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1.
Soil nitrogen conservation with continuous no-till management 总被引:1,自引:1,他引:0
John T. Spargo Marcus M. Alley Ronald F. Follett James V. Wallace 《Nutrient Cycling in Agroecosystems》2008,82(3):283-297
Tillage management is an important regulator of organic matter decomposition and N mineralization in agroecosystems. Tillage
has resulted in the loss of considerable organic N from surface soils. There is potential to rebuild and conserve substantial
amounts of soil N where no-till management is implemented in crop production systems. The objectives of our research were
to measure N conservation rate with continuous no-till management of grain cropping systems and evaluate its impact on mineralizable
and inorganic soil N. Samples were collected from 63 sites in production fields using a rotation of corn (Zea mays L.)—wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.)—double-crop soybean (Glysine max L.) across three soil series [Bojac (Coarse-loamy, mixed, semiactive, thermic Typic Hapludults), Altavista (Fine-loamy, mixed
semiactive, thermic Aquic Hapludults), and Kempsville (Fine-loamy, siliceous, subactive, thermic Typic Hapludults)] with a
history of continuous no-till that ranged from 0 to 14 yrs. Thirty-two of the sites had a history of biosolids application.
Soil cores were collected at each site from 0–2.5, 2.5–7.5 and 7.5–15 cm and analyzed for total N, Illinois soil N test-N
(ISNT-N), and [NH4 + NO3]-N. A history of biosolids application increased the concentration of total soil N by 154 ± 66.8 mg N kg−1 (310 ± 140 kg N ha−1) but did not increase ISNT-N in the surface 0 – 15 cm. Continuous no-till increased the concentration of total soil N by
9.98 mg N kg−1 year−1 (22.2 ± 21.2 kg N ha−1 year−1) and ISNT-N by 1.68 mg N kg−1 year−1 in the surface 0–15 cm. The implementation of continuous no-till management in this cropping system has resulted in conservation
of soil N.
相似文献
John T. SpargoEmail: |
2.
Reducing ammonia volatilization in a no-till soil by incorporating urea and pig slurry in shallow bands 总被引:3,自引:0,他引:3
Philippe Rochette Denis A. Angers Martin H. Chantigny J. Douglas MacDonald Marc-Olivier Gasser Normand Bertrand 《Nutrient Cycling in Agroecosystems》2009,84(1):71-80
Incorporation of broadcast pig slurry and urea into soil is incompatible with no-till production systems and alternative application
methods that reduce NH3-N loss are required. The objective of this study was to assess the impact of incorporating urea and pig slurry in shallow
furrows (banding) on NH3 volatilization. A field study was conducted on a silty loam soil that had been under no-till for 2 years. Ammonia volatilization
was measured for 29 days after urea and pig slurry (140 kg N ha−1) were broadcast or incorporated (5 cm) in bands. High urease activity and soil temperatures as well as an absence of rainfall
combined to result in large losses of NH3-N from all treatments. Broadcast urea lost the greatest proportion of applied N (64%) followed by banded urea (31%), broadcast
pig slurry (29%) and banded pig slurry (16%). High emissions from broadcast urea were consistent with previous reports of
large volatilization losses on no-till soils. Presence of crop residues and associated high urease activity (288 μg NH4-N g−1 h−1) at the surface of no-till soils were likely important factors contributing to these high emissions. Incorporation of slurry
and urea in bands was not as efficient in reducing volatilization as expected but not for the same reason. Relatively high
emissions from banded slurry were the result of an incomplete incorporation of slurry in the shallow bands and indicate that
the benefit of this practice is limited at high slurry application rates. In banded urea plots, hydrolysis of concentrated
urea likely resulted in high localized NH4
+ concentrations and pH, which increased NH3 source strength and emissions. Our results therefore suggest that incorporating urea in bands may not be as efficient for
reducing NH3 emissions as incorporation of broadcasted urea which results in lower soil urea concentrations. 相似文献
3.
Keisha N. Johnson Peter J. A. Kleinman Douglas B. Beegle Herschel A. Elliott Lou S. Saporito 《Nutrient Cycling in Agroecosystems》2011,90(2):201-212
Incorporation of manure slurry under reduced tillage conditions remains a challenge in the northeastern US. New technologies
to directly incorporate slurry are available but their agronomic and environmental benefits have generally not been quantified.
This study evaluated the effects of five manure slurry application methods on phosphorus (P) loss in runoff (broadcasting
with and without incorporation by tillage, shallow disk injection, banded application and aeration, and pressurized injection)
and a control (no manure). Research was conducted over a 2 year period in central Pennsylvania on a well-drained Hagerstown
silt loam (fine, mixed, semiactive, mesic Typic Hapludalf) under corn (Zea mays L.) production. Approximately 72 h after dairy (Bos Taurus) slurry application (56,000 l ha−1) to 10 × 13 m plots, a single rainfall simulation (68 mm h−1) was conducted in triplicate on 10 × 2 m areas within the plots. Trends in total P losses in runoff (kg ha−1) from plots varied between years and treatments. Aeration yielded lower losses than all other treatments in 2006 and was
amongst the lowest in 2007 with losses statistically similar to shallow disk and pressure injection. Remarkably, few differences
were apparent in losses of dissolved reactive P between treatments, reflecting high variability in runoff depths. Indeed,
variability in runoff depths resulted in some unexpected trends, including high loads from the unamended control and modest
loads from the tillage treatment. Results highlight tradeoffs in alternative manure slurry application practices but point
to the potential to significantly lower runoff P losses from reduced tillage systems receiving manure slurry. 相似文献
4.
Double-cropping annual ryegrass and bermudagrass to reduce phosphorus levels in soil with history of poultry litter application 总被引:1,自引:0,他引:1
J. J. Read K. R. Sistani J. L. Oldham G. E. Brink 《Nutrient Cycling in Agroecosystems》2009,84(1):93-104
Long-term application of poultry litter may result in excessively high soil phosphorus (P). This field study determined the
potential of ‘Coastal’ bermudagrass overseeded with ‘Marshall’ annual ryegrass and harvested for hay to reduce the level of
Mehlich-3 extractable P (M3-P) that had accumulated in a Savannah soil due to a 30-year history of broiler litter application
to bermudagrass, as well as antecedent litter rates of 0, 4.48, 8.96, 17.9, and 35.8 Mg ha−1 in 1999–2001. Following the cessation of litter, the plots were overseeded in fall 2001–2003 and fertilized in summer with
268 kg N ha−1 as NH4NO3. Applying 8.96 Mg ha−1 litter significantly elevated M3-P in surface soil (0–15 cm depth) from about 183 to 263 mg kg−1. Annual dry matter (DM) yield and P uptake generally increased as litter rate increased up to 17.9 Mg ha−1. Analysis of M3-P at four sampling dates from October 2002 to April 2004 found no significant effect of forage system or
its interaction with litter rate, and levels in both systems decreased by about 25, 27, 22, 26, and 29% at the five litter
rates, respectively. Ryegrass–bermudagrass significantly increased DM yield and P uptake, but did not translate to reductions
in M3-P, as compared to bermudagrass winter fallow. With no further litter additions and five harvests per year, both forage
systems removed about 49 kg ha−1 P with a DM yield of 15 Mg ha−1 and reduced M3-P by about 26 mg kg−1 annually. Bermudagrass performance is important in the remediation of high soil P.
相似文献
J. J. ReadEmail: |
5.
Antonio Delgado María Dolores Hurtado Luis Andreu 《Nutrient Cycling in Agroecosystems》2006,74(2):191-202
Reclamation of Guadalquivir river marshes (SW Spain) constitutes a representative example of wetland reclamation in Southern
Europe. Nowadays, this is an important area of tile-drained soils (40,000 ha) with an intensive irrigated agricultural production
where high fertilizer rates are usually applied. In tile-drained soils, flow through macropores or cracks, which connect the
nutrient rich topsoil with drain lines, can be an important pathway for nutrient transfer from soil. In order to study P loss
in these soils and how it is affected by soil amendment usually applied in the zone (phosphogypsum and manure) an experiment
was performed during two consecutive growing seasons on a reclaimed marsh soil from the Guadalquivir Valley. In the first
season (1998–1999), sugar beet (Beta vulgaris L.) was grown under sprinkler irrigation at a rate of 2.5 mm h−1; in the second (2000), cotton (Gossypium hirsutum L.) was grown under furrow irrigation at 8–10 mm h−1. The amendments applied included manure (30 Mg ha−1), and phosphogypsum (13 and 26 Mg ha−1). Drainage events were recorded, and water samples collected and analyzed for total P (TP), dissolved total P (DTP), and
dissolved reactive P (DRP). Total P in drainflow ranged from 0 to 0.818 mg l−1 in the 1998–1999 season and from 0 to 0.565 mg l−1 in the 2000 season. The major P form in drainflow was DRP, which accounted for about 50% of TP in the two growing seasons
(the mean DRP concentration was 0.068 mg l−1 in 1998–1999 and 0.043 mg l−1 in 2000). Dissolved organic P accounted for a higher portion of DTP in the first season (37%) than in the second (13%). A
larger load of phosphorus was observed on plots receiving manure. This treatment significantly increased (P<0.05) the cumulative drainflow during the 1998–1999 growing season (sprinkler irrigation, low drainflow rates). This is consistent
with the increased losses of TP, DTP, DAHP, and DRP resulting from this treatment in this growing season. In the following
season, DTP loading were significantly increased by manure (P<0.05). This seems to be related mainly to significantly increased DOP losses (P<0.01), particularly during the first drainage event. The higher fraction of applied water was lost by drainage under furrow
irrigation (high drainflow rates) is consistent with the high TP load during the 2000 growing season (199–285 g ha−1) relative to the 1998–1999 season (20–59 g ha−1). This difference in P losses was much greater than those resulting from amendment of the soil. 相似文献
6.
Phosphorus leaching through intact soil cores as influenced by type and duration of manure application 总被引:8,自引:0,他引:8
Elizabeth H. Brock Quirine M. Ketterings Peter J. A. Kleinman 《Nutrient Cycling in Agroecosystems》2007,77(3):269-281
Leaching of phosphorus (P) in manure-amended soils has received increased attention as a significant source of non-point source
P pollution. Intact soil cores were collected from fields on a farm in Southern New York to test the effects of long-term
dairy or poultry manure application on P leaching. Nine fields were selected (four poultry, four dairy, and one unamended)
to represent a broad range of P saturation levels (5.3 to 62.4%) in the topsoil (0–7.5 cm). Water was applied weekly at a
rate matching a 1-year return period storm for the study area (230 mm h−1). Dissolved reactive P (DRP) losses in leachate from all soil cores ranged from 0.007 to 0.055 kg P ha−1, except in two fields with long-term histories of dairy and poultry manure application, where losses averaged 0.21 and 0.45 kg P ha−1, respectively. Hydrographs of the field with the dairy manure history suggested preferential flow as an explanation of leachate
P enrichment. In the poultry manure amended field, high levels of soil P saturation throughout the profile suggested subsoil
P desorption as a factor controlling leachate P. Surface application of dairy manure to the soil cores (167 kg total P ha−1) increased the mean leachate DRP concentration from 1.5 to 10.5 fold. After five leaching events spanning 22 days, DRP concentrations
remained 2.0 to 13.4 fold above pre-manure application levels. This study points to saturation of P in subsoils by long-term
manure application as a key concern to P loss in leachate and highlights the role of annual manure additions on subsurface
P loss potential. 相似文献
7.
J. Kihara A. Bationo D. N. Mugendi C. Martius P. L. G. Vlek 《Nutrient Cycling in Agroecosystems》2011,90(2):213-225
Smallholder land productivity in drylands can be increased by optimizing locally available resources, through nutrient enhancement
and water conservation. In this study, we investigated the effect of tillage system, organic resource and chemical nitrogen
fertilizer application on maize productivity in a sandy soil in eastern Kenya over four seasons. The objectives were to (1)
determine effects of different tillage-organic resource combinations on soil structure and crop yield, (2) determine optimum
organic–inorganic nutrient combinations for arid and semi-arid environments in Kenya and, (3) assess partial nutrient budgets
of different soil, water and nutrient management practices using nutrient inflows and outflows. This experiment, initiated
in the short rainy season of 2005, was a split plot design with 7 treatments involving combinations of tillage (tied-ridges,
conventional tillage and no-till) and organic resource (1 t ha−1 manure + 1 t ha−1 crop residue and; 2 t ha−1 of manure (no crop residue) in the main plots. Chemical nitrogen fertilizer at 0 and 60 kg N ha−1 was used in sub-plots. Although average yield in no-till was by 30–65% lower than in conventional and tied-ridges during
the initial two seasons, it achieved 7–40% higher yields than these tillage systems by season four. Combined application of
1 t ha−1 of crop residue and 1 t ha−1 of manure increased maize yield over sole application of manure at 2 t ha−1 by between 17 and 51% depending on the tillage system, for treatments without inorganic N fertilizer. Cumulative nutrients
in harvested maize in the four seasons ranged from 77 to 196 kg N ha−1, 12 to 27 kg P ha−1 and 102 to 191 kg K ha−1, representing 23 and 62% of applied N in treatments with and without mineral fertilizer N respectively, 10% of applied P
and 35% of applied K. Chemical nitrogen fertilizer application increased maize yields by 17–94%; the increases were significant
in the first 3 seasons (P < 0.05). Tillage had significant effect on soil macro- (>2 mm) and micro-aggregates fractions (<250 μm >53 μm: P < 0.05), with aggregation indices following the order no-till > tied-ridges > conventional tillage. Also, combining crop
residue and manure increased large macro-aggregates by 1.4–4.0 g 100 g−1 soil above manure only treatments. We conclude that even with modest organic resource application, and depending on the number
of seasons of use, conservation tillage systems such as tied-ridges and no-till can be effective in improving crop yield,
nutrient uptake and soil structure and that farmers are better off applying 1 t ha−1 each of crop residue and manure rather than sole manure. 相似文献
8.
W. J. Dougherty L. L. Burkitt R. Corkrey D. M. Harvey 《Nutrient Cycling in Agroecosystems》2011,89(2):189-197
The application of phosphorus (P) fertilisers to grazed pasture systems can increase the export of P in surface runoff. This
increase can arise from interaction of recently applied fertiliser P with surface runoff (incidental effects) or the interaction
between pseudo-equilibrated soil P and surface runoff (systematic effects). The former can represent a large proportion of
annual exports. In this paper we investigate the effect of soil P buffering properties and fertiliser application strategy—split
versus single applications—on incidental fertiliser effects, using laboratory studies. We used a weak electrolyte solution
as a surrogate measure of runoff P and consequently defined ‘fertiliser half-life’ for six soils with widely differing P buffering
properties. There was a significant (P < 0.01) exponential decay relationship between soil P buffering and fertiliser half life. For soils with low P buffering
capacity, fertiliser half life was up to ~4 days, whereas for highly P buffered soils the half life was <0.5 day. There was
also a highly significant (P < 0.01) effect of P buffering capacity on the magnitude of the incidental fertiliser effect, with the magnitude increasing
as P buffering decreased. On one of our soils with buffering properties typical of soils used for dairying in SE Australia,
we compared the effect on soluble P of a single application of 40 kg P ha−1 with three applications of 13 kg P ha−1. A simple comparative measure of the risk associated with the two fertiliser strategies—the area under the time by concentration
curves—suggests that there is greater risk with a single application. Our results show that particular attention should be
paid to timing of P fertiliser application on poorly buffered soils. 相似文献
9.
Soybean-maize rotation is a profitable cropping system and is used under rain fed conditions in north China. Since crop yields
have been reported to decrease when K fertilizers are not used, we analyzed the productivity trends, soil-exchangeable and
non-exchangeable K contents, and K balance in a continuous cropping experiment conducted in an area with an alfisol soil in
the Liaohe River plain, China. The trial, established in early 1990 and continued till 2007, included 8 combinations of recycled
manure and N, P, and K fertilizers. In the unfertilized plot, the yields of soybean and maize were 1,486 and 4,124 kg ha−1 respectively (mean yield over 18 years). The yields of both soybean and maize increased to 2,195 and 7,476 kg ha−1, respectively, in response to the application of inorganic N, P, and K fertilizers. The maximum yields of soybean (2,424 kg ha−1) and maize (7,790 kg ha−1) were obtained in the plots under treatment with N, P, and K fertilizers and recycled manure. K was one of the yield-limiting
macronutrients: regular K application was required to make investments in the application of other mineral nutrients profitable.
The decrease in the yields of soybean and maize owing to the absence of K application averaged 400 and 780 kg ha−1, respectively. Soybean seed and maize grain yields significantly increased with the application of recycled manure. For both
these crops, the variation coefficients of grain were lower with treatments that included recycled manure than without treatment.
After 18 years, the soil-exchangeable and non-exchangeable K concentrations decreased; the concentrations in the case of treatments
that did not include K fertilizers were not significantly different. Treatment with N, P, and K fertilizers appreciably improved
the fertility level of the soil, increased the concentration of soil-exchangeable K, and decreased the non-exchangeable K
concentration. In soils under treatment with N, P, and K fertilizers and recycled manure, the soil-exchangeable and non-exchangeable
K levels in the 0–20 cm-deep soil layer increased by 34% and 2%, respectively, over the initial levels. Both soil-exchangeable
and non-exchangeable K concentrations were the highest with on treatment with N, P, and K fertilizers and recycled manure,
followed by treatment with N, P, and K fertilizers. These concentrations were lowest in unfertilized soils; the other treatments
yielded intermediate results. The results showed a total removal of K by the crops, and the amount removed exceeded the amount
of K added to the soil; in treatments that did not include K fertilizers, a net negative K balance was observed, from 184
to 575 kg ha−2. The combined use of N, P, and K fertilizers and recycled manure increased the K content of the 0–20 cm-deep soil layer by
125% compared to the increase obtained with the application of N, P, and K fertilizers alone. The results clearly reveal that
current mineral fertilizer applications are inadequate; instead, the annual application of recycled manure along with N, P,
and K fertilizers could sustain future yields and soil productivity. 相似文献
10.
Robert Zougmoré Abdoulaye Mando Leo Stroosnijder 《Nutrient Cycling in Agroecosystems》2010,88(1):17-27
The synergistic effect of soil and water conservation (SWC) measures (stone rows or grass strips) and nutrient inputs (organic
or mineral nutrient sources) was studied at Saria station, Burkina Faso. The reduction in runoff was 59% in plots with barriers
alone, but reached 67% in plots with barriers + mineral N and 84% in plots with barriers + organic N, as compared with the
control plots. Plots with no SWC measure lost huge amounts of soil (3 t ha−1) and nutrients. Annual losses from eroded sediments and runoff reached 84 kg OC ha−1, 16.5 kg N ha−1, 2 kg P ha−1, and 1.5 kg K ha−1 in the control plots. The application of compost led to the reduction of total soil loss by 52% in plots without barriers
and 79% in plots with stone rows as compared to the losses in control plots. SWC measures without N input did not significantly
increase sorghum yield. Application of compost or manure in combination with SWC measures increased sorghum grain yield by
about 142% compared to a 65% increase due to mineral fertilizers. Yields increase did not cover annual costs of single SWC
measures while application of single compost or urea was cost effective. The combination of SWC measures with application
of compost resulted in financial gains of 145,000 to 180,000 FCFA ha−1 year−1 under adequate rainfall condition. Without nutrient inputs, SWC measures hardly affected sorghum yields, and without SWC,
fertilizer inputs also had little effect. However, combining SWC and nutrient management caused an increase in sorghum yield. 相似文献
11.
Frank Eulenstein Armin Werner Matthias Willms Radosław Juszczak Sandro Luis Schlindwein Bogdan H. Chojnicki Janusz Olejnik 《Nutrient Cycling in Agroecosystems》2008,82(1):33-49
Oxidation of pyrite by nitrate (autotrophic denitrification) was identified as the main cause for sulfate increase in drinking
water wells in an agriculturally used watershed, located in the north of Lower Saxony (Germany). Nitrate, which inducts this
microbial catalyzed process, is drained into ground water predominantly from agricultural fertilization. The increase of sulfate
in the ground water can only be stopped by reducing nitrate leaching into the ground water. To analyze the negative influence
of agricultural fertilization on the quality of ground water different fertilization strategies were deducted for an investigated
area of 890 ha. Calculated on the basis of nutrient balance of soil surface, the current average nitrogen balance in the investigated
area amounts to 91 kg N ha-1 a−1. Farm-gate balance of nutrients is a strong indicator for assessing potential nutrient losses caused by leaching. This indicator
shows comparable accuracy to the calculated nutrient balance of soil surface which demands, however, much more data input
for calculations. Nitrate concentrations in seepage water in 2 m depth layer of the soil from agricultural fields were simulated
with the model HERMES for the whole investigated area (agricultural land + forest). The nitrate concentration in seepage water
was calculated for the whole area on the basis of farm-gate nutrient balance as an annual average, which amounts to 14.0 mg NO3–N l−1 (62 mg NO3 l−1). In order to keep the nitrate concentration of the ground water below the threshold value for drinking water (EU-water directive:
11.3 mg NO3–N l−1 (50 mg NO3 l−1) and to limit pyrite oxidation, different scenarios with simulation studies to optimize fertilization measures were developed.
Only those scenarios which assured reduction of an average nitrate concentration in the drainage water below 11.3 mg NO3–N l−1 (50 mg NO3 l−1) without profit cuts for the farms were analyzed.
相似文献
Janusz OlejnikEmail: |
12.
Annika Svanbäck Barbro Ulén Ararso Etana Lars Bergström Peter J. A. Kleinman Lennart Mattsson 《Nutrient Cycling in Agroecosystems》2013,96(2-3):133-147
In Sweden, subsurface transport of phosphorus (P) from agricultural soils represents the primary pathway of concern for surface water quality. However, there are mixed findings linking P in leachate with soil P and limited understanding of the interactive effects of applied P sources and soil test P on P leaching potential. Identifying soils that are susceptible to P leaching when manure is applied is critical to management strategies that reduce P loadings to water bodies. Intact soil columns (20 cm deep) from five long-term fertilization trials across Sweden were used in leaching experiments with simulated rainfall to explore the interactive effects of dairy cow (Bos taurus L.) manure application, soil test P and cropping system. Strong relationships were observed between ammonium lactate-extractable P in soil and dissolved reactive P (DRP) concentrations in leachate, although regression slopes varied across soils. For three soils, application of manure (equal to 21–30 kg P ha?1) to the soil columns significantly increased DRP leaching losses. The increase in DRP concentration was correlated to soil test P, but with wide variations between the three soils. For two soils leachate P concentrations after manure addition were independent of soil P status. Despite variable trends in P leaching across the different soils, P concentrations in leachate were always moderate from soils at fertilization rates equivalent to P removal with harvest. Results clearly stress the importance of long-term P balance to limit P leaching losses from Swedish agricultural soils. 相似文献
13.
Cynthia A. Cambardella Thomas B. Moorman Jeremy W. Singer 《Nutrient Cycling in Agroecosystems》2010,87(3):383-393
Coupling winter small grain cover crops (CC) with manure (M) application may increase retention of manure nitrogen (N) in
corn (Zea mays L.), -soybean [Glycine max (L.) Merr], cropping systems. The objective of this research was to quantify soil N changes after application of liquid swine
M (Sus scrofa L.) at target N rates of 112, 224, and 336 kg N ha−1 with and without a CC. A winter rye (Secale cereale L.)-oat (Avena sativa L.) CC was established prior to fall M injection. Surface soil (0–20 cm) inorganic N concentrations were quantified every
week for up to 6 weeks after M application in 2005 and 2006. Soil profile (0–120 cm in 5, 20-cm depth increments) inorganic
N, total N, total organic carbon and bulk density were quantified for each depth increment in the fall before M application
and before the CC was killed the following spring. Surface soil inorganic N on the day of application averaged
318 \textmg \textN \textkg - 1\textsoil 318\,{\text{mg}}\;{\text{N}}\;{\text{kg}}^{ - 1}{_{\text{soil}}} in 2005 and
186 \textmg \textN \textkg - 1\textsoil 186\,{\text{mg}}\;{\text{N}}\;{\text{kg}}^{ - 1}{_{\text{soil}} } in 2006 and stabilized at
150 \textmg \textN \textkg - 1\textsoil 150\,{\text{mg}}\;{\text{N}}\;{\text{kg}}^{ - 1}{_{\text{soil}}} in both years by mid-November. Surface soil NO3-N concentrations in the M band were more than 30 times higher in the fall of 2005 than in 2006. The CC reduced surface soil
NO3-N concentrations after manure application by 32% and 67% in mid- November 2005 and 2006, respectively. Manure applied at
224 kg N ha−1 without a CC had significantly more soil profile inorganic-N (480 kg N ha−1) in the spring after M application than manured soils with a CC for the 112 (298 kg N ha−1) and 224 (281 kg N ha−1) N rates, and equivalent inorganic N to the 336 (433 kg N ha−1) N rate. These results quantify the potential for cover crops to enhance manure N retention and reduce N leaching potential
in farming systems utilizing manure. 相似文献
14.
Microwave-Assisted Synthesis and Properties of a Novel Cationic Gemini Surfactant with the Hydrophenanthrene Structure 总被引:3,自引:0,他引:3
Weihong Jia Xiaoping Rao Zhanqian Song Shibin Shang 《Journal of surfactants and detergents》2009,12(3):261-267
A novel cationic gemini surfactant with the hydrophenanthrene structure has been synthesized from dehydroabietic acid by use
of conventional thermal conditions and microwave irradiation. Its structure was confirmed by IR, 1H NMR, and 13C NMR spectroscopy. It was found that microwave-assisted synthesis is an efficient means of preparation of this cationic gemini
surfactant, with shorter reaction times and higher yields. The title compound had high surface activity. The CMC was 3.1 × 10−5 mol L−1, γ
CMC was 26.3 mN m−1, and emulsifying power (with benzene) reached five days. Comparison of this gemini surfactant and its monomeric counterpart
proved the gemini surfactant was more surface active.
相似文献
Zhanqian SongEmail: |
15.
Krishna R. Tiwari Bishal K. Sitaula Roshan M. Bajracharya Trond Børresen 《Nutrient Cycling in Agroecosystems》2010,86(2):241-253
On-farm runoff plots were established during 2004 and monitored for 4 years in the Pokhare Khola watershed (Nepal) in a completely
randomized design with four replications of each three treatments: traditional Farmer Practice (FP) (Zea mays–Eleusine coracana), Reduced Tillage (RT; Z. mays–Vigna ungeuculata), and Commercial Vegetable with double dose of farm yard manure (CV; Z. mays–Capsicum species) to evaluate treatment effects on soil nutrient losses, nutrient balances and crop income on Bari land (rainfed terraces). Nutrient removal due to crop harvest was found to be significantly higher than nutrient loss through
soil erosion, and CV treatment exhibited a significantly higher N uptake (123 kg ha−1 year−1) through crop harvest than other treatments. Moreover, the CV treatment produced significantly higher income per unit area
of Bari land than the other treatments. Soil organic carbon and major nutrients losses (NPK) through soil erosion were minimal [25.5 kg ha−1 year−1 soil organic carbon (SOC) and 5.6:0.02:0.12 kg ha−1 year−1 nitrogen (N), phosphorus (P), potassium (K), respectively]. Result showed that no nutrients were lost through leaching. Nutrient
losses due to soil erosion and runoff were lower than previously reported in the Middle Mountain region, indicating a need
to re-evaluate the soil erosion and nutrient loss problems in this region. Interventions such as reduced tillage and double
dose of FYM with vegetable production were found to be effective in maintaining soil fertility and increasing farm income
compared to the traditional maize-millet production system. The nutrient balance calculations suggest that integrated nutrient
management techniques such as residue incorporation and application of FYM with a minimum application of chemical fertilizer
are potentially sustainable production approaches for the Mid-hills of Nepal. 相似文献
16.
Rice yield,potassium uptake and apparent balance under long-term fertilization in rice-based cropping systems in southern China 总被引:15,自引:0,他引:15
Huimin Zhang Minggang Xu Xiaojun Shi Zuzhang Li Qinghai Huang Xiujun Wang 《Nutrient Cycling in Agroecosystems》2010,88(3):341-349
Potassium (K) imbalances are of growing concern in southern China, where rice (Oryza sativa L.) is the primary food resource for a growing population. This study examined rice yield, K uptake and apparent balance
under long-term fertilization in rice-based systems at four experimental sites, including both rice-rice as well as rice–wheat
rotations. The experiments consist of four treatments: control (no fertilizer), nitrogen and phosphorus (NP), nitrogen, phosphorus
and potassium (NPK), and NPK plus manure (NPKM). Across all sites, rice yields increased by 3–20% due to K fertilization (NPK
vs. NP) and 4–20% due to manure application (NPKM vs. NPK). The mean internal K use efficiency (IE) was lower (32–56 kg kg−1) in treatments receiving K (NPK and NPKM) than in those without K application (36–91 kg kg−1—control and NP). Estimated from the logarithmic model, a total K uptake of 38–212 kg ha−1 was needed to produce 3–7 Mg ha−1 of rice grain. The annual apparent K balances were negative (17–245 kg ha−1 year−1), irrespective of mineral K application and site. But the negative K balance reduced by 27–88 kg ha−1 year−1 through application of mineral K in combination with manure. The higher negative apparent K balances under rice–wheat cropping
system were related to the lower K application rate and the soils rich in K-bearing minerals, while the lower negative apparent
K balances under rice–rice cropping system were related to the higher K application rate and the soils low in K-bearing minerals.
We conclude that a re-adjustment of the current K application rate is needed to improve the long-term rice production in southern
China. 相似文献
17.
A series of cleavable aryl sulfonate anionic surfactants were synthesized from cyanuric chloride, aliphatic amine and H-acid
mono sodium salt. Their structures were identified by 1H NMR, Infrared Spectrum (IR) and Elementary Analysis (EA). Their critical micelle concentrations (CMC) in aqueous solutions
at 25 °C were determined by a steady-state fluorescence probe method and a surface-tension method. With the increasing length
of the carbon chain, the value of their CMCs and surface tensions under CMC (γ
CMC) initially decreased and then reached a minimum (respectively 2.63 × 10−5 mol L−1 and 28.29 mN m−1) when the carbon number was 10. The CMC and γ
CMC then increased when the carbon number was increased to 12. The results showed that, compared with sodium dodecyl benzene
sulfonate (SDBS), such kinds of surfactants have much lower surface adsorption amounts and greater molecular areas on the
aqueous surface.
相似文献
Zhiyong HuEmail: |
18.
C. Wilson M. Undi M. Tenuta D. Tremorin L. Coppi D. Flaten K. M. Wittenberg K. H. Ominski 《Nutrient Cycling in Agroecosystems》2011,91(2):155-171
Liquid hog manure (LHM) is used to improve productivity of grasslands in western Canada. However, application of manure to
meet crop N requirements can result in excessive accumulation of P, especially in grazing systems. A three-year study was
carried out to assess the impact of timing of liquid hog manure application and harvest strategy on nutrient utilization and
accumulation by grasslands in southeast Manitoba. Liquid hog manure was applied annually at a full rate of 142 ± 20 kg available
N ha−1 in spring (Single application) or as two half rate applications of 70 ± 6 kg available N ha−1, one in fall and one in spring (Split application). Two harvest strategies, haying and grazing, were employed to export nutrients
from grasslands. Spring-applied manure averaged 8.9% dry matter, 5.7 g total N L−1, 1.5 g total P L−1, and 2.1 g total K L−1 and fall-applied manure from the same source averaged 3.9% dry matter, 4.4 g total N L−1, 0.7 g total P L−1, and 2.2 g total K L−1. Manure application based on grass N requirements resulted in at least two times more P and K applied than recommended for
Manitoba grasslands. Nutrient (N, P, and K) export from grasslands was five times higher when grass forage was harvested as
hay than through grazing. Average nutrient utilization when forage was harvested as hay was 153 kg N ha−1, 18 kg P ha−1, and 123 kg K ha−1 and was higher in the years with increased precipitation. Grazing was not effective in removing nutrients from grasslands
as indicated by lower N, P, and K utilization efficiency (% applied nutrient) in grazed (30% for N, 7% for P, and 18% for
K) relative to hayed (75% for N 32% for P, and 103% for K) paddocks. Nutrient accumulation was impacted by a combination of
harvest strategy and timing of manure application. Both single and split applications increased soil extractable nutrients,
but soil extractable nutrients were higher in grazed relative to hayed paddocks following single manure application. After
3 years of manure application, the amount of Olsen-P (62 kg ha−1) exceeded that required for optimal forage growth. However, soil levels did not exceed the soil Olsen-P regulatory threshold
(60 mg kg−1) that restricts manure P applications in Manitoba. An analysis of P balance, for this particular soil, indicated that a surplus
of 18.9 kg manure P ha−1 (in excess of forage P exported as hay or weight gain) increased the soil Olsen-P concentration by 1 mg kg−1. Nutrient utilization and accumulation will be impacted by timing of manure application and harvest strategy employed as
well as amount of precipitation received during the growing season. 相似文献
19.
Effects of fertilization on nutrient budget and nitrogen use efficiency of farmland soil under different precipitations in Northeastern China 总被引:3,自引:0,他引:3
Qiang Ma Wan-Tai Yu Shan-Min Shen Hua Zhou Zi-Shao Jiang Yong-Gang Xu 《Nutrient Cycling in Agroecosystems》2010,88(3):315-327
Based on a consecutive 16-year field trial and meteorological data, the effects of fertilization on the nutrient budget and
nitrogen use efficiency in farmland soil under different precipitation years were studied. With no fertilization treatment,
the grain yield of maize was 3,520 kg ha−1 (mean yield over 13 years). But the maximum yield increased to 7,470 kg ha−1 when treated with mineral N, P and K fertilizers and recycled manure. The nutrient uptake also increased by twofold to threefold
in NPKM treated field compared with that in the control treatment. The highest yields were obtained in years with normal precipitation,
despite the different fertilization schemes. The lowest yields were obtained in drought or waterlogging years, which were
44.7–58.5% of the yields in years with normal precipitation. It also appeared that the deficits of N, P and K were greater
in the years with proper precipitation than those in arid or flood years, because more production was removed from the field.
Soil total N decreased significantly when treated with mineral fertilizer or recycled manure alone. The maximum deficit of
soil total N was observed in control treatment (557 kg ha−1) from 1990 to 2005. The N treatment resulted in a significant negative balance of P, due to the high yield of the crop in
response to applied N. The application of NP or N to soils resulted in a greater negative K balance than that of the control.
The greatest negative balance of total P and available P were obtained under the control and N treatment, and the highest
deficit of soil total K and exchangeable K were obtained under NP treatment. We found that the rate of 150 kg N ha−1 year−1 was inadequate for maintaining soil N balance, and amendment of soil with organic source could not stop the loss of soil
P and K. The applying rates of 150 kg N ha−1 year−1, 25 kg P ha−1 year−1, and 60 kg K ha−1 year−1 combined with 2–3 t ha−1 organic manure were recommended to maintain soil fertility level. The nitrogen use efficiency (NUE) was greatly improved
in the years with proper precipitation and balanced fertilization. Higher NUE and grain yields were achieved under NPK and
NPKM treatments in years with normal precipitation. The results clearly demonstrated that both organic and mineral fertilizers
were needed to increase crop production, improve NUE and maintain soil fertility level. 相似文献
20.
Yurong Jiang Zhigang Xu Jimei Luan Pingqin Liu Weihong Qiao Zongshi Li 《Journal of surfactants and detergents》2008,11(1):73-78
By performing measurements of the equilibrium surface tensions of electrolyte solutions of three unsymmetrical bolaamphiphiles,
each of which has an aromatic ring and a ω-carboxyalkyl chain in its molecular structure, we conclude that the carboxyl and
sulfonate groups at both ends of the molecule—which enter the solution while the hydrophobic chain extends into the air—can
force these surfactants to adopt a looped configuration which looks like the letter “U” upside-down, resulting in regular
arrangements at the air/water interface and micelles in bulk solution. Surface tension measurements of these surfactants as
a function of added salt reveal the limiting surface tension to be less sensitive to the ionic strength in LiCl solution and
significantly sensitive to divalent Ca2+ and Mg2+ ions in hard water. This result reveals that the looped configuration of the molecule is the dominant factor in determining
whether the molecules of this surfactant are sensitive to ionic strength or not. This paper also reports briefly on the effect
of the interactions of divalent Ca2+ and Mg2+ ions with unsymmetrical bolaamphiphiles on the turbidity of hard water. These results suggest that the interactions of divalent
Ca2+ and Mg2+ ions with carboxyl groups are strong, and the two breaks in the surface tension curves disappear. In 200 ppm hard water,
the turbidity appears over just a small range of surfactant concentrations, showing that the presence of the Ca2+ and Mg2+ ions has little effect on the application of these surfactants.
相似文献
Weihong Qiao (Corresponding author)Email: |