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1.
In order to quantify the influence of land use systems on the level of soil organic matter (SOM) to develop recommendations, long-term field studies are essential. Based on a crop rotation experiment which commenced in 1970, this paper investigated the impact of crop rotations involving increased proportions of sugar beet on SOM content. To this end, soil samples were taken in 2010 and 2012 from the following crop rotation sequences: sugar beet–sugar beet–winter wheat–winter wheat (SB–SB–WW–WW = 50%), sugar beet–sugar beet–sugar beet–winter wheat (SB–SB–SB–WW = 75%), sugar beet–grain maize (SB–GM = 50%) and sugar beet-monoculture (SB = 100%); these were analysed in terms of total organic carbon (TOC) and microbial biomass carbon (MBC) content, MBC/TOC ratio and the TOC stocks per hectare. In addition, humus balances were created (using the software REPRO, reference period 12 years) in order to calculate how well the soil was supplied with organic matter. In the field experiment, harvest by-products (WW and GM straw as well as SB leaves) were removed. After 41 years, no statistically significant differences were measured between the crop rotations for the parameters TOC, MBC, MBC/TOC ratio and the TOC stock per hectare. However, the calculated humus balance was significantly affected by the crop rotation. The calculated humus balance became increasingly negative in the order SB–SB–WW–WW, SB–SB–SB–WW, SB monoculture and SB–GM, and correlated with the soil parameters. The calculated humus balances for the reference period did not reflect the actual demand for organic matter by the crop rotations, but instead overestimated it. 相似文献
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不同利用方式黑钙土有机碳组分剖面分布特征 总被引：1，自引：0，他引：1
为研究土地利用方式对土壤碳库的影响,以东北黑钙土区的天然草地、人工林地和耕地为研究对象,采集0—100 cm土体中不同土层样品(A、AB、Bk、BC和C层),测定不同利用方式土壤有机碳(SOC)、水溶性有机碳(WSOC)、轻组有机碳(LFOC)和重组有机碳(HFOC)含量。结果表明:3种利用方式SOC、LFOC和HFOC主要分布在A层,但草地WSOC含量在Bk层最多(0.27 g/kg)。由A~C层,3种土地利用方式土壤有机碳及组分有机碳含量总体均呈减少趋势,但减少程度明显不同,天然草地缓慢减少,人工林地急剧减少,耕地逐渐减少。草地转换为林地和开垦为耕地后,均造成土壤有机碳及组分有机碳含量减少,WSOC减少34%和48%,LFOC减少20%和37%,HFOC减少7%和5%,SOC减少10%和16%。草地转换为林地和开垦为耕地后,WSOC/SOC、LFOC/SOC显著降低,但HFOC/SOC却提高,说明草地被开垦后活性有机碳含量快速下降。土地利用方式和土层对SOC、WSOC和LFOC具有显著影响,且对SOC和HFOC叠加效应较强。同时,土壤理化性质也在一定程度上影响着SOC、WSOC、LFOC和HFOC。应制定合理土地利用管理政策,保护自然草地免遭破坏,减少土壤有机碳流失,发挥草地生态系统碳固存的重要作用。 相似文献
3.
Elmira Karbozova-Saljnikov Shinya Funakawa Takashi Kosaki 《Soil biology & biochemistry》2004,36(9):1373-1381
In North Kazakhstan there is concern about the degradation of Chernozem soil and agricultural sustainability by the inclusion and frequency of summer fallows in crop rotations in terms of their influence on the changes of soil organic matter (SOM) quality and quantity. We examined five fallow-wheat (Triticum aestivum L.) cropping systems with different frequencies of the fallow phase in Chernozem soil of North Kazakhstan; continuous wheat (CW), 6-y rotation (6R), 4-y rotation (4R), 2-y rotation (2R) and continuous fallow (CF). Soil samples were collected from the two phases of each rotation, pre- and post-fallow, and analyzed for potentially mineralizable C (PMC) and N (PMN), ‘light fraction’ organic matter (LF-OM), C (LF-C) and N (LF-N). Potentially mineralizable C was inversely proportional to the frequency of fallow and was highest in CW. Mineral N (min-N) and PMN were more responsive to rotation phase than other indices of SOM. Mineral N was higher in the post-fallow phase while PMN was higher in the pre-fallow phase. Light fraction organic matter was negatively correlated to the frequency of fallow and was higher in the pre-fallow than in the post-fallow phase in a rotation. The results suggested that the yearly input of plant residue in a less frequently fallowed system built up more PMC, whereas PMN was closely correlated to recent inputs of substrate added with plant residues. We conclude that a frequent fallow system may deplete SOM via accelerated mineralization. Also that LF-OM, PMC and PMN are more sensitive to detect subtle changes in SOM quality than total SOM. Our results may provide prediction of SOM response to fallow frequency in wheat-based rotation systems in Chernozem soils of semi-arid regions. 相似文献
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Nutrient cycling and greenhouse gas emissions from soil amended with biochar-manure mixtures 总被引：1，自引：0，他引：1
Carlos M. ROMERO Chunli LI Jen OWENS Gabriel O. RIBEIRO Tim A. MCALLISTER Erasmus OKINE Xiying HAO 《土壤圈》2021,31(2):289-302
Integrating biochar into cattle diets has recently emerged as a potential management practice for improving on-farm productivity.Yet,information concerning the cycling of biochar-manure mixtures is scarce.A 70-d incubation experiment was conducted within two surface(0–15 cm)Mollisols with contrasting textures,i.e.,sandy clay loam(Raymond)and clayey(Lethbridge),to evaluate the effects of biochar(3 Mg ha-1)on cumulative greenhouse gas(GHG)emissions and related fertility attributes in the presence or absence of cattle manure(120 Mg ha-1).Five treatments were included:i)non-amended soil(control,CK),ii)soil amended with pinewood biochar(B),iii)soil amended with beef cattle manure(M)(manure from cattle on a control diet),iv)soil amended with biochar-manure(BM)(manure from cattle on a control diet,with pinewood biochar added at 20 g kg-1of diet dry matter),and v)soil amended with B and M at the aforementioned rates(B+M).A total of 40 soil columns were prepared and incubated at 21℃and 60%–80%water-holding capacity.On average,total CO2fluxes increased by 2.2-and 3.8-fold under manure treatments(i.e.,M,BM,and B+M),within Raymond and Lethbridge soils,respectively,relative to CK and B.Similarly,total CH4 fluxes were the highest(P<0.05)in Raymond soil under B+M and BM relative to CK and B,and in Lethbridge soil under M and BM relative to CK and B.In Lethbridge soil,application of BM increased cumulative N2O emissions by 1.8-fold relative to CK.After 70-d incubation,amendment with BM increased(P<0.05)PO_4-P and NO_3-N+NH_4-N availability in Raymond and Lethbridge soils compared with B.A similar pattern was observed for water-extractable organic carbon in both soils,with BM augmenting(P<0.05)the occurrence of labile carbon over CK and B.It can be concluded that biochar,manure,and/or biochar-manure have contrasting short-term effects on the biogeochemistry of Mollisols.At relatively low application rates,biochar does not necessarily counterbalance manure-derived inputs.Although BM did not mitigate the flux of GHGs over M,biochar-manure has the potential to recycle soil nutrients in semiarid drylands. 相似文献
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秸秆和硫酸铝对淡黑钙土有机矿质复合体及有机碳分布的影响 总被引：2，自引：0，他引：2
以吉林省典型土壤淡黑钙土为研究对象,采用室内恒温培养法研究在不同秸秆和硫酸铝添加量下,淡黑钙土中有机矿质复合体的含量及有机碳在其中的分布,探讨有机矿质复合体对淡黑钙土固碳的贡献。结果表明:对于秸秆和硫酸铝添加的所有处理,复合体含量均表现为G_1(钠分散组)G_0(水分散组)G_2(钠质研磨分散组);与对照相比,秸秆和硫酸铝添加使得淡黑钙土中G_0组复合体的含量降低,G_2组复合体的含量明显上升,而对G_1组复合体的含量影响不大。单位质量复合体中有机碳的含量大小表现为G_2G_0G_1,G_2组复合体中的有机碳含量最高(平均含量为95.92 g·kg~(-1)),约为单位质量G_0组和G_1组复合体中有机碳含量的3倍,G_0组(平均含量为33.89 g·kg~(-1))略高于G_1组(平均含量为32.25 g·kg~(-1))。秸秆和硫酸铝添加均有助于提高G_0组复合体中有机碳的含量;而G_1组复合体有机碳含量的变化主要受秸秆添加量的影响,随着秸秆添加量的增加,G_1组复合体有机碳含量增加;秸秆对G_2组复合体中有机碳含量的提高具有促进作用,而硫酸铝的影响则相反。各组复合体对淡黑钙土固碳的贡献率取决于土壤中复合体的含量及单位质量复合体中有机碳的含量,其对固碳贡献的大小顺序为G_1G_0G_2;有机矿质复合体(G_0+G_1+G_2)质量仅占淡黑钙土质量的约四分之一,但其对于淡黑钙土固碳的贡献却为61.96%~73.56%。 相似文献
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不同秸秆还田模式对黑钙土团聚体特征的影响 总被引：10，自引：4，他引：6
通过5年田间定位试验,研究了不同玉米秸秆还田方式对黑钙土土壤团聚体含量、稳定性和团聚体有机碳贡献率的影响。结果表明:与秸秆不还田(CK)比较,秸秆还田处理能显著提高土壤大团聚体(>250μm)含量、团聚体平均重量直径(MWD)和几何平均直径(GMD)(P<0.05)。秸秆轮耕还田(SRT)比秸秆覆盖还田(SCR)能更有利于土壤大团聚体形成,但2个处理的土壤团聚体稳定性之间差异不显著。秸秆轮耕还田与秸秆不还田相比较能显著增加土壤各粒级团聚体有机碳含量和大团聚体有机碳贡献率,同时,秸秆轮耕还田比秸秆覆盖还田更有利于提高>2 000μm粒径和<53μm粒径团聚体有机碳含量,以及250～2 000μm粒径团聚体有机碳贡献率。相关性分析表明,土壤有机碳含量与土壤团聚体稳定性及其碳库之间存在极显著的正相关关系。旋耕/深翻的轮耕还田模式促进了耕层土壤大团聚体形成和土壤结构稳定,显著提高土壤团聚体碳库和对土壤有机碳的贡献,为东北黑钙土区较适宜的玉米秸秆还田模式之一。 相似文献
8.
R. P. Zentner G. P. Lafond D. A. Derksen C. N. Nagy D. D. Wall W. E. May 《Soil & Tillage Research》2004,77(2):125-136
Producers in the Canadian Prairies have begun to extend and diversify their cereal-based rotations by including oilseed and pulse crops, and by managing these newer cropping systems with minimum- and zero-tillage practices. This study examined the implications of these land use changes on non-renewable energy requirements (both direct and indirect), energy output, and energy use efficiency for monoculture cereal, cereal–oilseed, and cereal–oilseed–pulse rotations, each managed using conventional (CT), minimum (MT), and zero (ZT) tillage practices on a thin Black Chernozem in Saskatchewan, Canada. The crop rotations included: spring wheat (Triticum aestivum L.)–spring wheat–winter wheat–fallow (Ws–Ws–Ww–F), spring wheat–spring wheat–flax (Linum usitatissimum L.)–winter wheat (Ws–Ws–Fx–Ww), and spring wheat–flax–winter wheat–field pea (Pisum sativum L.) (Ws–Fx–Ww–P). The findings, based on 12 years of data, showed that non-renewable energy use for the complete cropping systems was largely unaffected by tillage method, but that it differed significantly with crop rotations. Energy requirements were lowest for Ws–Ws–Ww–F (average 6389 MJ ha−1), intermediate for Ws–Fx–Ww–P (11% more), and highest for the Ws–Ws–Fx–Ww (28% more). The substitution of pea for spring wheat in the Ws–Fx–Ww–P versus Ws–Ws–Fx–Ww rotation reduced total energy use by 13%, reflecting the minimal requirement for N fertilizer by pulses due to their ability to biologically fix N, and from the lower fertilizer N rate that was applied to spring wheat grown after the legume. The use of MT and ZT practices provided significant energy savings (compared to CT) in on-farm use of fuel and in machine operation and manufacture for some cropping system components (e.g., summerfallow preparation, spring wheat grown on pea stubble, and for pea grown on cereal stubble), but these savings were often offset by higher energy requirements for herbicides and for N fertilizer with conservation tillage management. Gross energy output averaged 32 315 MJ ha−1 for Ws–Ws–Ww–F, 41 287 MJ ha−1 (or 28% more) for Ws–Ws–Fx–Ww, and 42 961 (or 33% more) for Ws–Fx–Ww–P. Tillage method had little overall influence on energy output for the monoculture cereal and cereal–oilseed–pulse rotations, but it was generally lower with CT than with MT or ZT management for the cereal–oilseed rotation. Energy use efficiency, measured as grain produced per unit of energy input and as the ratio of energy output to energy input, was highest for the cereal–oilseed–pulse rotation (373 and 6.1 kg GJ−1, respectively) and lower, but generally similar, for the cereal–oilseed and monoculture cereal rotations (298 and 5.1 kg GJ−1, respectively). The use of conservation tillage management enhanced overall energy use efficiency for the two mixed rotations, but not for the monoculture cereal rotation. We concluded that adopting diversified crop rotations, together with minimum and zero tillage management practices, will enhance non-renewable energy use efficiency of annual grain production in this sub-humid region. 相似文献
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Hirohiko Nagano Soh Sugihara Miwa Matsushima Susumu Okitsu Valentina E. Prikhodko Elena Manakhova 《Soil Science and Plant Nutrition》2013,59(2):238-244
The effects of different land-use histories on contents of soil carbon (C) and nitrogen (N) and fluxes of greenhouse gases [carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)] measured using the closed chamber method were investigated in the Arkaim museum reserve located in the South Ural of Russia. A natural forest site (NF) and two grassland sites that had different land-use histories (CL: cropland until 1991; PST: pasture until 1991; both sites have been fallow for 18 years) were selected for soil sampling and gas flux measurements. The vegetation in NF was mainly Betula pendula Roth. with steppe cherry and grassy cover. Perennial grasses (Stipa spp., Festuca spp. and others) have been planted in CL and PST since 1991 to establish reserve mode, and the projective cover of these plants were?>?90% in both sites in 2009. Soil samples were taken from the A horizon in the three sites, and additionally samples of the O horizon were taken from NF. The contents of soil C and N [total C, total N, soluble organic C, soluble N and microbial biomass C (MBC)] in the O horizon of NF were the largest among all investigated soils (p?p?2 fluxes (i.e., CO2 efflux) in all three investigated sites were observed. The CO2 efflux in NF was significantly larger than in CL and PST (129, 30 and 25?mg C m?2 hour?1, respectively, p?2 efflux between CL and PST. There were no significant differences in the fluxes of CH4 and N2O among NF, CL and PST (p?>?0.05). Our current research indicated that, in soils of the Eurasian steppe zone of Russia, total C, total N and MBC were affected not only by current land-use (i.e., fallow grassland vs. natural forest) but also by past (until 18 years ago) land-use. 相似文献