Rice-Rape Rotation Benefits to Improve Radiation and Heat Use
Efficiencies and Mitigate Global
Warming Potential of Paddy Cropping Systems in Central China
Gong
Songling1,2, Li Chengwei1,2, Zhou Yong1,2, Yan
Xiaoyuan1,2, Zhu Rong1,2, Zhu Bo1,2* and Liu Zhangyong1,2
1Hubei Collaborative Innovation Centre for Grain Industry, College of
Agriculture, Yangtze University, Jingzhou, 434025, P.
R. China
2Engineering Research Center of Ecology and
Agricultural Use of Wetland, Ministry of Education, Yangtze University, Jingzhou, 434025, P. R. China
*For correspondence: 1984zhubo@163.com
Replacing bare fallow by rotation
with winter cereal crops such as winter wheat and oil rape have been used to
improve annual productivity in paddy cropping system in central China. However,
the effects of rotation on light and heat resources utilization and greenhouse
gases have yet to be measured. A two-year field experiment was conducted to
compare solar radiation and heat use efficiencies, methane (CH4)
and nitrous oxide (N2O) emissions and global warming potential
(GWP) of two winter rotations: rice-wheat and rice-rape taking rice-fallow as a
check. The results of this study showed that rice-wheat had the highest annual
grain yield (two-year means were 16.2 t ha-1) and annual above
ground biomass (32.9 t ha-1) followed by rice-rape and by
rice-fallow. No significant effect was observed for winter rotation on the
performance of rice grain yield and growth, in spite of a large quantity of
straw returning by winter crops. Solar radiation and heat resources utilization
and their production efficiency were improved in the winter season by rotation
with winter crops. Rice-wheat and rice-rape also increased light and heat
resources utilization efficiency from the annual perspective. Compared with
rice-fallow, CH4 flux in the rice season among the two studying
years was increased by 42.0% by rice-wheat but was decreased by 35.6% by
rice-rape. For the annual level, CH4 flux was promoted by 40.9% by
rice-wheat and declined by 35.5% by rice-rape. For the rice season the N2O
seasonal flux was increased by 54.2 and by 8.3% in rice-wheat and rice-rape
plots, respectively. The values for GWP and for yield-scaled GWP were highest
in rice-wheat and lowest in rice-rape system. In conclusion, rice-rape system
could be a better choice to increase solar radiation and heat resources utilization
and mitigate greenhouse gases emission. ©
2021 Friends Science Publishers
Keywords: Sustainability; Paddy cropping
system; Rotation; Greenhouse gases; Central China
Introduction
Agriculture development is now facing a worldwide concern
for sustainability mostly in three aspects: 1) food supply for an increasing
population; 2) improving resources utilization efficiency and 3) mitigating
detrimental items emission into the environment such as greenhouse gases (GHG).
As one of the most important staple food, rice (Oryza
sativa L.) feeds more than 50% of the world’s population (Zhou and Sun
2017). According to FAO (2019), China accounts for approximately 28% of the
global rice production and 18% of the world’s planting area. Food supply,
resources utilization and environmental issues in paddy ecosystems, especially
in central and south China are getting more and more concerns.
Previous research has confirmed that rotation in
paddy cropping systems, especially those with legumes could play an important
role in promoting nutrient cycling, improving soil fertility and maintaining
food production by reducing fertilizer investment (Nie
et al. 2019). The release of
environmental hazard compounds such as NO3- leaching and
N2O emission from farmland could also be reduced by rotation (Yu et al. 2014; Machado et al. 2021), or by replacing winter fallow with cover crops (Zhu et al. 2016). Fewer N losses were
observed from crop residues than from chemical fertilizers when residues were
incorporated into the soil in different rotation systems (Congreves et al. 2017; Taveira
et al. 2020).
Studies on agricultural resources utilization have
been focused on artificial nonrenewable resource inputs such as nitrogen
fertilizer (Liu
and Zhang 2011), irrigation water (Jia et al. 2020), etc. The local non-renewable climate resources including solar
radiation and heat are usually evaluated for single season crop production (Du et al. 2019). The analysis of cropping
effects on solar radiation and cumulative temperature use efficiency from an
annual perspective are quite few but in urgent need. As reported by Zhang et al. (2013), food production potential
of paddy ecosystems in central China has been increased greatly in the past
decades because of an increasing air
temperature. The most popular paddy cropping system in central China is single
rice followed by winter fallow or rotated with a winter crop such as winter
wheat (Triticum aestivum L.) and oil rape (Brassica campestris L.).
Therefore, the effects of rotation on radiation and accumulative temperature
use efficiency need to be clarified to make a better use of resource potential.
Agriculture is considered as a
major anthropogenic source of CH4 and N2O, accounting for
50 and 60% of total CH4 and N2O emissions, respectively
(Smith et al. 2007). About 30% of
agricultural CH4 and 11% of N2O emissions released to the
atmosphere are generated from rice paddies over the world (Mer and Roger 2001).
Compared with fallow, rotation with cereals such as wheat, or with a winter
cover may have profound effects on CH4 and N2O emissions
from paddy field by altering organic or inorganic fertilizers application
(Tellez-Rio et al. 2017) and complex
soil conditions (Kamp et al. 2001).
The effects of rotation on CH4 and N2O emissions from
paddy soils are yet to be measured to make a more sustainable rice production.
Rotation with winter crops has been
recognized as effective to promote nutrient cycling and reduce N2O
emission from paddy fields (Yu et al.
2014; Zhu et al. 2016). However, the
effects of winter crops rotation on radiation and heat use efficiencies, and
global warming potential of paddy systems are not well reported. Therefore,
this two-year field study was designed with the hypothesis that winter
rotations can improve resource use efficiencies and mitigate GHG emissions
compared with winter fallow in paddy systems of central China.
Materials
and Methods
Site
description
The field experiment (2017–2019)
was conducted in a farmer’s field in Jiangling County (30°12'N, 112°31'E),
Hubei province, central China. This region is in the middle reaches of Yangtze
River, one of the most important rice planting areas in China. The climate is
humid and mid-subtropical monsoon with an average temperature ranged from 16.0
to 16.4°C and an annual rainfall of 900–1100 mm. The soil is fluvo-aquic, and before the start of the experiment the
soil fertility was: 26.44 g kg-1 total carbon, 2.44 g kg-1 total
nitrogen, 170.9 mg kg-1 alkaline hydrolyzed nitrogen, 0.38 g kg-1
total phosphorus, 12.7 mg kg-1 Olsen extractable phosphorus,
159.0 mg kg-1 available potassium, and pH (H20) 6.9.
Treatments and agronomic details
The study was started at October 28 in 2016,
before that the cropping system in the experimental field was one season rice
followed by winter fallow for more than 10 years. In this study three rice
cropping systems were compared: rice-winter fallow (RF), rice-winter wheat (RW)
and rice-rape (RR). The
treatments were arranged in a completely randomized block design with three
replications. Nine plots of 98 m2 (14 m × 7 m) per individual plot
were used. Plots were separated by 0.5 m wide ridges covered with plastic film
to avoid water and nutrients runoffs.
Winter crops were transplanted or hand broadcast
after rice harvest and straw incorporation by a rotary tiller in late October.
For RR plots, rape seedlings (cv. Huayouza62, 30d) were transplanted at
a density of 30 cm × 30 cm with a single seedling per hill. Wheat (cv.
Zhengmai9023) seeds were hand broadcast at a rate of 225 kg ha-1 in
RW plots. The rape and wheat received the same base fertilizer application: 96
kg N ha-1, 60 kg P2O5 ha-1 and 132
kg K2O ha-1 (16:10:22% compound fertilizer). The rape was
applied with twice top dressings as 36 kg N ha-1 (urea) and 7.5 kg B
ha-1 (Na2B4O7·10H2O) each time while the
wheat was top dressed with urea at a rate of 45 kg N ha-1. RF plots
were kept fallow during the whole winter season. In early June, after winter
crops harvest and soil management, rice seedlings (cv. Longliangyouhuazhan,
30d) were transplanted at a spacing of 26 cm × 16 cm with 3 plants per hill.
Rice plants received a fertilizer application in the form of 225 kg N ha-1
(urea), 75 kg P2O5 ha-1 (calcium
superphosphate), and 180 kg K2O ha-1 (potassium
chloride). The fertilizer distribution was 40% N, 100% P2O5
and 50% K2O for base fertilizers; 30% N for topdressing at tillering
stage; 30% N and 50% K2O for the second topdressing at grain filling
stage. The rice field was flooded by a 3–5 cm depth of water except for the
mid-season drainage.
At maturity, grain yield of each crop was measured
by randomly selected two 4 m2 areas for each plot. The above-ground
biomass was separated into straw and grains and measured after oven drying at
75°C to constant weight.
CH4 and N2O flux
measurements
CH4 and N2O fluxes were
measured from June 2017 to May 2019, by using a closed chamber/gas chromatography
method (Sun et al. 2018). The closed
chamber (45 cm × 45 cm × 100 cm) was put into the groove of a base which was
fixed into the soil in each plot. Thereafter, water was filled into the groove
to seal the chamber so no gas leaking will happen between the chamber and the
covered field. A battery-driven fan was used to mix the air inside the chamber.
For each flux measurement, three gas samples intervals were collected from 9:00
to 11:00 am by using a 25-mL syringe at 0, 8 and 16 min respectively, after the
chamber was placed on the fixed base. The chamber was removed from its base
after each gas sampling event. Gas samples were taken at 10–15 d intervals
during the winter season and at 7–10 d intervals in the rice season.
CH4 and N2O
concentrations were determined by using a gas chromatograph (Agilent 7890B, CA,
USA) equipped with a hydrogen flame ionization detector (FID) and an electron
capture detector (ECD). The oven and FID were operated at 50 and 300°C,
respectively. The temperatures for the column and ECD detector were maintained
at 40 and 300°C, respectively.
Calculations for resource use
efficiency and GHG emissions
The CH4 and N2O
fluxes (Fi) were calculated based on the changes of
concentration (ΔC) over the time duration (Δt)
(Mosier et al. 2006). Cumulative CH4
and N2O emissions (CEi)
were calculated via the trapezoidal
integration of the mean flux over sampling intervals (Mosier et al. 2006).
(1)
CEi = (2)
Where ρ is the density
of CH4 or N2O, V is the volume of the chamber
above the enclosed soil with the area of A. T is the temperature inside
the chamber (°C). Di is the interval in days of the adjacent
two sampling events and 24 are the hours in a day.
Based on a 100-year time frame, the GWP
coefficient is 25 for CH4 and 298 for N2O to CO2
equivalent (IPCC 2007). We calculated the combined GWP for 100 years using Eq.
(3):
(3)
The yield scaled GWP was calculated according to
Shang et al. (2011).
Yield-scaled GWP = GWP/Y (4)
Where, Y is the crop grain yield for the gas
sampling season.
Data of radiation and temperature
use efficiencies, including radiation production efficiency (RPE), radiation
use efficiency (RUE), accumulative temperature production efficiency (ATPE) and
accumulative temperature use efficiency (ATUE) of ≥10°C were calculated by Chang et al.
(2016).
RPE (g MJ-1) = grain yield/solar
radiation (5)
RUE (%) = primary productivity/solar radiation (6)
ATPE (kg hm-2
°C-1 d-1) = grain yield/accumulative temperature (7)
ATUE (%) = accumulative
temperature during crop season / annual accumulative temperature (8)
Statistical analysis
Data were analyzed by
using the PROC ANOVA procedure in S.A.S. version 9.3 (S.A.S. Institute Inc.,
Cary, NC, USA). Means of rice yield, cumulative GHG emissions, GWP,
yield-scaled GWP, crop yield and resources utilization efficiency were compared
based on the least significant difference (LSD) test at the 0.05 probability
level.
Results
Yield performance
Across the 2-year observation, no
significant difference was detected for grain yield and above-ground biomass in
the rice season between rice-fallow and rotation systems of rice-wheat or
rice-rape (Fig. 1a, b). In spite of longer growing seasons for the winter
crops, their grain yields were much smaller than those of rice (Fig. 1a). Wheat
showed significant higher (P ≤ 0.05) grain yields than rape in paddy rotation systems in
both years (Fig. 1a). When it came to the annual total grain yield, rice-wheat
and rice-rape rotations had greater values than rice-fallow in both years. As
shown in Fig. 1b, rice-wheat had the highest annual above-ground biomass
because of a higher residue production from winter crops.
Solar radiation and heat efficiency
Indicators such as radiation production efficiency
(RPE), radiation use efficiency (RUE), accumulative temperature production
efficiency (ATPE) and accumulative temperature use efficiency (ATUE) of ≥10°C were
successfully used for solar radiation and heat resources utilization comparisons
among different farming systems. In this study, no significant difference was
observed for RPE and ATPE during the rice season (Table 1). In the winter
season, RPE and ATPE values were zero for rice-fallow because no crop was
planted or harvested during winter seasons. For rice-wheat and rice-rape, wheat
showed greater (P ≤ 0.05) RPE and ATPE values than rape (Table 1), mainly due to the higher grain
yields and dry matter accumulation in rice-wheat plots (Fig. 1). The lower
values for RPE and ATPE in the winter seasons could be attributed to the lower
temperature in wheat and rape growing seasons. When compared with rice-fallow,
the annual RPE and ATPE were significantly increased (P ≤ 0.05) by rice-wheat and by rice-rape
in both years (Table 1). By calculation based on above ground dry matter
accumulation, RUE values ranged from 0.80–1.68% (Table 1). The highest RUE
values were observed in rice-wheat rotation plots, followed by rice-rape and
rice-fallow. No significant diffidence was shown for RUE between rice-rape and
rice-fallow in 2018–2019. Both the rotation treatments improved ATUE values
significantly (P ≤ 0.05)
than rice-fallow. Rice-wheat and rice-rape plots had similar ATUE values
because of the same growing stages for the winter seasons.
The CH4 and N2O fluxes and
GWP
According to the two-year observation, CH4
emission rates ranged respectively from 0.05 mg m-2
h-1 to 21.52 mg m-2 h-1 for the rice seasons
and from 0 mg m-2 h-1 to 1.98 mg m-2 h-1
for the winter seasons (Fig. 2a). The three treatments showed a similar CH4
emission trend during the rice seasons. Two major peaks were detected for CH4
emission for all the treatments in rice seasons both in 2017 and in 2018. CH4
emission rates rose steadily after rice transplanting at early June and got its
first peak at late June when rice plants were at full tillering stage.
Thereafter, CH4 emission decreased sharply nearly to zero in the
mid-season drainage. CH4 emission started to increase again when the
field was flooded with water and got the second peak at middle August when rice
plants were at flowering stage. Little CH4 emission was observed for
the three treatments during the winter crop growing seasons (Fig. 2a). CH4
fluxes were calculated for the rice season, the winter season and the annual
level, respectively. As shown in Table 2, the two-year average values for CH4
flux in the rice season was increased by 42.0% by rice-wheat but was decreased
by 35.6% by rice-rape when compared with rice-fallow. For the annual level, CH4
flux was promoted by 40.9% by rice-wheat and declined by 35.5% by rice-rape.
Table 1: The 2-year (2017–2019) radiation and temperature
production efficiency and use efficiency of different cropping patterns
Year |
Treatment |
RPE (g MJ-1) |
RUE (%) |
ATPE (kg hm-2°C-1d-1) |
ATUE (%) |
||||
Rice season |
Winter season |
Annual |
Rice season |
Winter season |
Annual |
||||
2017–2018 |
|
|
|
|
|
|
|
|
|
|
RF |
0.51 ± 0.02 a |
0 c |
0.26 ± 0.01 b |
0.91 c |
5.17 ± 0.3 a |
0 c |
3.70 ± 0.18 b |
71.63 b |
|
RR |
0.52 ± 0.01 a |
0.16 ± 0.00 b |
0.35 ± 0.00 a |
1.23 b |
5.24 ± 0.1 a |
4.68 ± 0.61 b |
5.15 ± 0.05 a |
93.88 a |
|
RW |
0.52 ± 0.01 a |
0.26 ± 0.03 a |
0.40 ± 0.01 a |
1.68 a |
5.25 ± 0.1 a |
7.71 ± 0.77 a |
5.74 ± 0.16 a |
95.23 a |
2018–2019 |
|
|
|
|
|
|
|
|
|
|
RF |
0.45 ± 0.02 a |
0 c |
0.24 ± 0.02 b |
0.80 b |
4.4 ± 0.2 a |
0 c |
3.18 ± 0.17 b |
72.87 b |
|
RR |
0.47 ± 0.02 a |
0.15 ± 0.00 b |
0.29 ± 0.01 a |
1.01 b |
4.62 ± 0.2 a |
4.32 ± 0.05 b |
4.55 ± 0.18 a |
92.71 a |
|
RW |
0.47 ± 0.02 a |
0.25 ± 0.03 a |
0.37 ± 0.01 a |
1.48 a |
4.65 ± 0.2 a |
7.57 ± 0.66 a |
5.32 ± 0.16 a |
92.01a |
Mean ± standard deviation. Different lower-case letters indicate the
significantly differences (P < 0.05) based on LSD
multiple range tests. RF represents rice-fallow, RR represents rice-rape, RW
represents rice-wheat. RPE represents radiation production efficiency, RUE represents
radiation use efficiency, ATPE represents accumulative temperature
production efficiency of ≥10°C, ATUE represents accumulative temperature
use efficiency of ≥10°C
Fig. 1: Correlation between the
average crop grain yield (a) and above ground biomass (b). RF
represents rice-fallow, RR represents rice-rape, RW represents rice-wheat. The
Correlation shows positive correlation between grain yield and above ground
biomass
N2O emission rates ranged respectively
from 0 to 420.7 μg
m-2 h-1 for the rice seasons and from 0 to 169.5 μg m-2 h-1 for the winter seasons (Fig. 2b). In general, N2O
rates were greater in the rice seasons than in the winter seasons in the
two-year observation. Dramatically different N2O emission patterns
were measured among treatments and years. In the rice seasons and the beginning
of the winter season in 2017, most of the N2O rates were higher than
100 μg m-2 h-1 for
rice-wheat plots. For the year 2018, the rice season’s N2O rates
showed an impulse trend regardless of the treatments. N2O emission
peaks were obviously higher in 2018 than those in 2017 (Fig. 2b). When compared
with rice-fallow, N2O seasonal flux in the rice season was increased
by 54.2 and 8.3% in rice-wheat and rice-rape plots, respectively. For the
annual level, N2O emission was promoted by 66.7 and 26.3% in
rice-wheat and rice-rape plots, respectively (Table 2).
Global warming potential (GWP) was calculated
based on the data for CH4 and N2O annual emissions to
make an integrated estimation of the global warming effects of the greenhouse
gases emitted from the field. In this study, GWP values of CH4 and N2O
were highest in rice-wheat treatment and lowest in rice-rape treatment during
both years (Table 2). The increased GWP could be a result of a greater annual
CH4 emission as CH4 emission contributed the most part of GWP. We also estimated yield-scaled
GWP which was calculated as GWP
divided by grain yield. As shown in Table 2, yield-scaled GWP of rice-rape was
the lowest while no significant difference was found between rice-wheat and
rice-fallow.
Discussion
Although rotation with rape or with wheat showed
no effect on radiation and heat use efficiencies during the rice season;
however, rotation prompted the radiation and heat use efficiencies from the
perspective of annual production. Moreover, the CH4 and N2O
emissions from paddy soils differed with rotation with different winter crops
(Table 2).
There were diverse reports on the effects of
rotation on the main cereal crop yields when the same rotation pattern was
applied continuously over years. Crops followed by legume rotations usually
showed promoted nitrogen accumulation and higher grain yields (Yu et al. 2014; Zhu et al. 2016). Sometimes, yield reduction of the main crop resulted
from rotation could be attributed to the competition for nitrogen after the
incorporation of the second crop residue, such as rape and ryegrass because of
a high carbon/nitrogen ratio (Armstrong et al. 1996; Nie
et al. 2019), in spite that the
rotation treatments were coupled with crop residue return, which means an
additional nitrogen supply during the main rice crop season (Zhu et al. 2016). In this study, rotation
with wheat or with rape had no significant effect on the grain yield and above
ground biomass of rice for both years, possibly due to the high level of rice
grain yields (ranged from 12.1 to 13.6 t ha-1, Fig. 1a). However,
rotation prompted crops production from the perspective of annual production.
Rotation might change climate resources
utilization such as light and heat in two ways. First, when compared with
fallow, rotation with winter crops could utilize the light and heat resources
which would otherwise be wasted in the winter season (Chen et al. 2021). Second, the management of the winter crops might
affect the growth of the following main summer crop (Huang et al. 2006). In this study, rotation systems are more productive
than rice-fallow, mostly due to the winter crops utilization on light and
temperature resources. The annual yield and biomass advantages of rice-wheat
and rice-rape were mainly resulted from the significantly increased radiation
and temperature use efficiency (Table 1). Because of no difference was found
for rice grain yields, the yield based light and heat
utilization indices such as radiation production efficiency and accumulative
temperature production efficiency in the rice seasons were not significantly
affected by rotation in this study. When it comes to the winter season, wheat had
a greater potential than rape in improving light and temperature resources.
CH4 and N2O emissions are
closely related to farming system changes including crop species, fertilizer
application, water management and straw returning in paddy fields (Yao et al. 2017; Sumaira
et al. 2019; Zhao et al. 2020). The CH4
emission peaks observed in this study were similar with those measured in other
studies based on cropping system management (Zhang et al. 2015; Xu et al.
2016), when the paddy soil was flooded and the rice plants were at a rapid
growing stage. Winter rotation coupled with winter crops straw incorporation
didn't change the CH4 emission trend during the rice season.
However, the seasonal CH4 emission flux was dramatically different
among different winter rotations when compared with fallow. The increased CH4
emission for rice-wheat ranged 26.5–64.0% for the rice season and 29.1–55.6%
for the whole year, respectively. The promoted CH4 emission could be
attributed to the enhanced above ground biomass yield of wheat and a larger
quantity of straw returning into the soil after wheat harvest (Ma et al. 2009). Organic material
incorporation, especially those with a high C/N ratio, provided available
carbon substrate for CH4 production methanogens.
Similar with CH4 emission, N2O
emission flux was smaller in the winter seasons than in the rice seasons,
possibly due to the lower temperature. N2O production and emission
from paddy soils are mainly happened during the processes of nitrification and
denitrification (Wang et al. 2016).
Crop rotations associated with different organic carbon and nitrogen management
could change the substrate availability and the activity of functional
microorganisms. Rice-wheat increased N2O emission in the rice
seasons while no significant difference for rice-rape and rice-fallow. The
reason could be explained by the difference in the quality and quantity of
straw returning into the soil followed by different winter crops.
Global warming potential could be a useful
indicator to investigate integrative effects of different greenhouse gases from
agricultural systems. The relationship of food production and greenhouse gases
emission could be further measured by introducing the yield-scaled GWP. In
spite that the global warming potential of N2O is approximately 12
times larger than that of CH4, the average CH4 emissions
was nearly 35 times that of N2O, resulting in the major contribution
for GWP from CH4 emission (Table 2). Because of a significant
increase of CH4 emission, the GWP values were highest in rice-wheat,
followed by rice-fallow and rice-rape. The yield-scaled GWP was decreased by
rice-rape because of its lower CH4 emission.
Conclusion
Annual grain yield, radiation and heat resources
utilization and their production efficiency were improved by rotation with
winter crops. The CH4 emission from paddy soils as well as
yield-scaled GWP was increased by rice-wheat and decreased by rice-rape system.
These results suggested rice-rape could be more sustainable cropping pattern to
increase solar radiation and heat resources utilization and mitigate greenhouse
gases emission.
Acknowledgements
This work was
supported by the National Key Program of Research & Development of China
(2017YFD0301400), National Natural Science Foundation of China (No. 31870424),
Hubei Key Program of Research and Development (No. 2020BBA044, 2020BBB089).
Author Contributions
Gong Songling: Initial
draft and data analysis; Li Chengwei: Data
collection; Liu Zhangyong: Data analysis method; Zhu
Bo: Framework and overall idea of the paper.
Conflicts of Interest
The authors
declare there is no conflict of interest regarding the publication of this
paper.
Data Availability
The data will be
available upon reasonable request to the corresponding author.
Ethics Approval
Not applicable.
References
Armstrong EL, DP Heenan, JS Pate, MJ Unkovich (1996). Nitrogen benefits of lupins, field pea,
and chickpea to wheat production in south-eastern Australia. Crop Past Sci 48:39‒48
Chang Q, J Wang, WD Yu, N Wang, MX
Tan (2016). Tempo-spatial characteristics and impact factors of radiation use
efficiency of wheat-maize rotation system in Henan Province. Chin J Agrometeorol
37:316‒325
Chen ZK, P Li, SS Jiang, HY Chen, JP Wang, CG Cao (2021). Evaluation of
resource and energy utilization, environmental and economic benefits of rice
water-saving irrigation technologies in a rice-wheat rotation system. Sci Total Environ 24; Article 143748
Chang Q, J Wang, WD Yu, N Wang, MX
Tan (2016). Tempo-spatial characteristics and impact factors of radiation use
efficiency of wheat-maize rotation system in Henan Province. Chin J Agrometeorol
37:316‒325
Congreves KA, DC Hooker, A Hayes A,
EA Verhallen, LLV Eerd
(2017). Interaction of long-term nitrogen fertilizer application, crop
rotation, and tillage system on soil carbon and nitrogen dynamics. Plant Soil 410:113‒127
Du X, L Kong, M Xi, W Wu, J Chen, W Yue (2019).
Characteristics of resource allocation and utilization of rice-wheat double
cropping system in the Jianghuai area. Chin J Ecol Agric 27:1078‒1087
FAO - Food and Agriculture Organization statistical database (2019). Agricultural data available @ http://faostat3.fao.org
Huang GQ, YM Xiong, HY Qian, SB Wang, LW Liu, QG
Zhao (2006). Ecological analysis on crop rotation systems of paddy field. Acta Ecol Sin 26:1159‒1164
IPCC (2007). Climate Change 2007: The Physical Science
Basis Contribution of Working Group I to the Fourth Assessment Report of the
IPCC, p:104. Cambridge University Press, New York, USA
Jia Q, R Xu,
S Chang, C Zhang, Y Liu,W
Shi, Z Peng, F Hou (2020). Planting practices with nutrient strategies to improves
productivity of rainfed corn and resource use efficiency in semi-arid regions. Agric Water Manage 228; Article 105879
Kamp T, H Steindl, JC Munch (2001). Monitoring
trace gas fluxes (N2O, CH4) from different soils under
the same climatic conditions and the same agricultural management. Phyton 41:119‒130
Liu XJ, FS Zhang (2011). Nitrogen fertilizer
induced greenhouse gas emissions in China. Curr Opin Environ Sustain 5:407‒413
Ma J, E Ma, H Xu, K Yagi, ZC Cai (2009). Wheat straw management affects CH4
and N2O emission from rice fields, Soil Biol Biochem 41:1023‒1028
Machado PVF, RE Farrell, W Deen, RP Voroney, C Wagner-Riddle (2021). Contribution of crop
residue, soil, and fertilizer nitrogen to nitrous oxide emissions varies with
long-term crop rotation and tillage. Sci
Total Environ 767:145107
Mer JL, P Roger (2001) Production, oxidation, emission and consumption
of methane by soils: A review. Eur J Soil
Biol 37:25‒50
Mosier AR, AD Halvorson, CA Reule,
XJ Liu (2006). Net global warming potential and greenhouse gas intensity in
irrigated cropping systems in northeastern Colorado. J Environ Qual
35:1584‒1598
Nie J, L Yi, H Xu, Z Liu, Z Zeng, D Paul, WK George, AH Bruce, B Zhu (2019). Legumious cover crop Astragalus
sinicus enhances grain yields and nitrogen use
efficiency through increased tillering in an intensive double-cropping rice
system in southern China. Agronomy 9;
Article 554
Shang QY, XX Yang, CM Gao, PP Wu, JJ Liu, YC Xu, QR Shen, JW Zou, SW
Guo (2011). Net annual global warming potential and greenhouse gas intensity in
Chinese double rice-cropping systems: A 3-year field measurement in long-term
fertilizer experiments. Glob Change Biol
17:2196–2210
Smith P, D Martino, Z Cai, D Gwary, HH Janzen,
P Kuma, B McCarl, S Ogle, F O’Mara, C Rice, RJ Scholes,
O Sirotenko, M Howden, T
McAllister, G Pan, V Romanenkov, S Rose, U Schneider,
S Towprayoon (2007). Climate change 2007: Mitigation of climate change: contribution of
Working Group III to the Fourth Assessment Report of the Intergovernmental
Panel on Climate Change, Vol. 45, pp:497–540. Cambridge University Press,
Cambridge, UK and New York, USA
Sumaira H, T Jin, ZY Liu, B
Zhu, JW Nie, J Zhu (2019). Effects of land use
conversion from upland to paddy field on ammonia-oxidizing archaeal and
ammonia-oxidizing bacterial communities in Jianghan
plain, Hubei Province, China. Intl J
Agric Biol 21:421‒428
Sun LY, YC Ma, B Li, C Xiao, LX Fan, ZQ Xiong
(2018). Nitrogen fertilizer in combination with an ameliorant mitigated
yield-scaled greenhouse gas emissions from a coastal saline rice field in
southeastern China. Environ Sci Pollut Res 25:15896–15908
Taveira CJ, RE Farrell, C Wagner-Riddle, PVF Machado, KA Congreves (2020).
Tracing crop residue N into subsequent crops: Insight from long-term crop
rotations that vary in diversity. Field Crop Res 255:107904
Tellez-Rio A, A Vallejo, S García-Marco, D Martin-Lammerding, JL Tenorio, RM Rees, G Guardia (2017). Conservation
agriculture practices reduce the global warming potential of rainfed low N
input semi-arid agriculture. Eur J Agron 84:95‒104
Wang ML, RG Hu, JS Zhao, Y Kuzyakov, SR Liu
(2016). Iron oxidation affects nitrous oxide emission via donating electrons to denitrification in paddy soils. Geoderma 271:174‒180
Xu Y, M Zhan, CG Cao, SY Tian, JZ Ge, SY Li, MY Wang, GY Yuan (2016).
Improved water management to reduce greenhouse gas emissions in no-till
rapeseed–rice rotations in Central China. Agric Ecosyst Environ 221:87‒98
Yao Z, G Yan, X Zheng, R Wang, C Liu, K Butterbach-Bahl
(2017). Straw return reduces yield-scaled N2O plus NO emissions from
annual winter wheat-based cropping systems in the North China Plain. Sci Environ 509:174‒185
Yu Y, L Xue, Y Yang (2014). Winter legumes in
rice crop rotations reduces nitrogen loss, and improves rice yield and soil
nitrogen supply. Agron Sustain Dev 34:633‒640
Zhang T, Y Huang, X Yang (2013). Climate warming over the past three
decades has shortened rice growth duration in China and cultivar shifts have
further accelerated the process for late rice. Glob Change Biol 19:563‒570
Zhang ZS, LJ Guo, TQ Liu, CF Li, CG Cao (2015). Effects of tillage
practices and straw returning methods on greenhouse gas emission and net
ecosystem economic budget in rice-wheat cropping systems in central china. Atmos Environ 122:636‒644
Zhao YH, XB Wang, XB Zha, CY Feng, JG Yu, JG
Jiao, X Xiao (2020). Effects of plow tillage and different water and fertilizer
management methods on the soil properties and rice yields of paddy under wheat
straw returning. J Agric Res Environ 37:195‒201
Zhou YL, B Sun (2017). Nitrogen use efficiency of rice under cadmium
contamination: Influence of rice cultivar versus soil type. Pedosphere
27:1092‒1104
Zhu B, L Yi, H Xu, L Guo, Y Hu, Z Zeng, F Chen, Z Liu (2016).
Non-leguminous cover crop and nitrogen rate in relation to double rice grain
yield and nitrogen uptake in Dongting Lake Plain,
Hunan, China. J Integr
Agric 15:2507‒2514