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1.
Presently, more than 85% of the broiler chicken (Gallus gallus domesticus) litter (BCL) is being applied to pasture lands year-round. This practice results in nutrient losses and potentially unfavorable
environmental impacts particularly during the wet winter months. A field plot experiment was initiated in 2001 on a Ruston
silt loam in Mize, MS to identify the proper BCL application timing that enhances BCL nutrient uptake by crops while minimizing
undesirable nutrient buildup in soil. Seven treatments (BCL application timings) were employed on previously established “Coastal”
hybrid bermudagrass [Cynodon dactylon (L.) Pers.] plots. For each treatment, the quantity of broiler chicken litter (a mixture of chicken manure plus bedding materials)
needed for each plot was calculated based on the BCL total N content to provide 400 kg N ha−1 for top bermudagrass yield (18 Mg ha−1) and applied either as a single, two-way split, or three-way split at different dates as follow: May; May/June; April/May/June;
May/June/July; June/July/August; July/August/September; and August/September/October. Bermudagrass was harvested 5 times each
year for dry matter (DM) and nutrient uptake determination. Significant differences in DM yield were observed in each year
among application timings. The greatest DM yield was 18.6 Mg ha−1 for the single application in May and lowest at 15.0 Mg ha−1 for Aug/Sep/Oct application dates in 2001 and followed by the same trend in 2002. The N and P uptake by bermudagrass ranged
from 270 to 381, and 53 to 63 kg ha−1 respectively, in 2001. Similar trend, but lower values for nutrient uptake were observed in 2002. Significant differences
were observed among BCL application timings in regard to soil residual of total carbon (TC), total nitogen (TN), Mehlich 3
extracted P (M3-P), NO3–N, Cu, and Fe elements at the end of the study. In general, summer and early fall BCL applications resulted in greater buildup
of most of these elements. Based on the results of this study, there is a wide window (May–July) for BCL application timing
on bermudagrass considering the criteria of producing high yield and low soil residual nutrient. However, the best BCL application
timing should be in spring (late April–June) when minimum temperatures exceed those required (24–27°C) for bermudagrass growth. 相似文献
2.
Many contract swine producers are located in the southeastern U.S. In this region almost all of the swine effluent from swine
production is applied to warm-season perennial species such as bermudagrass [Cynodon dactylon (L.) Pers.] which is widely grown for summer grazing and hay production. A 3-yr study was conducted to investigate the impact
of forage double-cropping on nutrient accumulation and leaching in Mantachie fine loam soil fertilized with swine (Sus scrofa domesticus) lagoon effluent as the source of plant nutrients. Plots of previously established Tifton 44 bermudagrass were overseeded
in the fall with one of four winter annuals: berseem clover (Trifolium alexandrinum L.); crimson clover (T. incarnatum L.); ryegrass (Lolium multiflorum L.); or wheat (Triticum aestivum L.). Four plots of bermudagrass were not overseeded and considered as control. Plots were harvested in spring for cool-season
annual hay and in summer for bermudagrass hay. Swine effluent was applied during spring and summer on a need base. Suction
lysimeters were installed in selected plots at two depths to monitor nutrient leaching. Surface soil samples were taken to
determine baseline nutrient contents, followed by three other sampling dates during the study. Bermudagrass dry matter production
(3-yr average = 9.8 Mg ha−1) was not adversely affected by the overseeding treatments. Greatest dry matter production was achieved with bermudagrass
overseeded with ryegrass (3-yr average = 11.3 Mg ha−1). Soil pH decreased by almost one unit by the end of the study. While total P (TP) did not change much, Mehlich-3 P (M3-P),
K, Cu, and Zn increased significantly, Mg and Mn concentrations decreased by 2002 compared to the baseline levels. Soil P,
Mg, K, Fe, Mn, and Zn accumulation were greater under bermudagrass/wheat combination. In general, the influence of double
cropping on soil nutrient accumulation was not conclusive, however, this practice provides the year-round green forage for
grazing and haying. Nutrient concentrations in soil and lysimeter leachate were directly related to the quantity of effluent
applied. Results also demonstrated that effluent application must be coordinated with the nutrient requirements of the growing
forages in order to minimize accumulation and leaching. 相似文献
3.
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: |
4.
Application of manure to no-till soils: phosphorus losses by sub-surface and surface pathways 总被引:2,自引:0,他引:2
Peter J. A. Kleinman Andrew N. Sharpley Lou S. Saporito Anthony R. Buda Ray B. Bryant 《Nutrient Cycling in Agroecosystems》2009,84(3):215-227
The acceleration of surface water eutrophication attributed to agricultural runoff has focused attention on manure management
in no-till. We evaluated losses of phosphorus (P) in sub-surface and surface flow as a function of dairy manure application
to no-till soils in north-central Pennsylvania. Monitoring of a perennial spring over 36 months revealed that dissolved reactive
P (DRP) concentrations increased 3- to 28-fold above background levels whenever manure was broadcast to nearby field soils.
A study conducted with 30-cm deep intact soil cores indicated that incorporation of manure by tillage lowered P loss in leachate
relative to broadcast application, presumably due to the destruction of preferential flow pathways. More P was leached from
a sandy loam than a clay loam soil, although differences between soils were not as great as differences between application
methods. In contrast, rainfall simulations on 2-m2 field runoff plots showed that total P (TP) losses in surface runoff differed significantly by soil but not by application
method. Forms of P in surface runoff did change with application method, with DRP accounting for 87 and 24% of TP from broadcast
and tilled treatments, respectively. Losses of TP in leachate from manured columns over 7 weeks (0.22–0.38 kg P ha−1) were considerably lower than losses in surface runoff from manured plots subjected to a single simulated rainfall event
(0.31–2.07 kg TP ha−1). Results confirm the near-term benefits of incorporating manure by tillage to protect groundwater quality, but suggest that
for surface water quality, avoiding soils prone to runoff is more important.
相似文献
Peter J. A. KleinmanEmail: |
5.
In southern Africa, tillage research has focused on rainfed smallholder cropping systems, while literature on high-input irrigated
cropping systems is limited. We evaluated the effects of conventional (CT), minimum (MT) and no-till (NT) tillage systems
on soil organic carbon (SOC), bulk density, water-stable aggregates (WSA), mean weighted diameter (MWD) and crop yields in
an irrigated wheat–cotton rotation. Soil data were monitored in the first and final year, while yields were monitored seasonally.
Average bulk densities (1.5–1.7 Mg m−3) were similar among tillage systems, but often exceeded the critical limit (1.60 Mg m−3) for optimum root growth. Conversion from CT to MT and NT failed to ameliorate the high bulk densities associated with the
alluvial soil. SOC (g kg−1) at 0–15 cm was higher (P < 0.05) under MT (3.9–5.8) and NT (4.2–5.6) than CT (2.9–3.3). Corresponding horizon SOC stocks (Mg C ha−1) for the tillage treatments were; 9.3–13.9 (MT), 9.3–13.5 (NT) and 7.3–7.7 (CT). In the final year, significant (P < 0.05) tillage effects on SOC stocks were also observed at 15–30 cm. Cumulative SOC stocks (Mg C ha−1) in the 0–60 cm profile were higher (P < 0.05) under MT (32.8–39.9) and NT (32.9–41.6) than CT (27.8–30.9). On average, MT and NT sequestered between 0.55 and 0.78 Mg C ha−1 year−1 at 0–30 cm depth, but a net decline (0.13 Mg C ha−1 year−1) was observed under CT. At 0–30 cm, MT and NT had higher (P < 0.05) MWD (0.19–0.23 mm) and WSA (2.3–3.5%) than CT (MWD: 0.1–0.12 mm, WSA: ≈1.0%). Both MWD and WSA were significantly
(P < 0.05) correlated to SOC. Seasonal yields showed significant (P < 0.05) tillage effects, but 6-year mean yields (t ha−1) were similar (CT: 4.49, MT: 4.33, NT: 4.32 for wheat; CT: 3.30, MT: 2.82, NT: 2.83 for cotton). Overall, MT and NT improved
soil structural stability and carbon sequestration, while impacts on crop productivity were limited. Therefore, MT and NT
are more sustainable tillage systems for the semi-arid regions than conventional tillage.
S. Chakanetsa—Deceased. 相似文献
6.
Ranjan Bhattacharyya S. C. Pandey S. Chandra S. Kundu Supradip Saha B. L. Mina A. K. Srivastva H. S. Gupta 《Nutrient Cycling in Agroecosystems》2010,86(2):255-268
To date, the sustainability of wheat (Triticum
aestivum)–soybean (Glycine
max) cropping systems has not been well assessed, especially under Indian Himalayas. Research was conducted in 1995–1996 to 2004
at Hawalbagh, India to study the effects of fertilization on yield sustainability of irrigated wheat–soybean system and on
selected soil properties. The mean wheat yield under NPK + FYM (farmyard manure) treated plots was ~27% higher than NPK (2.4 Mg ha−1). The residual effect of NPK + FYM caused ~14% increase in soybean yield over NPK (2.18 Mg ha−1). Sustainable yield index values of wheat and the wheat–soybean system were greater with annual fertilizer N or NPK plots
10 Mg ha−1 FYM than NPK alone. However, benefit:cost ratio of fertilization, agronomic efficiency and partial factor productivity of
applied nutrients were higher with NPK + FYM than NPK, if FYM nutrients were not considered. Soils under NPK + FYM contained
higher soil organic C (SOC), total soil N, total P and Olsen-P by ~10, 42, 52 and 71%, respectively, in the 0–30 cm soil layers,
compared with NPK. Non-exchangeable K decreased with time under all treatments except NPK. Total SOC in the 0–30 cm soil layer
increased in all fertilized plots. Application of NPK + FYM also improved selected soil physical properties over NPK. The
NPK + FYM application had better soil productivity than NPK but was not as economical as NPK if farmers had to purchase manure. 相似文献
7.
J. M. Pereira R. M. Tarré R. Macedo C. de Paula Rezende B. J. R. Alves S. Urquiaga R. M. Boddey 《Nutrient Cycling in Agroecosystems》2009,83(2):179-196
Excessive intensification of dairy and beef cattle production systems in the industrialised countries has led to serious problems
of pollution of water resources and the atmosphere. In order to develop an appropriate alternative, a few studies have been
made by various research teams in Brazil, using low fertiliser inputs and modest animal stocking rates. The objective of this
present study was to evaluate the effect of different stocking rates of beef cattle, and the introduction of a forage legume
(Desmodium ovalifolium (Prain) Wall.), on the long-term sustainability of pastures of Brachiaria humidicola (Rendle) Schweick established in the Atlantic forest region of Brazil in the extreme south of the State of Bahia. Annual
maintenance fertilisation was restricted to additions of 11 and 6 kg ha−1 of P and K, respectively (and no N). Live weight gain (LWG) of Zebu steers was evaluated for stocking rates of 2, 3 and 4 head ha−1 during six grazing periods from 1988 to 1997. Forage intake and the proportion of legume in the acquired ration was determined
using steers fitted with oesophageal fistulae. The bolus samples were analysed manually in 1988–1989, and using the 13C natural abundance technique in 1995. There was no significant response of LWG to the presence of the legume in the acquired
ration. LWG in the final grazing period (1995–1996) was similar to that recorded in 1988–1989 at all stocking rates, suggesting
that this management regime resulted in long-term sustainable production even in the absence of the legume or of a N fertiliser
input. This was confirmed by the soil fertility analyses for 1988 and 1997, where only levels of P showed a significant decrease.
The net aerial primary productivity (NAPP) of the pasture was determined for 1995, the largest component being deposited litter
(21–33 Mg DM ha−1 year−1), followed by forage intake (6.4–12.2 Mg DM ha−1 year−1). 相似文献
8.
Influence of organic amendments on growth, yield and quality of wheat and on soil properties during transition to organic production 总被引:3,自引:0,他引:3
K. A. Gopinath Supradip Saha B. L. Mina Harit Pande S. Kundu H. S. Gupta 《Nutrient Cycling in Agroecosystems》2008,82(1):51-60
A transition period of at least 2 years is required for annual crops before the produce may be certified as organically grown.
The purpose of this study was to evaluate the effects of three organic amendments on the yield and quality of wheat (Triticum aestivum L.) and on soil properties during transition to organic production. The organic amendments were composted farmyard manure
(FYMC), vermicompost and lantana (Lantana spp. L.) compost applied to soil at four application rates (60 kg N ha−1, 90 kg N ha−1, 120 kg N ha−1 and 150 kg N ha−1). The grain yield of wheat in all the treatments involving organic amendments was markedly lower (36–65% and 23–54% less
in the first and second year of transition, respectively) than with the mineral fertilizer treatment. For the organic treatments
applied at equivalent N rates, grain yield was higher for FYMC treatment, closely followed by vermicompost. In the first year
of transition, protein content of wheat grain was higher (85.9 g kg−1) for mineral fertilizer treatment, whereas, in the second year, there were no significant differences among the mineral fertilizer
treatment and the highest application rate (150 kg N ha−1) of three organic amendments. The grain P and K contents were, however, significantly higher for the treatments involving
organic amendments than their mineral fertilizer counterpart in both years. Application of organic amendments, irrespective
of source and rate, greatly lowered bulk density (1.14–1.25 Mg m−3) and enhanced pH (6.0–6.5) and oxidizable organic carbon (13–18.8 g kg−1) of soil compared with mineral fertilizer treatment after a 2-year transition period. Mineral fertilized plots, however,
had higher levels of available N and P than plots with organic amendments. All the treatments involving organic amendments,
particularly at higher application rates, enhanced soil microbial activities of dehydrogenase, β-glucosidase, urease and phosphatase
compared with the mineral fertilizer and unamended check treatments. We conclude that the application rate of 120 kg N ha−1 and 150 kg N ha−1 of all the three sources of organic amendments improved soil properties. There was, however, a 23–65% reduction in wheat
yield during the 2 years of transition to organic production. 相似文献
9.
Sampson Agyin-Birikorang Yoana C. Newman Augustine K. Obour Gabriel N. Kasozi 《Nutrient Cycling in Agroecosystems》2012,92(1):91-105
Environmental benefits associated with reduced rates of nitrogen (N) application, while maintaining economically optimum yields
have economic and social benefits. Although N is an indispensable plant nutrient, residual soil N could leach out to contaminate
groundwater and surface water resources, particularly in sandy soils. A 2-year field study was conducted in an established
bermudagrass (Cynodon dactylon) pasture in the Lower Suwannee Watershed, Florida, to evaluate N application rates on forage yield, forage quality, and nitrate
(NO3-N) leaching in rapidly permeable upland sandy soils. Four N application rates (30, 50, 70, and 90 kg N ha−1 harvest−1) corresponding to 0.33, 0.55, 0.77 and IX, respectively, of recommended N rate (90 kg N ha−1 harvest−1) for bermudagrass hay production in Florida were evaluated vis-à-vis an unfertilized (0 N) control. Suction cups were installed
near the center of each plot at two depths (30 and 100 cm) to monitor NO3-N leaching. The grass was harvested at 28 days intervals to determine dry matter yield, N uptake, and herbage nutritive value.
Nitrogen application at the recommended rate produced the greatest total dry matter yield (~18.4 Mg ha−1 year−1), but a modeled economically optimum N rate of ~57 kg N ha−1 harvest−1 (~60% of the recommended N rate) projected an average dry matter yield of ~17.3 Mg ha−1 year−1, which represents >90% of the observed maximum yield. Nitrogen application increased nutritive quality of the grass, but
increases in N application rate above 30 kg N ha−1 did not result in significant increases in in vitro digestible organic matter concentration, and tissue crude protein was
not significant above 50 kg N ha−1. Across the sampling period, treatments with N rates ≤50 kg N ha−1 harvest−1 had leachate NO3-N concentration below the maximum contaminant limit of <10 mg l−1. Conversely, applying N at rates ≥70 kg N ha−1 harvest−1 resulted in leachate N concentration that exceeded the maximum contaminant limit, and suggest high risk of impacting groundwater
quality, if such rates are applied to soils with coarse (sand) textures. The study demonstrates that recommendation of a single
N application rate may not be appropriate under all agro-climatic conditions and, thus, a site-specific evaluation of best
N management strategy is critical. 相似文献
10.
P. Ebanyat N. de Ridder A. de Jager R. J. Delve M. A. Bekunda K. E. Giller 《Nutrient Cycling in Agroecosystems》2010,87(2):209-231
Targeting of integrated management practices for smallholder agriculture in sub-Saharan Africa is necessary due to the great
heterogeneity in soil fertility. Experiments were conducted to evaluate the impacts of landscape position and field type on
the biomass yield, N accumulation and N2-fixation by six legumes (cowpea, green gram, groundnut, mucuna, pigeonpea and soyabean) established with and without P during
the short rain season of 2005. Residual effects of the legumes on the productivity of finger millet were assessed for two
subsequent seasons in 2006 in two villages in Pallisa district, eastern Uganda. Legume biomass and N accumulation differed
significantly (P < 0.001) between villages, landscape position, field type and P application rate. Mucuna accumulated the most biomass (4.8–10.9 Mg ha−1) and groundnut the least (1.0–3.4 Mg ha−1) on both good and poor fields in the upper and middle landscape positions. N accumulation and amounts of N2-fixed by the legumes followed a similar trend as biomass, and was increased significantly by application of P. Grain yields
of finger millet were significantly (P < 0.001) higher in the first season after incorporation of legume biomass than in the second season after incorporation.
Finger millet also produced significantly more grain in good fields (0.62–2.15 Mg ha−1) compared with poor fields (0.29–1.49 Mg ha−1) across the two villages. Participatory evaluation of options showed that farmers preferred growing groundnut and were not
interested in growing pigeonpea and mucuna. They preferentially targeted grain legumes to good fields except for mucuna and
pigeonpea which they said they would grow only in poor fields. Benefit-cost ratios indicated that legume-millet rotations
without P application were only profitable on good fields in both villages. We suggest that green gram, cowpea and soyabean
without P can be targeted to good fields on both upper and middle landscape positions in both villages. All legumes grown
with P fertiliser on poor fields provided larger benefits than continuous cropping of millet. 相似文献
11.
Relationship between residue quality,decomposition patterns,and soil organic matter accumulation in a tropical sandy soil after 13 years 总被引:2,自引:0,他引:2
A. Puttaso P. Vityakon P. Saenjan V. Trelo-ges G. Cadisch 《Nutrient Cycling in Agroecosystems》2011,89(2):159-174
The objectives of this study were to investigate decomposition patterns and soil organic matter (SOM) accumulation of incorporated
residues (10 Mg ha−1 year−1) of different quality, and identify microbiological parameters sensitive to changes in SOM dynamics, in a 13-year-old field
experiment on a sandy soil in Northeast Thailand. Mass loss was fastest in groundnut stover (high N), followed by rice straw
(high cellulose) and tamarind (intermediate quality), and slowest in dipterocarp (high lignin and polyphenol) following a
double exponential pattern. The decomposition rate k
1 (fast pool) was positively correlated with cellulose (r = 0.70*) while k
2 (slow pool) was negatively related to lignin (r = −0.85***) and polyphenol (r = −0.81**) contents of residues. Residue decomposition was sensitive to indigenous soil organic nitrogen (SON), particularly
during later stages (R
2 = 0.782**). Thirteen years’ addition of tamarind residues led to largest soil organic carbon (SOC) (8.41 Mg ha−1) accumulation in topsoil (0–20 cm), while rice straw yielded only 5.54 Mg ha−1 followed by the control (2.72 Mg ha−1). The highest SON (0.78 Mg N ha−1) was observed in the groundnut treatment. Increases in SOC were negatively correlated with cellulose content of residues
(r = −0.92***) and microbial respiration (CO2-C) losses, while SON was governed by organic N added. During later decomposition stages, there was a high efficiency of C
utilization (low qCO2) of decomposer communities especially under tamarind with the lowest qCO2 and CO2-C evolution loss. This study suggests that N-rich residues with low cellulose and moderate lignin and polyphenol contents
are best suited to improve SOM content in tropical sandy soils. 相似文献
12.
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: |
13.
G. L. Velthof I. E. Hoving J. Dolfing A. Smit P. J. Kuikman O. Oenema 《Nutrient Cycling in Agroecosystems》2010,86(3):401-412
Managed grasslands are occasionally ploughed up and reseeded in order to maintain or increase the sward productivity. It has
been reported that this renovation of grassland is associated with a flush of soil organic nitrogen (N) mineralization and
with a temporary increase in soil mineral N contents. Here, we report on the effects of method and time of grassland renovation
on herbage yield, nitrate (NO3
−) leaching and nitrous oxide (N2O) emission. Field experiments were carried out at three sites (two sandy soils and a clay soil) in the Netherlands for three
years. Renovation of grassland increased the percentage of Perennial ryegrass from 48–70% up to more than 90%. However, averaged
over three years, dry matter yields were higher for the reference (not reseeded) swards (on average 13.6 Mg ha−1 for the highest N application rate) than for the renovated grasslands (12.2–13.1 Mg ha−1 dry matter). Grassland renovation in April did not increase N leaching in comparison to the reference. However, renovation
in September increased the risk of leaching, because mineral N contents in the 0–90 cm were in November on average 46–77 kg N
ha−1 higher than in the reference. Contents of dissolved organic N (DON) in the soil were not affected by renovation. Renovation
increased N2O emissions by a factor of 1.8–3.0 relative to the reference grassland. Emissions of N2O were on average higher after renovation in April (8.2 kg N2O-N ha−1) than in September (5.8 kg N2O-N ha−1). Renovation without ploughing (i.e. only chemically destruction of the sward) resulted in a lower percentage of perennial
ryegrass (60–84%) than with ploughing (>90%). Moreover, N2O emissions were higher after renovation without ploughing than with ploughing. Clearly, farmers need better recommendations
and tools for determining when grassland renovation has beneficial agronomic effects. Losses of N via leaching and N2O emission after renovation can probably not be avoided, but renovation in spring in stead of autumn in combination with ploughing
and proper timing of fertilizer application can minimize N losses. 相似文献
14.
Long-term tillage,straw management and N fertilization effects on quantity and quality of organic C and N in a Black Chernozem soil 总被引:4,自引:0,他引:4
Soil, crop and fertilizer management practices may affect the amount and quality of organic C and N in soil. A long-term field
experiment (growing barley, wheat, or canola) was conducted on a Black Chernozem (Albic Argicryoll) loam at Ellerslie, Alberta,
Canada, to determine the influence of 19 (1980 to 1998) or 27 years (1980 to 2006) of tillage (zero tillage [ZT] and conventional
tillage [CT]), straw management (straw removed [SRem]and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha−1 in SRet and 0 kg N ha−1 in SRem plots) on total organic C (TOC) and N (TON), and light fraction organic C (LFOC) and N (LFON) in the 0–7.5 and 7.5–15 cm
or 0–5, 5–10 and 10–15 cm soil layers. The mass of TOC and TON in soil was usually higher in SRet than in SRem treatment (by 3.44 Mg C ha−1 for TOC and 0.248 Mg N ha−1 for TON after 27 years), but there was little effect of tillage and N fertilization on these parameters. The mass of LFOC
and LFON in soil tended to increase with SRet (by 285 kg C ha−1 for LFOC and 12.6 kg N ha−1 for LFON with annual rate of 100 kg N ha−1 for 27 years), increased with N fertilizer application (by 517 kg C ha−1 for LFOC and 36.0 kg N ha−1 for LFON after 27 years), but was usually higher under CT than ZT (by 451 kg C ha−1 for LFOC and 25.3 kg N ha−1 for LFON after 27 years). Correlations between soil organic C or N fractions were highly significant in most cases. Linear
regressions between crop residue C input and soil organic C or N were significant in most cases. The effects of tillage, straw
management and N fertilizer on soil were more pronounced for LFOC and LFON than TOC and TON, and also in the surface layers
than in the deeper layers. Tillage and straw management had little or no effect on C:N ratios, but the C:N ratios in light
organic fractions significantly decreased with increasing N rate (from 20.06 at zero-N to 18.91 at 100 kg N ha−1). Compared to the 1979 results, in treatments that did not receive N fertilizer (CTSRem0, CTSRet0, ZTSRem0 and ZTSRet0), CTSRem0 resulted in a net decrease in TOC concentration (by 1.9 g C kg−1) in the 0–15 cm soil layer in 2007 (after 27 years), with little or no change in the CTSRet0 and ZTSRem0 treatments, while there was a net increase in TOC concentration (by 1.2 g C kg−1) in the ZTSRet0 treatment. Straw retention and N fertilizer application at 50 and 100 kg N ha−1 rates showed a net positive effect on TOC concentration under both ZT (ZTSRet50 by 2.3 g C kg−1 and ZTSRet100 by 3.1 g C kg−1) and CT (CTSRet50 by 3.5 g C kg−1 and CTSRet100 by 1.6 g C kg−1) treatments in 2007 compared to 1979 data. In conclusion, the findings suggest that retention of straw, application of N
fertilizer and elimination of tillage would improve soil quality, and this might increase the potential for N supplying power
of the soil and sustainability of crop productivity. 相似文献
15.
T. M. Aye M. J. Hedley P. Loganathan R. D. B. Lefroy N. S. Bolan 《Nutrient Cycling in Agroecosystems》2009,83(2):111-123
Phosphorus (P) deficiency is a major constraint for crop production in many parts of the world including Myanmar and field
research into management of P fertilizers and P responsiveness of crops on infertile soils has been limited. The purpose of
this study is to determine maize yield response to different forms of P fertilizers on an acidic (pH 4.9) P deficient (Olsen-P
8 mg kg−1) Yellow Earth (Acrisol) in Southern Shan State, Myanmar and to establish relationships between soil Olsen-P test values (0.5 M
sodium bicarbonate extracted P) and maize yield. Field experiments were conducted during two cropping seasons. There were
15 treatments in total: P was applied at seven rates of a soluble P fertilizer as Triple superphosphate (TSP) (0–120 kg P ha−1) to establish a P response curve; one rate of a partially soluble P fertilizer (Chinese partially acidulated phosphate rock,
CPAPR) and two organic P fertilizers (farmyard manure (FYM) and Tithonia diversifolia) at 20 kg P ha−1; combination of TSP and CPAPR at 20 kg P ha−1 with FYM and Tithonia at 20 kg P ha−1; an additional treatment (TSP 20 kg P ha−1 plus 2.5 t ha−1 dolomite) for assessing the liming effect of a local dolomite. In Year 1, applications of TSP at 40–60 kg P ha−1 produced near maximum grain yields, whereas in Year 2 this could be achieved with a reapplication of 20–30 kg P ha−1 on top of the residual value of the Year 1 application. In both years, CPAPR, TSP and Tithonia at 20 kg P ha−1 significantly increased maize grain yield, but FYM failed to increase grain yield. In Year 1, CPAPR and TSP effects on grain
yield were higher than that of Tithonia but in Year 2 the effects were same for all these three treatments. In both years
the combination of FYM (20 kg P ha−1) with TSP (20 kg P ha−1) produced significantly higher grain yield than TSP at 20 kg P ha−1 whereas 40 kg P ha−1 of TSP application did not significantly increase grain yield over the TSP application at 20 kg P ha−1. Similar results were obtained when half the P applied as CPAPR was substituted with P from Tithonia and FMP during the first
year. The combined data from the two years experiment suggests that 90% of maximum maize grain yields can be obtained by raising
the Olsen-P to 30–35 mg P ha−1 soil at the silking stage of growth. Olsen-P for the treatments at silking in Year 1 was: Control < FYM, Tithonia < TSP,
CPAPR and in Year 2 was: Control < FYM < Tithonia < TSP, CPAPR. The results showed that for a long-term approach, repeated
annual applications of Tithonia can be considered as a potential P source for improving soil P status in P deficient Yellow
Earths. 相似文献
16.
Soil organic carbon fractions after 16-years of applications of fertilizers and organic manure in a Typic Rhodalfs in semi-arid tropics 总被引:5,自引:0,他引:5
K. Banger G. S. Toor A. Biswas S. S. Sidhu K. Sudhir 《Nutrient Cycling in Agroecosystems》2010,86(3):391-399
Agricultural soils can act as a potential sink of the increased carbon dioxide in the atmosphere if managed properly by application
of organic manures and balanced fertilizers. However, the rate of carbon (C) sequestration in soils is low in warm climates
and thus the short term changes in soil organic carbon (SOC) contents are almost negligible. Therefore, the knowledge about
other C fractions that are more sensitive or responsive and indicative of the early changes in SOC can help to determine the
effect of the management practices on soil C sequestration. The objective of this study was to determine the soil C sequestration
after 16-years of applications of chemical fertilizers and farmyard manure (FYM) to rice (Oryza sativa)—cowpea (Vigna unguiculata) rotation system in a sandy loam soil (Typic Rhodalfs). The treatments were—(1) one control (no fertilizer or FYM); (2) three chemical fertilizer treatments [100 kg N ha−1 (N), 100 kg N ha−1 + 50 kg P2O5 ha−1 (NP), 100 kg N ha−1 + 50 kg P2O5 ha−1 + 50 kg K2O ha−1 (NPK)]; (3) one integrated treatment [(50 kg N ha−1 + 25 kg P2O5 ha−1 + 25 K2O ha−1) + (50 kg N ha−1 from FYM)]; and (4) one organic treatment at10 Mg ha−1 FYM. Compared to the control treatment, the increase in SOC was 36, 33, and 19% greater in organic, integrated, and NPK treatments.
The 16-years application of fertilizers and/or FYM resulted in much greater changes in water soluble C (WSC), microbial biomass
C (MBC), light fraction of C (LFC), and particulate organic matter (POM) than SOC. Of the SOC, the proportion of POM was highest
(24–35%), which was followed by LFC (12–14%), MBC (4.6–6.6%), and WSC (0.6–0.8%). The application of fertilizers and/or FYM
increased the mean weight diameter of soil aggregates; thus provided physical protection to SOC from decomposition. Our results
suggests that the application of fertilizers and/or FYM helps to sequester C in the soil and that the labile fractions of
C can be used as indicators to determine the amount of C sequestered as a result of different management practices. 相似文献
17.
Crop productivity and nutrient use efficiency as affected by long-term fertilisation in North China Plain 总被引:3,自引:0,他引:3
Yingchun Wang Enli Wang Daolong Wang Shaomin Huang Yibing Ma Chris J. Smith Ligang Wang 《Nutrient Cycling in Agroecosystems》2010,86(1):105-119
Nutrient inputs into crop production systems through fertilisation have come under increased scrutiny in recent years because
of reduced nutrient use efficiency and increased environmental impact. Fifteen years of experimental data on dynamics of N,
P and K in soil, crop yield and nutrient uptake from nine fertilisation treatments at Zhengzhou, North China Plain, were used
to analyse the contribution of different fertilisation treatments to crop yield, nutrient use efficiency and accumulation
of nutrients in soil. The results showed that both N and P were limiting factors for crop growth. Without additional N and
P fertilisation, only a very low yield level (ca 2 t ha−1 for wheat and 3 t ha−1 for maize) could be maintained. To achieve the potential productivity (i.e. yield level free of water and nutrient stresses)
of wheat (6.9 t ha−1) and maize (8.3 t ha−1), wheat would need, on average, 170 kg N ha−1, 32 kg P ha−1 and 130 kg K ha−1, while maize would need 189 kg N ha−1, 34 kg P ha−1 and 212 kg K ha−1. The N and P demands correspond well to the N and P levels supplied in one of the fertilisation treatments (NPK), while K
deficiency could occur in the future if no crop residues were returned or no extra K was applied. On average under this NPK
treatment, 80% of N and 71% of P could be recovered by the wheat–maize system. Treatments with nutrient inputs higher than
the NPK treatment and treatments without combination of N and P have led to accumulation of N and P in the soil profile. The
input levels of N and P in the NPK treatment are recommended in fertiliser management, with additional K to avoid future soil
K deficiency. 相似文献
18.
Wetlands in south-western Australia are often situated in the interdunal depressions of coastal sand dunes and have catchments
with significant areas of native vegetation. While farming and urbanization are two common sources of nutrients, natural processes
such as P release from catchment litter and its significance as a P source for these waters have rarely been investigated.
We studied litter production in a wooded catchment, and the leaching potential of litter P over the wet season. High concentrations
of P, from 1.2–4.6 mg l−1 (non-flooded conditions) to 1.5–5.7 mg l−1 (flooded conditions) were leached from litter during the ‘first flush’ of the wet season. Overall 25.7–84.1% of the total
P in litter was released via leachate during rainy months of May to November, mostly during the ‘first flush’. This equals
a load of 0.91 kg P ha−1 year−1 in response to annual leaf litter production on this catchment. The source was relatively small compared with the fertiliser
P use in agricultural soils of the region (3.1–9.8 kg P ha−1 year−1) but was comparable with P export from agricultural catchments. Catchment litter as a source of P will need to be accounted
for in the wetland management. 相似文献
19.
Soil organic carbon changes and distribution in cultivated and restored grassland soils in Saskatchewan 总被引:1,自引:0,他引:1
The impacts of grassland restoration on amounts, forms and distribution of soil organic carbon (SOC) were examined in paired
cultivated and restored grassland catenae of the Missouri Coteau region in south-central Saskatchewan, Canada. Total SOC (0–15 cm
depth) and light fraction organic carbon (LFOC) (0–7.5 cm) contents were determined in paired catenae in upland areas, and
in the surface (0–15 cm) and at depth (>15 cm) in the wetland fringe areas. Mass of SOC was higher in the restored grassland
catenae than in the cultivated equivalents. In both the cultivated and restored grassland catenae at the three sites, footslope
positions consistently had a higher mass of SOC. However, the shoulder positions showed the greatest response in soil C sequestration
to grass seed-down, with a 1.4–2.9 Mg ha−1 year−1 SOC increase apparent over an approximately eight-year period. The mass of LFOC and the proportion of SOC comprised of LFOC
was also higher in the restored grassland, reflective of higher recent C inputs. Rates of C sequestration in the Missouri
Coteau based on SOC differences in the paired comparisons were estimated to be 0.3–2.9 Mg C ha−1 year−1, depending upon site and slope position. In the wetland fringe region of the landscape, the three sites also had higher surface
or subsurface SOC in the grassland restoration. In general, SOC changes at depth (below 15 cm) in the restored grasslands
appeared to be less consistent than changes in SOC in the surface 0–15 cm soil. In conclusion, the findings suggest that a
switch to permanent cover on these soils will significantly increase C sequestered in the soil. 相似文献
20.
O. O. Oladeji G. O. Kolawole G. O. Adeoye G. Tian 《Nutrient Cycling in Agroecosystems》2006,76(1):1-10
Plant residues are being suggested as an amendment to enhance P release from rock phosphate, however, plant residue enhanced P release could depend on the residue quality, application rate and placement method. Effects of plant residue quality, application rate and placement method on solubility and P release from rock phosphate (PR) were studied in laboratory and field experiments. Leaves of ten woody and␣herbaceous species were incubated in a P-deficient soil with Sokoto PR under laboratory conditions to study the effects of residue quality on P release from PR. Effects of residue application rate and placement method were investigated in a field trial with five rates (0, 1, 2, 4 and 8 t DM ha−1) of leaves of Dactyladenia barteri, two placement methods (incorporation and mulching), and two levels of Sokoto PR (0 and 60 kg P ha−1) in a split-split plot design replicated three times. The plant residues were applied 4 weeks before the main season planting. Maize (main season) followed by cowpea (minor season) was used as test plant. In the laboratory incubation study, addition of plant residues increased the soil pH. Phosphorus released at 8 weeks was greater for plant residues with high C/N ratio, and low magnesium and potassium. In the field trial, soil pH was not affected by the addition of plant residues. Residue placement method showed little effects on P availability from PR. When residues were incorporated with PR, soil Olsen P was highest at lower rates of residues (1 and 2 t DM ha−1) at maize planting. Maize P concentration and P uptake were highest at the incorporation of 4 t DM ha−1 residues with PR. Incorporation at higher rate (8 t DM ha−1) resulted in the greatest P uptake of the second crop, cowpea. The study shows the potential of plant residues in enhancing P release from PR. However, there could be initial immobilization of P, but this could be overcome within a short period if residues of high C/N ratio are used. A lower rate of residues (1–4 t DM ha−1) is efficient at releasing PR–P for short-term effect especially if incorporated. 相似文献