Organic amendment is considered as an effective way to increase soil organic carbon （SOC） stock in croplands. To better understand its potential for SOC sequestration, whether SOC saturation could be observed in an ...Organic amendment is considered as an effective way to increase soil organic carbon （SOC） stock in croplands. To better understand its potential for SOC sequestration, whether SOC saturation could be observed in an intensive agricultural ecosystem receiving long-term composted manure were examined. Different SOC pools were isolated by physical fractionation techniques ofa Cambisol soil under a long-term manure experiment with wheat-maize cropping in North China Plain. A field experiment was initiated in 1993, with 6 treatments including control （i.e., without fertilization）, chemical fertilizer only, low rate of traditional composted manure （7.5 t ha-h）, high rate of traditional composted manure （15 t ha-~）, low rate ofbio-composted manure （7.5 t ha-h） and high rate of bio-composted manure （15 t ha-h）. The results showed that consecutive （for up to 20 years） composted manure amendments significantly improved soil macro-aggregation, aggregate associated SOC concentration, and soil structure stability. In detail, SOC concentration in the sand-sized fraction （〉53 ~tm） continued to increase with manure application rate, while the silt （2-53 I.tm） and clay （〈2 ~tm） particles showed no further increase with greater C inputs, exhibiting the C saturation. Further physical separation of small macro-aggregates （250-2 000 tam） into subpools showed that the non-protected coarse particulate organic matter （cPOM, 〉250 pro） was the fraction in which SOC continued to increase with increasing manure application rate. In contrast, the chemical and physical protected C pools （i.e., micro-aggregates and silt-clay occluded in the small macro- aggregates） exhibited no additional C sequestration when the manure application rate was increased. It can be concluded that repeated manure amendments can increase soil macro-aggregation and lead to the increase in relatively stable C pools, showing hierarchical saturation behavior in the intensive cropping system of North China Plain.展开更多
Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive ...Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive agricultural region in the Huang- Huai-Hai Plain of China. Prior to modelling, validation of the DNDC model against field data sets of SOC from Quzhou Experimental Station in the Huang-Huai-Hai Plain was conducted at the site scale. We compared the simulated results with the observed SOC in Huantai County during 1982-2011 under two different classification methods of simulation unit （the first method integrated soil type and land use of Huantai County to form the overlapped modeling units; the second selected the 11 administrative towns as the modeling units）, and achieved a high accuracy in the model simulation with the improvement of the model parameters. Regional SOC （0-20 cm） density and stocks for Huantai County in the years 2012-2031 were predicted under different scenarios of farming management. Compared with current management practices, optimized fertilization （20% decrease of mineral N）, crop straw incorporation （90%） and appropriate animal manure input （40 kg N ha-1 yr-1） could achieve the highest level of SOC density （56.8% higher than 2011） in the period of 2012-2031. The research highlighted the importance of crop straw incorporation, optimized N fertilization and integration of crop production with ani- mal husbandry on the farmland carbon sequestration for maintaining a high land productivity in the Huang-Huai-Hai Plain.展开更多
华北地区是我国重要的粮食产区,以冬小麦(Triticumaestivum L.)和夏玉米(Zea mays L.)的集约化种植模式为主,而水资源缺乏和化肥过量投入却限制了该地区农业的可持续发展;为此,在在提高水氮利用效率和保证作物高产的同时,增加土壤氮库...华北地区是我国重要的粮食产区,以冬小麦(Triticumaestivum L.)和夏玉米(Zea mays L.)的集约化种植模式为主,而水资源缺乏和化肥过量投入却限制了该地区农业的可持续发展;为此,在在提高水氮利用效率和保证作物高产的同时,增加土壤氮库、推广应用水肥一体化技术很有必要。研究2015~2017年在山东桓台进行冬小麦和夏玉米滴灌施肥田间试验,探讨水分管理技术对作物产量、水分和氮肥利用效率以及对土壤氮库的影响;田间试验设漫灌和滴灌两种灌溉方法和三种氮肥用量,漫灌有0、600 kg hm-2yr-1两个施氮量处理(FN0,FN600),滴灌有0、420、600 kg hm-2yr-1三个施氮量处理(DN0、DN420和DN600)。结果表明,施肥处理间小麦和玉米产量均无显著差异,其中,较FN600,优化滴灌(DN420)处理下小麦和玉米产量分别增加5.8%和7.2%,作物地上部吸氮量增加4.6%。滴灌条件下,减氮30%后(DN420)能分别增加偏生产力(PFP)、表观氮素利用率(ANUE)、水分利用率(WUE)和灌溉利用率(IWUE)达47.4%、49.0%、3.4%和4.6%;与常规施肥处理相比,DN420能分别增加PFP、ANUE、WUE和IWUE达49.3%、52.0%、34.5%和101.9%。漫灌施肥处理导致无机氮在深层土壤(80~100 cm)的累积,增加氮素淋溶风险,滴灌施肥则会有利于氮素在表层土壤(0~40 cm)的累积,有利于作物吸收利用。经过2年试验后,表层土(0~20 cm)全氮的含量以滴灌施肥处理(DN420:1.27 g kg-1;DN600:1.28 g kg-1)最高。滴灌处理+优化施肥能增加作物产量,提高水氮利用效率,降低土壤氮素向深层土壤迁移,该措施在华北地粮食生产区推广使用,有利于集约化农业的可持续发展。展开更多
Addressing concerns about mitigating greenhouse gas （GHG） emissions while maintaining high grain yield requires improved management practices that achieve sustainable intensification of cereal production systems. In...Addressing concerns about mitigating greenhouse gas （GHG） emissions while maintaining high grain yield requires improved management practices that achieve sustainable intensification of cereal production systems. In the North China Plain, a field experiment was conducted to measure nitrous oxide （N2O） and methane （CH4） fluxes during the maize （Zea mays L.） season under various agricultural management regimes including conventional treatment （CONT） with high N fertilizer application at a rate of 300 kg N ha-1 and overuse of groundwater by flood irrigation, optimal fertilization 1 treatment （OPTIT）, optimal fertilization 2 treatment （OPT2T）, and controlled-release urea treatment （CRUT） with reduced N fertilizer application and irrigation, and a control （CK） with no N fertilizer. In contrast to CONT, balanced N fertilization treatments （OPT1T, OPT2T, and CRUT） and CK demonstrated a significant drop in cumulative N20 emission （1.70 v.s. 0.43-1.07 kg N ha-l）, indicating that balanced N fertilization substantially reduced N20 emission. The vMues of the N20 emission factor were 0.42%, 0.29%, 0.32%, and 0.27% for CONT, OPTIT, OPT2T, and CRUT, respectively. Global warming potentials, which were predominantly determined by N20 emission, were estimated to be 188 kg CO2-eq ha-1 for CK and 419-765 kg CO2-eq ha-1 for the N fertilization treatments. Global warming potential intensity calculated by considering maize yield was significantly lower for OPT1T, OPT2T, CRUT, and CK than for CONT. Therefore, OPTIT, OPT2T, and CRUT were recommended as promising management practices for sustaining maize yield and reducing GHG emissions in the North China Plain.展开更多
基金funded by the National Natural Science Foundation of China(31261140367,31170489 and 30870414)the China Postdoctoral Science Foundation(201104164 and 20100470408)the S&T Innovation Program of Chinese Academy of Agricultural Sciences
文摘Organic amendment is considered as an effective way to increase soil organic carbon （SOC） stock in croplands. To better understand its potential for SOC sequestration, whether SOC saturation could be observed in an intensive agricultural ecosystem receiving long-term composted manure were examined. Different SOC pools were isolated by physical fractionation techniques ofa Cambisol soil under a long-term manure experiment with wheat-maize cropping in North China Plain. A field experiment was initiated in 1993, with 6 treatments including control （i.e., without fertilization）, chemical fertilizer only, low rate of traditional composted manure （7.5 t ha-h）, high rate of traditional composted manure （15 t ha-~）, low rate ofbio-composted manure （7.5 t ha-h） and high rate of bio-composted manure （15 t ha-h）. The results showed that consecutive （for up to 20 years） composted manure amendments significantly improved soil macro-aggregation, aggregate associated SOC concentration, and soil structure stability. In detail, SOC concentration in the sand-sized fraction （〉53 ~tm） continued to increase with manure application rate, while the silt （2-53 I.tm） and clay （〈2 ~tm） particles showed no further increase with greater C inputs, exhibiting the C saturation. Further physical separation of small macro-aggregates （250-2 000 tam） into subpools showed that the non-protected coarse particulate organic matter （cPOM, 〉250 pro） was the fraction in which SOC continued to increase with increasing manure application rate. In contrast, the chemical and physical protected C pools （i.e., micro-aggregates and silt-clay occluded in the small macro- aggregates） exhibited no additional C sequestration when the manure application rate was increased. It can be concluded that repeated manure amendments can increase soil macro-aggregation and lead to the increase in relatively stable C pools, showing hierarchical saturation behavior in the intensive cropping system of North China Plain.
基金financially supported by the Non-profit Research Foundation for Agriculture, China (201103039)the National Natural Science Foundation of China (31261140367 and 31370527)
文摘Using the biogeochemical model den itrification/decomposition （DN DC）, the dynamic changes of soil organic carbon （SOC） of farmland from the 1980s to 2030s were investigated in Huantai County, a typical intensive agricultural region in the Huang- Huai-Hai Plain of China. Prior to modelling, validation of the DNDC model against field data sets of SOC from Quzhou Experimental Station in the Huang-Huai-Hai Plain was conducted at the site scale. We compared the simulated results with the observed SOC in Huantai County during 1982-2011 under two different classification methods of simulation unit （the first method integrated soil type and land use of Huantai County to form the overlapped modeling units; the second selected the 11 administrative towns as the modeling units）, and achieved a high accuracy in the model simulation with the improvement of the model parameters. Regional SOC （0-20 cm） density and stocks for Huantai County in the years 2012-2031 were predicted under different scenarios of farming management. Compared with current management practices, optimized fertilization （20% decrease of mineral N）, crop straw incorporation （90%） and appropriate animal manure input （40 kg N ha-1 yr-1） could achieve the highest level of SOC density （56.8% higher than 2011） in the period of 2012-2031. The research highlighted the importance of crop straw incorporation, optimized N fertilization and integration of crop production with ani- mal husbandry on the farmland carbon sequestration for maintaining a high land productivity in the Huang-Huai-Hai Plain.
文摘华北地区是我国重要的粮食产区,以冬小麦(Triticumaestivum L.)和夏玉米(Zea mays L.)的集约化种植模式为主,而水资源缺乏和化肥过量投入却限制了该地区农业的可持续发展;为此,在在提高水氮利用效率和保证作物高产的同时,增加土壤氮库、推广应用水肥一体化技术很有必要。研究2015~2017年在山东桓台进行冬小麦和夏玉米滴灌施肥田间试验,探讨水分管理技术对作物产量、水分和氮肥利用效率以及对土壤氮库的影响;田间试验设漫灌和滴灌两种灌溉方法和三种氮肥用量,漫灌有0、600 kg hm-2yr-1两个施氮量处理(FN0,FN600),滴灌有0、420、600 kg hm-2yr-1三个施氮量处理(DN0、DN420和DN600)。结果表明,施肥处理间小麦和玉米产量均无显著差异,其中,较FN600,优化滴灌(DN420)处理下小麦和玉米产量分别增加5.8%和7.2%,作物地上部吸氮量增加4.6%。滴灌条件下,减氮30%后(DN420)能分别增加偏生产力(PFP)、表观氮素利用率(ANUE)、水分利用率(WUE)和灌溉利用率(IWUE)达47.4%、49.0%、3.4%和4.6%;与常规施肥处理相比,DN420能分别增加PFP、ANUE、WUE和IWUE达49.3%、52.0%、34.5%和101.9%。漫灌施肥处理导致无机氮在深层土壤(80~100 cm)的累积,增加氮素淋溶风险,滴灌施肥则会有利于氮素在表层土壤(0~40 cm)的累积,有利于作物吸收利用。经过2年试验后,表层土(0~20 cm)全氮的含量以滴灌施肥处理(DN420:1.27 g kg-1;DN600:1.28 g kg-1)最高。滴灌处理+优化施肥能增加作物产量,提高水氮利用效率,降低土壤氮素向深层土壤迁移,该措施在华北地粮食生产区推广使用,有利于集约化农业的可持续发展。
基金Supported by the National Natural Science Foundation of China(Nos.30870414 and 31170489)the Special Fund for Agroscientific Research in the Public Interest of China(No.201103039)
文摘Addressing concerns about mitigating greenhouse gas （GHG） emissions while maintaining high grain yield requires improved management practices that achieve sustainable intensification of cereal production systems. In the North China Plain, a field experiment was conducted to measure nitrous oxide （N2O） and methane （CH4） fluxes during the maize （Zea mays L.） season under various agricultural management regimes including conventional treatment （CONT） with high N fertilizer application at a rate of 300 kg N ha-1 and overuse of groundwater by flood irrigation, optimal fertilization 1 treatment （OPTIT）, optimal fertilization 2 treatment （OPT2T）, and controlled-release urea treatment （CRUT） with reduced N fertilizer application and irrigation, and a control （CK） with no N fertilizer. In contrast to CONT, balanced N fertilization treatments （OPT1T, OPT2T, and CRUT） and CK demonstrated a significant drop in cumulative N20 emission （1.70 v.s. 0.43-1.07 kg N ha-l）, indicating that balanced N fertilization substantially reduced N20 emission. The vMues of the N20 emission factor were 0.42%, 0.29%, 0.32%, and 0.27% for CONT, OPTIT, OPT2T, and CRUT, respectively. Global warming potentials, which were predominantly determined by N20 emission, were estimated to be 188 kg CO2-eq ha-1 for CK and 419-765 kg CO2-eq ha-1 for the N fertilization treatments. Global warming potential intensity calculated by considering maize yield was significantly lower for OPT1T, OPT2T, CRUT, and CK than for CONT. Therefore, OPTIT, OPT2T, and CRUT were recommended as promising management practices for sustaining maize yield and reducing GHG emissions in the North China Plain.
