With rapid urbanization and economic growth, Chinese traditional rice-legume production is increasingly replaced by vegetable and horticultural flower production, which could affect soil properties. This study was con...With rapid urbanization and economic growth, Chinese traditional rice-legume production is increasingly replaced by vegetable and horticultural flower production, which could affect soil properties. This study was conducted near Kunming City, Yunnan Province, Southwest China to investigate how soil phosphorus （P） sorption and desorption processes respond to land use changes and to relate P sorption and desorption parameters to soil properties. Soil samples （0-20, 20-40, 40-60, 60-80 and 80-100 cm） were collected from five sites representing four land use types： rice-legume production in a two-crop, one-year rotation （Rice）, vegetable production in open fields （Vegetable）, recent （〈 3 years） conversion from open fields to plastic-film greenhouse vegetable and flower production at two sites （VFCS1 and VFCS2）, and longer-term （〉 10 years） plastic-film greenhouse vegetable and flower production （VFCL）. The changes in land use affected soil pH, electrical conductivity, available N and P and organic carbon content in topsoil and subsoil. In turn, these changes of soil properties influenced soil P sorption capacity. The P sorption maximum （Smax） was affected by land use types, soil sampling depth and their interactions （P 〈 0.0001）. For surface soil, Smax was in the order of Rice （1 380 mg kg-1） 〉 VFCL （1 154 mg kg-1） 〉 VFCS2 （897 mg kg-1） 〉 VFCS1 （845 mg kg-1） 〉 Vegetable （747 mg kg-1）. The lowest Sm^x generally occurred at the surface （except for Rice at 80-100 cm） and increased with depth. The amount of P desorbed during the 8 successive extractions was in the range 23%-44% of sorbed P, and was not affected by land use types or sampling depths. The decreases in Smax suggested that soil P sorption capacity decreased when rice-legume production converted to more intensive vegetation and flower production and caution should be exercised when applying P fertilizer to minimize potential leaching and runoff P loss to the environment.展开更多
Improving the level of intensive cultivated land use is an important measure to ensure food security and promote the sustainable development of the regional society and economy.Based on data from the statistical yearb...Improving the level of intensive cultivated land use is an important measure to ensure food security and promote the sustainable development of the regional society and economy.Based on data from the statistical yearbook of Maoming City and its counties and districts from 2005 to 2018 and the land use change database of Maoming City for 2018,this study constructed an evaluation index system for four aspects:cultivated land use intensity,cultivated land use degree,cultivated land output benefit and cultivated land sustainable use status.The level of intensive use of cultivated land in Maoming City from 2004 to 2017 was evaluated by AHP,the range method and the comprehensive evaluation model,and its temporal and spatial characteristics were evaluated.The results revealed three major points.(1)The intensive use of cultivated land in Maoming City in the past 14 years was good,and its level showed an overall upward trend,with the intensive use degree of cultivated land rising from 0.4045 in 2004 to 1.3148 in 2017.(2)The levels of intensive use of cultivated land in each county and district of Maoming City were generally on the rise,with no significant differences between them.However,according to the regional distribution,the intensive use level of cultivated land was highest in Maonan District,while it was relatively low in Dianbai County.The largest increase in the level of cultivated land intensive use was in Gaozhou,and the smallest was in Dianbai County.(3)According to the existing problems of cultivated land utilization in Maoming City,combined with the current international and domestic measures to effectively improve the level of intensive use of cultivated land,four suggestions are put forward:to improve the efficiency of cultivated land utilization and effectively protect basic farmland;to improve the overall urban planning and rationally adjust the layout of construction land;to raise farmers’awareness of the intensive use of cultivated land;and to increase agricultural investment and improve agricultural infrastructure.展开更多
基金Supported by the Yunnan Provincial Department of Science and Technology,China(No.2006YX35)the National Natural Science Foundation of China(No.31260504)
文摘With rapid urbanization and economic growth, Chinese traditional rice-legume production is increasingly replaced by vegetable and horticultural flower production, which could affect soil properties. This study was conducted near Kunming City, Yunnan Province, Southwest China to investigate how soil phosphorus （P） sorption and desorption processes respond to land use changes and to relate P sorption and desorption parameters to soil properties. Soil samples （0-20, 20-40, 40-60, 60-80 and 80-100 cm） were collected from five sites representing four land use types： rice-legume production in a two-crop, one-year rotation （Rice）, vegetable production in open fields （Vegetable）, recent （〈 3 years） conversion from open fields to plastic-film greenhouse vegetable and flower production at two sites （VFCS1 and VFCS2）, and longer-term （〉 10 years） plastic-film greenhouse vegetable and flower production （VFCL）. The changes in land use affected soil pH, electrical conductivity, available N and P and organic carbon content in topsoil and subsoil. In turn, these changes of soil properties influenced soil P sorption capacity. The P sorption maximum （Smax） was affected by land use types, soil sampling depth and their interactions （P 〈 0.0001）. For surface soil, Smax was in the order of Rice （1 380 mg kg-1） 〉 VFCL （1 154 mg kg-1） 〉 VFCS2 （897 mg kg-1） 〉 VFCS1 （845 mg kg-1） 〉 Vegetable （747 mg kg-1）. The lowest Sm^x generally occurred at the surface （except for Rice at 80-100 cm） and increased with depth. The amount of P desorbed during the 8 successive extractions was in the range 23%-44% of sorbed P, and was not affected by land use types or sampling depths. The decreases in Smax suggested that soil P sorption capacity decreased when rice-legume production converted to more intensive vegetation and flower production and caution should be exercised when applying P fertilizer to minimize potential leaching and runoff P loss to the environment.
基金The Guangdong Province Education Science Planning Project(2019GXJK080)The Guangdong Province Philosophy and Social Science Planning Project(GD19YYJ03)。
文摘Improving the level of intensive cultivated land use is an important measure to ensure food security and promote the sustainable development of the regional society and economy.Based on data from the statistical yearbook of Maoming City and its counties and districts from 2005 to 2018 and the land use change database of Maoming City for 2018,this study constructed an evaluation index system for four aspects:cultivated land use intensity,cultivated land use degree,cultivated land output benefit and cultivated land sustainable use status.The level of intensive use of cultivated land in Maoming City from 2004 to 2017 was evaluated by AHP,the range method and the comprehensive evaluation model,and its temporal and spatial characteristics were evaluated.The results revealed three major points.(1)The intensive use of cultivated land in Maoming City in the past 14 years was good,and its level showed an overall upward trend,with the intensive use degree of cultivated land rising from 0.4045 in 2004 to 1.3148 in 2017.(2)The levels of intensive use of cultivated land in each county and district of Maoming City were generally on the rise,with no significant differences between them.However,according to the regional distribution,the intensive use level of cultivated land was highest in Maonan District,while it was relatively low in Dianbai County.The largest increase in the level of cultivated land intensive use was in Gaozhou,and the smallest was in Dianbai County.(3)According to the existing problems of cultivated land utilization in Maoming City,combined with the current international and domestic measures to effectively improve the level of intensive use of cultivated land,four suggestions are put forward:to improve the efficiency of cultivated land utilization and effectively protect basic farmland;to improve the overall urban planning and rationally adjust the layout of construction land;to raise farmers’awareness of the intensive use of cultivated land;and to increase agricultural investment and improve agricultural infrastructure.
