Effects of multiple soil conditioners on a mine site acid sulfate soil for vetiver growth

A pot experiment was conducted to investigate the effects of various soil treatments on the growth of vetiver grass ( Vetiveria zizanioides (L.) Nash) with the objective of formulating appropriate soil media for use in sulfide-bearing mined areas. An acidic mine site acid sulfate soil (pH 2.8) was treated with different soil conditioner formula including hydrated lime, red mud (bauxite residues), zeolitic rock powder, biosolids and a compound fertilizer. Soils treated with red mud and hydrated lime corrected soil acidity and reduced or eliminated metal toxicity enabling the establishment of vetiver grass.Although over-liming affected growth, some seedlings of vetiver survived the initial strong alkaline conditions. Addition of appropriate amounts of zeolitic rock powder also enhanced growth, but over-application caused detrimental effects. In this experiment, soil medium with the best growth performance of vetiver was 50 g of red mud, 10 g of lime, 30 g of zeolitic rock powder and 30 g of biosolids with 2 000 g of mine soils (100% survival rate with the greatest biomass and number of new shoots), but adding a chemical fertilizer to this media adversely impacted plant growth. In addition, a high application rate of biosolids resulted in poorer growth of vetiver, compared to a moderate application rate.     

The influence of soil aeration on growth and elemental absorption of greenhouse‐grown seedling pecan trees

Abstract

‘Dodd’ pecan seedlings were exposed to 3 levels of soil aeration for 30 days; 100%, 5%, and 0% of the container surface exposed to the atmosphere. These treatments resulted in about 21%, 13.5%, and 3% soil O₂and 0.3%, 5%, and 13% soil CO₂for 100%, 5%, and 0% of the container surface exposed, respectively. Restricting soil aeration induced partial stomatal closure, and decreased leaf number, leaf area, and leaf, trunk and root dry weights. The decrease in root dry weight associated with reduced soil aeration exceeded the decrease in top dry weight by about 50%. Translocation of N and P to the leaves was reduced when soil aeration was restricted, but root N and P concentrations were increased compared to trees grown in well aerated soil. Leaf elemental concentrations of Ca, Mg, and Mn were lower when trees were exposed to reduced soil aeration. Zinc and Fe concentrations were greater in the roots of trees with low aeration, but leaf and trunk concentrations of Zn and Fe were not affected     

Effects of freeze–thaw cycles and the soil water content on carbon and nitrogen changes in different soil types of Heilongjiang Province,China

To reveal the influence of freeze–thaw cycles (FTCs) on soil carbon and nitrogen changes, six typical soils in Northeast China were selected as the research objects to conduct a FTC simulation test in an artificial climate chamber. Three soil volumetric water contents (10%, 20%, 30%) and eight FTCs (0, 2, 4, 6, 8, 10, 15, 20) were set. The results showed that the soil organic carbon (SOC) and microbial biomass carbon (MBC) contents of different soil types under the FTCs initially exhibited a downward and then an upward trend, while the dissolved organic carbon (DOC) content exhibited an upward and then a downward trend. Otherwise, the fourth and sixth FTCs were the key points of change. The SOC, MBC and DOC contents in paddy fields were higher than those in dry fields, showing upward and then downward trends spatially from northeast to southwest. The SOC and MBC contents in each soil type were the highest at the 20% water content, and the DOC content gradually increased with increasing water content. The ammonium nitrogen (NH₄⁺-N) content in different soil types at different water contents under the FTCs showed an upward trend first, then a downward trend and finally an upward trend. The NH₄⁺-N content in paddy fields was higher than that in dry fields. The nitrate nitrogen (NO₃^‒-N) content showed a downward trend first, then an upward trend and finally a downward trend. The NO₃^‒-N content in dry fields was higher than that in paddy fields. The NH₄⁺-N contents in the three soil types on the Sanjiang Plain were significantly higher than those on the Songnen Plain. The NH₄⁺-N and NO₃^‒-N contents showed upward trends with increasing water content, but the differences were not significant. The results have implications for the study of different types of soils and provide references for research on the mechanism of soil carbon and nitrogen transformation in typical farming areas in Northeast China.     

Excessive nitrogen application decreases grain yield and increases nitrogen loss in a wheat–soil system

Abstract

Excessive use of nitrogen (N) fertilizers in wheat fields has led to elevated NO₃-N concentrations in groundwater and reduced N use efficiency. Three-year field and ¹⁵N tracing experiments were conducted to investigate the effects of N application rates on N uptake from basal and topdressing ¹⁵N, N use efficiency, and grain yield in winter wheat plants; and determine the dynamics of N derived from both basal and topdressing ¹⁵N in soil in high-yielding fields. The results showed that 69.5–84.5% of N accumulated in wheat plants derived from soil, while 6.0–12.5%and 9.2–18.1% derived from basal ¹⁵N and top ¹⁵N fertilizer, respectively. The basal N fertilizer recovery averaged 33.9% in plants, residual averaged 59.2% in 0–200 cm depth soil; the topdressing N fertilizer recovery averaged 50.5% in plants, residual averaged 48.2% in 0–200 cm soil. More top ¹⁵N was accumulated in plants and more remained in 0–100 cm soil rather than in 100–200 cm soil at maturity, compared with the basal ¹⁵N. However, during the period from pre-sowing to pre-wintering, the soil nitrate moved down to deeper layers, and most accumulated in the layers below 140 cm. With an increase of N fertilizer rate, the proportion of the N derived from soil in plants decreased, but that derived from basal and topdressing fertilizer increased; the proportion of basal and top ¹⁵N recovery in plants decreased, and that of residual in soil increased. A moderate application rate of 96–168 kg N ha^?1 led to increases in nitrate content in 0–60 cm soil layer, N uptake amount, grain yield and apparent recovery fraction of applied fertilizer N in wheat. Applying above 240 kg N ha^?1 promoted the downward movement of basal and top ¹⁵N and soil nitrate, but had no significant effect on N uptake amount; the excessive N application also obviously decreased the grain yield, N uptake efficiency, apparent recovery fraction of applied fertilizer N, physiological efficiency and internal N use efficiency. It is suggested that the appropriate application rate of nitrogen on a high-yielding wheat field was 96–168 kg N ha^?1.     

Effect of nitrogen and phosphorus on ‘delicious’ apple trees grown in caliche soil in the greenhouse

Abstract

In a greenhouse study, mono‐ammonium phosphate applications to ‘Delicious’ (Oregon spur cv) apple trees, Malus domestica Borkh., improved a low‐vigor condition associated with a caliche soil. The moderate rate of mono‐ammonium phosphate (6 grams per tree) resulted in trees with greater shoot extension, leaf numbers, a higher percent leaf phosphorus, and less purple leaf margins or spots than other soil treatments or the control. By September, trees treated with the highest rate of mono‐ammonia phosphate (12 grams per tree) had the highest level of leaf phosphorus and significantly higher levels of leaf phosphorus than all forms of nitrogen‐only fertilizer (ammonium nitrate, ammonium sulfate, calcium nitrate, and urea). In most cases, applications of the nitrogen‐only fertilizers, reduced leaf phosphorus levels throughout the experiment.     

Impact of organic residues and mineral fertilizer application on soil–crop system: II soil attributes

The effects of crop residues alone (Cr⁺) or combined with inorganic fertilizer (FCr⁺) sewage sludge (SS) and humentos (H) on soil properties were studied in a five-season wheat–guar rotation. Incorporation of Cr⁺ and SS significantly decreased pH by 5–9%. Highest organic carbon (OC) was observed in SS plots, whereas Cr⁺ resulted in values threefold that of the control. The added effect of Cr⁺ (46%) combined with fertilizer on total nitrogen (TN) was greater than Cr⁺ by 28%. The fraction of total residue N mineralized was 71%, whereas net N mineralized in Cr⁺, SS, H and FCr⁺ plots at 0–20 and 20–40 cm depths were 39.8, 52.3, 11.4, 66.7 mg kg^?1 and 21.2, 27.9, 8.2, 41.2 mg kg^?1, respectively. Integrated application of Cr⁺ with fertilizer had a synergistic effect on P content (3.49–3.69 units), but soil levels has never exceeded 13 mg P kg ^?1. Sole Cr⁺ significantly increased topsoil cation-exchange capacity (CEC) compared with the control treatment (9.39–21.59%). Application of SS, FCr⁺ and Cr⁺ significantly increased water-holding capacity and decreased bulk density by 9–15% and 8–9%, respectively, suggesting that such practice can restore the productivity of degraded soils and improve crop yields.     

Effects of long‐term applications of various nitrogen sources on chemical soil properties and composition of bromegrass hay

Effects of 15 annual applications (from 1979 to 1993) of ammonium nitrate (AN), urea, ammonium sulfate (AS), and calcium nitrate (CN) applied at 168 and 336 kg N ha^‐1 to bromegrass (Bromus inermis Leyss.) on soil acidification, and concentration of aluminum (Al), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in soil and in hay were investigated in a field experiment on a thin Black Chemozemic (Typic Boroll) soil in Alberta, Canada. Soil was acidified and the concentration of extractable Al, Fe, and Mn was increased by nitrogen (N) application, but the magnitude varied with N source. Soil acidification was greatest with AS, followed by AN and urea, with no effect of CN. At 336 kg N ha^‐1 rate, soil was acidified to a depth of 10, 15 and 30 cm with urea, AN AS, respectively. Soil acidification was also greater at 336 kg than 168 kg N ha^‐1. The CaCl₂‐extractable Al and Fe in the 0–15 cm layer increased with N application, which closely followed the decrease in soil pH from various N sources. Extractable Al and Fe concentration in the 15–30 cm layer increased in response to reduction in soil pH by AS only, and there was no change in the extractable Al and Fe below the 30‐cm depth by any form of N. The DTPA‐extractable Mn in soil generally changed in response to N application. There was no effect of N source on the DTPA‐extractable Zn and Cu in soil. When soil pH had been lowered from N application, the concentration of Al in hay decreased while Zn concentration increased. The Mn concentration in forage increased markedly in response to reduced soil pH from application of AN, urea and AS. There was no effect of N fertilization on the Cu and Fe concentration in hay. In conclusion, the magnitude of soil acidification, changes in the Al, Fe, and Mn concentrations in soil and changes in the Al, Zn, and Mn concentrations in bromegrass hay varied with N source. The results suggest the need for periodic monitoring of soil pH and consideration of liming costs in the economics of various N fertilizers.     

Losses of 15N-nitrogen by plant–soil system after herbicide application on black oat

Recent studies have demonstrated that the use of glyphosate or glufosinate-ammonium herbicides for some cover crop desiccation in conservationist systems could favor nitrogen (N) losses from the soil–plant system. In this context, the objective of this study was to evaluate the losses of N by the plant–soil system after the desiccation of black oat (Avena strigosa Schreb.) with the application of herbicides glyphosate, glufosinate-ammonium, or paraquat. Two greenhouse experiments were implemented using black oat plants fertilized with labeled (¹⁵N) ammonium nitrogen, and the N loss of the plant–soil system was quantified. The desiccation of black oat with glyphosate caused a reduction in root dry mass by approximately 60% in both experiments. The glyphosate and glufosinate-ammonium reduced the amount of N present in the aboveground portion; however, the paraquat herbicide did not modify it. None of the herbicides applied affected N losses in the black oat plant–soil system. However, 5–15% of the N applied as fertilizer was lost up to harvest. The results suggest that black oat can be used as a cover crop in direct sowing in order to avoid nitrogen losses in the soil–plant system.     

Effects of autumn foliar application of 15n‐urea on nitrogen storage and reuse in apple 1

Effects of autumn foliar application of N‐urea on N storage and reuse in young apple seedling (Malus Pumila Mill.) were studied. Foliar application of urea^‐15 N (3.5%) during autumn enhanced the retranslocation of leaf N to other plant parts and increased stored N. Foliar N sprays increased the proteolytic activities of the leaves; therefore, such activities appear to be a major mechanism of retranslocation of leaf N. Foliar applied N enabled the plant to produce more growth during the following seasons. A considerable portion of the plant total N during second and third years was attributable to the foliarly applied N during the first year.     

Effect of root pruning and nitrogen fertilization on growth of young ‘fuji’ apple (Malus domestica borkh.) trees

This study examined the effect of root pruning (RP) and nitrogen fertilization (NF) alone or in combination (RP-NF) on growth properties of 3-year-old ‘Fuji’ apple (Malus domestica Borkh.) trees. The results of pot experiments showed that the trees were sensitive to RP and NF alone or in combination in terms of root architecture, leaf photosynthesis, and canopy growth. Compared with the control, NF and RP-NF increased root length density and tips, while RP and RP-NF decreased root surface area and volume. RP alone reduced coarse root length (2.0–4.0 and >4.0 mm diameter), while RP-NF simultaneously increased fine root length (≤1.0 mm diameter) and reduced coarse root length. Moreover, RP increased leaf chlorophyll content and transpiration rate, while RP-NF increased net photosynthetic rate and water use efficiency. RP-NF resulted in no differences in dry matter weight, root-shoot ratio, or leaf area compared with the control. Inhibiting vegetative growth by RP-NF provided an effective way to improve water use efficiency of young apple trees.     

Long-term effect of manure and mineral fertilizer application on the distribution of organic nitrogen fractions in soil under a rice–wheat cropping system

A long-term experiment was used to evaluate the effect of integrated nutrient management on the distribution of soil organic N fractions and their contribution to N nutrition of a rice–wheat system. Continuous application of mineral fertilizers, alone or in combination with organic manures for 7 years, led to a marked increase in total N, hydrolysable N (amino acid-N, amino sugar-N, ammonia-N, hydrolysable unknown-N) and non-hydrolysable N compared with their original status in soil. However, continuous rice–wheat cropping without any fertilization resulted in depletion of total N, hydrolysable N and non-hydrolysable N by 21.3, 23.5 and 15.1% over their initial status in surface soil. The effect of press mud (PM) treatment was more pronounced in increasing total and hydrolysable N compared with farmyard manure (FYM) or green manure (GM) treatment. Incorporation of PM, FYM and GM along with mineral fertilizers increased the total N content by 32.8, 18.3 and 5.1% and that of hydrolysable N by 25.7, 19.6 and 9.5%, respectively, over mineral fertilizer treatment. Among the most important fractions, amino sugar-N, amino acid-N and ammonia-N were found to be most the important fractions contributing to grain yield and nitrogen uptake of rice and wheat crops.     

Interactive effects of wheel‐traffic and tillage system on soil carbon and nitrogen

Abstract

Wheel‐traffic induced soil compaction has been shown to limit crop productivity, and its interaction with tillage method could affect soil nutrient transformations. A study was conducted during 1993–1994 to determine interactive effects of tillage method (conventional tillage and no‐tillage) and wheel‐traffic (traffic and no traffic) on soil carbon (C) and nitrogen (N) at a long‐term (initiated 1987) research site at Shorter, Alabama. The cropping system at this study site is a corn (Zea mays L.) ‐ soybean [Glycine max (L.) Merr] rotation with crimson clover (Trifolium incarnatum L.) as a winter cover crop. Soil organic C, total N, and microbial biomass carbon (MBC) were not significantly affected by six years of traffic and tillage treatments. However, conventional tillage compared to no‐tillage almost doubled the amount of CO₂‐C respired over the entire observation period and during April 1994 field operations. Soil respiration was stimulated immediately after application of wheel‐ traffic, but nontrafficked soils produced greater amounts of CO₂‐C compared to trafficked soils during other periods of observation. Nitrogen mineralization was significantly lower from no‐tillage‐trafficked soils compared to conventional tillage‐trafficked and no‐tillage‐nontrafficked soils for the 1993 growing season. A laboratory incubation indicated the presence of relatively easily mineralizable N substrates from conventional tillage‐trafficked soil compared to conventional tillage‐nontrafficked and no‐till‐trafficked soils. For the coarse textured soil used in this study it appears that conventional tillage in combination with wheel‐traffic may promote the highest levels of soil microbial activity.     

Dynamics of maize straw–derived nitrogen in soil aggregates as affected by fertilization

Journal of Soils and Sediments - The addition of maize residue nitrogen (N) to the soil strongly influences soil N accumulations, but the specific contributions of maize residue N to soil...     

Effects of climate factors and soil properties on soil nutrients and elemental stoichiometry across the Huang–Huai–Hai River Basin,China

Purpose

Soil nutrients, elemental stoichiometry, and their associated environmental control play important roles in nutrient cycling. The objectives of this study were (1) to investigate soil nutrients and elemental stoichiometry, especially potassium and its associative elemental stoichiometry with other nutrients under different land uses in terrestrial ecosystems; (2) to discuss the impacts of climate factors, soil texture, and soil physicochemical properties; and (3) to identify the key factors on soil nutrient levels and elemental stoichiometry.

Materials and methods

Soil data, including pH, bulk density (BD), cation exchange capacity (CEC), volumetric water content (VMC), clay, silt and sand contents, total carbon (TC), nitrogen (TN), phosphorous (TP) and potassium (TK), available nitrogen (AN), phosphorus (AP), potassium (AK), and soil organic matter (SOM) under different land-use types, were collected, and their elemental stoichiometry ratios were calculated. Climate data including temperature, precipitation, relative humidity, wind speed, and evapotranspiration were collected. The least significant difference test and one-way analysis of variance were applied to investigate the variability of soil nutrients and elemental stoichiometry among land-use types; the ordinary least squares method and the general linear model were used to illustrate the correlations between soil nutrients, elemental stoichiometry, and soil properties or climate factors and to identify the key influencing factors.

Results and discussion

Woodlands had the highest SOM, TN, AN, and AK contents, followed by grasslands, croplands, and shrublands, while the TP and TK contents only varied slightly among land-use types. SOM, TN, AN, N/P, and N/K were strongly negatively correlated to soil pH (p <?0.05) and were strongly positively correlated to soil CEC (p <?0.05). For soil texture, only C/N was moderately negatively correlated to silt content but moderately positively correlated to sand content (p <?0.05). For climate factors, SOM, TN, AN, N/P, and N/K were significantly negatively correlated to evapotranspiration and temperature (p <?0.05), and the correlations were usually moderate. Soil pH explained most of the total variation in soil nutrients, and climate factors explained 5.64–28.16% of soil nutrients and elemental stoichiometry (except for AP (0.0%) and TK (68.35%)).

Conclusions

The results suggest that climate factors and soil properties both affect soil nutrients and elemental stoichiometry, and soil properties generally contribute more than climate factors to soil nutrient levels. The findings will help to improve our knowledge of nutrient flux responses to climate change while also assisting in developing management measures related to soil nutrients under conditions of climate change.

     

Effects of soil compaction and water‐filled pore space on soil microbial activity and N losses

Abstract

Soil compaction is a significant production problem for agriculture because of its negative impact on plant growth, which in many cases has been attributed to changes in soil N transformations. A laboratory experiment was conducted to study the effect of soil compaction and water‐filled pore space on soil microbial activity and N losses. A hydraulic soil compaction device was used to evenly compress a Norfolk loamy sand (fine‐loamy, siliceous, thermic Typic Kandiudults) soil into 50 mm diameter by 127 mm long cores. A factorial arrangement of three bulk density levels (1.4, 1.6, and 1.8 Mg/m³) and four water‐filled pore space levels (60, 65, 70, 75%) was used. Fertilizer application of 168 kg N/ha was made as 1.0 atom % ¹⁵N as NH₄NO₃. Soil cores were incubated at 25°C for 21 d. Microbial activity decreased with both increasing water‐filled pore space and soil bulk density as measured by CO₂‐C entrapment. Nitrogen loss increased with increasing bulk density from 92.8 to 334.4 g N/m³ soil at 60% water‐filled pore space, for 1.4 and 1.8 Mg/m³, respectively. These data indicate that N loss and soil microbial activity depends not only on the pore space occupied by water, but also on structure and size of soil pores which are altered by compaction.     

Impact of organic residues and mineral fertilizer application on soil–crop systems I: yield and nutrients content

A five-season experiment was initiated to study the effects of the recycling of some organic residues on a soil–crop system of a guar–wheat rotation in a sandy clay loam soil located in the semi-arid tropics of Sudan. Treatments included: incorporation of crop residues alone after harvest (Cr⁺), with (FCr⁺) or without (FCr^?) inorganic fertilizer, sewage sludge (SS) and humentos (H). Grain yield of wheat in FCr⁺ and Cr⁺ treatments was significantly higher than that obtained in FCr^? and control plots by ～22?62% and 116?119%, respectively. When crop residues were incorporated with inorganic fertilizer, the priming effect of crop residues on straw yield (106%) was almost double that of the priming effect of inorganic fertilizer (56%). The sustainable yield index of wheat straw dry matter for the control, crop residue, humentos, inorganic fertilizer, combined fertilizer and crop residue and sewage sludge was 28, 27, 8, 35, 21 and 38%, respectively. In general, N, P and K of straw dry matter (SDM) was in the order of FCr⁺ > FCr^? > SS > Cr⁺> H > C. The findings suggest that repeated incorporation of crop residues with inorganic fertilizer and applications of SS could both sustain wheat performance in the dryland ecosystems.     

Effect of α-casein on DNA adsorption by Andosols and by soil components

Andosols and the soil components (allophanes, humic acids, and goethite) had been autoclaved to destroy the nuclease activity of soil microflora. DNA adsorption by allophanes and Andosols was decreased by increasing the amount of α-casein added to the allophanes and to soils up to casein concentration of 5 mg ml^?1. DNA adsorption by humic acids was significantly increased by increasing the amount of α-casein up to 1.0 mg ml^?1, whereas the addition of 20 mg α-casein ml^?1 completely blocked DNA adsorption. These results can explain why the addition of excess skim milk is operationally needed for effective DNA extraction from Andosols. The amount of DNA adsorbed by Andosols treated with dephosphorylated α-casein was significantly higher than that of not treated Andosols (p?相似文献   

Identification of the effects of long-term application of nitrogen fertilizer on the availability of 11 elements in soils and their supply to ‘Jonathan’ apple trees by using simultaneous multi-element analysis

Abstract

The objective of this study was to investigate the effects of long-term application of ammoniacal N fertilizer for 43?years on the availability of 10 essential elements (B, N, Mg, K, Ca, Mn, Fe, Ni, Cu, and Zn) and Al in root-zone soils and their supply to ‘Jonathan’ apple trees. To achieve this objective, we used simultaneous multi-element analysis. To estimate the soil depth from which the apple trees took up these elements, we calculated the ratios of their concentrations in the N fertilized plot (N plot) to those in the no N plot (0?N plot) (N/0N ratio). Long-term N fertilization significantly increased the fruit and leaf N/0N ratios of N and Mn and significantly decreased that of K. These ratios in the fruits and leaves were similar to those in the 20–90?cm soil layer. This result suggests that N, K, and Mn in the fruits and leaves were supplied from the 20–90?cm soil layer. The N/0N ratios of all 11 elements in the fruits and leaves were significantly positively correlated with those in the 20–90?cm soil layer, but not in the 0–20?cm soil layer. Our findings indicate that long-term N fertilization altered the tree nutrition of not only N, but also K and Mn. These changes in the tree nutrition were ascribed to the fertilizer-induced changes in the availability of elements in the subsoils.     

Influence of two “nitrogen regulators”; on soil n transformations and movement

Abstract

Experiments were conducted to assess the potential influence of a commercial product, EXTEND, on nitrogen transformations and movement in a sandy soil. Neither nitrapyrin (a commercially‐available nitrification inhibitor) nor EXTEND significantly affected the rate of NH₄ ⁺‐N or NO₃ ^‐‐N movement through a column of soil treated with urea‐ammonium nitrate liquid fertilizer. Nitrapyrin effectively inhibited nitrification, but the nitrification rate in the EXTEND treated systems were the same as control.