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1.
Abstract

This trial was carried out to establish an appropriate nutrient solution for Aglaonema commutatum and to investigate the nutritional effects generated by modifications in the solution. Six treatments were tested: control (T0; pH 6.5, E.C. 1.5 dS m?1, 6 mmol L?1 NO3 ?‐N, and 6 mmol L?1 K+); high nitrogen (N) level (T1; 9 mmol L?1 6:3 NO3 ?–NH4 +); N form (T2; 6 mmol L?1 N‐NH4 +); high K+ level (T3; 12 mmol L?1 K+); high electrical conductivity (T4; E.C. 4 dS m?1, 25 mmol L?1 NaCl), and basic pH (T5; pH 8). At the end of the cultivation, leaf, shoot, and root dry weights and elemental concentrations were determined. Nutrient contents and total plant uptake were calculated from the dry weights and nutrient concentrations. Plant K+ uptake increased with application of K+ or basic nutrient solution. The uptake and transport of calcium (Ca) were enhanced by the use of NO3 ?‐N and inhibited by the presence of other cations in the medium (NH4 +, K+, Na+) and by basic pH. Magnesium (Mg) uptake increased with NO3 ?‐N application and with pH. Sodium (Na) uptake was the highest in the saline treatment (T4), followed by the basic pH treatment. Sodium accumulation was detected in the roots (natrophobic plant), where the plant generated a physiological barrier to avoid damage. Dry weight did not differ significantly (p<0.05) among treatments except in the NaCl treatment. These results may help in the formulation of nutrient solutions that take into account the ionic composition of irrigation water and the physiological requirements of plants.  相似文献   

2.
STUDIES ON SOIL COPPER   总被引：11，自引：0，他引：11  
Adsorption isotherms were determined for the specific adsorption of copper by soils and soil constituents. Adsorption was found to conform to the Langmuir equation. The Langmuir constants, a (adsorption maximum) and b (bonding term), were calculated. Soils were found to have specific adsorption maxima at pH 5.5 of between 340 and 5780 μg g?1, and a multiple regression analysis revealed that organic matter and free manganese oxides were the dominant constituents contributing towards specific adsorption. Adsorption maxima for soil constituents followed the order manganese oxides > organic matter > iron oxides > clay minerals, which supported the findings for whole soils. The cation exchange capacities (non-specific adsorption) of the test soils were found to be far greater than the specific adsorption maxima. However, evidence suggests that, for the relatively small amounts of copper normally present in soils, specific adsorption is the more important process in controlling the concentration of copper in the soil solution.  相似文献   

3.
The aim of this trial was to study the nutritional behavior generated by modifications in the salt concentration in the nutrient solution used for the fertigation of Cordyline fruticosa var. Red Edge plants. Four treatments were tested: T1 [control, 1.5 dS m?1, 14.3 mmol L?1 sodium chloride (NaCl)]; T2 (2.5 dS m?1, 22.2 mmol L?1 NaCl); T3 (3.5 dS m?1, 32.7 mmol L?1 NaCl); and T4 (4.5 dS m?1, 38.2 mmol L?1 NaCl). There is an accumulation of sodium (Na+) in roots, stem, and petiole when salinity increases, which avoid leaf damages. Potassium (K) concentration increases with the intermediate saline treatments in stems and leaves but decreases when plants are fertigated with T4. Calcium (Ca) accumulates in roots with T3 and T4, in stems with T4, and in petioles and leaves with T3. Magnesium (Mg) concentration is greater in stems, petioles, and leaves of T4, but is greater in roots of T3. Plants fertigated with the three saline treatments extract 1.4 times more Na+ than T1 plants. The greatest K+ extraction is observed in T2, followed by T3, and T4. T2, T3, and T4 plants extracted more Ca2+ than T1 plants. Finally, Mg2+ extractions in T3 are twice as much as they are in T1, while in T4 and T2 are much greater.  相似文献   

4.
ABSTRACT

The performance of DNDC (DeNitrification-DeComposition) and RothC (Rothamsted Carbon model) in simulating soil organic carbon (SOC) storage in soils under rice (Oryza sativa L.) – wheat (Triticum aestivum L.), maize (Zea mays L.) – wheat and cotton (Gossypium hirsutum L.) – wheat cropping systems was evaluated on field and regional scale. Field experiments consisted of N, NP, NK, PK, NPK, FYM, N + FYM, NPK + FYM, and control (UF) treatments. DNDC and RothC over-estimated SOC storage by 0.35–1.16 Mg C ha?1 (6–21%) in surface layer with manure application, compared with inorganic fertilizer treatments by 1.01–1.16 Mg C ha?1 (14–18%). Although RothC only slightly over-estimated SOC stocks, DNDC provided a better match for measured versus simulated SOC stocks (R 2 = 0.783*, DNDC; 0.669*, RothC, p < .05). Model validation on independent datasets from long-term studies on rice–wheat (R 2 = 0.935**, DNDC; R 2 = 0.920**, RothC, p < .01) and maize–wheat (R 2 = 0.895** for DNDC and R 2 = 0.967** for RothC, p < .01) systems showed excellent agreement between measured and simulated SOC stocks. On a regional scale, change in SOC storage under Scenario 1 (NPK) was significant up to 8 years of simulation, with no change thereafter. In Scenario 2 (NPK + FYM), DNDC simulated SOC storage after 10 years was 2.0, 0.4, and 1.4 Mg C ha?1 in three systems, respectively. Amount of C sequestered in silt + clay fraction varied between 0.31 and 0.97 kg C 10 years?1 (Mg silt + clay)?1 under Scenario 1, and between 0.78 and 2.67 kg C 10 years?1 (Mg silt + clay)?1 under Scenario 2.  相似文献   

5.
ABSTRACT

Soil degradation due to salinization and sodication is the paramount threat in Indo-Gangetic plains. The studies on reclamation and management of such soils can provide a pragmatic solution for improving fertility and productivity of these soils. Lack of organic matter and poor availability of nutrients are the major factors for low productivity of sodic soils. Rice-wheat is a major cropping system in Indo-Gangetic alluvial plain region even in reclaimed sodic soils and farmers used inorganic fertilizers only to get higher yields. In this study, we used different organic sources of amendments in conjunction with different nitrogen (N) doses supplied through inorganic fertilizers to investigate the combined effect of organic and inorganic amendments on soil fertility and the productivity of rice- wheat system in sodic soils. Salt tolerant varieties of rice and wheat were grown in sodic soil (pH: 9.30, EC: 1.12 dSm?1 and exchangeable sodium percentage, ESP: 52) during 2014–15 to 2016–17 in a field experiment with 13 treatment combinations of organic and inorganic amendments (T1- (control) 100% of recommended dose of N (RDN), T2-municipal solid waste compost (MSWC) @10 t ha?1 + 50%RDN, T3- MSWC @10 t ha?1 + 75% RDN,T4- MSWC @10 t ha?1 + 100%RDN, T5-Vermicompost (VC) @10 t ha?1 + 50% RDN, T6- VC @10 t ha?1 + 75% RDN, T7-VC@10 t ha?1 + 100% RDN, T8- Farm yard manure (FYM) @ 10 t ha?1 + 50% RDN,T9- FYM@10 t ha?1 + 75%RDN, T10- FYM@10 t ha?1 + 100% RDN, T11-Pressmud (PM) @10 t ha?1 + 50% RDN, T12-PM@10 t ha?1 + 75%RDN, and T13- PM @ 10 t ha?1 + 100% RDN). Use of organic amendments supplemented with reduced dose of N through inorganic fertilizer has significantly improved soil bio-physical and chemical properties. Application of VC@10 t ha?1 + 100% RDN (T7) decreased soil bulk density, pH, EC, ESP and Na content to 2.0, 4.2, 26.5, 42.8, and 56.6% respectively and increased soil organic carbon by 34.6% over control (T1). Soil fertility in terms of available N, P, K, Ca, and Mg increased by 20.5, 33.0, 36.4, and 44%, respectively, over control (T1). Soil microbial biomass carbon, nitrogen, and phosphorus also improved significantly due to combined use of organic amendments and inorganic fertilizers over the only use of inorganic fertilizers. Decreasing in soil sodicity and increasing soil fertility showed significant increase (P < 0.05) in crop growth, growth indices, and grain yields of rice and wheat. The study revealed that combined use of VC or MSW compost @10 t ha?1 in conjunction with 75% RDN through inorganic fertilizers in sodic soils proved sustainable technology for restoration of degraded sodic soils and improving crop productivity.  相似文献   

6.
The electric charge characteristics of five Ando (B) and two Red-Yellow B horizon soils and two weathered pumices were studied by measuring the retention of NH4+ and Cl? at different pH values and NH4Cl concentrations. The magnitude of their negative charge (CEC; meq/100g) was dependent on pH and NH4Cl concentration (C; m) as represented by a regression equation: log CEC =apH +blog C +c. The values of the coefficient a (0.017 to 0.342), b (0.031 to 0.274) and c (1.41 to ? 1.26) were correlated and depended on the kind of clay minerals present. A similar equation: log AEC =a’ pH +b’ log C+c’ was also found for the positive charge in the Ando soils, but there was little difference in the values of a’(?0.204 to ?0.251), b’(0.181 to 0.253) and c’(2.06 to 2.46) between the soils. It was shown that the equations generally hold for soils with constant and/or variable charges and describe adsorption equilibria in which NH4+ and H+, and Cl? and OH? compete for cation- and anionexchange sites, respectively. The significance and utility of the coefficients is discussed.  相似文献   

7.
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8.
There is a need for determinations of soil organic carbon (SOC) and inorganic carbon (SIC) due to increasing interest in soil carbon sequestration. Two sets of soil samples were collected separately from the Yanqi Basin of northwest China to evaluate loss-on-ignition (LOI) method for estimating SOC and SIC in arid soils through determining SOC using an element analyzer, a modified Walkley-Black method and a LOI method with combustion at 375℃ for 17 h and determining SIC using a pressure calcimeter method and a LOI procedure estimated by a weight loss between 375 to 800℃. Our results indicated that the Walkley-Black method provided 99%recovery of SOC for the arid soils tested. There were strong linear relationships(r > 0.93, P < 0.001) for both SOC and SIC between the traditional method and the LOI technique. One set of soil samples was used to develop relationships between LOI and SOC(by the Walkley-Black method), and between LOI and SIC(by the pressure calcimeter method), and the other set of soil samples was used to evaluate the derived equations by comparing predicted SOC and SIC with measured values. The mean absolute errors were small for both SOC (1.7 g C kg-1) and SIC(1.22 g C kg-1), demonstrating that the LOI method was reliable and could provide accurate estimates of SOC and SIC for arid soils.  相似文献   

9.
Response of the integrated use of mycorrhiza, inorganic and organic manures on microbial variables and yield performance of colocasia (Colocasia esculenta L.) was studied in an acid Alfisol. Significantly highest mean cormel yield (14.13 t ha?1) was recorded due to application of super optimal doses of nitrogen, phosphorus, and potassium (NPK). Integrated application of lime + farmyard manure (FYM) + ½ NPK + zinc sulfate (ZnSO4) has recorded the highest dehydrogenase activity (2.048 µg TPF hr?1 g?1) and Fluorescein Diacetate Hydrolysis assay (1.855 µg g?1 hr?1). The highest acid and alkaline phosphatase activities (77.67 and 51.18 µg PNP g?1 h?1, respectively) were observed due to Vesicular Arbuscular Mycorrhiza (VAM) inoculation in combination with lime + FYM + ½ NPK. Dehydrogenase and phosphatase activities had a highly significant relationship with cormel yield and the biochemical constituents of colocasia. The study emphasized the conjunctive use of balanced inorganic fertilizers and organic manures to enhance the enzymatic activities and to realize higher crop yields of colocasia in acid Alfisols.  相似文献   

10.
ABSTRACT

Salt-affected soils expand around the world and become a critical handicap for high crop yield. Saline-sodic soil contributed a major portion in salt-affected soils. Such types of soils have a sizable amount of Na+ in nutrient medium and that reduce the K+ uptake in plants. A hydroponic experiment was performed to investigate the ameliorative effect of different doses of potassium fertilizer (K1 = 0.3, K2 = 0.6 and K3 = 1.2 mM L?1) on rice (Oryza sativa L.) under different ECw (6 dS m?1) and SARw [12 and 24 (mmol L?1)1/2] levels. Application of K+ at elevated levels under saline-sodic conditions improved the concentration of anti-oxidant enzymes, plant physiological, and biochemical attributes by improving the K+: Na+ ratio in plant tissues. Total phenolic content, total soluble protein, and soluble sugar content of rice plant were increased with an increase in potassium dose and saline-sodicity. Maximum K+: Na+ ratios, 4.13 and 2.0 were observed in shoot and root, respectively upon application of K+ at 1.2 mM L?1 in a solution having ECw: SARw level of 6: 12. This study suggested that application of potassium at elevated levels (1.2 mM L?1) has enhanced the rice growth by reducing the harmful effect of Na+ salts on plant physiology, biochemical attributes, and anti-oxidant enzymes under specific saline-sodic conditions.  相似文献   

11.
This trial was carried out to study the influence of the nutrient solution on the microelements concentration and distribution in C. fruticosa var. ‘Red Edge' plants. Four treatments were tested: T1 [control, 1.5 dS m?1, 14.3 mmol L?1 sodium chloride (NaCl)], T2 (2.5 dS m?1, 22.2 mmol L?1 NaCl), T3 (3.5 dS m?1, 32.7 mmol L?1 NaCl) and T4 (4.5 dS m?1, 38.2 mmol L?1 NaCl). In roots and stems, iron (Fe) concentrations were lower in the no saline treatment. Stems accumulated more Fe with treatments T3 and T4. Copper concentration and extraction were not affected by salinity. The highest manganese (Mn) concentration in roots was observed in T2, while in petioles was higher in T3 and T4. Manganese extraction reached higher levels in the saline treatments in roots and stems, while in petioles it was lower in T1, T2 and T3. In roots, zinc (Zn) concentration was lower with the extreme treatments. Micronutrients concentration in leaves was unaffected by salinity, because an exclusion mechanism that consists on accumulation in roots and stems was developed.  相似文献   

12.
The soil solution chemistry of a podzolized soil in the north of Sweden was monitored for four years using percolation lysimeters. Weak organic acids were a major constituent of the soil solution and are important because of their ability to form complexes with aluminium. Dissolved organics leached from the mor layer enhance the weathering rate in the eluvial horizon by forming complexes with aluminium, especially during the autumn when the leaching of dissolved organics was greatest. The weak organic acids were titrated and their pKa values were evaluated. Aluminium was speciated with an ion-exchange method and by applying equilibrium calculations. Formation constants for the organic aluminium complexes were calculated to be log KAlong=5.42±0.32 m ?1 (n=13) in spring and summer and log KAlorg=4.87±0.14 m ?1 (n=6) in autumn. Equilibria of Al3+ with solid phases were also examined using solubility constants. Percolation lysimeters below undisturbed and cut-off mor layers were compared.  相似文献   

13.
Interaction between dilute (mg L?1) NaF solutions and clay suspensions (0.08 % w/v) has been examined as a function of pH (range 3 to 8), clay type (Na+- or Ca2+-kaolinite, illite, montmorillonite) and NaF concentration. No F loss from solution was detected at pH > 6.5, while enhanced uptake was found on decreasing the pH, especially in the 4 to 3 region. Removal of F from 1 to 6 × 10?4 M NaF was only slightly dependent on weight of solid, but did increase with [F?]. It is proposed that F losses are due to the formation of sparingly soluble Al species (e.g. cryolite, Na fluoro silicate), occasionally augmented with CaF2 formation (Ca2+-clays). The Al is released by proton attack on the lattice, following conversion of the suspended solids into the unstable H+-form, either through acid addition (pH < 5) or through hydrolysis of the Na+-form material. The latter process was most pronounced with the illite and montmorillonite samples. The amount of F fixed by montmorillonite was roughly double that held by the other two clays, and had a maximum value (pH 3) of ～ 4 mg g?1, using 11 mg L?1 NaF solutions. Soluble fluoro-complexes, similar in quantity to the retained F, were detected, in many of the studies. It was concluded that contact of the clay components of soils or sediments with mg L?1 levels of F in adjacent aqueous phases would result in only a minor proportion being retained.  相似文献   

14.
ABSTRACT

Orchard efficiency (OE) is one of the indices of evaluating the sustainability in production behavior of citrus orchards. A wide range of soil properties broadly categorized into particle size distribution, water soluble and exchangeable cations, and soil available nutrients were investigated in relation to efficiency of Nagpur mandarin (Citrus reticulata Blanco) orchards established on smectite rich three soil orders (Entisols, Inceptisols, and Vertisols) representing 18 locations of central India. The soil properties, viz., free calcium carbonate (CaCO3), clay content, water soluble- and exchangeable-calcium (Ca2 +), available nitrogen (N), phosphorus (P), and zinc (Zn) contributed significantly towards variation in OE. The threshold limit of these limiting soil properties was further established using multivariate quadratic regression models as: 132.1 g kg? 1 free CaCO3, 418.1 g kg? 1 clay, 149.9 mg L? 1 water soluble Ca2 +, 25.9 cmol(p+) kg? 1 exchangeable Ca2 +, 114.6 mg kg? 1 available N, 12.8 mg kg? 1 available P, and 0.96 mg kg? 1 available Zn in relation to optimum OE of 82.1%. These reference values were very close to those obtained from best fit models, and could be effectively utilized in addressing soil related production constraints for precision-aided citriculture.  相似文献   

15.
Aggregation, particle size, and chemical composition affect the colour of the soil. We have attempted to quantify and understand these effects in 12 Mediterranean soils. We measured the CIELAB colour variables hab, L*, and C*ab in aggregated and dispersed soil samples, and also in coarse sand, fine sand, silt, and clay samples before and after sequential removal of organic matter, carbonates, and Fe oxides. Grassmann's colour‐mixing equations adjusted by regression analysis described the colour of the dispersed soil from its particle‐size fractions with an error of 1% for hab, 4% for L*, and 9% for C*ab. This suggests that the contribution of each fraction to the colour of the dispersed soil can be accurately calculated by its colorimetric data weighted by its content and a regression coefficient, which was greatest for clay. We inferred the influence of a component within each fraction by measuring the colour changes after its removal. Iron oxides reduced hab of the silicated substrate by 19%, reduced L* by 12%, and increased C*ab by 64% in all particle‐size fractions. Carbonates and organic matter had little influence: the former because they impart little colour to the silicates and the latter because there was little of it. The CIELAB colour‐difference between dispersed and aggregated soil (mean ΔE*ab = 15.3) was due mainly to ΔL* (?14.7). Aggregation contributed to diminishing L* of dispersed soil by 34%. Scanning electron microscopy showed that Fe oxides and organic coatings cover the surface of aggregates thereby influencing soil colour.  相似文献   

16.
Cesium-137 (137Cs) is strongly adsorbed on clay minerals, especially on illite. The adsorption of Cs+ on reference clay minerals, however, has not been fully investigated in relation to the presence of illite. The objective of this study was to clarify the effect of impurities (i.e., illite and vermiculite), present in reference smectite group minerals and kaolin minerals, on the retention of Cs+. The clay mineralogy of the reference minerals was characterized by X-ray diffraction (XRD). The radiocesium interception potential (RIP) was measured as an index of the Cs+ retention ability of clays. The content of illite in clay was represented by the total potassium (K) content given that illite is a major source of K in the clay fraction. The content of vermiculite in clay was represented by the Cs fixation capacity induced by Cs saturation followed by heating of samples at 110°C. Metabentonite and beidellite gave extremely high RIP values compared with other smectite group minerals, although a peak for illite (at 1.0 nm) was not observed in XRD analysis. The reference smectite and kaolin minerals showed a range of RIP values, even though their RIP values are theoretically zero. The RIP values had a significant positive correlation with the total K content of all the reference clay minerals (rs = 0.621*). This indicated that the retention ability for 137Cs depended more on the content of illite, as impurity, rather than the type of bulk mineral. Hence, the contribution of illite to the magnitude of the RIP was elucidated by the combination of measurement of total K content and XRD analysis.  相似文献   

17.
The acid- and base-buffering properties of 84 non-calcareous surface soil samples were studied by batch titration with HCI or KOH at a constant ionic strength of I = 0.1. The soil samples were classified according to their pH of zero point of titration (ZPT). Differential buffer values, dB(H) or dB(OH) (H+ or OH? as meq kg?1 needed to reduce or increase the soil pH sequentially by 0.5 units, respectively), were introduced to describe the course of titration curve and the intensity of buffer action. In all soils, the first acid-buffer value, dB(H)0→0.5, varied from 8 to 78 meq kg?1 and the second one, dB(H)0.5→1, from 10 to 138 meq kg?1. The corresponding base-buffer values, dB(OH)0→0.5 and dB(OH)0.5→1, ranged from 10 to 48 and from 14 to 44 meq kg?1, respectively. The most acid soils were most strongly buffered against acid, and the soils with the highest initial pH against base. The results reveal the acid-buffering by exchange reactions to be very important. In the soils with ZPT≦5.4, the first acid-buffer value was dependent on the content of organic matter and oxalate-soluble Al, whereas in the more acid soils the role of clay became significant. Thus, it was concluded that at higher pHs the foremost inactivation of H+ is attributable to soil components of pH-dependent charges, and the significance of constituents of permanent charges to increase with proceeding acidification. In strongly acid soils (ZPT≦4.8) the very effective buffering seemed to be primarily due to the dissolution of Al-hydroxides and, thus, to exert detrimental effects on the edaphic environment. The general rank of soil factors explaining the variation in the base-buffer values was in accord with the neutralization sequence, i.e. the strongest acid in the soil being neutralized first. In the strongly acid soils (ZPT≦4.8) the base-buffer values seemed to depend on the clay as well as KCl- and NH4OAc-extractable Al, whereas in the soils with higher initial pH mostly on organic C.  相似文献   

18.
Dynamic light scattering and phase analysis light scattering have been used to study organo-clay complexes and aggregate stability of Haplic Stagnosols depending on land use. The study of agricultural soils afforested for 45 years showed that the value of the effective diameter of organo-clay complexes slightly decreased compared to that in arable soil but remains still higher than that in the forest soil. Multiple linear regression statistical models were developed to predict the effective diameter of the particles. The best model (r = 0.95), where all parameters were significant (P < 0.05), included the clay content, clay carbon concentration, total iron (Fet) and soil color coordinates (L*, a*, b*). In the upper horizons, the effective diameter depends on the organic matter content, whereas iron oxides with surfaced position play the main role in the underlying horizons. Intensive tillage moves the colloidal system to coagulation and after withdrawal of arable Haplic Stagnosol from the agricultural production, the colloidal system tends to restore its peptization stability. However, it should be noted that the afforestation period (45 years) of arable Haplic Stagnosols is not enough for a full recovery of organo-clay complexes peptization stability.  相似文献   

19.
A factorial experiment based on a completely randomized design with three replicates was conducted to evaluate effects of sixteen different mixtures of organic nitrogen sources and antibiotics which were supplemented to an Murashige and Skoog (MS) medium containing 4 mg L?1 2,4-Dichlorophenoxyacetic acid (2,4-D), 0.4 mg L?1 benzyl-aminopurine (BAP), 30 g L?1 sucrose, 8 g L?1 Agar-agar on fresh weight and dry weight (assessed after three days of drying at 70°C) of calli and in vitro callogenesis from scutellum of four indigenous Iranian Indica rice (Oryza sativa L.) cultivars, including ‘Hashemi’, ‘Gerdeh’, ‘Hasani’, and ‘Gharib’. It was found that proline at 2.8 g L?1 is the most effective source of organic nitrogen in enhancing growth, whereas asparagine at 0.75 g L?1 inhibited the calli growth. Hygromycin at 50 mg L?1, with slight differences between the cultivars, could effectively stunt the growth of untransformed calli. Mixture of cefotaxime (250 mg L?1) and vancomycin (250 mg L?1) did not have any significant effects on calli growth, although this treatment was slightly phytotoxic.  相似文献   

20.
中国南方黄泥田土壤中养分淋失严重,尤其是氮(N)和钾(K),不仅造成资源浪费和潜在环境威胁,还严重制约作物的可持续生产。采用室内土柱模拟培养,研究尿素(U)和尿素硝铵(UAN)中单独添加脲酶抑制剂N-丁基硫代磷酰三胺(NBPT)和硝化抑制剂2-氯-6-(三氯甲基)吡啶(CP),及两者配合施用对黄泥田土壤中K素淋溶特征的影响,探讨提高黄泥田供钾能力的施肥技术。不同氮肥种类淋溶液中,K~+平均浓度大小表现为UAN处理(103.0 mg·kg~(-1))高于U处理(93.9 mg·kg~(-1)),且抑制剂处理间存在明显差异。培养结束时(第72 d),UAN处理K~+淋失量较U处理高6.7%。U各处理淋溶液中K~+累积量大小表现为UU+NBPTU+NBPT+CPU+CPCK,其中U+NBPT、U+CP和U+NBPT+CP处理较U处理分别降低8.7%、20.2%和14.9%;UAN各处理淋溶液中K~+累积量表现为UANUAN+NBPTUAN+NBPT+CPUAN+CPCK,其中UAN+NBPT、UAN+CP和UAN+NBPT+CP处理较UAN处理分别降低6.0%、13.8%和9.2%。不同施肥处理K~+淋溶率表现为UANUAN+NBPTUUAN+NBPT+CPUAN+CPU+NBPTU+NBPT+CPU+CP。培养中期(第36 d),U和UAN处理肥际微域中土壤速效钾含量显著降低,而添加CP处理有效维持土壤中较高的速效钾含量。与单施NBPT相比,配施CP可以减少黄泥田土壤中NO_3~-淋溶,增加土壤晶格对K~+的固定,减轻K~+淋溶风险,有效时间超过72 d。对各处理淋溶液中K~+累积量(y)随NO_3~-累积量(x)的变化进行拟合,其中以线性方程(y=ax+b)和Elovich方程(y=alnx+b)的拟合度最高,且抑制剂处理间a、b值均存在明显差异。总之,在黄泥田土壤中单施CP,或与NBPT配施可以有效增加K~+吸附,降低土壤中K~+淋溶损失,减轻养分淋失风险,提高肥料利用率。  相似文献   

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