不同施肥管理对红壤性水稻土有机碳、氮形态的影响

A long-term experiment beginning in 1981 in Jinxian County of Jiangxi Province, subtropical China, was conducted in a paddy field under a double rice cropping system with four different fertilization regimes, including 1) no fertilizer as control (CK), 2) balanced chemical N, P, and K fertilizers (NPK), 3) organic manure using milk vetch and pig manure in the early and late rice growing season, respectively (OM), and 4) balanced chemical fertilizers combined with organic manure (NPKM). Samples (0-17 cm) of the paddy field soil, which was derived from Quaternary red clay, were collected after the late rice harvest in November 2003 for determination of total organic carbon (TOC) and total nitrogen (TN) and fractions of organic C and N. Results showed that TOC and TN in the NPKM and OM treatments were significantly higher than those in other two treatments (CK and NPK). Application of organic manure with or without chemical fertilizers significantly increased the contents of all fractions of organic C and N, whereas chemical fertilizer application only increased the contents of occluded particulate organic C (oPOC) and amino acid N. In addition, application of organic manure significantly enhanced the proportions of free particulate organic carbon (fPOC) and oPOC in total C, and those of amino sugar N and amino acid N (P < 0.01) in total N. In contrast, chemical fertilizer application only increased the proportions of oPOC and amino acid N (P < 0.05). There were no significant differences in either contents or proportions of soil organic C and organic N fractions between the NPKM and OM treatments. These indicated that organic manure application with or without chemical fertilizers played the most significant role in enhancing soil organic C and N quantity and quality in the paddy field studied.     

紫色水稻土的有机金属-矿物胶体复合物对磷的吸附、解吸特征

The kinetic characteristics of P adsorption and desorption by organo-mineral colloidal complexes (OMC) were studied using acid, calcareous and neutral purple paddy soils taken from Chongqing and Sichuan, China. The results showed that the P adsorption capacity of the organo-mineral colloidal complexes differed with the soil tyes, being higher for the acid and calcareous purple soils than for the neutral purple soils. Partial removal of the organic matter increased the adsorption capacity of the colloidal complexes. A very significant positive correlation was found between the amounts of P desorbed from OMC and the P saturation degrees. The P adsorption reaction was quick at the early stage and slowed later. The raise of temperature increased P adsorption capacity and P adsorption rate of the colloidal complexes. The adsorption processes could be described by the Elovich equation.     

磷素迁移的动力学方程

Studies on kinetics of adsorption and release of phosphorus by soil, a new field in soil chemistry, began only over ten years ago (He et al., 1989; Wang and Zhu, 1988; Zhang and Zhang, 1991; Lin, 1989; Lin and Xue, 1989; Jiang, 1993; Xue et al., 1995; Lü et al., 1997). The stress of this field is laid on the speed at which a soil system reaches balance between adsorption and release of phosphorus. Being more close to the field condition and helpful to explain the mechanism of adsorption and release of the phosphorus by the soil, kinetic methods have attracted much attention of the researchers (Aharoni et al., 1991; Griffin and Jurinak, 1974). Different kinetic equations have been used to describe the characteristics of the adsorption and release of phosphorus by the soil (He et al., 1989; Wang and Zhu, 1988; Lü et al., 1997); however, until now which equations are better remains a point of debate. Phosphorus transport in soil is, in fact, a comprehensive process, which includes adsorption, fixation and release of phosphorus by the soil. This study aimed to determine equations useful for describing phosphorus transport process through fitting the phosphorus transport processes in four soils sampled from Shaanxi Province using 17 types of kinetics equations selected.     

中国湖南省主要水稻土类型的氨固定

The contents, affecting factors, seasonal changes and availability of fixed ammonium in major types ofpaddy soils derived from different parent materials in Hunan Province, China, were studied using the Silva-Bremner method by laboratory and pot experiments. Results showed that the content of fixed ammoniumin the plough horizons ranged from 88.3 mg kg-1 to 388.1 mg kg-1, with 273.2 ± 77.7 mg kg-1 on average,accounting for 11.2% of total soil N on average. Content of fixed ammonium decreased in the order of newlylacustrine clayey paddy soil ＞ alluvial sandy paddy soil ＞ purple clayey paddy soil ＞ newly alluvial sandypaddy soil ＞ yellow clayey paddy soil ＞ reddish-yellow clayey paddy soil ＞ granitic sandy paddy soil. Therewere four distribution patterns of fixed ammonium in the profiles to 1-m depth, i.e., increase with the depth,decrease with increasing depth, no distinct change with the depth, and abrupt increase or decrease in somehorizon. Percentage of fixed ammonium in total N increased with the depth in most of the soils. Fixationof NH4+ by soil was higher at 30 ℃ than at 20 ℃ and 40 ℃, and continuous submergence benefited thefixation of NH4+ in newly alluvial sandy paddy soil, purple clayey paddy soil and alluvial sandy paddy soil,while alternating wetting and drying contributed to the fixation of NH4+ in yellow clayey paddy soil mostly.Fixed ammonium content in the test paddy soils was significantly correlated with ＜ 0.01 mm clay content(P ＜ 0.05), but not with ＜ 0.001 mm clay content, total N, organic N and organic matter. Fixed ammoniumcontent varied with rice growth stages. Application of N fertilizer promoted fixation of NH4+ by soil, and Nuptake by rice plant promoted release of fixed ammonium from the soil. Recently fixed ammonium in paddysoil after N fertilizer application was nearly 100% available to rice plant, while native fixed ammonium wasonly partly available, varying with the soil type and rice type.     

稻田土壤甲烷排放模型: Ⅰ. 模型的建立

With an understanding of the processes of methane production, oxidation and emission, a semi-empirical model, focused on the contributions of rice plants to the processes and also the influence of environmental factors, was developed to predict methane emission from rice paddy soils. In the present model, the amount of methane transported from the soil to the atmosphere was determined by the rates of CH₄ production and an emitted fraction. The rates of CH₄ production in irrigated rice soils were computed from the availability of methanogenic substrates that are primarily derived from rice plants and added organic matter and the influence of soil texture, soil redox potential and temperature. The fraction of methane emitted was assumed to be modulated by the rice plants and declines with rice growth and development. To make it applicable to a wider area with limited data sets, a simplified version of the model was also derived to predict methane emission in a more practical manner.     

不同养分和水分模式对水稻土化学和微生物学质量参数的影响

A field experiment was conducted from 1999 to 2002 to compare and evaluate the effects of nutrient and water regimes on paddy soil quality by investigating soil chemical and microbiological parameters. Four nutrient regimes, a control, chemical fertilizers only (CF), chemical fertilizers with swine manure (SM), and chemical fertilizers with wheat straw (WS), and two soil moisture regimes, continuous waterlogging (CWL) and alternate wetting and drying (AWD), were investigated. With SM and WS total organic carbon and total nitrogen in the paddy soil were significantly higher (P < 0.05) than those with CF. A similar effect for organic amendments was observed in the soil light fraction organic C (LFOC), water-soluble carbohydrates (WSC), and water-soluble organic C (WSOC). CWL, in particular when swine manure was incorporated into the paddy soil, markedly decreased soil redox potential (Eh) and increased total active reducing substances (ARS). Meanwhile, as compared to CF, SM and WS significantly (P < 0.05) increased soil microbial biomass C (MBC) and mineralizable carbon, with differences in AWD being higher than CWL. In addition, SM and WS treatments significantly (P < 0.05) improved rice above-ground biomass and grain yield, with AWD being greater than CWL. Thus, for ecologically sustainable agricultural management of paddy soils, long-term waterlogging should be avoided when organic manure was incorporated into paddy soil.     

过量施用磷肥对红壤发育的水稻土化学性质的影响及其与水稻生长的关系

A filed experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejing Province to elucidate the effect of excess P application on some important characteristics of soil properies and its relation to nutrient status and grain yields of rice crops.The experimental results indicated that adequate fertilizer P(15 kg P hm^-2)could increase the content of soil available P at the tillering stage of early rice,the contents of N,P and K in the shoots of early rice at primary growth stages,and the grain yield of early rice by increasing valid ears per hectare and weight per thousand grains,which,was mainly related to the higher contents of reduced,non-reduced and total sugar in the shoot at the heading stage, And early rice supplied with excessive P could not yield more than that applied with adequate, P de to the reduction in the valid grain percentage and weight per thousead grains. In addition,one-time excess P supply at a rate as high as 90 kg P hm^-2 could not improve the soil P fertility in case the soil available P content was lower than the initial(3.74mg kg^-1 soil) after an early rice-late rice rotaion,and made a decline in the grain yield increased by per kilogram fertilzer P.Thus,one-time excess P supply should not be adopted for soils with a large P fixation capacity like the paddy soils derived from red soils.     

我国东南部地区土壤养分的退化

A total of 2 190 soil nutrient data in the Second National Soil Survey of China were collected to assess the degradation of soil nutrients in the hilly region of Southeast China. The definition of soil nutrient degradation is suggested firstly, then the evaluation criteria are set up and the current status of degradation of red soil and latosol is assessed. The percentages of areas in four grades of soil nutrient degradation, i.e., slightly deficient, medium deficient, severely deficient and extremely deficient, were 21.3%, 43.3%, 16.2% and 3.0% for soil total N; 0.7%, 6.4%, 16.7% and 76.2% for soil available P; and 25.4%, 26.3%, 8.6% and 5.0% for soil available K, respectively. The severity of soil nutrient degradation was in the order of P > N > K. The major factors leading to the degradation of soil nutrients in quantity include soil erosion, leaching and the consumption by crops. And the principal factor affecting the degradation of soil nutrients in availability is the fixation of N, P and K, especially the fixation of phosphorus. The average amount of P fixed by soils is 408 mg kg^-1, and upland soils can fix more P than paddy soils.     

长期施用化肥和有机肥对太湖地区水稻土有机碳特征的影响

A long-term experiment set up in 1980 compared the effects of applying manures and chemical fertilizers on a paddy soil in the Taihu Lake region,China.Of the fourteen randomly distributed treatments consisting of different combinations of organic manure,inorganic nitrogen (N),phosphorus (P),and potassium (K),and rice straw,eight were selected for the present study in 2007.Application of organic manure plus straw significantly increased soil organic carbon (SOC) content of the topsoil (0-10 cm) compared to that of chemical fertilizers alone.The content of SOC was relatively stable in the 10-30 cm layer in the chemical fertilizer treatments and in the 20-40 cm layer in the manure treatments.The stable carbon isotope ratio (δ 13 C) ranged from 24‰ to 28‰ and increased gradually with depth.The content of SOC was significantly (P < 0.05) negatively correlated with δ 13 C.In the 0-20 cm layer,the δ 13 C value significantly decreased in the treatments of manure alone (M),manure and chemical N and P fertilizers (MNP),manure and chemical N,P,and K fertilizers (MNPK),manure,rice straw,and chemical N fertilizer (MRN),and chemical N fertilizer and rice straw (CNR),as compared with the no-fertilizer control.In the 30-50 cm layer,however,the ratio significantly increased in all the treatments except Treatment CNR.Mineralization of organic C peaked in the first 2-4 d of incubation and gradually leveled off thereafter over the first 3 weeks,being faster in the manure treatments than the chemical fertilizer treatments.The average rate of mineralization varied from 55.36 to 75.46 mL CO 2 kg-1 d-1 and that of stable mineralization from 10 to 20 mL CO 2 kg-1 d-1.In eight weeks of incubation,cumulative mineralization was always higher in the manure treatments than the chemical fertilizer treatments,being the highest in Treatment MRN.Combined humus in the soil was mainly (over 50%) composed of tightly combined fraction.The loosely combined humus and its ratio of humic acid (HA) to fulvic acid (FA) significantly increased with long-term application of organic manure and chemical fertilizers.It could be concluded that the cycle of organic C in the paddy soil ecosystem studied was stable over the long-term application of fertilizers and continued cultivation.     

中国南方红壤上作物产量和土壤性质对长期施肥的响应

A 15-year fertilization experiment with different applications of inorganic N, P and K fertilizers and farmyard manure (M)was conducted to study the yield and soil responses to long-term fertilization at Qiyang, Hunan Province, China. Average grain yields of wheat and corn (1 672 and 5 111 kg ha^-1, respectively)for the treatment NPKM were significantly higher than those (405 and 310 kg ha^-1)of the unfertilized control and single inorganic fertilizer treatments. Compared with the corresponding initial values of the experiment, all treatments showed a yield decline of 9 to 111 kg ha^-1 year^-1 in wheat and 35 to 260 kg ha^-1 year^-1 in corn, respectively, and a significant pH decline of 0.07 to 0.12 pH year^-1, except for the treatments PK and NPKM. After long-term fertilization, the soil organic C, soil available P, exchangeable Ca²⁺ and Mg²⁺ and available Cu²⁺ and Zn²⁺ contents were higher in the treatment NPKM than in the treatments applied with inorganic fertilizer only. Compared to the treatment NPK, the treatment NPKM, where manure partially replaced inorganic N, had a positive impact on arresting the decline of soil pH. This improved grain yields of wheat and corn, suggesting that application of NPK fertilizer in combination with farmyard manure is important to maintain soil fertility and buffering capacity in red soil.     

Phosphorus Adsorption and Bioavailability in a Paddy Soil Amended with Pig Manure Compost and Decaying Rice Straw

Phosphorus (P) availability in soil is closely related not only to soil P content but also to soil physicochemical and biological properties, which are closely associated with P sorption and biochemical transformation. The aims of this study were to determine the effects of pig manure compost (PMC) or decaying rice straw (DRS) added to a paddy soil on soil pH, soil organic carbon (SOC), dissolved organic carbon (DOC), acid phosphatase, microbial biomass P, soil test P (Olsen P), and P uptake by rice (Oryza sativa L. cv. ‘Liaoyan’). Phosphorus adsorption characterization affected by PMC‐ or DRS‐derived DOC was also studied. Compared with the control, both PMC and DRS treatments increased soil pH, SOM, DOC, microbial biomass P, and Olsen P, and the activity of acid phosphatase during the 110‐day incubation period. Phosphorus adsorption in soil decreased with DOC extracted from PMC and DRS and was well fit by the Langmuir equation. The Olsen P in the PMC‐ and DRS‐treated soil was correlated with both DOC content and acid phosphatase activity. Both PMC and DRS treatments significantly increased dry‐matter yield and P uptake in rice shoot. In conclusion, the increased P availability in the paddy soil was not only a result of direct P supplied following organic manure incorporation, but also an indirect result of reduction in P sorption on the solid phase of the paddy soil by DOCs which were derived from DRS or PMC.     

Effect of presubmergence and green manuring (Sesbania aculeata) on nutrition and yield of wetland rice (Oryza sativa L.) on a sodic soil

Summary A field experiment was conducted to evaluate the effect of 0, 1 and 2 weeks' submergence prior to the transplantation of rice (presubmergence), with and without Sesbania aculeata green manure, on the yield and nutrition of rice in a highly sodic soil [pH 10.3, exchangeable sodium percentage (ESP) 86.4]. Green manuring significantly enhanced the yield of rice and contributed 112 kg N/ha. One week's presubmergence with incorporated green manure improved the yield of rice significantly over that obtained with no previous flooding, giving a yield on a par with that obtained with 2 weeks' submergence. The beneficial effect of presubmergence without green manure on rice yield was of lesser magnitude and was significant only when it was continued for 2 weeks. Cultivation of rice under submerged conditions improved the sodic soil, and green manuring enhanced the process of reclamation by further decreasing the pH value and the exchangeable Na of soil. Green manuring considerably improved organic C, available N, P, and K status of the soil and enhanced the uptake of N, P, Ca, Mg, S, Fe, Mn, and Zn by the crop. Effects of submergence and green manuring on the availability of Fe, Mn, Zn, and P in soil and their role in the nutrition of rice are discussed.     

Wirkungen organischer Substanzen auf Boden- und Düngerphosphat. Teil 2: Einfluß verschiedener organischer Stoffe auf die Mobilität von Dünger-P

Effekt of various organic substances on the mobility of fertilizer P Using model trials, studies were carried out on the influence of long-term organic manuring as well as incubation with rotted straw, maize roots, and slurry, on both the diffusion of ³²P from added (NH₄)₂H³²PO₄ in a ‘soil block’and the fixation rate of fertilizer phosphate in the soil. 1. In the “soil block experiment”, preincubation for 7 days with slurry (added to a low-P brown earth soil at a rate of 5% D. M.) increased diffusion of P as compared to an equivalent amount of added inorganic P. Preincubation with rotted straw resp. maize roots had only insignificant effects. 2. Long-term organic manuring with farmyard manure (P-long-term field trials Weihenstephan) had a significant positive effect on the diffusion of P in the soil block in contrast to annual application of mineral P. Effects of straw manuring were markedly less. 3. Addition of maize roots (5% D. M. to a non P-treated or P-enriched brown earth soil) resulted in a reduced fixation of labelled fertilizer phosphate (by 2–8%), longer preincubation periods, however, increased fixation. Preincubation with rotted straw increased P fixation by 2 to 4% as compared to an equivalent addition of inorganic P (diammonium phosphate).     

土壤对磷的吸持特性及其与土壤供磷指标之间的关系

本试验测定了浙江省几种代表性土壤对磷的等温吸持特性。实测值与Frundlich、Langmuir、两项式Langmuir和Temkin方程都很符合,相关系数变化范围在0.919-0.999之间,都达到极显著水平。其中以简单Langmuir等温式与本实验资料最为吻合。从Langmuir方程得到的土壤吸持特性值(k×q_m)被认为与土壤供磷特性有关。几种供试样品的(k×q_m)值是:针铁矿21100>黄筋泥4218>黄筋泥田991>青紫泥798>粉泥田660>高岭石485>老黄筋泥田423>泥质田298。根据土壤吸持特性值以田菁进行盆栽试验来估算作物磷肥需要量,结果表明,供磷强度0.3ppm P基本能满足田菁早期生长的需要。为使不同土壤达到相同的供磷强度,(k×q_m)值大的土壤要求更高的有效磷值。供试土壤的几种磷素指标:E值、Bray1-P值和(NaOH-Na₂C₂O₄)法值对(k×q_m)值的变化比较敏感,而EDTA-P和Olsen-P指标对(k×q_m)值的变化较为迟钝。     

The interactive effects of biochar and cow manure on rice growth and selected properties of salt-affected soil

Salt-affected soil induces detrimental influences on paddy rice (Oryza sativa L.) growth and ameliorating the influences could be done with organic amendments, such as animal manure and biochar. The aims of the current study are: (1) to examine the interactive effects of biochar and cow manure on rice growth and on selected properties of salt-affected soil, and (2) to identify potential mechanisms related to the amendments. Saline-sodic soil was used for a net house experiment with two experimental factors: biochar (no-biochar, rice-husk, and -straw biochar) and cow manure (with and without cow manure). Without the manure, addition of both rice-hush and – straw biochar significantly increased rice growth, whereas a combination of individual biochar with manure did not show a positive synergistic effect. The interactive effect of two factors was not significant on available P and exchangeable K concentrations, but the main effects of the two factors were significant. Biochar addition resulted in higher soil cation exchange capacity (CEC) (28.8 to 29.0 cmol_c kg^?1) than the control (25.6 cmol_c kg^?1), but manure addition did not. Improved nutrient availabilities such as P and K, as well as CEC are among the potential mechanisms accounting for the enhanced rice growth with biochar.     

Long-term manuring and fertilization influence soil inorganic phosphorus transformation vis-a-vis rice yield in a rice–wheat cropping system

A study on the rice–wheat cropping system was conducted at Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, to assess the effects of long-term manuring and fertilization on transformation of the inorganic phosphorus (P) fraction in soil after 22 years of the crop cycle. Soil samples were collected after Kharif from seven treated plots having different types of organic amendments like farm yard manure, paddy straw and green manuring with 50% substitution of nitrogen levels in rice crop only. The result showed that the yield trend of rice was maintained due to the buildup of P from various organic inputs. Although cultivation for 22 years without adding any fertilizer caused a significant decrease in almost all the forms of P viz. avail-P, saloid P, iron phosphorus fraction (Fe–P), aluminum phosphorus fraction (Al–P), calcium phosphorus fraction (Ca–P) and total P in control. Partial substitution of inorganic fertilizer N (50%) with organics, however, caused a significant increase in almost all the P fractions in soil over the control. The relative abundance of all the fractions of inorganic P irrespective of treatments was as follows: Fe–P > reductant soluble P fraction > occluded P > Al–P > Ca–P > saloid P. Saloid and Fe–P were the dominating fractions responsible for 92% variation of available P and total P levels, respectively.     

配施有机肥对潜育化水稻土的培肥效果

为探索潜育化水稻土的培肥措施,通过田间试验研究了有机无机肥配施对潜育化低产水稻土产量和土壤养分有效性的影响。结果显示:连续2季施用有机肥后,潜育化水稻土产量显著提高,以早稻配施紫云英-晚稻配施猪粪处理的产量最高。添加有机肥降低了潜育化水稻土耕层土壤p H值。早稻配施紫云英,晚稻配施猪粪处理的有机质提高明显,比NPK处理提高了15.22%;早稻配施紫云英,晚稻配施猪粪处理的潜育化水稻土全氮含量比单施化肥处理提高4.19%;早稻配施紫云英,晚稻单施化肥处理的潜育化水稻土有效磷含量提高最多,比NPK处理提高了4.92%;相比于NPK处理,早稻配施紫云英,晚稻单施化肥处理的土壤速效钾含量比两季均单施化肥处理提高了13.2%。因此,潜育化水稻土适当配施有机肥可以提高土壤养分有效性,增加水稻产量,可以作为培肥改良潜育化水稻土的参考方法。     

不同熟化度红壤及红壤性水稻土的腐殖质组成及其特性

土壤腐殖质是评价红壤肥力的重要因素^[2],根据前人研究^[8,3,1]:一般土壤腐殖质的含量及组成受土壤地带性的影响。胡敏酸与富啡酸的比值自南向北逐渐递增,红壤胡敏酸与富啡酸的比值小于1。本文着重研究同一地区自然成土因素类同的情况下,红壤通过水旱耕作和培肥,土壤腐殖质的组成及特性的变化。     

Different response of silicate fertilizer having electron acceptors on methane emission in rice paddy soil under green manuring

Cultivation of green manure plants during the fallow season in rice paddy soil has been strongly recommended to improve soil properties. However, green manuring may impact greenhouse gas emission, methane (hereafter, CH₄) in particular, under the flooded rice cultivation and thus, application of chemical amendments being electron acceptors can be an effective mitigation strategy to reduce CH₄ emissions in irrigated rice (Oryza sativa L.) field amended with green manure. To investigate the effect of iron (Fe) slag silicate fertilizer (hereafter, silicate fertilizer), which was effective in reducing CH₄ emission and increasing rice productivity, in green manure-amended paddy soil, the aboveground biomass of Chinese milk vetch (hereafter, vetch) was added at rates of 0, 10, 20, and 40 Mg (fresh weight) ha⁻¹ before the application of silicate fertilizer, which was added at rates of 0 and 2.3 Mg ha⁻¹. Silicate fertilization reduced the seasonal CH₄ flux by ca. 14.5% and increased rice yield by ca. 15.7% in the control (no vetch application) treatment. However, CH₄ production was increased by silicate fertilization in vetch-treated soil particularly at the initial rice growing stage, which was probably due to the enhanced decomposition of added organic matters by the silicate liming effect. In conclusion, silicate fertilization is not effective in reducing CH₄ production in green manure-amended rice paddy soils and its use should be properly controlled.     

有机物料长期施用对稻田土壤养分的影响

通过2010—2021年连续12年的长期定位试验，研究了紫云英、水稻秸秆、商品有机肥等有机物料还田施用对稻田土壤养分的影响。结果表明：施用有机物料可以有效提高稻田土壤氮磷钾和有机质等含量。与单施化肥处理相比，紫云英还田土壤碱解氮含量增加6.97%，商品有机肥配施土壤有效磷含量增加49.30%，水稻秸秆还田土壤速效钾含量增加49.32%。3种有机物料处理土壤有机质增加相近(6.0%～7.5%)，可以改善土壤酸性但差异不显著。不同有机物料对土壤基础养分的增加差异显著，紫云英还田土壤固氮能力最强，商品有机肥配施土壤磷素增加最明显，秸秆还田土壤钾素提高最显著。可见，有机物料长期还田施用是一种培肥土壤的有效措施，有助于稻田土壤的可持续利用。