共查询到20条相似文献,搜索用时 15 毫秒
1.
Christina Tonitto Mark B. David Changsheng Li Laurie E. Drinkwater 《Nutrient Cycling in Agroecosystems》2007,78(1):65-81
Using the DeNitrification–DeComposition (DNDC) model we compare conventional, fertilizer-driven corn–soybean rotations to
alternative management scenarios which include the management of cereal rye cover crops and corn–soybean–wheat–red clover
rotations. We conduct our analysis for tile-drained, silty clay loam soils of Illinois. DNDC simulations suggest that, relative
to conventional rotations, a nitrate leaching reduction of 30–50% under corn and of 15–50% under soybean crops can be achieved
with diversified rotations, an outcome which corroborates results from a quantitative literature review we previously conducted
using a meta-analysis framework. Additionally, over a 10-year simulation, legume-fertilized systems are predicted to result
in 52% lower N2O gas flux relative to fertilizer-driven systems. We identify soil organic carbon storage, legume N-fixation rate, and cereal
rye cover crop growth as areas requiring further development to accurately apply DNDC to diversified cropping systems. Overall,
DNDC simulation suggests diversified rotations that alternate winter and summer annuals have the potential to dramatically
increase N retention in agroecosystems. 相似文献
2.
Long term effects of fertilization on carbon and nitrogen sequestration and aggregate associated carbon and nitrogen in the Indian sub-Himalayas 总被引:4,自引:0,他引:4
Ranjan Bhattacharyya Ved Prakash S. Kundu A. K. Srivastva H. S. Gupta S. Mitra 《Nutrient Cycling in Agroecosystems》2010,86(1):1-16
An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining
soil productivity and also for restraining global warming by CO2 evolution. Results of a long-term (30 year) experiment in the Indian Himalayas under rainfed soybean (Glycine max L.)—wheat (Triticum aestivum L.) rotation was analyzed to determine the influence of mineral fertilizer and farmyard manure (FYM) application at 10 Mg ha−1 on SOC and total soil nitrogen (TSN) stocks and distribution within different aggregate size fractions. Fertilizers (NP,
NK and NPK) and FYM in combination with N or NPK were applied before the soybean crop every year and no nutrient was applied
before the wheat crop. Results showed that addition of FYM with N or NPK fertilizers increased SOC and TSN contents. The overall
gain in SOC in the 0- to 45-cm soil depth interval in the plots under NPK + FYM treatment over NPK was 17.18 Mg C ha−1 in 30 year. The rate of conversion of input C to SOC was about 19% of each additional Mg C input per hectare. SOC content
in large size aggregates was greater than in smaller size aggregates, and declined with decreased aggregate size. Thus, long-term
soybean–wheat rotation in a sandy loam soil of the Indian Himalayas sequestered carbon and nitrogen. Soil organic C and TSN
sequestration in the 0.25- to 0.1-mm size fraction is an ideal indicator of long-term C and N sequestration, since this fraction
retained maximum SOC/TSN stock. 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.
Under semiarid conditions the response of crops to synthetic fertilizers is often reduced. Organic fertilizers can be used
to provide a continuous source of nutrients for the crops. The soil nitrogen and crop yield in a rotation of durum wheat (Triticum durum)–fallow-barley (Hordeum vulgare)–vetch (Vicia sativa) were studied during 4 years when synthetic fertilizer (chemical), compost (organic) or no fertilizer (control) were applied
in a field with high initial contents of soil NO3–N (> 400 kg N ha−1), phosphorus (22 mg kg−1) and potassium (> 300 mg kg−1). Changes in soil organic matter, phosphorus and potassium were also measured. During the crop period, chemical fertilization
significantly increased the content of soil NO3–N in the first 0.30 m of soil with respect to organic fertilization and the control. The yield of wheat and barley was not
increased after applying chemical or organic fertilizer with respect to the unfertilized plots. The estimated losses of nitrogen
were similar for the three types of fertilization, as well as the uptake of nitrogen for the total biomass produced. The initial
levels of organic matter and phosphorus were maintained, even in the plots that were not fertilized, while the potassium decreased
slightly. Thus, the rotation and burying of crop residues were enough to maintain the crop yield and the initial content of
nutrients. 相似文献
5.
Contribution of legumes towards N economy in cereal-based cropping systems is well-known but there has been a gradual decline
in the cultivation of grain legumes, threatening sustainability of maize (Zea mays)–wheat (Triticum aestivum) cropping system in north-western India. A study was made to evaluate and quantify the effect of different grain legumes
on productivity, profitability, N economy and soil fertility in maize–wheat cropping system at New Delhi during 2002–2004.
Five legumes, viz. blackgram (Vigna mungo), greengram (Vigna radiata), cowpea (Vigna unguiculata), groundnut (Arachis hypogaea) and soybean (Glycine max) were either intercropped with maize or grown in sole cropping, and their residues were incorporated before the following
crop of wheat, which was grown with varying rates of N, viz. 0, 40, 80 and 120 kg N ha−1. Maize-equivalent productivity was significantly more with intercropped greengram (16.1–29.9%), cowpea (24.8%) and groundnut
(11.1–16.6%) than in sole maize. Land equivalent ratio and other competitive functions were favourably influenced with intercropped
maize + greengram and maize + cowpea. Addition of N through legume residues varied from 11.5–38.5 kg ha−1 in intercropped system and 17.5–83.5 kg ha−1 in sole cropping, which improved productivity of following wheat to a variable extent. Nitrogen economy in wheat was 21 kg ha−1 due to residue incorporation of intercropped greengram, cowpea and groundnut; and 49–56 kg N ha−1 of sole cropped greengram and groundnut. Residual soil fertility in terms of organic C and KMnO4-N showed an improvement under maize-based intercropping systems followed by wheat, and the beneficial effect was more pronounced
with sole cropping of legumes due to greater addition of residues. Apparent N balance as well as actual change in KMnO4-N at the end of study was positive in most intercropped legumes as well as sole cropping systems, with greater improvement
noticed under groundnut, soybean and greengram. Net returns were marginal with maize-based intercropping or sole cropping
of legumes, but improved considerably with wheat, particularly when greengram, cowpea and groundnut were grown in the previous
season. The studies suggested that inclusion of grain legumes, particularly greengram, cowpea and groundnut was beneficial
for improving productivity, profitability, N economy and soil fertility in maize–wheat cropping system. 相似文献
6.
Chun Song Enli Wang Xiaozeng Han Richard Stirzaker 《Nutrient Cycling in Agroecosystems》2011,89(3):363-374
A 19-year field experiment on a Mollisol agroecosystem was carried out to study the productivity of a wheat-maize-soybean
rotation and the changes in soil carbon and nutrient status in response to different fertiliser applications in Northeast
China. The experiment consisted of seven fertiliser treatments: (1) unfertilised control, (2) annual application of P and
K fertilisers, (3) N and K fertilisers, (4) N and P fertilisers, (5) N, P and K fertilisers, (6) N, K and second level P fertilisers,
and (7) N, P and second level K fertilisers. Without fertiliser, the Mollisols could support an average yield of 1.88 t ha−1 for wheat, 3.89 t ha−1 for maize and 2.12 t ha−1 for soybean, compared to yields of 3.20, 9.30 and 2.45 t ha−1 respectively for wheat, maize and soybean if the crop nutrient demands were met. At the potential yield level, the N, P and
K removal by wheat are 79 kg N ha−1, 15 kg P ha−1, and 53 kg K ha−1, by maize are 207 kg N ha−1, 47 kg P ha−1, and 180 kg K ha−1, by soybean are 174 kg N ha−1, 18 kg P ha−1, and 55 kg K ha−1. Crop yield, change in soil organic carbon (SOC), and the total and available nutrient status were used to evaluate the fertility
of this soil over different time periods. This study showed that a fertiliser strategy that was able to maintain yields in
the short term (19 years) would not maintain the long term fertility of these soils. Although organic carbon levels did not
rise to the level of virgin soil in any treatment, a combination of N, P and K fertiliser that approximated crop export was
required to stabilise SOC and prevent a decline in the total store of soil nutrients. 相似文献
7.
Susantha Jayasundara Claudia Wagner-Riddle Gary Parkin Peter von Bertoldi Jon Warland Bev Kay Paul Voroney 《Nutrient Cycling in Agroecosystems》2007,79(2):141-159
Best management practices are recommended for improving fertilizer and soil N uptake efficiency and reducing N losses to the
environment. Few year-round studies quantifying the combined effect of several management practices on environmental N losses
have been carried out. This study was designed to assess crop productivity, N uptake from fertilizer and soil sources, and
N losses, and to relate these variables to the fate of fertilizer 15N in a corn (Zea mays L.)-soybean (Glycine max L.)-winter wheat (Triticum aestivum L.) rotation managed under Best Management (BM) compared with conventional practices (CONV). The study was conducted from
May 2000 to October 2004 at Elora, Ontario, Canada. Cumulative NO3 leaching loss was reduced by 51% from 133 kg N ha−1 in CONV to 68 kg N ha−1 in BM. About 70% of leaching loss occurred in corn years with fertilizer N directly contributing 11–16% to leaching in CONV
and <4% in BM. High soil derived N leaching loss in CONV, which occurred mostly (about 80%) during November to April was attributable
to 45–69% higher residual soil derived mineral N left at harvest, and on-going N mineralization during the over-winter period.
Fertilizer N uptake efficiency (FNUE) was higher in BM (61% of applied) than in CONV (35% of applied) over corn and wheat
years. Unaccounted gaseous losses of fertilizer N were reduced from 27% of applied in CONV to 8% of applied in BM. Yields
were similar between BM and CONV (for corn: 2000 and 2003, wheat: 2002, soybean: 2004) or higher in BM (soybean: 2001). Results
indicated that the use of judicious N rates in synchrony with plant N demand combined with other BMP (no-tillage, legume cover
crops) improved FNUE by corn and wheat, while reducing both fertilizer and soil N losses without sacrificing yields. 相似文献
8.
Effects of 15 years of manure and inorganic fertilizers on soil organic carbon fractions in a wheat-maize system in the North China Plain 总被引:13,自引:0,他引:13
Qiong Liang Haiqing Chen Yuanshi Gong Mingsheng Fan Hefa Yang Rattan Lal Yakov Kuzyakov 《Nutrient Cycling in Agroecosystems》2012,92(1):21-33
Soil organic carbon (SOC) and its labile fractions are strong determinants of chemical, physical, and biological properties,
and soil quality. Thus, a 15-year experiment was established to assess how diverse soil fertility management treatments for
winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) cropping system affect SOC and total N (TN) concentrations in the North China Plain. The field experiment included three
treatments: (1) unfertilized control (CK); (2) inorganic fertilizers (INF); and (3) farmyard manure (FYM). Concentrations
of SOC, TN, and different labile SOC fractions were evaluated to 1-m depth. In comparison with INF and CK, FYM significantly
increased SOC and TN concentrations in the 0–30 cm depth, and also those of dissolved organic C (DOC), microbial biomass C
(MBC), hot-water extractable C (HWC), permanganate oxidizable C (KMnO4–C), and particulate organic C (POC) in the 0–20 cm depth. Despite the higher crop yields over CK, application of INF neither
increased the SOC nor the labile C fractions, suggesting that by itself INF is not a significant factor affecting SOC sequestration.
Yet, POC (18.0–45.8% of SOC) and HWC (2.0–2.8%) were the most sensitive fractions affected by applications of FYM. Significantly
positive correlations were observed between SOC and labile organic C fractions in the 0–20 cm depth. The data support the
conclusion that, wherever feasible and practical, application of FYM is important to soil C sequestration and improving soil
quality under a wheat/maize system in the North China Plain. 相似文献
9.
T. A. Basamba E. Barrios B. R. Singh I. M. Rao 《Nutrient Cycling in Agroecosystems》2007,77(2):127-141
Soil fertility replenishment is a critical factor that many farmers in the tropical American hillsides have to cope with to
increase food crop production. The effect of three planted fallow systems (Calliandra houstoniana-CAL, Indigofera zollingeriana-IND, Tithonia diversifolia-TTH) and a crop rotation (maize/beans-ROT) on soil nitrogen mineralization, organic matter and phosphorus fractions was compared
to the usual practice of allowing natural regeneration of native vegetation or natural fallow management (NAT). Studies were
conducted on severely degraded Colombian volcanic-ash soils, 28 months after fallow establishment, at two on-farm experimental
sites (BM1 and BM2) in the Cauca Department. Tithonia diversifolia had a significantly higher contribution to exchangeable Ca, K and Mg as well as B and Zn; the order of soil nutrient contribution
was TTH > CAL > IND > NAT > ROT. On the other hand, lND had significantly higher soil NO3−–N at both experimental farms as compared to all the other fallow system treatments. For the readily available P fraction,
CAL and ROT had significantly higher H2O–Po and resin-Pi, respectively, in the 0–5 cm soil layer; whereas TTH showed significantly higher values for both H2O–Po and resin-Pi in the 5–10 cm soil layer. Significant effects were observed on the weights of the soil organic matter fractions
which decreased in the order LL (Ludox light) > LM (Ludox intermediate) > LH (Ludox heavy). Indigofera zollingeriana showed greater C, N and P in the soil organic matter fractions than all the other fallow treatments, with NAT having the
lowest values. It is concluded that planted fallows can restore soil fertility more rapidly than natural fallows. 相似文献
10.
S. S. Malhi S. A. Brandt R. Lemke A. P. Moulin R. P. Zentner 《Nutrient Cycling in Agroecosystems》2009,84(1):1-22
A field experiment was conducted from 1995 to 2006 on a Dark Brown Chernozem (Typic Boroll) loam soil at Scott, Saskatchewan,
Canada to determine the influence of input level and crop diversity on accumulation and distribution of nitrate-N and extractable
P in the soil profile, and soil pH, dry aggregation, organic C and N, and nutrient balance sheets in the second 6-year rotation
cycle (2001–2006). Treatments were combinations of three input levels (organic input under conventional tillage—ORG; reduced
input under no-till—RED; and high input under conventional tillage—HIGH), three crop diversities (fallow-based rotations with
low crop diversity—LOW; diversified rotations using annual cereal, oilseed and pulse grain crops—DAG; and diversified rotations
using annual grain and perennial forage crops—DAP), and six crop phases including green manure (GM), chem-fallow or tilled-fallow
(F). Amount of nitrate-N in 0-240 cm soil was usually highest under the HIGH input-LOW crop diversity treatment and lowest
under the ORG input-DAP crop diversity treatment. The distribution of nitrate-N in various soil depths suggested downward
movement of nitrate-N up to 240 cm depth, especially with LOW crop diversity compared to DAP crop diversity, and with HIGH
input. In some years, the ORG input systems had higher nitrate-N than the RED or HIGH input systems, which was attributed
to low extractable P in soil for optimum crop growth and reduced nutrient uptake with ORG input management. Extractable P
in soil was higher by a small margin for HIGH or RED input relative to ORG input in the 0–15 cm layer, suggesting little downward
movement of P. Crop diversity did not affect extractable soil P due to the low baseline levels of P in this soil. The proportion
of fine dry aggregates (<1.3 mm, erodible fraction) in 0–5 cm soil was highest with LOW crop diversity-HIGH input system,
and lowest with DAG diversity-RED input system. The opposite was true for large aggregates (>12.7 mm). Wet aggregate stability
was higher for RED input compared to ORG and HIGH input, which was attributed to the increase in the concentration of organic
C in aggregates in the RED input system. Amount of light fraction organic matter (LFOM), light fraction organic C (LFOC) and
light fraction organic N (LFON) in 0–15 cm soil was higher for RED input compared to ORG and HIGH inputs, and higher for DAG
and DAP crop diversities than for LOW crop diversity. Soil N and P were usually deficient under ORG input management, but
large amounts of N and P were unaccounted for, or in surplus, under RED and HIGH inputs, despite a marked increase in plant
N and P uptake and crop yield compared to ORG input. Overall, our findings suggest that soil quality can be improved and nutrient
accumulation in the soil profile can be minimized by increasing cropping frequency, reducing/eliminating tillage, and using
appropriate combinations of fertilizer input and diversified cropping. 相似文献
11.
Changes in soil nutrient content and enzymatic activity under conventional and zero-tillage practices in an Indian sandy clay loam soil 总被引:1,自引:0,他引:1
B. L. Mina Supradip Saha Narendra Kumar A. K. Srivastva H. S. Gupta 《Nutrient Cycling in Agroecosystems》2008,82(3):273-281
For 3 years we studied the impact of different tillage practices on biological activity, major nutrient transformation potential
in a sandy clay loam soil and crop yield in a Himalayan subtemperate region. Field agroecosystems with a rotation of two grain
crops per year (lentil-finger millet) received four different tillage practices: zero–zero (ZZ), conventional–conventional
(CC), zero–conventional (ZC), and conventional–zero (ZC) tillage. Most of the chemical parameters were influenced by the type
of tillage practice. ZZ increased the soil organic carbon (SOC) content in the upper soil layer from 6.8 to 7.5 mg g−1 soil. Similarly available N was increased by 6.1% in ZZ over CC. Under zero tillage soil generally had higher P and K content
than under other tillage practices. Soil carbohydrate content was also increased from 3.1 to 4.9 mg g−1 and dehydrogenase activity was also increased significantly under continuous zero-tillage practice. Alkaline phosphatase,
protease, and cellulase were most sensitive to changes due to tillage management. Alkaline phosphatase and protease activity
was greater (by 9.3–48.1%) in the zero-tillage system over conventional practice. In contrast, cellulase activity was more
(by 31.3–74.6%) in conventional practice than other management practices. We suggest that, by understanding the effects of
tillage on soil biological properties, soil quality and agricultural sustainability of subtemperate hill agro-ecosystems may
be improved. 相似文献
12.
A field experiment was conducted in a 7-year old alfalfa stand to compare the influence of time and method of terminating
alfalfa stands on crop yield, seed quality, N uptake and recovery of applied N for wheat (Triticum aestivum L.) and canola (Brassica napus L.), soil properties (ammonium-N, nitrate-N, bulk density, total and light fraction organic C and N), and N2O emissions on a Gray Luvisol (Typic Cryoboralf) loam near Star City, Saskatchewan, Canada. The treatments were a 3 × 3 × 4
factorial combination of three termination methods [herbicide (H), tillage (T), and herbicide + tillage (HT)], three termination
times (after cut 1 and cut 2 in 2003, and in spring 2004) and four rates of N (0, 40, 80 and 120 kg N ha−1) applied at seeding to wheat-canola rotation from 2004 to 2007. In the termination year, soil nitrate-N was considerably
higher in T or HT treatments than in the H treatment and decreased with delay in termination. In the first crop year, seed
and straw yields of wheat grown on T and HT treatments were significantly greater than H alone (by 1,055–1,071 kg seed ha−1 and by 869–929 kg straw ha−1), due to greater content of soil available N in T treatments. Yields decreased with delay in termination time. In general,
yield and N uptake in seed and straw, and protein concentration tended to increase with increasing N rate. A greater yield
increase occurred on the H compared to T and HT treatments from the first increments of N applied. Nitrous oxide emissions
were generally low and there were no treatment differences evident when cumulative 4-year N2O-N losses were compared. Appropriate N fertilization was able to compensate for yield reductions due to delayed termination
timing, but could not do so entirely for yield reductions on the H compared to T or HT termination method. The amounts of
TOC, TON, LFOC and LFON after four growing seasons were usually higher or tended to be higher under H treatment than under
T treatment in the 0–5 cm soil layer, but the opposite was true in the 5–10 cm or 10–15 cm soil layers. 相似文献
13.
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
14.
Yadvinder-Singh R. K. Gupta Gurpreet-Singh Jagmohan-Singh H. S. Sidhu Bijay-Singh 《Nutrient Cycling in Agroecosystems》2009,84(2):141-154
Development of a sustainable and environment friendly crop production system depends on identifying effective strategies for
the management of tillage and postharvest crop residues. Three-year (2004–2007) field study was initiated on two soil types
to evaluate the effect of straw management (burning, incorporation and surface mulch) and tillage (conventional tillage and
zero tillage) before sowing wheat and four nitrogen rates (0, 90, 120 and 150 kg N ha−1) on crop yields, N use efficiency, and soil fertility in the northwestern India. Effect of tillage and straw management on
nitrogen transformation in soils was investigated in a laboratory incubation study. In sandy loam, grain yield of wheat with
straw mulch-zero-till (ZT) was 7% higher compared to when residues were burnt-ZT but it was similar to straw burnt-conventional
till (CT), averaged across 3 years. In silt loam, grain yield of wheat with straw mulch-ZT was 4.4% higher compared to straw
incorporated-CT, but it was similar to straw burnt-CT. Response to N application was generally observed up to 150 kg N ha−1 except in 2004–2005 on sandy loam where N response was observed up to 120 kg N ha−1, irrespective of straw and tillage treatments. In sandy loam, RE was lower (49%) for straw burnt-ZT than in other treatments
(54–56%). In silt loam, RE was higher in straw mulch-ZT compared with straw incorporation-CT (65 vs. 58%). In sandy loam,
AE was higher in straw burnt-CT and straw mulch-ZT compared with the other treatments (19.2 vs. 16.9 kg grain kg−1 N applied). In silt loam, AE was lower in straw incorporation-CT than in other treatments (16.0 vs. 17.6 kg grain kg−1 N applied). Rice yield and N uptake were not influenced by straw and tillage management treatments applied to the preceding
wheat. Recycling of rice residue (incorporation and surface mulch) compared with straw burning increased soil organic carbon
and the availability of soil P and K. There was more carbon sequestration in rice straw mulch with zero tillage (25%) than
in straw incorporation with conventional tillage (17%). Soil N mineralization at 45 days after incubation was 15–25% higher
in straw retention plots compared with on straw burnt plots. 相似文献
15.
Long-term use of soil, crop residue and fertilizer management practices may affect some soil properties, but the magnitude
of change depends on soil type and climatic conditions. Two field experiments with barley, wheat, or canola in a rotation
on Gray Luvisol (Typic Cryoboralf) loam at Breton and Black Chernozem (Albic Argicryoll) loam at Ellerslie, Alberta, Canada,
were conducted to determine the effects of 19 or 27 years (from 1980 to 1998 or 2006 growing seasons) 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 pH, extractable P, ammonium-N and nitrate–N in the 0–7.5, 7.5–15, 15–30 and 30–40 cm or 0–15, 15–30, 30–60, 60–90
and 90–120 cm soil layers. The effects of tillage, crop residue management and N fertilization on these chemical properties
were usually similar for both contrasting soil types. There was no effect of tillage and residue management on soil pH, but
application of N fertilizer reduced pH significantly (by up to 0.5 units) in the top 15 cm soil layers. Extractable P in the
0–15 cm soil layer was higher or tended to be higher under ZT than CT, or with SRet than SRem in many cases, but it decreased significantly with N application (by 18.5 kg P ha−1 in Gray Luvisol soil and 20.5 kg P ha−1 in Black Chernozem soil in 2007). Residual nitrate–N (though quite low in the Gray Luvisol soil in 1998) increased with application
of N (by 17.8 kg N ha−1 in the 0–120 cm layer in Gray Luvisol soil and 23.8 kg N ha−1 in 0–90 cm layer in Black Chernozem soil in 2007) and also indicated some downward movement in the soil profile up to 90 cm
depth. There was generally no effect of any treatment on ammonium-N in soil. In conclusion, elimination of tillage and retention
of straw increased but N fertilization decreased extractable P in the surface soil. Application of N fertilizer reduced pH
in the surface soil, and showed accumulation and downward leaching of nitrate–N in the soil profile. 相似文献
16.
Phosphorus loss by surface runoff from agricultural field plots with different cropping systems 总被引:1,自引:0,他引:1
Phosphorus (P) loss from agricultural fields through surface runoff may contribute to the eutrophication of surface waters.
The objective of this study was to evaluate surface runoff and P transport from different cropping systems during 2007–2009.
The treatments consisted of a control (wheat/fallow) and three double cropping systems: wheat/corn (Zea mays L.), wheat/cotton (Gossypium hirsutum L.), and wheat/soybean [Glycine max (L.) Merr.]. Wheat/fallow was not fertilized and had no crop planted during the summer crop growing season. The four treatments
were randomly assigned to 12 plots of 5 × 2 m on a silt clay soil. Surface runoff from natural rainfall was sampled for P
analysis during the 3 years. Double cropping systems, when compared with wheat/fallow, reduced runoff volume and losses of
total dissolved P (TDP), particular P (PP), and total P (TP). Wheat/soybean was the most beneficial system reducing the 3-years
mean runoff volume by 58%, TDP loss by 81%, PP loss by 89%, and TP loss by 85%, compared with wheat/fallow. The 3-years flow-weighted
mean (FWM) concentrations of TDP, PP, and TP followed the order wheat/fallow > wheat/cotton > wheat/corn > wheat/soybean.
The least temporal variations of the P concentrations and losses were observed from wheat/soybean. Therefore, selecting wheat/soybean
as the main double cropping system appears to be a practical method for controlling runoff and associated P loss from farmland
under similar weather and soil conditions. 相似文献
17.
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
18.
19.
Green leaf manuring with prunings of Leucaena leucocephala is regarded as a useful source of N to plants but the actual substitution of N fertilizer, release and recovery of N as well
as effects on soil fertility are not adequately studied. The present studies investigated the effect of sole and combined
use of Leucaena prunings and urea N fertilizer in different proportions on productivity, profitability, N uptake and balance in maize (Zea mays)–wheat (Triticum aestivum) cropping system at New Delhi during 2002–2003 and 2003–2004. Varying quantities of Leucaena green leaf biomass containing 3.83–4.25% N (18.2–20.5 C:N ratio) were applied to provide 0, 25, 50, 75 and 100% of recommended
N (120 kg ha−1) to both maize and wheat before sowing. In general, direct application of urea N increased the productivity of both crops
more than Leucaena green leaf manure, but the reverse was true for the residual effect of these sources. The productivity of maize increased
progressively with increasing proportions of N through urea fertilizer and was 2.41–2.52 t ha−1 with 60 kg N ha−1 each applied through Leucaena and urea, which was at par with that obtained with 120 kg N ha−1 through urea alone (2.56–2.74 t ha−1). Similarly, wheat yield was also near maximum (4.46–5.11 t ha−1) when equal amounts of N were substituted through Leucaena and urea. Residual effects were obtained on the following crops and were significant when greater quantity of N (>50%) was
substituted through Leucaena. Nitrogen uptake and recovery were also maximum with urea N alone, and N recovery was higher in maize (33.4–42.1%) than in
wheat (27.3–29.8%). However, recovery of residual N in the following crop was more from Leucaena N alone (8.5–10.3%) than from urea fertilizer (1.7–3.8%). Residual soil fertility in terms of organic C and KMnO4 oxidizable N showed improvement with addition of Leucaena prunings, which led to a positive N balance at the end of second cropping cycle. Net returns were considerably higher with
wheat than with maize, and were comparatively lower with greater proportion of Leucaena because of its higher cost. Nonetheless, it was beneficial to apply Leucaena and urea on equal N basis for higher productivity and sustainability of this cereal-based cropping system. 相似文献
20.
Agronomic and economic evaluation of site-specific nutrient management for irrigated wheat in northwest India 总被引:1,自引:0,他引:1
Harmandeep S. Khurana Steven B. Phillips Bijay-Singh Marcus M. Alley Achim Dobermann Ajmer S. Sidhu Yadvinder-Singh Shaobing Peng 《Nutrient Cycling in Agroecosystems》2008,82(1):15-31
Similar to other regions of Asia, irrigated wheat (Triticum aestivum L.) yield increases in Punjab, India, have slowed in recent years. Future yield increases may occur in smaller increments
through fine-tuning of crop management mainly by accounting for the large spatial and temporal variation in soil characteristics.
On-farm experiments were conducted from 2002–03 to 2004–05 on 56 irrigated wheat farms (hereafter referred to as ‘sites’)
in six key irrigated rice (Oryza sativa L.)-wheat regions of Punjab to evaluate an approach for site-specific nutrient management (SSNM). Site-specific N–P–K applications
were calculated by accounting for the indigenous nutrient supply, yield targets, and nutrient demand as a function of the
interactions between N, P, and K. The performance of SSNM was tested for two wheat crops. Compared with the current farmers’
fertilizer practice (FFP), average grain yield increased from 4.2 to 4.8 Mg ha−1, while plant N, P, and K accumulations increased by 12–20% with SSNM. The gross return above fertilizer cost (GRF) was about
13% greater with SSNM than with FFP. Improved timing and/or splitting of fertilizer N increased N recovery efficiency from
0.17 kg kg−1 in FFP plots to 0.27 kg kg−1 in SSNM plots. The agronomic N use efficiency was 63% greater with SSNM than with FFP. As defined in our study, SSNM has
potential for improving yields and nutrient use efficiency in irrigated wheat. Future research must build on the present approach
to develop a more practical way for achieving similar benefits across large areas without site-specific modeling and with
minimum crop monitoring. 相似文献