Land use change significantly influences soil properties. There is little information available on the long-term effects of post-reclamation from grassland to cropland on soil properties. We compared soil carbon （C）...Land use change significantly influences soil properties. There is little information available on the long-term effects of post-reclamation from grassland to cropland on soil properties. We compared soil carbon （C） and nitrogen （N） storage and related soil properties in a 50-year cultivation chronosequence of grassland in the agro-pastoral ecotone of Inner Mongolia. Field surveys on land use changes during the period of 1955-2002 were conducted to build a chronosequence of cropland of different ages since the conversion from grassland. The results showed that soil C and N storage, soil texture, and soil nutrient contents varied with land use types and cropland ages （P〈0.01）. In the 0-30 cm soil layer, the soil organic carbon （SOC） density was significantly lower in the crop- lands （3.28 kg C/m2 for C50 soil） than in the grasslands （6.32 kg C/m2）. After 5, 10, 15, 20, 35, and 50 years of crop planting （years since the onset of cultivation）, the SOC losses were 17%, 12%, 19%, 47%, 46%, and 48%, respec- tively, compared with the grasslands. The soil total nitrogen （TN） density of the grasslands was 65 g N/m2, and TN density of the cropland soil was 35 g N/m2 after 50 years of crop planting. Both the SOC and TN densities could be quantitatively determined by a negative exponential function of cropland age （P〈0.0001, R2=0.8528; P〈0.0001, R2=0.9637）. The dissolved organic carbon （DOC） content, pH value were decreased; and the soil bulk density and soil available potassium （AK） content, clay content, and sand content were increased since the conversion of grassland into cropland during the 50-year period. Our results show soil nutrients were higher in grassland than in cropland. The conversion of grasslands to croplands induced a loss of soil C storage and changes of related soil properties. The reclamation time of cultivated soil （cropland age） had significant effects on soil properties in the study area.展开更多
The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time s...The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time series of temperature and precipitation in spring when sandstorms often occur in the area. Based on meteorological data for a 46-year period from 1959 to 2004, multi-scale variations and abrupt changes in temperature and precipitation were analyzed with the Mexican hat function （MHF） wavelet method, showing the multi-scale variation characteristics of temperature and precipitation, as well as the periods and change points at different time scales. The relationship between temperature and precipitation was obtained using the wavelet analysis method. Obvious staggered features of the variations of spring temperature and precipitation were observed in this agro-pastoral ecotone. The strongest oscillation periods of spring temperature variations were 1 and 22 years, while for precipitation, the strongest oscillation periods of variations were 2, 8, and 22 years. In addition, lower spring temperature corresponded to lower precipitation, whereas higher temperature yielded higher precipitation rate.展开更多
With global climate change, the agricultural light-temperature potential productivity in the agro-pastoral ecotone has increased. This offers a good opportunity to develop agriculture in the agro-pastoral ecotone. How...With global climate change, the agricultural light-temperature potential productivity in the agro-pastoral ecotone has increased. This offers a good opportunity to develop agriculture in the agro-pastoral ecotone. However, the agro-pastoral ecotone is also an ecologically fragile area in which land degradation challenges agricultural development. As population grows and the need for food increases, the land carrying capacity of the agro-pastoral ecotone becomes insufficient, and the human–land relationship is not harmonious. Such conditions have limited the agricultural and rural development in the ecotone. The paper demonstrates how land engineering may improve land quality and support agricultural development in the ecotone based on studies at a research station established in 2015 in Yulin,Shaanxi Province, China. The studies target three factors: soil improvement, crop selection,and field management. The results show that:(1) The highest yield of crops planted on improved land is close to or even higher than that achieved under previous crop growth conditions. For instance, the corn yields can exceed 25%.(2) The potatoes grown on the improved land yield the highest gross income, reaching 67,200 yuan/ha. By way of land engineering,input costs can be balanced in 3–5 years.(3) As a result of land engineering, some villages in Yulin City have realized sustainable agricultural and even rural development, and promotion of this model will support the sustainable development of agriculture in the agro-pastoral ecotone.展开更多
为研究撂荒年限对农田土壤的影响,本试验于8月植物生长旺季进行,选取未撂荒农田(CK)、撂荒7年(7a)、15年(15a)和30年(30a)的农田采集土壤样品,室内计算分析土壤理化特征的变化规律,结果表明,撂荒显著提高了土壤容重,降低了土壤孔隙度和...为研究撂荒年限对农田土壤的影响,本试验于8月植物生长旺季进行,选取未撂荒农田(CK)、撂荒7年(7a)、15年(15a)和30年(30a)的农田采集土壤样品,室内计算分析土壤理化特征的变化规律,结果表明,撂荒显著提高了土壤容重,降低了土壤孔隙度和土壤pH。与未撂荒地对比,撂荒显著提高了土壤有机碳(Soil organic carbon,SOC)、全氮(Soil total nitrogen,TN)和全磷(Soil total phosphorus,TP)的含量。因此,长期撂荒对土壤养分状况具有显著改善作用。不同撂荒年限土壤含水量与土壤养分指标均呈显著正相关,长期撂荒下更少的蒸散耗水量减少了土壤水分的损失,使土壤养分得到了积累。本研究可为坝上农牧交错带撂荒地的合理规划提供理论支撑。展开更多
本研究旨在探究适合晋北地区饲用燕麦(Avena sativa L.)轮作制度及各区域饲用燕麦产量对气候变化和轮作制度的响应。为此,基于已验证的APSIM(Agricultural Production System sIMulator)设定3种轮作制度,即O-O(饲用燕麦连作)、P-O(马铃...本研究旨在探究适合晋北地区饲用燕麦(Avena sativa L.)轮作制度及各区域饲用燕麦产量对气候变化和轮作制度的响应。为此,基于已验证的APSIM(Agricultural Production System sIMulator)设定3种轮作制度,即O-O(饲用燕麦连作)、P-O(马铃薯-饲用燕麦轮作)、M-O(玉米-饲用燕麦轮作),结合气候模型对晋北18个站点进行模拟研究。结果表明:APSIM可有效模拟晋北地区玉米,马铃薯和饲用燕麦的生产,归一化均方根误差NRMSE小于21%,一致性系数d大于0.90;平鲁、神池、左云饲用燕麦产草量高(16,020~20,817 kg hm^(-2));对比MID与BAS时期,各站点O-O、M-O、P-O饲用燕麦产草量增加5.49%~23.20%;对比END和MID时期,代县、大同等10站点O-O、M-O和P-O的饲用燕麦产草量提高0.27%~9.15%,繁峙仅O-O产草量显著下降22.76%;P-O系统有更多的季后土壤水分留存,多数情况下实行该系统更利于饲用燕麦高稳产;土壤储水能力较差但植物可利用水分较高的阳高点,易因预测情景的降雨量提高弥补燕麦生长旺盛期被利用的水分,利于耗水较多的O-O。综上,本研究结果有助于挖掘晋北区域饲用燕麦生产对区域气候变化的响应机制,并为饲用燕麦高产、稳产的科学管理提供理论基础。展开更多
基金funded by the National Natural Science Foundation of China(41165010)the State Key Basic Research and Development Plan of China(2007CB106806)the State Key Laboratory Fund of Institute of Atmospheric Physics,Chinese Academy of Sciences(LAPC-KF-2008-03)
文摘Land use change significantly influences soil properties. There is little information available on the long-term effects of post-reclamation from grassland to cropland on soil properties. We compared soil carbon （C） and nitrogen （N） storage and related soil properties in a 50-year cultivation chronosequence of grassland in the agro-pastoral ecotone of Inner Mongolia. Field surveys on land use changes during the period of 1955-2002 were conducted to build a chronosequence of cropland of different ages since the conversion from grassland. The results showed that soil C and N storage, soil texture, and soil nutrient contents varied with land use types and cropland ages （P〈0.01）. In the 0-30 cm soil layer, the soil organic carbon （SOC） density was significantly lower in the crop- lands （3.28 kg C/m2 for C50 soil） than in the grasslands （6.32 kg C/m2）. After 5, 10, 15, 20, 35, and 50 years of crop planting （years since the onset of cultivation）, the SOC losses were 17%, 12%, 19%, 47%, 46%, and 48%, respec- tively, compared with the grasslands. The soil total nitrogen （TN） density of the grasslands was 65 g N/m2, and TN density of the cropland soil was 35 g N/m2 after 50 years of crop planting. Both the SOC and TN densities could be quantitatively determined by a negative exponential function of cropland age （P〈0.0001, R2=0.8528; P〈0.0001, R2=0.9637）. The dissolved organic carbon （DOC） content, pH value were decreased; and the soil bulk density and soil available potassium （AK） content, clay content, and sand content were increased since the conversion of grassland into cropland during the 50-year period. Our results show soil nutrients were higher in grassland than in cropland. The conversion of grasslands to croplands induced a loss of soil C storage and changes of related soil properties. The reclamation time of cultivated soil （cropland age） had significant effects on soil properties in the study area.
基金supported by the National Natural Science Foundation of China (Grant No. 100262001)the Advanced University Science Foundation of Inner Mongolia (Grant No. NJzy08044)the Ph. D. Foundation of Inner Mongolia Agricultural University (Grant No. BJ07-27)
文摘The unique regional climate characteristics are among the main reasons for the frequent wind-sand activity in arid and cold areas in the agro-pastoral ecotone in Inner Mongolia, China. This paper focuses on the time series of temperature and precipitation in spring when sandstorms often occur in the area. Based on meteorological data for a 46-year period from 1959 to 2004, multi-scale variations and abrupt changes in temperature and precipitation were analyzed with the Mexican hat function （MHF） wavelet method, showing the multi-scale variation characteristics of temperature and precipitation, as well as the periods and change points at different time scales. The relationship between temperature and precipitation was obtained using the wavelet analysis method. Obvious staggered features of the variations of spring temperature and precipitation were observed in this agro-pastoral ecotone. The strongest oscillation periods of spring temperature variations were 1 and 22 years, while for precipitation, the strongest oscillation periods of variations were 2, 8, and 22 years. In addition, lower spring temperature corresponded to lower precipitation, whereas higher temperature yielded higher precipitation rate.
基金National Key Research and Development Program of China,No.2017YFC0504705National Natural Science Foundation of China,No.41771191,No.41471143
文摘With global climate change, the agricultural light-temperature potential productivity in the agro-pastoral ecotone has increased. This offers a good opportunity to develop agriculture in the agro-pastoral ecotone. However, the agro-pastoral ecotone is also an ecologically fragile area in which land degradation challenges agricultural development. As population grows and the need for food increases, the land carrying capacity of the agro-pastoral ecotone becomes insufficient, and the human–land relationship is not harmonious. Such conditions have limited the agricultural and rural development in the ecotone. The paper demonstrates how land engineering may improve land quality and support agricultural development in the ecotone based on studies at a research station established in 2015 in Yulin,Shaanxi Province, China. The studies target three factors: soil improvement, crop selection,and field management. The results show that:(1) The highest yield of crops planted on improved land is close to or even higher than that achieved under previous crop growth conditions. For instance, the corn yields can exceed 25%.(2) The potatoes grown on the improved land yield the highest gross income, reaching 67,200 yuan/ha. By way of land engineering,input costs can be balanced in 3–5 years.(3) As a result of land engineering, some villages in Yulin City have realized sustainable agricultural and even rural development, and promotion of this model will support the sustainable development of agriculture in the agro-pastoral ecotone.
文摘为研究撂荒年限对农田土壤的影响,本试验于8月植物生长旺季进行,选取未撂荒农田(CK)、撂荒7年(7a)、15年(15a)和30年(30a)的农田采集土壤样品,室内计算分析土壤理化特征的变化规律,结果表明,撂荒显著提高了土壤容重,降低了土壤孔隙度和土壤pH。与未撂荒地对比,撂荒显著提高了土壤有机碳(Soil organic carbon,SOC)、全氮(Soil total nitrogen,TN)和全磷(Soil total phosphorus,TP)的含量。因此,长期撂荒对土壤养分状况具有显著改善作用。不同撂荒年限土壤含水量与土壤养分指标均呈显著正相关,长期撂荒下更少的蒸散耗水量减少了土壤水分的损失,使土壤养分得到了积累。本研究可为坝上农牧交错带撂荒地的合理规划提供理论支撑。
文摘本研究旨在探究适合晋北地区饲用燕麦(Avena sativa L.)轮作制度及各区域饲用燕麦产量对气候变化和轮作制度的响应。为此,基于已验证的APSIM(Agricultural Production System sIMulator)设定3种轮作制度,即O-O(饲用燕麦连作)、P-O(马铃薯-饲用燕麦轮作)、M-O(玉米-饲用燕麦轮作),结合气候模型对晋北18个站点进行模拟研究。结果表明:APSIM可有效模拟晋北地区玉米,马铃薯和饲用燕麦的生产,归一化均方根误差NRMSE小于21%,一致性系数d大于0.90;平鲁、神池、左云饲用燕麦产草量高(16,020~20,817 kg hm^(-2));对比MID与BAS时期,各站点O-O、M-O、P-O饲用燕麦产草量增加5.49%~23.20%;对比END和MID时期,代县、大同等10站点O-O、M-O和P-O的饲用燕麦产草量提高0.27%~9.15%,繁峙仅O-O产草量显著下降22.76%;P-O系统有更多的季后土壤水分留存,多数情况下实行该系统更利于饲用燕麦高稳产;土壤储水能力较差但植物可利用水分较高的阳高点,易因预测情景的降雨量提高弥补燕麦生长旺盛期被利用的水分,利于耗水较多的O-O。综上,本研究结果有助于挖掘晋北区域饲用燕麦生产对区域气候变化的响应机制,并为饲用燕麦高产、稳产的科学管理提供理论基础。
