-wheat season and NTS also had the lowest annual crop water use. There was lower winter-wheat yield under NTS, the annual water use efficiency was also lower than the other treatments. In terms of annual yield and water use efficiency, there was the need to increase winter-wheat yield under NTS thereby increasing annual production. This is critical because of the high water-saving capacity of NTS, which is a key crop cultivation issue in the North China Plain.
Four tillage methods - conventional tillage without straw (CT), conventional tillage with straw incorporation (CTS), rotary tillage with straw incorporation (RTS) and no-tillage with straw mulch (NTS) - were used to study the effects of tillage on annual yield and water use efficiency in winter-wheat/summer-maize cultivation system in the North China Plain. Results showed that different tillage methods significantly influenced winter wheat yield and water use efficiency. Different tillage methods did not significantly influence yield and water use of summer maize, tillage with straw incorporation increased yield of summer maize. Although differences in winter wheat yield under RTS, CTS and CT were not significant, fewer effective panicles of winter wheat yield under NTS led to significantly lower yield, compared with other treatments. Compared with CT, NTS decreased annual yield by 5.13%, while RTS, CTS increased annual yield by 2.69% and 2.33%. The tillage methods had significant effects on soil water content in winter-wheat season, but had no impact on soil water content in summer-maize season. Also NTS improved soil water content and water storage in winter-wheat season. Compared with CT, NTS increased soil water storage by 39.07 mm and 26.65 mm in two consecutive years. In terms of crop water use, soil water accounted for the largest proportion of winter-wheat water use, followed by irrigation and precipitation. While precipitation accounted for the largest proportion of summer-maize water use, some precipitation contributed to soil water storage. NTS improved soil water storage in winter-wheat and also limited soil water use, implying that water use was lowest under NTS during winter-wheat season. Compared with CT, NTS saved 22.40 mm of soil water in winter-wheat season and NTS also had the lowest annual crop water use. There was lower winter-wheat yield under NTS, the annual water use efficiency was also lower than the other treatments. In terms of annual yield and water use efficiency, there was the need to increase winter-wheat yield under NTS thereby increasing annual production. This is critical because of the high water-saving capacity of NTS, which is a key crop cultivation issue in the North China Plain.
2014, 22(7): 757-765.
doi: 10.3724/SP.J.1011.2014.40202
Abstract:
A considerable amount of evidence has shown that intercropping enhances biodiversity that in turn suppresses pests and diseases. However, few works have been done on exploring the possibility of intercropping rice with other crops in wetlands to reduce pest/insect damage via diversified agro-ecosystem. In this study, a field experiment was conducted to look into the effect of rice and arrowhead (Sagittaria sagittifolia) intercropping on pest/disease occurrence without use of agrochemicals, and to evaluate yield performance. Meanwhile the effects of the intercropping on the microenvironment and photosynthetic gas exchange of rice leaf were examined. Results showed that the rice/arrowhead intercropping did not effectively suppress the population growth of rice hopper and Cnaphalocrocis medinalis. However, the intercropping system significantly reduced the occurrence of rice blast and sheath blight diseases. Compared with monocropping system, the intercropping system dropped the occurrence of rice blast at elongation and heading stages significantly by 64.29% and 88.24%, respectively. Diseased hill rate of rice sheath blight at filling and milk-ripening stages also reduced under intercropping. Normally, CAT, POD and SOD activities increased when crops were subjected to pathogenic attack. In this study, CAT, POD and SOD activities were lower under intercropping than under monocropping treatments at filling and milk-ripening stages. Elevated enzyme activity under monocropping was positively related with rice defense against higher disease incidence. Analyses of micro-environmental factors showed that intercropping decreased air humidity on rice leaf surface in morning and noon periods. Meanwhile, leaf absorbed photosynthetically active radiation was higher under intercropping system for most of the daytime. The modified micro-environment benefited the depression of breeding and spread of pathogens in paddy fields. Net photosynthetic rate, transpiration rate and stomatal conductance of rice leaf were higher under intercropping system than monoculture system during most of the daytime. This suggested that intercropping improved light utilization rate and photosynthetic efficiency of rice. In the study, the land equivalent ratio of the intercropping system was 1.17. This also suggested that rice/arrowhead intercropping not only effectively reduced the occurrence of rice disease, but also produced higher crop yields and greater land use efficiency.
A considerable amount of evidence has shown that intercropping enhances biodiversity that in turn suppresses pests and diseases. However, few works have been done on exploring the possibility of intercropping rice with other crops in wetlands to reduce pest/insect damage via diversified agro-ecosystem. In this study, a field experiment was conducted to look into the effect of rice and arrowhead (Sagittaria sagittifolia) intercropping on pest/disease occurrence without use of agrochemicals, and to evaluate yield performance. Meanwhile the effects of the intercropping on the microenvironment and photosynthetic gas exchange of rice leaf were examined. Results showed that the rice/arrowhead intercropping did not effectively suppress the population growth of rice hopper and Cnaphalocrocis medinalis. However, the intercropping system significantly reduced the occurrence of rice blast and sheath blight diseases. Compared with monocropping system, the intercropping system dropped the occurrence of rice blast at elongation and heading stages significantly by 64.29% and 88.24%, respectively. Diseased hill rate of rice sheath blight at filling and milk-ripening stages also reduced under intercropping. Normally, CAT, POD and SOD activities increased when crops were subjected to pathogenic attack. In this study, CAT, POD and SOD activities were lower under intercropping than under monocropping treatments at filling and milk-ripening stages. Elevated enzyme activity under monocropping was positively related with rice defense against higher disease incidence. Analyses of micro-environmental factors showed that intercropping decreased air humidity on rice leaf surface in morning and noon periods. Meanwhile, leaf absorbed photosynthetically active radiation was higher under intercropping system for most of the daytime. The modified micro-environment benefited the depression of breeding and spread of pathogens in paddy fields. Net photosynthetic rate, transpiration rate and stomatal conductance of rice leaf were higher under intercropping system than monoculture system during most of the daytime. This suggested that intercropping improved light utilization rate and photosynthetic efficiency of rice. In the study, the land equivalent ratio of the intercropping system was 1.17. This also suggested that rice/arrowhead intercropping not only effectively reduced the occurrence of rice disease, but also produced higher crop yields and greater land use efficiency.
2014, 22(7): 766-773.
doi: 10.3724/SP.J.1011.2014.40377
Abstract:
To explore the biological indices of soil fertility and quality evaluation of purple arid hillside field in the Three Gorges Reservoir of China, the contents of soil microbial carbon (SMBC) and soil microbial nitrogen (SMBN) in crop-mulberry agro-forest system in purple arid hillside field in the Three Gorges Reservoir was studied. The study used the arid hillside crop field protected by mulberry as a typical soil and water conservation mode to determine the biological indices of soil fertility and quality. The experiment consisted of four treatments, which were CT treatment (crops were planted along transverse slope), T1 treatment (crops were planted along transverse slope with mulberry trees on upper-slope and lower-slope), T2 treatment (crops were planted along transverse slope with mulberry trees on upper-slope, middle-slope and lower-slope); T3 treatment (crops was planted along transverse slope with mulberry trees on middle-slope and the four sides of the slope. The results showed that slope length and layout of mulberry caused significant differences in SMBC and SMBN contents. The T1 treatment significantly limited the contribution of SMBN to total nitrogen but averagely increased SMBC by 23.43 mg·kg-1. Also the treatment T3 significantly reduced microbial quotient and averagely increased SMBN by 21.81 mg·kg-1. Furthermore, soil microbial biomass was highly significantly correlated with soil carbon and nitrogen in treatment CT. However, SMBC and SMBN in different layouts of mulberry were largely not significantly correlated with soil carbon and nitrogen in purple arid hillside field crop-mulberry system. Therefore while hillside field crop-mulberry modes increased soil microbial biomass to some extent, the viability between SMBN and SMBC in purple arid hillside field crop-mulberry system in the Three Gorges Reservoir was not consistent. The study showed that both SMBN and SMBC were datable evaluation indices of soil quality in purple arid hillside fields.
To explore the biological indices of soil fertility and quality evaluation of purple arid hillside field in the Three Gorges Reservoir of China, the contents of soil microbial carbon (SMBC) and soil microbial nitrogen (SMBN) in crop-mulberry agro-forest system in purple arid hillside field in the Three Gorges Reservoir was studied. The study used the arid hillside crop field protected by mulberry as a typical soil and water conservation mode to determine the biological indices of soil fertility and quality. The experiment consisted of four treatments, which were CT treatment (crops were planted along transverse slope), T1 treatment (crops were planted along transverse slope with mulberry trees on upper-slope and lower-slope), T2 treatment (crops were planted along transverse slope with mulberry trees on upper-slope, middle-slope and lower-slope); T3 treatment (crops was planted along transverse slope with mulberry trees on middle-slope and the four sides of the slope. The results showed that slope length and layout of mulberry caused significant differences in SMBC and SMBN contents. The T1 treatment significantly limited the contribution of SMBN to total nitrogen but averagely increased SMBC by 23.43 mg·kg-1. Also the treatment T3 significantly reduced microbial quotient and averagely increased SMBN by 21.81 mg·kg-1. Furthermore, soil microbial biomass was highly significantly correlated with soil carbon and nitrogen in treatment CT. However, SMBC and SMBN in different layouts of mulberry were largely not significantly correlated with soil carbon and nitrogen in purple arid hillside field crop-mulberry system. Therefore while hillside field crop-mulberry modes increased soil microbial biomass to some extent, the viability between SMBN and SMBC in purple arid hillside field crop-mulberry system in the Three Gorges Reservoir was not consistent. The study showed that both SMBN and SMBC were datable evaluation indices of soil quality in purple arid hillside fields.
2014, 22(7): 774-781.
doi: 10.3724/SP.J.1011.2014.40110
Abstract:
The biological characteristics of population of rice 'Xiangzhaoxian 45' of throwing transplanting under three nitrogen levels [N1: 105 kg(N)·hm-2 (low nitrogen dose); N2: 135 kg(N)·hm-2 (low nitrogen dose); N3: 165 kg(N)·hm-2 (regular nitrogen dose)] combined with 3 seedling densities [M1: 0.27 million hills per hectare (regular seedling rate); M2: 0.315 million hills per hectare (high seedling rate); M3: 0.36 million hills per hectare (high seedling rate)] in a split-plot trial field were compared. The results showed that treatment of high seedling rate with low nitrogen rate (N2M3) were the best combination for high yield. Plant height and growth period increased with increasing nitrogen dose, but not significantly changed with increasing seedling density. The growth period under N3 was 7.0 days and 3.4 days longer than that under N2 and N1, respectively. Tiller number increased with increasing nitrogen rate and dropped with increasing seedling density. Regression analysis showed quadratic polynomial relationship among nitrogen application rate (X1), seedling density (X2) and yield (Y). The ma-ximum yield occurred at Y = 8.60 t·hm-2, corresponding with X1 = 127.5 kg(N)·hm-2 of nitrogen rate and X2 = 0.48 million hills per hectare of rice seedling density, it's yield was similar to N2M3, and it was 22.7% reduction in nitrogen rate in comparison with regular nitrogen (N3). Thus the best nitrogen application rate for early rice was 127.5-135 kg(N)·hm-2 and the best seedling density was 3.60 × 105 - 4.80 × 105 hills·hm-2. The study showed that increasing seedling rate and decreasing nitrogen rate could lay the basis of early rice cultivation for maximum yield in the study area. In summary, the time contradiction between double season rice of throwing transplanting could be solved by increasing seedlings rate and decreasing nitrogen rate in early rice fields. This benefited low environmental pollution and alleviated eutrophication of water agro-ecosystems.
The biological characteristics of population of rice 'Xiangzhaoxian 45' of throwing transplanting under three nitrogen levels [N1: 105 kg(N)·hm-2 (low nitrogen dose); N2: 135 kg(N)·hm-2 (low nitrogen dose); N3: 165 kg(N)·hm-2 (regular nitrogen dose)] combined with 3 seedling densities [M1: 0.27 million hills per hectare (regular seedling rate); M2: 0.315 million hills per hectare (high seedling rate); M3: 0.36 million hills per hectare (high seedling rate)] in a split-plot trial field were compared. The results showed that treatment of high seedling rate with low nitrogen rate (N2M3) were the best combination for high yield. Plant height and growth period increased with increasing nitrogen dose, but not significantly changed with increasing seedling density. The growth period under N3 was 7.0 days and 3.4 days longer than that under N2 and N1, respectively. Tiller number increased with increasing nitrogen rate and dropped with increasing seedling density. Regression analysis showed quadratic polynomial relationship among nitrogen application rate (X1), seedling density (X2) and yield (Y). The ma-ximum yield occurred at Y = 8.60 t·hm-2, corresponding with X1 = 127.5 kg(N)·hm-2 of nitrogen rate and X2 = 0.48 million hills per hectare of rice seedling density, it's yield was similar to N2M3, and it was 22.7% reduction in nitrogen rate in comparison with regular nitrogen (N3). Thus the best nitrogen application rate for early rice was 127.5-135 kg(N)·hm-2 and the best seedling density was 3.60 × 105 - 4.80 × 105 hills·hm-2. The study showed that increasing seedling rate and decreasing nitrogen rate could lay the basis of early rice cultivation for maximum yield in the study area. In summary, the time contradiction between double season rice of throwing transplanting could be solved by increasing seedlings rate and decreasing nitrogen rate in early rice fields. This benefited low environmental pollution and alleviated eutrophication of water agro-ecosystems.
2014, 22(7): 782-789.
doi: 10.3724/SP.J.1011.2014.40007
Abstract:
To clarify the characteristics of carbon and nitrogen metabolism in wheat plants under different nitrogen application and the relationship between carbon metabolism and wheat scab, a field experiment was conducted in Yuzhou County of Henan Province using 5 nitrogen rates of 0 kg(N) hm-2, 120 kg(N) hm-2, 180 kg(N) hm-2, 240 kg(N) hm-2, 360 kg(N) hm-2 and two winter wheat genotypes of multi-spike cultivar 'Yumai49-198' (YM49-198) and big spike variety 'Zhoumai16' (ZM16). The results indicated that the soluble sugar content and C/N from wintering to flowering stages showed a "V" type, and was lowest at jointing stage, with the lowest values of 80-200 mg·g-1 and 3-10, respectively, for two cultivars. The maximum differences among different treatments appeared at flowering stage, when the soluble sugar content and C/N of nitrogen treatments were 15.4%?47.7%, 24.5%?63.1%, respectively, lower than those of the non nitrogen treatment. The total nitrogen content increased with the increase of nitrogen application rate, and difference among treatments reached the maximum at jointing and flowering stages. The accumulation of soluble sugar and nitrogen showed an increasing trend. Correlation analysis showed that the total nitrogen content at jointing and flowering stages were significantly negatively correlated with soluble sugar content. The soluble sugar content, C/N at jointing and flowering stages showed a linear relationship with wheat scab incidence and disease index. This indicated that the carbon and nitrogen metabolism from jointing to flowering stages had a greater impact on the scab of wheat.
To clarify the characteristics of carbon and nitrogen metabolism in wheat plants under different nitrogen application and the relationship between carbon metabolism and wheat scab, a field experiment was conducted in Yuzhou County of Henan Province using 5 nitrogen rates of 0 kg(N) hm-2, 120 kg(N) hm-2, 180 kg(N) hm-2, 240 kg(N) hm-2, 360 kg(N) hm-2 and two winter wheat genotypes of multi-spike cultivar 'Yumai49-198' (YM49-198) and big spike variety 'Zhoumai16' (ZM16). The results indicated that the soluble sugar content and C/N from wintering to flowering stages showed a "V" type, and was lowest at jointing stage, with the lowest values of 80-200 mg·g-1 and 3-10, respectively, for two cultivars. The maximum differences among different treatments appeared at flowering stage, when the soluble sugar content and C/N of nitrogen treatments were 15.4%?47.7%, 24.5%?63.1%, respectively, lower than those of the non nitrogen treatment. The total nitrogen content increased with the increase of nitrogen application rate, and difference among treatments reached the maximum at jointing and flowering stages. The accumulation of soluble sugar and nitrogen showed an increasing trend. Correlation analysis showed that the total nitrogen content at jointing and flowering stages were significantly negatively correlated with soluble sugar content. The soluble sugar content, C/N at jointing and flowering stages showed a linear relationship with wheat scab incidence and disease index. This indicated that the carbon and nitrogen metabolism from jointing to flowering stages had a greater impact on the scab of wheat.
2014, 22(7): 790-797.
doi: 10.3724/SP.J.1011.2014.40070
Abstract:
Determining the factors that influence saturated hydraulic conductivity of topsoils and developing appropriate pedo-transfer functions are important prerequisites for modeling field soil water and salt movement and the amendment of soil salinization in salt-laden coastal farmlands. In order to achieve these goals, soil saturated hydraulic conductivity and a number of associated soil physico-chemical properties were measured in a typical salt-laden costal farmland. The characterization of saturated hydraulic conductivity of the soil profile was discussed and principal component analysis conducted on the soil basic properties with potential impacts on saturated hydraulic conductivity. The pedo-transfer functions suitable for indirect estimation of saturated hydraulic conductivity in the study area were established. Results indicated that soil saturated hydraulic conductivity generally exhibited a decreasing trend from surface soil to subsurface soil, and an increasing trend from subsurface soil to substratum of the soil profile. The 20?40 cm soil layer had the least saturated hydraulic conductivity, with a range of 2.75?6.73 cm·d-1. It was classified as the lowest water permeability due to the presence of soil compaction and plow pan. The profile characterization of bulk density was generally contrary to that of saturated hydraulic conductivity, and this was not surprising as bulk density represented the total state of porosity which was closely related to soil permeability. Results of correlation analysis showed that the contents of sand particles and organic matter had significant positive correlation with saturated hydraulic conductivity. Also soil bulk density, soil salinity and sodium adsorption ratio (SAR) had adverse impacts on saturated hydraulic conductivity. In addition to soil physical attributes (such as bulk density, soil porosity and soil texture), soil chemical factors (including fertility and salinity) also considerably influenced saturated hydraulic conductivity. The correlation between saturated hydraulic conductivity and soil basic properties provided the basis for further principal component analysis. The factors influencing saturated hydraulic conductivity were grouped into four principal components - soil water retention capacity component, state of soil salinity and alkalinity, soil fertility characteristics and soil texture. With a total of 78.17% of the variance explained, the explainable total variances of the four principal components were 28.91%, 21.02%, 17.59% and 10.65%, respectively. This also indicated that some important basic soil properties were not taken into account in the use of the datasets in this study. The most commonly used Vereecken pedo-transfer function exhibited satisfactory fitting and estimation performance. The prediction capability improved when soil salinity was added to soil data input for Vereecken pedo-transfer function. The modified Vereecken_1 pedo-transfer function (in which soil salinity was directly used) was the most appropriate method with the best prediction accuracy and suitability. The established Vereecken_1 pedo-transfer function in this study can be used to estimate saturated hydraulic conductivity from easily measurable or readily available soil properties such as soil sand/clay content, soil bulk density, soil salinity and soil organic matter content. The research findings provided support for indirect estimation of saturated hydraulic conductivity and numerical modeling of soil water flow and salt transport in salt-laden coastal farmlands.
Determining the factors that influence saturated hydraulic conductivity of topsoils and developing appropriate pedo-transfer functions are important prerequisites for modeling field soil water and salt movement and the amendment of soil salinization in salt-laden coastal farmlands. In order to achieve these goals, soil saturated hydraulic conductivity and a number of associated soil physico-chemical properties were measured in a typical salt-laden costal farmland. The characterization of saturated hydraulic conductivity of the soil profile was discussed and principal component analysis conducted on the soil basic properties with potential impacts on saturated hydraulic conductivity. The pedo-transfer functions suitable for indirect estimation of saturated hydraulic conductivity in the study area were established. Results indicated that soil saturated hydraulic conductivity generally exhibited a decreasing trend from surface soil to subsurface soil, and an increasing trend from subsurface soil to substratum of the soil profile. The 20?40 cm soil layer had the least saturated hydraulic conductivity, with a range of 2.75?6.73 cm·d-1. It was classified as the lowest water permeability due to the presence of soil compaction and plow pan. The profile characterization of bulk density was generally contrary to that of saturated hydraulic conductivity, and this was not surprising as bulk density represented the total state of porosity which was closely related to soil permeability. Results of correlation analysis showed that the contents of sand particles and organic matter had significant positive correlation with saturated hydraulic conductivity. Also soil bulk density, soil salinity and sodium adsorption ratio (SAR) had adverse impacts on saturated hydraulic conductivity. In addition to soil physical attributes (such as bulk density, soil porosity and soil texture), soil chemical factors (including fertility and salinity) also considerably influenced saturated hydraulic conductivity. The correlation between saturated hydraulic conductivity and soil basic properties provided the basis for further principal component analysis. The factors influencing saturated hydraulic conductivity were grouped into four principal components - soil water retention capacity component, state of soil salinity and alkalinity, soil fertility characteristics and soil texture. With a total of 78.17% of the variance explained, the explainable total variances of the four principal components were 28.91%, 21.02%, 17.59% and 10.65%, respectively. This also indicated that some important basic soil properties were not taken into account in the use of the datasets in this study. The most commonly used Vereecken pedo-transfer function exhibited satisfactory fitting and estimation performance. The prediction capability improved when soil salinity was added to soil data input for Vereecken pedo-transfer function. The modified Vereecken_1 pedo-transfer function (in which soil salinity was directly used) was the most appropriate method with the best prediction accuracy and suitability. The established Vereecken_1 pedo-transfer function in this study can be used to estimate saturated hydraulic conductivity from easily measurable or readily available soil properties such as soil sand/clay content, soil bulk density, soil salinity and soil organic matter content. The research findings provided support for indirect estimation of saturated hydraulic conductivity and numerical modeling of soil water flow and salt transport in salt-laden coastal farmlands.
2014, 22(7): 798-805.
doi: 10.3724/SP.J.1011.2014.40086
Abstract:
The technique of using Yellow River sediment to fill damaged farmlands in mining subsidence areas not only fully and rationally use Yellow River water and sediment resources, but also effectively increase farmland areas and improve regional environment. Infiltration is an important indicator for farmland soil and water conservation and nutrient retention. Lab infiltration apparatus was used to measure the vertical infiltration of reclaimed farmlands with Yellow River sediment fill. The aim of the study was to obtain the soil infiltration characteristics in Yellow River sediment fill farmland in the second year, and analyze and compare the experimental infiltration results of the first and second years of reclamation. Five infiltration models were selected to fit the characteristic curves of infiltration. The results showed that mean initial infiltration rate and mean stable infiltration rate of control farmland were 13.95 mm·min-1 and 4.36 mm·min-1, which were 1.12 times and 2.19 times higher than that of fill farmlands in the second year of reclamation. The discrepancy was caused by the compaction effect of machi- nery used in the land reclamation process. The standard deviations of initial infiltration and stable infiltration rates of fill farmlands were 1.98 mm·min-1 and 2.1 mm·min-1, significantly lower than those of control farmland (P < 0.05). Thus the infiltration capacity of fill farmlands was steadier than control land. The mean initial infiltration rate and mean stable infiltration rate of fill farmlands in the second year of reclamation were 12.48 mm·min-1 and 1.99 mm·min-1, respectively; 1.51 times and 1.43 times higher than that in the first year of reclamation. This suggested that infiltration rate of fill farmlands increased significantly (P < 0.05) after two years of corn-wheat crop rotation. Thus farming practices, root development and the activities of soil microorganisms and small animals enhanced self-recovery capacity of fill farmlands. Therefore the study proposed cultivation of corps with well-developed root system to improve soil infiltration capacity in fill farmlands. In terms of the estimation of soil infiltration rated, Mezencev model was the best for fill farmland, followed by Kostiakov model, NRCS model, Horton model and the Philip model. For control farmlands, Kostiakov model was the best, followed by Mezencev model, NRCS model, Horton model and Philip model. For both fill farmlands and control farmlands, Mezencev model had the best fit result, followed by Kostiakov model, NRCS model, Horton model and then Philip model. As the difference in assessment index between Mezencev model and Kostiakov model was small (P> 0.05), both models had small fitting errors. However, because some of the parameters of Mezencev model (a semi-empirical model) had real physical meaning, Mezencev model was considered to be better than Kostiakov model. In addition, the rankings of the models based on different assessment indices were basically similar. This led to a considerable consistency in RMSE, R2, SSE and Ajust-R2of infiltration models. This study provided research methods for determining farmland infiltration characteristics and the significant results were achieved. The results therefore provided the scientific basis for the reconstruction and improvement of fill farmland soils. The study as well provided certain guiding codes and practical values for the management of farmland irrigation and drainage.
The technique of using Yellow River sediment to fill damaged farmlands in mining subsidence areas not only fully and rationally use Yellow River water and sediment resources, but also effectively increase farmland areas and improve regional environment. Infiltration is an important indicator for farmland soil and water conservation and nutrient retention. Lab infiltration apparatus was used to measure the vertical infiltration of reclaimed farmlands with Yellow River sediment fill. The aim of the study was to obtain the soil infiltration characteristics in Yellow River sediment fill farmland in the second year, and analyze and compare the experimental infiltration results of the first and second years of reclamation. Five infiltration models were selected to fit the characteristic curves of infiltration. The results showed that mean initial infiltration rate and mean stable infiltration rate of control farmland were 13.95 mm·min-1 and 4.36 mm·min-1, which were 1.12 times and 2.19 times higher than that of fill farmlands in the second year of reclamation. The discrepancy was caused by the compaction effect of machi- nery used in the land reclamation process. The standard deviations of initial infiltration and stable infiltration rates of fill farmlands were 1.98 mm·min-1 and 2.1 mm·min-1, significantly lower than those of control farmland (P < 0.05). Thus the infiltration capacity of fill farmlands was steadier than control land. The mean initial infiltration rate and mean stable infiltration rate of fill farmlands in the second year of reclamation were 12.48 mm·min-1 and 1.99 mm·min-1, respectively; 1.51 times and 1.43 times higher than that in the first year of reclamation. This suggested that infiltration rate of fill farmlands increased significantly (P < 0.05) after two years of corn-wheat crop rotation. Thus farming practices, root development and the activities of soil microorganisms and small animals enhanced self-recovery capacity of fill farmlands. Therefore the study proposed cultivation of corps with well-developed root system to improve soil infiltration capacity in fill farmlands. In terms of the estimation of soil infiltration rated, Mezencev model was the best for fill farmland, followed by Kostiakov model, NRCS model, Horton model and the Philip model. For control farmlands, Kostiakov model was the best, followed by Mezencev model, NRCS model, Horton model and Philip model. For both fill farmlands and control farmlands, Mezencev model had the best fit result, followed by Kostiakov model, NRCS model, Horton model and then Philip model. As the difference in assessment index between Mezencev model and Kostiakov model was small (P> 0.05), both models had small fitting errors. However, because some of the parameters of Mezencev model (a semi-empirical model) had real physical meaning, Mezencev model was considered to be better than Kostiakov model. In addition, the rankings of the models based on different assessment indices were basically similar. This led to a considerable consistency in RMSE, R2, SSE and Ajust-R2of infiltration models. This study provided research methods for determining farmland infiltration characteristics and the significant results were achieved. The results therefore provided the scientific basis for the reconstruction and improvement of fill farmland soils. The study as well provided certain guiding codes and practical values for the management of farmland irrigation and drainage.
2014, 22(7): 806-812.
doi: 10.3724/SP.J.1011.2014.40071
Abstract:
Although phenolic acids and secondary terpenoid metabolites respectively from shikimate pathway and isoprene metabolic pathway are the main plant allelochemicals, it is far from conclusion in academic circles on what allelochemicals cause rice allelopathy. Thus far, most studies on rice root exudates have been conducted in laboratory conditions. Furthermore, few reports have been made on the changes in allelopathic substances in the rhizoshpere soil of different allelopathic potential rice cultivars especially under stressful field conditions. This paper studied the differences in allelopathic compounds including phenolic acids and terpenoids extracted from the rhizosphere soils of strong allelopathic rice cultivar 'PI312777' and its counterpart 'Lemont' and those from the control soil without any plants under dry and wet soil conditions in the seedling nursery. Putative allelochemicals of rhizosphere soil extracts were then identified via GC-MS (Gas Chromatograph-Mass Spectrometer-computer) and HPLC (High-performance liquid chromatography). The results showed that the compositions of phenolic acids and terpenoid compounds were similar but the contents of them were different in different treated rhizosphere soils and controls. Under moderate drought stress, the total content of five phenolic acids such as caffeic acid, 4-hydroxybenzoic acid, vanillic acid, ferulic acid and cinnamic acid, increased in all treated rhizosphere soils, and allelopathic rice 'PI312777' showed the highest increases in the total content of the five phenolic acids, which was 2.84 times higher than that of control soil under wet treatment. In addition, among 27 detected and identified terpenoids, 17 were oxygenic monoterpenoid compounds in the extracts of rhizosphere soil samples. Under drought stress, the contents of monoterpenes, oxygenated monoterpenes, oxygenated sesquiterpenes and total terpene showed the changing patterns with different extents and different trends in different treated rhizosphere soils. The relative content of monoterpene was significantly increased in rhizosphere soils under rice 'PI312777', but decreased in rhizosphere soils under the counterpart 'Lemont'. Based on the results, the cause and its mechanism of the weed-suppression in the two rice accessions under the field condition were further discussed.
Although phenolic acids and secondary terpenoid metabolites respectively from shikimate pathway and isoprene metabolic pathway are the main plant allelochemicals, it is far from conclusion in academic circles on what allelochemicals cause rice allelopathy. Thus far, most studies on rice root exudates have been conducted in laboratory conditions. Furthermore, few reports have been made on the changes in allelopathic substances in the rhizoshpere soil of different allelopathic potential rice cultivars especially under stressful field conditions. This paper studied the differences in allelopathic compounds including phenolic acids and terpenoids extracted from the rhizosphere soils of strong allelopathic rice cultivar 'PI312777' and its counterpart 'Lemont' and those from the control soil without any plants under dry and wet soil conditions in the seedling nursery. Putative allelochemicals of rhizosphere soil extracts were then identified via GC-MS (Gas Chromatograph-Mass Spectrometer-computer) and HPLC (High-performance liquid chromatography). The results showed that the compositions of phenolic acids and terpenoid compounds were similar but the contents of them were different in different treated rhizosphere soils and controls. Under moderate drought stress, the total content of five phenolic acids such as caffeic acid, 4-hydroxybenzoic acid, vanillic acid, ferulic acid and cinnamic acid, increased in all treated rhizosphere soils, and allelopathic rice 'PI312777' showed the highest increases in the total content of the five phenolic acids, which was 2.84 times higher than that of control soil under wet treatment. In addition, among 27 detected and identified terpenoids, 17 were oxygenic monoterpenoid compounds in the extracts of rhizosphere soil samples. Under drought stress, the contents of monoterpenes, oxygenated monoterpenes, oxygenated sesquiterpenes and total terpene showed the changing patterns with different extents and different trends in different treated rhizosphere soils. The relative content of monoterpene was significantly increased in rhizosphere soils under rice 'PI312777', but decreased in rhizosphere soils under the counterpart 'Lemont'. Based on the results, the cause and its mechanism of the weed-suppression in the two rice accessions under the field condition were further discussed.
2014, 22(7): 813-820.
doi: 10.3724/SP.J.1011.2014.31160
Abstract:
Climate change has significantly influenced agricultural production in Sichuan, a main grain producing region in China. Scientific evaluation of the impact of climate change on rice production is crucial for sustainable development of regional agriculture. In this study, daily meteorological data for the period 1961?2010 from 45 weather stations were collected along with phenological data of rice for the period of 1981?2010 in order to analyze the temporal and spatial distributions of potential productivity of rice in Sichuan. The whole area of Sichuan was divided into 8 regions, including 7 rice growing regions and one non-rice growing region. Photosynthetic potential productivity, light-temperature potential productivity and climate potential productivity of rice in each region were calculated and the corresponding spatial and temporal variations analyzed. The improvements in potential yields of rice were further analyzed by comparison of potential productivity to actual yield. The results showed that while photosynthetic potential productivity was high in the southern Sichuan, it was low in central Sichuan. Light-temperature potential productivity was high in the northern and low in the southern regions. Climate potential productivity was high in central Sichuan and low in the northern and southern regions. Decreasing sunshine hours in the last five decades led to the declines in rice photosynthetic potential productivity since the 1980s. Temperature increase benefited light-temperature potential productivity of rice and the peak value of light-temperature potential productivity was in 2006. Precipitation was one of the main limitations and decreasing precipitation resulted in low climate potential productivity since the 1990s. A significant gap was noted between potential productivity and actual yield and the potential for improving rice yield declined with the decades. There was urgent need to develop science and technology in order to make better use of the climate resources and raise the yield of rice in the study area.
Climate change has significantly influenced agricultural production in Sichuan, a main grain producing region in China. Scientific evaluation of the impact of climate change on rice production is crucial for sustainable development of regional agriculture. In this study, daily meteorological data for the period 1961?2010 from 45 weather stations were collected along with phenological data of rice for the period of 1981?2010 in order to analyze the temporal and spatial distributions of potential productivity of rice in Sichuan. The whole area of Sichuan was divided into 8 regions, including 7 rice growing regions and one non-rice growing region. Photosynthetic potential productivity, light-temperature potential productivity and climate potential productivity of rice in each region were calculated and the corresponding spatial and temporal variations analyzed. The improvements in potential yields of rice were further analyzed by comparison of potential productivity to actual yield. The results showed that while photosynthetic potential productivity was high in the southern Sichuan, it was low in central Sichuan. Light-temperature potential productivity was high in the northern and low in the southern regions. Climate potential productivity was high in central Sichuan and low in the northern and southern regions. Decreasing sunshine hours in the last five decades led to the declines in rice photosynthetic potential productivity since the 1980s. Temperature increase benefited light-temperature potential productivity of rice and the peak value of light-temperature potential productivity was in 2006. Precipitation was one of the main limitations and decreasing precipitation resulted in low climate potential productivity since the 1990s. A significant gap was noted between potential productivity and actual yield and the potential for improving rice yield declined with the decades. There was urgent need to develop science and technology in order to make better use of the climate resources and raise the yield of rice in the study area.
2014, 22(7): 821-827.
doi: 10.3724/SP.J.1011.2014.31068
Abstract:
From comparisons and connections, the relationships and differences between farmland productivity classes and farmland natural quality grades were explored at county scale in this paper. The farmland productivity grades and farmland natural quality grades in Hengdong County were respectively evaluated by dividing evaluation units with overlay methods, determining quantitative indexes with system cluster analysis, choosing qualitative indicators affecting assessment results with Delphi, computing evaluation factor weights with analytic hierarchy process (AHP) and establishing relational models between indicators and grades with Fuzzy mathematical method. The grade transition distribution was recorded using GIS overlay analysis and the regularities and reasons discussed. The results indicated that farmland productivity grade was one degree lower than farmland natural quality grade in Hengdong County. The proportion of the area of the first five grades of farmland natural quality was 91.29%, but only 74.37% for farmland productivity. The ratio of the area of high, medium and low grades of farmland productivity was 32︰42︰26, but 33︰43︰24 for farmland natural quality. The distribution law of the proportion of area was respectively greater for medium grade field than for high and low grades fields. In terms of percent distribution, significant differences were observed between paddy field and dry land in farmland productivity, higher grades (1, 2 and 3) were mainly distributed in paddy fields. Even distribution among different grades was noted in farmland natural quality. Grade transition percent between farmland productivity grades and farmland natural quality grades clearly showed the extent of differences and spatial distributions of corresponding grades fields. The distribution order of transition percent was plain areas > hilly areas > mountainous areas. Differences in evaluation indicators and weights were the main factors for the differences between two evaluation methods. However, the differences in evaluation objects and sample points also induced some differences in the evaluation results for similar blocks in the two evaluation methods.
From comparisons and connections, the relationships and differences between farmland productivity classes and farmland natural quality grades were explored at county scale in this paper. The farmland productivity grades and farmland natural quality grades in Hengdong County were respectively evaluated by dividing evaluation units with overlay methods, determining quantitative indexes with system cluster analysis, choosing qualitative indicators affecting assessment results with Delphi, computing evaluation factor weights with analytic hierarchy process (AHP) and establishing relational models between indicators and grades with Fuzzy mathematical method. The grade transition distribution was recorded using GIS overlay analysis and the regularities and reasons discussed. The results indicated that farmland productivity grade was one degree lower than farmland natural quality grade in Hengdong County. The proportion of the area of the first five grades of farmland natural quality was 91.29%, but only 74.37% for farmland productivity. The ratio of the area of high, medium and low grades of farmland productivity was 32︰42︰26, but 33︰43︰24 for farmland natural quality. The distribution law of the proportion of area was respectively greater for medium grade field than for high and low grades fields. In terms of percent distribution, significant differences were observed between paddy field and dry land in farmland productivity, higher grades (1, 2 and 3) were mainly distributed in paddy fields. Even distribution among different grades was noted in farmland natural quality. Grade transition percent between farmland productivity grades and farmland natural quality grades clearly showed the extent of differences and spatial distributions of corresponding grades fields. The distribution order of transition percent was plain areas > hilly areas > mountainous areas. Differences in evaluation indicators and weights were the main factors for the differences between two evaluation methods. However, the differences in evaluation objects and sample points also induced some differences in the evaluation results for similar blocks in the two evaluation methods.
2014, 22(7): 828-836.
doi: 10.3724/SP.J.1011.2014.31257
Abstract:
Due to the lack of scientific evidence and methodology for selection of sites for High Quality Capital Farmland Construction Project (HQCFCP), this research focused mainly on exploring and evaluating methods of HQCFCP site selection. Based on the understanding of the principles of set pair analysis (SPA), Liangping County of Chongqing City was selected as a case study research area. According to the malleability of the original relations and through improvement of the analysis method by extending the three-level justification into four-level, and integrating the entropy method with set pair analysis, an evaluation on the reasonability of site selection was finally conducted for the implementation of 14 HQCFCPs in 2014. The SPA and en-tropy method composed of the construction of evaluation index system and classification standard along with the calculation of entropy indices and connections as well as the determination of evaluation levels. Also in order to verify the feasibility and reasonability of SPA, the SPA conclusions were compared with conclusions from fuzzy synthetic evaluation (FSE). The results showed that the sites selection of HQCFCPs in Liangping County was largely reasonable. Specifically, based on the level of justification standard, the sites selection for HQCFCPs at Shuanggui Village of Jindai Town was classified as reasonable. Only two villages (Leying Village of Yinping Town and Tiangu Village of Liangshan Town) had moderate unreasonability for HQCFCPs sites selection. Sites selection for HQCFCPs construction on the rest of the 11 projects areas were all evaluated as moderately reasonable. The influencing factors of site selection reasonability for HQCFCPs mainly included the depth of top soil layer, soil organic matter content, density of water system and the rate of guaranteed irrigation. The SPA results were basically similar to FSE results. In some project areas, the results seem to be different, although no inconsistency was noted. The application of SPA evaluation method yielded more information and was more beneficial to displaying the diversity of various evaluation units. Moreover, the results were more accurate and reliable and the method was therefore practicable and valuable. This study provided the scientific evidence for the selection of sites for HQCFCPs establishment in Liangping County. It also provided the needed information on the reasonability of site selection by using scientifically feasible method.
Due to the lack of scientific evidence and methodology for selection of sites for High Quality Capital Farmland Construction Project (HQCFCP), this research focused mainly on exploring and evaluating methods of HQCFCP site selection. Based on the understanding of the principles of set pair analysis (SPA), Liangping County of Chongqing City was selected as a case study research area. According to the malleability of the original relations and through improvement of the analysis method by extending the three-level justification into four-level, and integrating the entropy method with set pair analysis, an evaluation on the reasonability of site selection was finally conducted for the implementation of 14 HQCFCPs in 2014. The SPA and en-tropy method composed of the construction of evaluation index system and classification standard along with the calculation of entropy indices and connections as well as the determination of evaluation levels. Also in order to verify the feasibility and reasonability of SPA, the SPA conclusions were compared with conclusions from fuzzy synthetic evaluation (FSE). The results showed that the sites selection of HQCFCPs in Liangping County was largely reasonable. Specifically, based on the level of justification standard, the sites selection for HQCFCPs at Shuanggui Village of Jindai Town was classified as reasonable. Only two villages (Leying Village of Yinping Town and Tiangu Village of Liangshan Town) had moderate unreasonability for HQCFCPs sites selection. Sites selection for HQCFCPs construction on the rest of the 11 projects areas were all evaluated as moderately reasonable. The influencing factors of site selection reasonability for HQCFCPs mainly included the depth of top soil layer, soil organic matter content, density of water system and the rate of guaranteed irrigation. The SPA results were basically similar to FSE results. In some project areas, the results seem to be different, although no inconsistency was noted. The application of SPA evaluation method yielded more information and was more beneficial to displaying the diversity of various evaluation units. Moreover, the results were more accurate and reliable and the method was therefore practicable and valuable. This study provided the scientific evidence for the selection of sites for HQCFCPs establishment in Liangping County. It also provided the needed information on the reasonability of site selection by using scientifically feasible method.
A marginal model-based study of the ultimate influence of China's urbanization evolution on cropland
2014, 22(7): 837-842.
doi: 10.3724/SP.J.1011.2014.30899
Abstract:
Urbanization is a national strategy support for sustainable socio-economic development, which has become an inevitable way of achieving modernization in China. The process of urbanization is closely related with changes in land use. Proposed by the report delivered at the 18th National Congress of the Communist Party of China (CPC), China should continue to promote the process of urbanization. The influence of rapid evolution of urbanization on cropland is related with cropland protection and food security. It is therefore of great practical significance to explore the ultimate effect of the laws of urbanization evolution on cropland so as to formulate cropland protection policies in relation to efficient management of the evolution of urbanization in China. The extended Kaya Identity and Logarithmic Mean Divisia Index (LMDI) decomposition models were used to estimate the proportion of dwindling of cropland caused by China's urbanization from 1997 to 2011. In reference to the marginal theory and marginal effect model, the decreasing proportion of croplands due to urbanization evolution was used as the dependent variable and the level of urbanization used as the independent variable to establish the marginal cropland influence model in SPSS software and regression analysis. By using time as independent variable, marginal change rate of cropland as dependent variable, a curve of marginal influence change rate of China's urbanization evolution on cropland was constructed. Then based on the curve, the ultimate moment of minimum urbanization evolution influence on cropland was estimated. The results showed that with evolution of urbanization, the area of land under cropland fell, dropping from 595 900 hm2 in 1997 down to 317 300 hm2 in 2011. The annual average trend of decline was 434 900 hm2. The marginal change rate of cropland dropped from 0.183 3 in 1997 to 0.037 8 in 2011, and with an annual average of 11%. The curve best fitting marginal change rate of cropland was a U-shaped parabola with the minimum point in 2010, which meant year 2010 was the ultimate time of urbanization influence on cropland. The results not only provided reference for the scientific formulation and management of land use and the coordination of evolution of urbanization policies and cropland protection, but also provided the way for similar studies at provincial scale.
Urbanization is a national strategy support for sustainable socio-economic development, which has become an inevitable way of achieving modernization in China. The process of urbanization is closely related with changes in land use. Proposed by the report delivered at the 18th National Congress of the Communist Party of China (CPC), China should continue to promote the process of urbanization. The influence of rapid evolution of urbanization on cropland is related with cropland protection and food security. It is therefore of great practical significance to explore the ultimate effect of the laws of urbanization evolution on cropland so as to formulate cropland protection policies in relation to efficient management of the evolution of urbanization in China. The extended Kaya Identity and Logarithmic Mean Divisia Index (LMDI) decomposition models were used to estimate the proportion of dwindling of cropland caused by China's urbanization from 1997 to 2011. In reference to the marginal theory and marginal effect model, the decreasing proportion of croplands due to urbanization evolution was used as the dependent variable and the level of urbanization used as the independent variable to establish the marginal cropland influence model in SPSS software and regression analysis. By using time as independent variable, marginal change rate of cropland as dependent variable, a curve of marginal influence change rate of China's urbanization evolution on cropland was constructed. Then based on the curve, the ultimate moment of minimum urbanization evolution influence on cropland was estimated. The results showed that with evolution of urbanization, the area of land under cropland fell, dropping from 595 900 hm2 in 1997 down to 317 300 hm2 in 2011. The annual average trend of decline was 434 900 hm2. The marginal change rate of cropland dropped from 0.183 3 in 1997 to 0.037 8 in 2011, and with an annual average of 11%. The curve best fitting marginal change rate of cropland was a U-shaped parabola with the minimum point in 2010, which meant year 2010 was the ultimate time of urbanization influence on cropland. The results not only provided reference for the scientific formulation and management of land use and the coordination of evolution of urbanization policies and cropland protection, but also provided the way for similar studies at provincial scale.
2014, 22(7): 843-849.
doi: 10.3724/SP.J.1011.2014.31132
Abstract:
The purpose of this paper was to reconstruct the value theory of cropland resources and to protect croplands, to deepen our understanding of the value of cropland resources. The paper used the Shanghuang Experimental Area as a case study of the loess hilly-gully region to analyze the value system of cropland resources and proposed an efficient estimation method. The evaluated value system included economic value, social insurance value and ecological service value. Based on the method, the paper quantitatively analyzed the economic value, social insurance value and ecological service value of cropland resources in Shanghuang Experiment Area for 1982, 2000 and 2010, respectively representing the periods of before governance, governance and Grain for Green. The results suggested that the total value of croplands was low in 1982, which was only 43 700 Yuan·hm-2. During the periods of governance (1982 to 2000) and of Grain for Green (2001 to 2010), the value of cropland resources rapidly grew. It increased to 241 348 Yuan·hm-2 during governance period and to 564 738 Yuan·hm-2 during Grain for Green period. Economic value growth was the fastest during the whole study period, which was only 8 700 Yuan·hm-2 in 1982, increased to 109 600 Yuan·hm-2 2000 and to 218 600 Yuan·hm-2 in 2010. The proportion of cropland economic value in 1982 was only 19.91%, which increased to 45.41% in 2000 and to 38.71% in 2010. Next was social insurance value, which was only 21 108 Yuan·hm-2 in 1982 but increased to 83 656 Yuan·hm-2 in 2000 and 249 956 Yuan·hm-2 in 2010. Ecological service value continuously rose, rising from only 13 893 Yuan·hm-2 in 1982 to 48 091 Yuan·hm-2 in 2000 and 96 182 Yuan·hm-2 in 2010. Difference factors were responsible for the changes in cropland resources value in different periods. From 1982 to 2000, scientific and technological factors played significantly influence on the changes in cropland value. From the year 2001 to 2010, policy factors significantly drove cropland value. In order to further promote the value of cropland resources, it was necessary to strengthen the implementation of the policies on returning farmland to woodland and grassland, improving the quality and cultivation intensity of croplands and taking measures for agricultural water-saving. This could improve cropland resources allocation level in the loess hilly-gully region.
The purpose of this paper was to reconstruct the value theory of cropland resources and to protect croplands, to deepen our understanding of the value of cropland resources. The paper used the Shanghuang Experimental Area as a case study of the loess hilly-gully region to analyze the value system of cropland resources and proposed an efficient estimation method. The evaluated value system included economic value, social insurance value and ecological service value. Based on the method, the paper quantitatively analyzed the economic value, social insurance value and ecological service value of cropland resources in Shanghuang Experiment Area for 1982, 2000 and 2010, respectively representing the periods of before governance, governance and Grain for Green. The results suggested that the total value of croplands was low in 1982, which was only 43 700 Yuan·hm-2. During the periods of governance (1982 to 2000) and of Grain for Green (2001 to 2010), the value of cropland resources rapidly grew. It increased to 241 348 Yuan·hm-2 during governance period and to 564 738 Yuan·hm-2 during Grain for Green period. Economic value growth was the fastest during the whole study period, which was only 8 700 Yuan·hm-2 in 1982, increased to 109 600 Yuan·hm-2 2000 and to 218 600 Yuan·hm-2 in 2010. The proportion of cropland economic value in 1982 was only 19.91%, which increased to 45.41% in 2000 and to 38.71% in 2010. Next was social insurance value, which was only 21 108 Yuan·hm-2 in 1982 but increased to 83 656 Yuan·hm-2 in 2000 and 249 956 Yuan·hm-2 in 2010. Ecological service value continuously rose, rising from only 13 893 Yuan·hm-2 in 1982 to 48 091 Yuan·hm-2 in 2000 and 96 182 Yuan·hm-2 in 2010. Difference factors were responsible for the changes in cropland resources value in different periods. From 1982 to 2000, scientific and technological factors played significantly influence on the changes in cropland value. From the year 2001 to 2010, policy factors significantly drove cropland value. In order to further promote the value of cropland resources, it was necessary to strengthen the implementation of the policies on returning farmland to woodland and grassland, improving the quality and cultivation intensity of croplands and taking measures for agricultural water-saving. This could improve cropland resources allocation level in the loess hilly-gully region.
2014, 22(7): 850-858.
doi: 10.3724/SP.J.1011.2014.30944
Abstract:
The Chinese government launched the Grain for Green project in 1999 to mitigate increasing soil erosion and land degradation in the Loess Plateau. By using Huining County of Gansu Province as a typical Loess Plateau region, the impact of the Grain for Green project on the livelihoods of the local people in the Loess Plateau was investigated. The research data were collected through face-to-face household questionnaire survey and from environmental, social and economic statistics as well as relevant government reports. Data analysis was conducted in SPSS statistical software and relevant satisfaction indices computed. Changes in land use, cropping structures and animal raising forms, and farm family income were analyzed along with farmers' satisfaction with the effects of the Grains for Green project. The study revealed changes in land use structure since the implementation of the Grain for Green project from 2000 to 2010. About 4.48% of the cultivated land was turned into grassland and forest. There was 0.08 hm2 over 25° slope cultivated land not returned to forest or grassland for per househole. Therefore there was the need to enhance implementation of the project and consolidate all project achievements. The results showed increases in yields and cultivated land areas of local major crops, including cereals, tuber crops, beans and oil crops. This was as a result of increased investment in cultivated lands and intensification of agricultural practices such as terrace construction. With the promotion of mulching cultivation techniques such as plastic film mulching for maize by Huining go- vernment, the acreage of land under maize had increased approximately 3 times. Animal husbandry had increased slightly due to severe natural conditions such as drought and insufficient forage production and supply. This suggested that the local breeding industry was still at a low stage. Based on increased farming risk due to drought, there was need to enhance farmers' consciousness of environmental protection. Also because wages were higher in cities than that in counties, most households chose to work in cities. This suggested that cities wage was the most important source of income of farmers, accounting for 62.69% of total income. Investigating farmers' satisfaction with the Grain for Green project suggested a general satisfaction with the project. About 9 of 11 impact indicators responses were positive. Dissatisfaction mainly came from worsening employment opportunities and low wages, respectively with satisfaction degrees of ?0.1 and ?0.2. The study was expected to positively contribute to further implementation of the Grain for Green project and sustainable ecosystem management in the Loess Plateau.
The Chinese government launched the Grain for Green project in 1999 to mitigate increasing soil erosion and land degradation in the Loess Plateau. By using Huining County of Gansu Province as a typical Loess Plateau region, the impact of the Grain for Green project on the livelihoods of the local people in the Loess Plateau was investigated. The research data were collected through face-to-face household questionnaire survey and from environmental, social and economic statistics as well as relevant government reports. Data analysis was conducted in SPSS statistical software and relevant satisfaction indices computed. Changes in land use, cropping structures and animal raising forms, and farm family income were analyzed along with farmers' satisfaction with the effects of the Grains for Green project. The study revealed changes in land use structure since the implementation of the Grain for Green project from 2000 to 2010. About 4.48% of the cultivated land was turned into grassland and forest. There was 0.08 hm2 over 25° slope cultivated land not returned to forest or grassland for per househole. Therefore there was the need to enhance implementation of the project and consolidate all project achievements. The results showed increases in yields and cultivated land areas of local major crops, including cereals, tuber crops, beans and oil crops. This was as a result of increased investment in cultivated lands and intensification of agricultural practices such as terrace construction. With the promotion of mulching cultivation techniques such as plastic film mulching for maize by Huining go- vernment, the acreage of land under maize had increased approximately 3 times. Animal husbandry had increased slightly due to severe natural conditions such as drought and insufficient forage production and supply. This suggested that the local breeding industry was still at a low stage. Based on increased farming risk due to drought, there was need to enhance farmers' consciousness of environmental protection. Also because wages were higher in cities than that in counties, most households chose to work in cities. This suggested that cities wage was the most important source of income of farmers, accounting for 62.69% of total income. Investigating farmers' satisfaction with the Grain for Green project suggested a general satisfaction with the project. About 9 of 11 impact indicators responses were positive. Dissatisfaction mainly came from worsening employment opportunities and low wages, respectively with satisfaction degrees of ?0.1 and ?0.2. The study was expected to positively contribute to further implementation of the Grain for Green project and sustainable ecosystem management in the Loess Plateau.
2014, 22(7): 859-865.
doi: 10.3724/SP.J.1011.2014.31248
Abstract:
This paper used Qixia City (which lies in the center of Jiaodong Peninsula) as a case study of typical mountain areas to investigate catchment-based landscape pattern divisions with cluster analysis of landscape indices generated from digital elevation model (DEM). Firstly, Landsat TM image (2010) covering the whole study area was interpreted and geo-referenced to generate the landscape patterns in Qixia City and the corresponding relief map (1︰25 000) vectorized to build DEM model. Then 300 catchments were divided using hydrology extension support in ArcGIS. Taking into account ecological significance and features of common landscape indices as well as local ground truth, five indices were selected for the analysis. The indices included edge density (ED), Shannon's diversity index (SDI), coefficient of variance of patch size (PSCOV), area-weighted mean patch fractal dimension (AWMPFD) and core area density (CAD). Based on average elevation and spatial distributions, landscape patterns in each catchment were analyzed. The effects of human activity and natural disturbance on regional landscape ecology were also discussed in the paper. All the indices analyzed in each catchment were synthesized using cluster analysis and combined with dominant landscape type in the catchment to build zoning maps of landscape. The results suggested that ED and CAD values increased as altitude gradually increased and significant vertical differentiation characteristics were noted. The SDI values gradually grew smaller with increasing altitude. Then PSCOV values showed inverted U-shaped trend with increasing altitude. The AWMPFD values did not show significant vertical differentiation characteristics. Three landscape ecology classes were regionalized in Qixia City. ClassⅠhad the smallest land area (10.14%) and stable agricultural zones. This implied that the landscape structure and scale were very stable and needed protection. Class Ⅱ had the biggest land area (50.93%). Here, a variety of landscape types had spatially cross distributions with complex patchy shapes. This area belonged to the transition zone of natural landscape and cultural landscape which needed strengthened land use planning and rational distribution of industry. Class Ⅲ had the bigger land area (35.92%) and was mainly concentrated in high altitude areas with main land use types of woodland and grassland. Thus larger reclamation of land in this class was a very difficult task in terms of development and utilization. The study argued that the use of landscape metrics in landscape zoning better reflected prominent landscape features and spatial variation patterns of landscape ecological structure. To a certain extent therefore, the study provided a significant guidance on planning and utilization of land in Qixia City.
This paper used Qixia City (which lies in the center of Jiaodong Peninsula) as a case study of typical mountain areas to investigate catchment-based landscape pattern divisions with cluster analysis of landscape indices generated from digital elevation model (DEM). Firstly, Landsat TM image (2010) covering the whole study area was interpreted and geo-referenced to generate the landscape patterns in Qixia City and the corresponding relief map (1︰25 000) vectorized to build DEM model. Then 300 catchments were divided using hydrology extension support in ArcGIS. Taking into account ecological significance and features of common landscape indices as well as local ground truth, five indices were selected for the analysis. The indices included edge density (ED), Shannon's diversity index (SDI), coefficient of variance of patch size (PSCOV), area-weighted mean patch fractal dimension (AWMPFD) and core area density (CAD). Based on average elevation and spatial distributions, landscape patterns in each catchment were analyzed. The effects of human activity and natural disturbance on regional landscape ecology were also discussed in the paper. All the indices analyzed in each catchment were synthesized using cluster analysis and combined with dominant landscape type in the catchment to build zoning maps of landscape. The results suggested that ED and CAD values increased as altitude gradually increased and significant vertical differentiation characteristics were noted. The SDI values gradually grew smaller with increasing altitude. Then PSCOV values showed inverted U-shaped trend with increasing altitude. The AWMPFD values did not show significant vertical differentiation characteristics. Three landscape ecology classes were regionalized in Qixia City. ClassⅠhad the smallest land area (10.14%) and stable agricultural zones. This implied that the landscape structure and scale were very stable and needed protection. Class Ⅱ had the biggest land area (50.93%). Here, a variety of landscape types had spatially cross distributions with complex patchy shapes. This area belonged to the transition zone of natural landscape and cultural landscape which needed strengthened land use planning and rational distribution of industry. Class Ⅲ had the bigger land area (35.92%) and was mainly concentrated in high altitude areas with main land use types of woodland and grassland. Thus larger reclamation of land in this class was a very difficult task in terms of development and utilization. The study argued that the use of landscape metrics in landscape zoning better reflected prominent landscape features and spatial variation patterns of landscape ecological structure. To a certain extent therefore, the study provided a significant guidance on planning and utilization of land in Qixia City.
2014, 22(7): 866-874.
doi: 10.3724/SP.J.1011.2014.31220
Abstract:
In livestock pollution control, the attitudes and behaviors of various stakeholders have not only been influenced by ecological and economic conditions and their interrelationships, but also directly affected the effectiveness of pollution management which is critical for sustainable development in rural regions. In order to improve the effectiveness and public participation in livestock pollution control in ecologically sensitive areas, this study explored a new idea of governance to effectively control pollution from livestock farms through socio-ecological lens by using the water sourcing buffer zone of Xiqin Water Plant in Nanping City (Fujian Province, China) as a case study. The Mitchell scoring method was used to identify and classify stakeholders. A theory-driven analytical framework was formulated to examine the differences in ecological, social and economic desires among different stakeholders, the relationship networks of pig farmers, village committee members and the general public, and the roles and impacts of these stakeholders in pollution governance. This framework was tested in an empirical analysis using data collected through face-to-face interviews and direct observations of 13 village committees and 111 households in the water sourcing zone of Xiqin Water Plant. Tobit regression was used to identify the factors influencing the attitudes of stakeholders toward pollution control in pig farming. Logistic regression was used to determine the factors influencing the behavior of stakeholders in controlling pollution. The results showed that the social, economic and ecological desires of stakeholders and their social networks had statistically significant impacts on governance decisions-making. Attitudes toward pollution control differed across stakeholders - pig farmers, upstream inhabitants and village committees preferred economic development while downstream inhabitants and village committees favored environmental protection. Village committees had significantly higher attitude scores in supporting pollution control than the inhabitants and pig farmers. Individual attitude scores varied significantly with gender, desire type, education and age. Females and the elderly had a weaker desire for pollution control and the higher education folks showed more positive attitude toward pollution control. While the attitude of stakeholders was not correlated with behavior in pollution control, the desire and relationship with pig farmers significantly affected behavior. Stakeholders with weaker desires were more likely to choose active participatory behavior in pollution control. Then stakeholders with closer relationship with pig farmers were less likely to choose active participatory behavior. The lack of public participation because of negligence of ecological, economic and social desires, and obstruction from local social relationship networks impeded pollution control in pig farming in the study area. A new livestock pollution governance approach was proposed, which sought the transformation of government-led pollution control systems into shared multi-stakeholder governance systems by taking into account the ecological, economic and social desires of stakeholders and local social relationship networks, balancing the interests of different stakeholders and taking advantage of local social networks. Strengthening education, promoting the participation of the elderly and women in decision-making and establishing mechanisms for total village pig control, upstream-downstream ecological compensations, tradable pig emission permits and eco-certified pig raising subsidies could guide the attention of stakeholders for environmental benefits. Environmental protection advocacy, training and guidance focused on local clan organizations, elderly associations, civil society organizations, farmers' cooperative organizations and village elites could promote the overall social networks to more effectively support pollution control.
In livestock pollution control, the attitudes and behaviors of various stakeholders have not only been influenced by ecological and economic conditions and their interrelationships, but also directly affected the effectiveness of pollution management which is critical for sustainable development in rural regions. In order to improve the effectiveness and public participation in livestock pollution control in ecologically sensitive areas, this study explored a new idea of governance to effectively control pollution from livestock farms through socio-ecological lens by using the water sourcing buffer zone of Xiqin Water Plant in Nanping City (Fujian Province, China) as a case study. The Mitchell scoring method was used to identify and classify stakeholders. A theory-driven analytical framework was formulated to examine the differences in ecological, social and economic desires among different stakeholders, the relationship networks of pig farmers, village committee members and the general public, and the roles and impacts of these stakeholders in pollution governance. This framework was tested in an empirical analysis using data collected through face-to-face interviews and direct observations of 13 village committees and 111 households in the water sourcing zone of Xiqin Water Plant. Tobit regression was used to identify the factors influencing the attitudes of stakeholders toward pollution control in pig farming. Logistic regression was used to determine the factors influencing the behavior of stakeholders in controlling pollution. The results showed that the social, economic and ecological desires of stakeholders and their social networks had statistically significant impacts on governance decisions-making. Attitudes toward pollution control differed across stakeholders - pig farmers, upstream inhabitants and village committees preferred economic development while downstream inhabitants and village committees favored environmental protection. Village committees had significantly higher attitude scores in supporting pollution control than the inhabitants and pig farmers. Individual attitude scores varied significantly with gender, desire type, education and age. Females and the elderly had a weaker desire for pollution control and the higher education folks showed more positive attitude toward pollution control. While the attitude of stakeholders was not correlated with behavior in pollution control, the desire and relationship with pig farmers significantly affected behavior. Stakeholders with weaker desires were more likely to choose active participatory behavior in pollution control. Then stakeholders with closer relationship with pig farmers were less likely to choose active participatory behavior. The lack of public participation because of negligence of ecological, economic and social desires, and obstruction from local social relationship networks impeded pollution control in pig farming in the study area. A new livestock pollution governance approach was proposed, which sought the transformation of government-led pollution control systems into shared multi-stakeholder governance systems by taking into account the ecological, economic and social desires of stakeholders and local social relationship networks, balancing the interests of different stakeholders and taking advantage of local social networks. Strengthening education, promoting the participation of the elderly and women in decision-making and establishing mechanisms for total village pig control, upstream-downstream ecological compensations, tradable pig emission permits and eco-certified pig raising subsidies could guide the attention of stakeholders for environmental benefits. Environmental protection advocacy, training and guidance focused on local clan organizations, elderly associations, civil society organizations, farmers' cooperative organizations and village elites could promote the overall social networks to more effectively support pollution control.
Editor-in-chief：LIU Changming
Competent Authorities：Chinese Academy of Sciences
Sponsored by：Institute of Genetics and Developmental Biology, Chinese Academy of Sciences; China Ecological Economics Society
Organizer：Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
ISSN 2096-6237
CN 13-1432/S
- Chinese core periodicals
- Core Chinese Sci-Tech Periodicals
- China's Top Science and Technology Periodicals
- Covered by Chinese Science Citation Database (CSCD)
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