GIES Case Study on Liuhe Rice Permanent Basic Farmland,
Jilin Province of China
ZHAO Ling¹ GAO Jiayu¹ WEI Jiaxin¹ YUE Yuxuan2 GU
Xiaohui3
ZHANG Qiong4 DONG Jiwei3 TAO Yuan3 LI Qiang5 GONG Wanming6 AN Fenghong7 ZOU Lixin8 WANG Maohua9 ZONG Guoli10 QIAN Jiaqi11 QIN Yong12 ZHANG Minglu13 GUO Ruiguang14 YAN
Hongwei15
LI Dajing16 WANG Jun17 LIU Tiecheng18 CAO Dan19 SHI Yu20* MENG Xiangjun21*
YU Yunbo22 HOU Zhengfa23 GUAN Yanli24 ZHANG Xicai25 YU Hongjun26
LI Bin27 QIN
Zhishuang¹ TANG
Duanwu1
ZHAO Zizheng1
1.Jilin Agricultural University, Changchun 130118, China; 2.The People's Government of Liuhe County, Jilin Province, Liuhe 135399, China; 3.The Market Regulation Bureau of Liuhe County, Jilin Province, Liuhe 135399, China; 4.The Agricultural Technology Extension Station of Liuhe County, Jilin Province, Liuhe 135199,China; 5.The People's Government of Liuhe Town, Liuhe County, Jilin Province, Liuhe 135300, China; 6.The People's Government of Xiangyang Town, Liuhe County, Jilin Province, Liuhe 135305, China; 7.The People's Government of Ankou Town, Liuhe County, Jilin Province, Liuhe 135304, China; 8.The People's Government of Shengshui Town, Liuhe County, Jilin Province, Liuhe 135308, China; 9.The People's Government of Hengtong Town, Liuhe County, Jilin Province, Liuhe 135307, China; 10.The People's Government of Sanyuanpu Korean Town, Liuhe County, Jilin Province, Liuhe 135321, China; 11.The People's Government of Wudaogou Town, Liuhe County, Jilin Province, Liuhe 135319, China; 12.The People's Government of Hongshi Town, Liuhe County, Jilin Province, Liuhe 135325, China; 13.The People's Government of Tuoyaoling Town, Liuhe County, Jilin Province, Liuhe 135311, China; 14.The People's Government of Liunan Township, Liuhe County, Jilin Province, Liuhe 135323, China; 15.The People's Government of Gushanzi Town, Liuhe County, Jilin Province, Liuhe 135312, China; 16.The People's Government of Liangshuihezi Town, Liuhe County, Jilin Province, Liuhe 135317, China; 17.The People's Government of Luotongshan Town, Liuhe County, Jilin Province, Liuhe 135315, China; 18.The People's Government of Shijiadian Township, Liuhe County, Jilin Province, Liuhe 135314, China; 19.The People's Government of Jiangjiadian Korean Township, Liuhe County, Jilin Province, Liuhe 135316, China; 20.Jilin Academy of Agricultural Sciences (Northeast Innovation Center of Chinese Academy of Agricultural Sciences), Changchun 130033, China; 21.Jilin University of Finance and Economics, Changchun 130117, China; 22.Liuhe County Jiangjiadian Frog Field Rice Industry Co., Ltd., Jilin Province, Liuhe 135316, China; 23.Jilin Liuhe Guoxin Sheji Shangpin Agricultural Development Co., Ltd.,Liuhe 135306, China; 24.Jilin Province Liuli Grain Co.Ltd., Liuhe 135119, China; 25.Sijiazi Village, Jiangjiadian Korean Ethnic Township, Liuhe County, Jilin Province, Liuhe 135316, China; 26.Liuhe County Jiangjiadian Fengtian Rice Industry Co., Ltd., Jilin Province, Liuhe 135316, China; 27.Liaoning University, Shenyang 110036, China.
Abstract：The Changbai Mountain
basalt platform constitutes a rare volcanic agricultural ecological unit in
China. Located in the hinterland of the Longgang Mountains, Liuhe County
features parent materials of volcanic ash derived from the weathering of
Cenozoic basalt, irrigation with natural mineral water, a cool monsoon climate,
and an ecological background with high vegetation coverage. Endowed with
superior natural conditions, it produces nutrient-rich, safe and clean volcanic
ash-derived rice, which serves as the core resource foundation for the national
geographical indication certification trademark of "Liuhe Rice". Taking
Liuhe County as the research area, this study systematically elaborates the
nutritional quality and safety advantages of volcanic ash-derived rice based on
data including regional landform, meteorology, water quality, soil conditions,
cultivar characteristics, rice detection indicators and socio-economic
statistics. It further constructs a sustainable development model integrating
habitat protection, green production, whole-industry chain management, brand
operation and technological empowerment. The results show that the irrigation
water in Liuhe County is rich in calcium and magnesium; the local soil contains
abundant organic matter and mineral elements, with heavy metal contents far
below the national risk screening values. The local rice is enriched with
calcium, magnesium, phosphorus, selenium and other nutritional elements, with
lead and cadmium undetected or at extremely low levels, presenting significantly
better nutritional value and safety performance than conventional rice. Through
ecological redline regulation, soil conservation, green planting and breeding,
standardized production, traceability monitoring and integrated
agriculture-culture-tourism development, the county has realized the
coordinated development of rare habitat protection and industrial quality &
efficiency improvement. This study provides a scientific basis and practical
model for ecological conservation, value realization of characteristic
agricultural products and rural revitalization in volcanic rock areas. The case
dataset covers geographic location data, physical geographic data, rice
cultivar information, operation and management data, as well as photographic
and image materials of the study area. The dataset is stored in SHP, TIF, XLSX,
DOCX and JPG formats, with an original data volume of 205 MB and a compressed
size of 80.8 MB in a single archived file.
Keywords:
Liuhe County; rice; permanent farmland; volcanic
ash matrix; GIES; Case 38
DOI:
https://doi.org/10.3974/geodp.2026.04.02
CSTR: https://cstr.escience.org.cn/CSTR:20146.14.2026.04.02
1 Introduction
Against the backdrop of consumption upgrading and the in-depth
advancement of the rural revitalization strategy, the protection and
sustainable development of high-quality geographical indication products have
become a major focus of market attention[1].
As a crucial ecological barrier and species gene bank in China, the Changbai Mountains boast unique geological,
geomorphological and climatic conditions, fostering a wide variety of
agricultural products with distinct regional characteristics, among which volcanic
ash matrix rice is a typical representative.
Liuhe County is situated in the hinterland of the Longgang Mountains
within the Changbai Mountain Nature Reserve, where
basalt landforms formed by Cenozoic volcanic activities are widely distributed.
After long-term weathering, these volcanic rocks have gradually evolved into
special mineral-rich soils. Combined with irrigation from natural mountain
springs of the Changbai Mountain branches, as well as
sufficient sunlight and large diurnal temperature differences brought by the
temperate continental monsoon climate, rice growth remains stable and premature
senescence in late autumn is effectively avoided. These superior conditions
jointly endow Liuhe volcanic ash matrix rice with unique quality attributes. As
a traditional agricultural region, Liuhe County is free from large-scale
industrial pollution sources in its surrounding areas. With a forest coverage
rate of 56.8%, it maintains a relatively intact ecosystem, creating an ideal
natural growth environment for volcanic ash matrix rice.
Nevertheless, with the continuous growth of market demand, the volcanic
ash matrix rice industry is confronted with multiple development challenges.
These include: protecting the fragile volcanic ash ecosystem and preventing
soil degradation and water pollution while expanding cultivation scales;
improving product added value and enhancing market competitiveness through
standardized production and brand building; and establishing a scientific data
monitoring system to underpin the sustainable development of the industry.
In response to the national development philosophy of “lucid waters and
lush mountains are invaluable assets” and to facilitate the high-quality
development of characteristic agriculture in the Changbai
Mountain region, this study takes volcanic ash matrix rice in the Liuhe
production area as the research object. It aims to provide practical references
for the ecological protection and sustainable utilization of volcanic ash
matrix rice resources in the Changbai Mountains
through typical case analysis.
2 Introduction to Dataset Metadata
The basic information of Case Dataset of
Geographical Indication Habitat for Liuhe Rice on Changbai
Mountain Basalt Platform with Volcanic Ash Substrate[2],
including dataset title, authors, geographical coverage, data period, data
composition, data publishing and sharing platform, as well as data sharing
policy, is summarized in Table 1.
Table 1 Brief Metadata Table of Case Study
on Habitat Protection and Sustainable Development of Liuhe Rice with Volcanic
Ash Matrix on the Basalt Platform of Changbai
Mountain
|
Entries |
Descriptions |
|
|
Dataset Name |
Case Study on Habitat Protection and Sustainable Development of
Volcanic Ash-Based Rice in the Changbai Mountain
Platform of Liuhe |
|
|
Dataset Short
Name |
Liuhe Volcanic Ash-Based Rice |
|
|
Author
Information |
|
|
|
Geographic Region |
Liuhe County, Tonghua City, Jilin Province |
|
|
Data Time Period |
2000-2024 |
|
|
Data Format |
.shp 、.tif、.xlsx 、.docx
、.jpg |
|
|
Data Volume |
80.8 Mb |
|
|
Dataset Composition |
Case Study Area Location Data,
Physical Geographic Data, Rice Variety Characteristic Data, Operation and
Management Data, Photos and Images |
|
|
Publication and Sharing Service
Platform |
Global Change Research Data
Publishing System(http://www.geodoi.ac.cn) |
|
|
Address |
No. 11A, Datun
Road, Chaoyang District, Beijing 100101, Institute of Geographic Sciences and
Natural Resources Research, Chinese Academy of Sciences |
|
|
Data Sharing Policy |
(1) The
"Data" is made openly available to the whole society via the
internet system in the most convenient manner, allowing users to freely
browse and download it free of charge; (2) End users
utilizing the "Data" must cite the data source according to the
prescribed citation format in references or an appropriate location; (3) Users of
value-added services or those disseminating and distributing the
"Data" in any form (including via computer servers) are required to
sign a written agreement with the Editorial Office of the *Journal of Global
Change Data* to obtain permission; (4) Authors
creating new data by extracting partial records from the "Data"
must adhere to the 10% citation principle. This means that data records
extracted from this dataset should constitute less than 10% of the total
records in the new dataset, and the source of the extracted data records must
be duly acknowledged[3]. |
|
|
Data and Paper Retrieval System |
DOI，CSTR，Crossref，DCI，CSCD，CNKI，SciEngine，WDS，GEOSS，PubScholar， CKRSC |
3 Case Area Overview
3.1 Scope of the Study
Area
The case area of this study is Liuhe County (Figure 1). Located in the
southeastern part of Jilin Province and the northwest of Tonghua
City, Liuhe County lies between 41°54′N–42°35′N and 125°17′E–126°35′E, in the
transitional zone from the Changbai Mountains to the Songliao Plain, with a distance of 260 km from the main
body of the Changbai Mountains. It covers a total
land area of 3,348 km², and administratively governs 15 townships, 3
sub-districts and 219 administrative villages.
Figure 1 Geographical Location Map of the Case Area
（Referencing the standard map with the map examination approval number Ji
S (2019) 047）.
3.2 Characteristics of Terrain and Geomorphology
Liuhe County is located in the transitional zone between the Changbai Mountains and the Songliao
Plain. The terrain is generally high in the southeast and southwest and low in
the northeast, showing an overall tilting pattern from the southwest and
southeast toward the northeast. The landforms are dominated by low and medium
mountains, volcanic lava platforms, and river valley basins. The low and medium
mountains, mostly distributed in the south-central and southeastern parts of
the county, have an altitude ranging from 400 m to 1000 m, with the highest
peak reaching 1293 m. The lava platforms, accounting for 5% of the total county
area, are concentrated in the southeastern county territory as part of the
Longgang Volcanic Group, featuring relatively flat ground and steep slopes at
the edges. River valley basins occupy 15% of the total area and are distributed
along the Yitong River, Santong River, Hani River, Woji River and other water systems. With flat terrain and
fertile soil, these areas serve as the core agricultural regions of Liuhe
County (Figure 2-3).
Figure 2 Figure
Elevation Classification Map of the Case Area
Figure 3 Figure X Slope Classification Map
of the Case Area
3.3 Land Use and Land
Cover (LULC)
Landsat 5 and Landsat 9 data of the study area were obtained from the
Geospatial Data Cloud[1], and the
Normalized Difference Vegetation Index (NDVI) was calculated..
The land use and vegetation distribution in Liuhe County present distinct
spatial differentiation characteristics. The low and medium mountainous areas
are dominated by forest land with high vegetation coverage, acting as a crucial
ecological barrier. The lava platform areas enjoy improved vegetation coverage
and favorable hydrothermal conditions, which are suitable for the development
of characteristic agriculture such as rice planting. The river valley basins
maintain relatively stable vegetation coverage and serve as the major
agricultural production areas.
Cultivated land in Liuhe County is predominantly covered by thin
volcanic ash soil with a single cropping system per year, belonging to the
grain production zone in the black soil transition belt. The high Normalized
Difference Vegetation Index (NDVI) in the study area (Figure 4) reflects
superior ecological background conditions and vigorous growth of paddy field
vegetation. High vegetation coverage effectively maintains the stability of
paddy field ecosystems, reduces the risks of soil erosion and non-point source
pollution, and further forms a unique habitat support system composed of
"basalt platform + volcanic ash substrate + wetland and reservoir
groups"(Figure 5).
Figure 4 Vegetation
Index Classification Map of the Case Area
Figure 5 Land Use Map of the Case
Area
3.4 Meteorological
Characteristics
Liuhe County features a temperate continental
monsoon climate, with climatic conditions highly suitable for the growth of
high-quality japonica rice. The synchronization of rainfall and heat in summer
facilitates vigorous rice growth and dry matter accumulation. A large diurnal
temperature range in autumn promotes the translocation of photosynthates to
grains and enhances the synthesis of starch and flavor substances. Although
there is no rice cultivation in the long, cold and snowy winter, low temperatures
effectively reduce the overwintering population of pests and diseases and lower
reliance on pesticides.
In this region, the average temperature in
January is -15.001 ℃, and the average temperature in July is 21.548 ℃.
The annual precipitation totals 736.3 mm, mostly concentrated from June to
August. The annual sunshine duration reaches 2,560 hours, including 1,160 hours
during the rice growth period. The active accumulated temperature ≥10
℃
ranges from 2214 ℃ to 2948 ℃, with a
frost-free period of 130–140 days (Figure 6）[2]; data from Liuhe Meteorological Bureau). The
relatively short frost-free period exerts selective pressure for early-maturing
rice varieties, concentrates the grain-filling stage within the period with
optimal light and heat conditions, and comprehensively improves the taste
quality and safety of Liuhe rice.
|
|
|
|
|
|
Figure 6 Climate Characteristics
Change Map of the Case Area
3.5 Water Quality
Characteristics
The case area is rich in
water resources, with 3 medium-sized reservoirs and 97 small reservoirs. More
than 60 rivers of varying sizes originate from the Changbai
Mountains, covering a water area of 7,600 hm², and the average annual
total water resource volume reaches 1.28 billion m³.
The unique hydrological system characterized by abundant water yield, clean
water quality, mineral replenishment and precise water regulation not only
meets the physiological water demand of rice, but also promotes dry matter accumulation.
It serves as a critical ecological foundation for the distinctive properties of
Liuhe rice, including green production, high quality and calcium enrichment.
A total of 11 water
samples were collected from paddy fields, irrigation canals and sunning water
ponds in the study area (Figure 7).
Figure 7 Spatial distribution of
water sampling sites in the study area
Water quality test results (Table 3)
indicated that the pH value ranged from 6.99 to 7.57, and the electrical
conductivity varied from 90.5 to 420 μS/cm. The
calcium and magnesium contents were 5844-63018 μg/L
and 1908-20605 μg/L, respectively. The local water is
rich in minerals and presents a low-salinity, neutral to weakly alkaline
condition, which fundamentally guarantees rice safety and the formation of
mineral-rich nutritional characteristics.
Table 3 Detection Data of Nutrient
Substances in Water Quality of the Study Area
|
Samples |
pH |
Total Water-Soluble Salt Content (Electrical
Conductivity at 25°C) (μS/cm) |
Mg |
P |
K |
Ca |
Mo |
Mn |
Fe |
|
Sample1 |
7.57 |
153 |
7384 |
24.7 |
1380 |
9411 |
1.2 |
0.95 |
118 |
|
Sample2 |
7.38 |
110 |
5301 |
42.1 |
586 |
5844 |
0.72 |
0.982 |
432 |
|
Sample19 |
7.04 |
173 |
5646 |
27.3 |
1109 |
15505 |
0.71 |
1.340 |
167 |
|
Sample21 |
7.30 |
188 |
9260 |
55.4 |
901 |
13648 |
0.99 |
1.160 |
101 |
|
Sample22 |
7.28 |
167 |
5574 |
38.5 |
978 |
15927 |
0.23 |
0.770 |
162 |
|
Sample23 |
7.12 |
90.5 |
1908 |
61.8 |
1871 |
6785 |
0.46 |
3.110 |
449 |
|
Sample24 |
6.99 |
414 |
20605 |
45.6 |
369 |
63018 |
0.83 |
2444 |
231 |
|
Sample25 |
7.37 |
420 |
18163 |
67.0 |
452 |
54753 |
0.78 |
11.700 |
71 |
|
Sample26 |
7.45 |
316 |
9239 |
58.8 |
1914 |
44909 |
1.69 |
5.510 |
80 |
|
Sample27 |
7.48 |
327 |
8146 |
69.1 |
426 |
41162 |
0.55 |
3.700 |
164 |
|
Sample28 |
7.48 |
256 |
8286 |
47.7 |
660 |
32305 |
1.11 |
1.830 |
52 |
Explanation
of Sample Numbers:Water
samples in this study were collected in multiple batches, with samples from
each batch numbered independently according to the sampling sequence. Thus, the
sample IDs are non-consecutive, and this numbering scheme does not affect the
reliability of subsequent statistical analyses or conclusions.
Among the 11 tested water samples, the concentrations of all hazardous
substances were far below the limit values specified in the national Farmland
Irrigation Water Quality Standard (GB 5084-2021) (Table 4).
Table 4 Heavy Metal Detection Data of
Water Environment in the Study Area
|
Samples |
Cr |
Ni |
Cu |
Zn |
As |
Se |
Cd |
Hg |
Pb |
|
Sample1 |
0.286 |
0.8 |
0.84 |
Not Detected |
0.78 |
0.378 |
Not Detected |
0.276 |
0.05 |
|
Sample2 |
0.41 |
1.34 |
1.16 |
Not Detected |
0.93 |
0.444 |
Not Detected |
0.194 |
0.141 |
|
Sample19 |
0.185 |
1.05 |
0.69 |
Not Detected |
1.01 |
0.185 |
Not Detected |
0.087 |
0.094 |
|
Sample21 |
0.278 |
1.35 |
1.36 |
Not Detected |
1.28 |
0.170 |
Not Detected |
0.090 |
0.107 |
|
Sample22 |
0.232 |
0.57 |
2.49 |
Not Detected |
1.07 |
0.064 |
Not Detected |
0.089 |
Not Detected |
|
Sample23 |
0.741 |
0.90 |
3.65 |
0.97 |
1.46 |
1.08 |
Not Detected |
0.089 |
0.094 |
|
Sample24 |
0.263 |
2.46 |
2.88 |
0.883 |
2.31 |
0.438 |
Not Detected |
0.100 |
Not Detected |
|
Sample25 |
0.123 |
1.22 |
2.55 |
Not Detected |
4.73 |
0.118 |
Not Detected |
0.092 |
Not Detected |
|
Sample26 |
0.386 |
0.71 |
4.42 |
Not Detected |
1.88 |
0.322 |
Not Detected |
0.088 |
Not Detected |
|
Sample27 |
0.316 |
0.45 |
2.23 |
Not Detected |
1.36 |
0.023 |
Not Detected |
0.086 |
Not Detected |
|
Sample28 |
0.299 |
0.70 |
3.03 |
Not Detected |
1.51 |
0.096 |
Not Detected |
0.086 |
Not Detected |
|
Basic Control Limits for Farmland
Irrigation Water Quality[4] |
≤100 |
≤200 |
≤500 |
≤2000 |
≤50 |
≤20 |
≤10 |
≤1 |
≤200 |
Explanation of Sample Numbers:Water samples in this
study were collected in multiple batches, with samples from each batch numbered
independently according to the sampling sequence. Thus, the sample IDs are
non-consecutive, and this numbering scheme does not affect the reliability of
subsequent statistical analyses or conclusions.
3.6 Soil Characteristics
Liuhe County features a
unique volcanic landform. Basalt magma upwelled through massive crustal
fractures, forming the extensive Changbai Mountain
basalt platform. In this study, nine soil samples were collected from
concentrated rice cultivation fields in the case area (Figure 8). The
determination of trace element contents in soil samples was conducted by the
Jilin Academy of Agricultural Sciences (Northeast Innovation Center for
Agricultural Science and Technology of China).
Figure 8 Distribution of
soil sampling sites in the study area
The soil samples
exhibited a pH range of 5.36–6.26, soil organic
matter of 11.7-34.3 g/kg, and total potassium content of 18280-24570 mg/kg.
Contents of calcium, magnesium, iron and manganese were sufficient (Table 5).
Specifically, the calcium concentration was significantly higher than that in
conventional paddy soils. From the perspective of growth regulation, calcium
strengthens the cell wall structure of rice plants and improves lodging
resistance and disease resistance. Accordingly, the calcium content of Liuhe
rice is considerably higher than that of common rice, greatly enhancing its
nutritional value. As a core component of chlorophyll, magnesium can
effectively promote photosynthetic efficiency.
Table
5 Soil
Nutrient Detection Data of the Study Area
|
Elements |
Soil 21 |
Soil 22 |
Soil 23 |
Soil 24 |
Soil 25 |
Soil 26 |
Soil 27 |
Soil 28 |
Soil 19 |
Average Value |
|
pH |
5.36 |
5.78 |
5.80 |
5.90 |
5.68 |
6.08 |
5.89 |
6.26 |
5.93 |
5.85 |
|
OM（g/kg) |
27.40 |
20.60 |
31.00 |
20.70 |
17.10 |
20.00 |
26.30 |
11.70 |
34.3 |
23.23 |
|
TN (mg/kg) |
1690 |
1940 |
2570 |
2110 |
2140 |
2710 |
1740 |
2160 |
1950 |
2112.22 |
|
TP (mg/kg) |
1130 |
830 |
1080 |
930 |
940 |
1210 |
970 |
760 |
843.3 |
965.92 |
|
TK (mg/kg) |
20610 |
19500 |
20090 |
19630 |
20290 |
18280 |
24570 |
18950 |
19200 |
20124.44 |
|
Mg (mg/kg) |
6449 |
7974 |
9074 |
6726 |
8081 |
11867 |
8309 |
8042 |
8336 |
8317.56 |
|
Ca (mg/kg) |
4336 |
3577 |
4058 |
2940 |
5546 |
25358 |
10707 |
4396 |
4156 |
7230.44 |
|
Mn (mg/kg) |
679 |
473 |
368 |
439 |
828 |
549 |
509 |
563 |
533 |
549 |
|
Fe (mg/kg) |
34223 |
36100 |
36341 |
32428 |
31425 |
36376 |
36296 |
31910 |
33426 |
34280.56 |
Explanation of Sample
Numbers: Soil samples in this study were collected in multiple batches, with
samples from each batch numbered independently according to the sampling
sequence. Thus, the sample IDs are non-consecutive, and this numbering scheme
does not affect the reliability of subsequent statistical analyses or
conclusions.
In the nine soil
samples, the concentrations of chromium, nickel, copper, zinc, arsenic,
cadmium, mercury and lead were all far lower than the risk screening values
specified in GB 15618-2018. The average contents of copper, zinc and cadmium
were 27.8 mg/kg, 101.1 mg/kg and 0.24 mg/kg, accounting for only 55.6%, 50.5% and 62.2% of the
corresponding screening values, respectively. As shown in Table 6, the study
area presents excellent soil environmental quality with a clean and
pollution-free condition, which provides a fundamental guarantee for the safe
and high-quality production of rice grown on volcanic ash substrates.The extremely low contents of chromium and
nickel further confirm that no excessive heavy metals were dissolved when
surface water flowed through the basalt strata, demonstrating the stability and
safety of the volcanic rock filtration system. It is fully verified that
benefited from superior natural ecological conditions and unique volcanic
geology, local water sources are free from anthropogenic pollution. Such
high-quality water resources constitute one of the core cornerstones for
establishing the green, organic, safe and healthy brand positioning of volcanic
ash-derived rice.
Table 6 Statistical Table of Soil
Heavy Metal Contents in the Study Area
|
Elements |
Soil 21 |
Soil 22 |
Soil 23 |
Soil 24 |
Soil 25 |
Soil 26 |
Soil 27 |
Soil 28 |
Soil 19 |
Average
Value |
Agricultural
Land Soil Pollution Risk Screening Values [5] |
|
Cr(mg/kg) |
147.7 |
100.8 |
88.3 |
74.3 |
72.3 |
94.7 |
220.1 |
83.5 |
82.3 |
107.1
|
≤250 |
|
Ni(mg/kg) |
32.3 |
30.6 |
35.6 |
30.8 |
31.7 |
37.3 |
30.9 |
34.8 |
37.7 |
33.5
|
≤70 |
|
Cu(mg/kg) |
33.7 |
21.1 |
28.6 |
24.0 |
31.9 |
35.8 |
26.4 |
25.1 |
23.3 |
27.8
|
≤50 |
|
Zn(mg/kg) |
90.5 |
89.5 |
111 |
83.8 |
99.8 |
173 |
83.1 |
90.6 |
88.8 |
101.1
|
≤200 |
|
As(mg/kg) |
11.9 |
7.53 |
7.05 |
7.18 |
19.5 |
10.1 |
5.54 |
7.82 |
7.44 |
9.34
|
≤30 |
|
Cd(mg/kg) |
0.260 |
0.228 |
0.337 |
0.205 |
0.295 |
0.2 |
0.212 |
0.240 |
0.261 |
0.28
|
≤0.4 |
|
Hg(mg/kg) |
0.0682 |
0.0388 |
0.0421 |
0.0363 |
0.0425 |
0.0478 |
0.0217 |
0.0386 |
0.0511 |
0.043
|
≤0.5 |
|
Pb(mg/kg) |
30.8 |
26.3 |
29.1 |
23.6 |
29.9 |
47.4 |
21.1 |
25.3 |
25.1 |
28.7 |
≤100 |
Explanation of Sample Numbers:Soil samples in this study
were collected in multiple batches, with samples from each batch numbered
independently according to the sampling sequence. Thus, the sample IDs are
non-consecutive, and this numbering scheme does not affect the reliability of
subsequent statistical analyses or conclusions.
4 Nutritional Value and Product Characteristics of
Liuhe Rice
4.1 Main Cultivar
Characteristics
（1）
Wuyou Rice
No. 4
Wuyudao No.4 is a conventional
japonica rice variety with a late-maturing growth characteristic. It features
translucent rice grains and excellent eating quality. Cultivated with frequent
shallow water irrigation and alternate wetting and drying irrigation regimes,
this variety presents outstanding grain quality.
Its whole growth period
is 143 days, and it requires an active accumulated temperature of approximately
2850 ℃ above 10 ℃, belonging to the medium-late maturing type. The plant has a
compact plant type and erect flag leaves, with a plant height of 122.1 cm,
green stems and leaves, and strong tillering capacity. The effective panicle
number reaches 4.095 million panicles per hectare.With
a panicle length of 19.5 cm, it belongs to the curved panicle type, with an
average grain number per panicle of 115.8 and a seed setting rate of 78.4%. The
grains are spindle-shaped; the glumes and glume apices are yellow with rare
awns, and the 1000-grain weight is 27.7 g.
In accordance with the agricultural industry standard
NY/T593-2002 Quality of Edible Rice Varieties issued by the Ministry of
Agriculture and Rural Affairs, its quality indexes are as follows: brown rice
rate 84.7%, milled rice rate 72.7%, head rice rate 64.8%, grain length 6.3 mm,
length-width ratio 2.7, chalky grain rate 46.0%, chalkiness degree 7.0%,
transparency grade 1, alkali spreading value 7.0 grade, gel consistency 65 mm,
amylose content 16.6%, and crude protein content 7.30%. The rice quality meets
the grade-IV quality requirements for edible japonica rice varieties[7].
（2）
Zhongkefa Rice No. 5
Zhongkefa No. 5 is a conventional
japonica rice cultivar with a whole growth period of 150.1 days. Its plant
height is 102.8 cm, and the panicle length is 17.8 cm. The effective panicle
number reaches 4.095 million panicles per hectare, with 118.3 grains per
panicle, a seed setting rate of 79.9%, and a 1000‑grain weight of 26.9 g.
The comprehensive rice blast index was 2.0 and 2.4 in two consecutive years,
and the maximum neck blast loss rate reached Grade 5, indicating moderate
susceptibility to rice blast. The main grain quality indicators are as follows:
the head rice rate is 70.1%, the chalky grain rate is 6.0%, the chalkiness
degree is 1.8%, the amylose content is 16.1%, the gel consistency is 70 mm, and
the length‑width ratio is 3.0. The
grain quality meets the Grade‑II standard specified by
the agricultural industry standard Quality of Edible Rice Varieties [8].
This cultivar was awarded the Gold Medal in the japonica rice group at the
Fifth National High‑Quality Rice Evaluation.
Featuring high yield, strong lodging resistance, and stable excellent grain
quality, Zhongkefa No. 5 exhibits prominent
comprehensive advantages in large‑scale rice production in
volcanic ash substrate areas.
（3）
Jihong No. 6
Jihong No. 6 is a
medium-late maturing aromatic japonica rice variety belonging to the genus
Oryza in the Poaceae family. Its whole growth period
is about 138 days, with a plant height of 104 cm, panicle length of 17.3 cm,
and 1000-grain weight of 24.0 g. In terms of disease resistance, it shows
moderate resistance to seedling blast and leaf blast, and is susceptible to
panicle blast.In accordance with the agricultural
standard NY/T593-2002 Quality of Edible Rice Varieties formulated by the
Ministry of Agriculture and Rural Affairs, its grain quality indicators are as
follows: brown rice rate 82.6%, milled rice rate 74.3%, head rice rate 70.4%,
grain length 5.0 mm, length-width ratio 1.7, chalky grain rate 13.0%,
chalkiness degree 1.3%, transparency grade 1, alkali spreading value 6.7, gel
consistency 88 mm, amylose content 15.6%, and protein content 6.88%. The rice
quality complies with the quality requirements for Grade 2 edible japonica rice
varieties.
4.2 Product Quality Data
Two rice varieties were
sampled in this study. Rice Sample 1, labeled “Jitong”
for inspection, was randomly collected from family farms in Jiangjiadian
Township and identified as super rice (including Jihong
No. 6 and other small-grain varieties with similar agronomic traits. These
varieties are not distinguished during procurement, processing and sales, and
are collectively referred to as super rice). Rice Sample 2, labeled “Jiangdao”, was a mixed sample taken from family farms in Sijiazi Village of Jiangjiadian
Korean Ethnic Township, Watian Rice Industry and Guoxin Rice Industry, with the cultivar being Wuyou No. 4 (Daohuaxiang No. 2).
All samples were sent to the Institute of Agricultural Product Quality and
Safety, Heilongjiang Academy of Agricultural Sciences for testing, and the
results are presented in Table 7 and Table 8.
Rice samples from the study
area contained high levels of calcium, phosphorus and magnesium. The calcium
content ranged from 67.3 mg/kg to 71.6 mg/kg, phosphorus from 879 mg/kg to 907
mg/kg, and magnesium from 200 mg/kg to 211 mg/kg, which reflected the enrichment
effect of mineral elements in volcanic rock soil. In addition, trace elements
including zinc, manganese, iron and selenium were all detected, indicating the
unique advantages of volcanic ash‑matrix rice in trace element nutrition.
Magnesium is an essential mineral involved in hundreds of human biochemical
reactions, and plays a critical role in neuromuscular function maintenance as
well as blood glucose and blood pressure regulation. Accordingly, rice products
from this region show strong market competitiveness in terms of rich trace
element composition.
Table
7 Trace
Element (Nutrient) Test Data of Rice Samples in the Case Area
Unit:
mg/kg
|
Samples |
Sample 1 |
Sample 2 |
|
Ca |
71.6 |
67.3 |
|
K |
888 |
652 |
|
P |
907 |
879 |
|
Mg |
211 |
200 |
|
Mn |
12.3 |
11.3 |
|
Fe |
4.09 |
3.20 |
|
Zn |
12.9 |
13.3 |
|
Co |
0.00477 |
0.00438 |
|
Se |
0.043 |
0.097 |
|
Cu |
1.92 |
1.74 |
|
Mo |
0.426 |
0.436 |
|
Ti |
0.167 |
0.134 |
|
Si |
69.6 |
57.5 |
The
heavy metal contents in both rice samples complied with the limit requirements
specified in the National Food Safety Standard — Contaminant Limits in Food
(including Amendment No.1) (Table 8). It indicated that Liuhe County achieved
effective control of harmful elements without any excessive pollutants,
ensuring the edible safety of rice products. The local rice possesses favorable
edible safety as well as high nutritional and health value.
Table 8 Detection
Data of Safety and Sanitation Indicators for Rice Samples in the Study Area
Unit:
mg/kg
|
Samples |
JiTong |
JiangDao |
Limit Index for Pollutants in Food[6] |
|
Pb |
Not Detected |
Not Detected |
0.2 |
|
Cd |
0.0136 |
0.0164 |
0.2 |
|
Cr |
0.0911 |
0.0840 |
1.0 |
|
Ni |
Not Detected |
Not Detected |
/ |
|
As |
0.0993 |
0.128 |
0.35 |
|
Hg |
0.00552 |
0.00464 |
0.02 |
5 Socioeconomic
Development and Rice Industrial Operation and Management
5.1
Socioeconomic Conditions of Liuhe County
From 2020 to 2023, Liuhe County experienced continuous population
outflow, while its economic development level improved steadily and the
comprehensive agricultural production capacity was gradually enhanced. As a
traditionally advantageous and characteristic industry in Liuhe, the rice
industry relies on superior black soil resources and favorable ecological
conditions, and plays a vital role in quality improvement, efficiency
promotion, soil and water conservation, and planting structure optimization. By
reducing the scale of low-efficiency cultivation and developing high-quality
and high-end rice products, the industry has effectively accelerated the
high-quality development of county-level agriculture.
Table
9 Agricultural Economic Statistics of Liuhe County (2020–2023)[3]
|
|
resident population （ten thousand people） |
Gross Regional Product (100 million yuan) |
Gross Domestic Product per capita (yuan) |
Added Value of Primary Industry (100 million yuan) |
Grain Cultivated Area (ha) |
Grain Yield (107 kg) |
Rice Cultivated Area (ha) |
Rice Yield (107 kg) |
|
2020 |
35.39 |
79.92 |
22485 |
21.18 |
88350 |
56.68 |
20180 |
14.1 |
|
2021 |
26.49 |
82.74 |
30782 |
21.56 |
88400 |
57.7 |
18458 |
13.2 |
|
2022 |
25.53 |
88.83 |
34152 |
24.18 |
89439 |
58.4 |
16374 |
11.45 |
|
2023 |
25.19 |
92.27 |
36384 |
23.81 |
89664 |
59.4 |
16136 |
11.41 |
5.2 History and Heritage of Rice Production
According to historical
records, rice cultivation in Liuhe County originated in the early Tang Dynasty
(the early 7th century). In the 32nd year of the Guangxu reign of the Qing
Dynasty (1906),
irrigation canals were officially constructed to divert water for field
irrigation, and paddy fields began large-scale contiguous cultivation. During
this period, systematic water conservancy irrigation facilities and
standardized rice cultivation techniques were initially formed. Liuhe rice has
long been renowned both domestically and internationally for its full and plump
grain shape, crystal clear appearance, rich and mellow flavor, balanced
nutritional components, and pure natural taste. From the Song, Yuan, Ming to
Qing dynasties, Liuhe rice was designated as exclusive tribute rice for
successive royal courts, ranking equally with the three major treasures of
Northeast China (ginseng, mink fur, and pilose antler) and specially supplied
for royal consumption. After the founding of the People’s Republic of China, Liuhe rice, with its
unique and unparalleled edible quality and nutritional value, was selected as
special rice for state banquets in the Great Hall of the People.
As documented in the
Liuhe County Chronicles, more than 3,300 hectares of cultivated land had been
reclaimed when the county was officially established in 1902. The major food
crops included soybeans,
sorghum, corn, millet, wheat and
small red beans,
followed by rice, upland rice, barley, barnyard grass, buckwheat and mung beans. In the early stage
of county establishment, a number of Korean ethnic households migrated to Liuhe, introducing systematic
rice planting techniques and formally promoting local large-scale rice
cultivation.
In 1949, when the People’s Republic of China was
founded, the local rice planting area had reached 4,652 hm². The ancestors of the Korean ethnic group formed unique
ecological planting traditions adapted to local volcanic rock landforms over a
long period of production practice. They preferred local japonica rice
varieties with strong barren tolerance and excellent eating taste, adopted
organic manure as the main base fertilizer combined with a small amount of
chemical fertilizer to nourish volcanic ash soil, and followed traditional
solar terms for standardized farming: seed soaking in the Spring Equinox and
centralized harvesting in the Autumnal Equinox, forming a traditional
agricultural custom of arranging all field management activities according to
natural climate rhythms. In terms of irrigation, a combined open and hidden
canal system was constructed using natural fissure groundwater from volcanic rock
layers, with open canals for water diversion and underground ditches for
efficient drainage. Farmers abided by the ancient irrigation principle of
shallow irrigation during the tillering stage, deep water irrigation during the
booting stage, and field drying during the mature stage, realizing the
ecological water-saving mode of alternate wetting and shallow irrigation. In
terms of rice processing and daily consumption, the traditional custom of fresh
grinding and instant eating has been maintained. Stone milling technology is
adopted to retain natural nutritional components to the greatest extent. Brown
rice is used for nutritional porridge, and rice slurry is processed into
characteristic local delicacies. After autumn harvest, a traditional New Rice
Festival is held regularly, where villagers steam newly harvested rice and make
rice cakes to celebrate bumper harvests and inherit and respect traditional
farming civilization. In terms of cultural inheritance and technical promotion,
the traditional mode of experienced farmers teaching young growers is adopted
to pass down core ecological planting skills. Modern local agricultural
enterprises integrate ancient traditional farming experience with contemporary
advanced agricultural technologies, widely applying bio-organic fertilizers,
intelligent field environment monitoring equipment and standardized green cultivation
management modes. Meanwhile, characteristic agricultural culture exhibition
halls have been built and regular field technical training courses organized,
enabling the traditional volcanic ash substrate rice farming culture to be
innovatively inherited and revitalized in the modern agricultural era.
In
addition, Liuhe County has made positive progress in integrating the
inheritance of traditional cultivation techniques with modern technologies for
volcanic ash matrix rice. By holding fresh rice festivals and carrying out
agricultural technology training, the local government has not only protected
and inherited the century-old rice culture featured by volcanic ash matrix
cultivation, but also promoted the application of modern technologies in
traditional agriculture, injecting new impetus into the sustainable development
of the volcanic ash matrix rice industry.
5.3 Whole-process Quality Control of Rice Production
Liuhe County has
established a standardized planting and whole-process quality control system
for rice cultivated on volcanic ash substrates. An integrated management system
covering seedling raising, field cultivation, irrigation, fertilization, green
pest prevention, harvesting, processing, warehousing and quality inspection has
been formed. By implementing the "Six Unifications" management model,
classified harvesting and separate storage by cultivar are realized, and key
production links are traceable throughout the whole chain, so as to guarantee
the stable quality of local rice products.
5.3.1 Seed Treatment
Before seed soaking,
spread rice seeds evenly to a thickness of 5–7 cm and sun‑dry them for 2–3 days
under weak light, with turning 3-4 times per day. Fungicides are applied for
seed disinfection; the liquid level should be 15 cm above the seeds. The seeds
are soaked for 5–7 days with an accumulated temperature of 100 ℃ and stirred
twice daily. Seed coating agents can also be used as an alternative. During
germination acceleration, the seed pile thickness shall not exceed 50 cm, the
temperature is controlled at 28–30 ℃, and turning is conducted 3–4 times per
day. After 80% of the seeds break through the glume, the seeds are transferred
to a cool and shaded place for slow cooling and subsequent use.
5.3.2 Sowing
The greenhouse shall be
covered 15 days before sowing. The seedbed is shallowly tilled to a depth of
5–10 cm, and fully watered one day in advance. After sieving, the bed soil is
adjusted to a pH value of 4.5-5.5 for later use. Sowing is conducted in early
to mid-April using flat trays or bowl blanket seedling raising methods. For
machine-transplanting trays, 100–120 g of germinated seeds are
sown per tray; for manual-transplanting trays, the seeding rate is 60–80 g per
tray, and 4–6 seeds are placed in each bowl for bowl seedling cultivation.
5.3.3 Nursery Management
Precise phased
regulation is adopted for nursery management. From sowing to seedling
emergence, the seedbed shall be thoroughly watered in a timely manner in case
of water shortage. The plastic film shall be removed when the seedling
emergence rate exceeds 60%, and the greenhouse temperature shall be controlled
within 30 ℃. From seedling emergence to the 1.1-leaf stage, the greenhouse
temperature is maintained at 25 ℃-28 ℃ to keep the bed soil moist. During the
1.1-2.5 leaf stage, the temperature is kept at approximately 25 ℃, and moderate
ventilation is carried out on sunny days for seedling hardening. From the
2.5-leaf stage to transplanting, ventilation is increased when the minimum
nighttime temperature is higher than 10 ℃. The film is removed at night 7–10
days before transplanting to harden seedlings. Meanwhile, the
"three-belt" technical measures are implemented: 15–20 g of ammonium
sulfate is applied per square meter of seedbed; thiamethoxam is sprayed to
control rice leafminer; and Bacillus subtilis is
applied to promote seedling regreening and tillering.
5.3.4 Transplanting
Transplanting is carried
out from May 15 to 25 with a planting specification of 30 cm × (13-20 cm), with
17-25 hills per square meter. Uniform planting depth is maintained during
transplanting to avoid seedling bending and missing hills.
5.3.5 Field Management
Field management
strictly follows the principles of heavy base fertilizer application, nitrogen
reduction and delayed application of tiller fertilizer, and equal dosage of
panicle fertilizer and tiller fertilizer. For base fertilizer, 20–40 m³ of
decomposed farmyard manure is applied per hectare, combined with phosphorus
fertilizer, potassium fertilizer and zoned quantitative nitrogen fertilizer;
zinc sulfate is additionally applied in saline-alkali land. Tiller fertilizer
is applied in mid-June, and panicle fertilizer together with supplementary
potassium fertilizer is supplied in early to mid-July.
Differentiated zoned
irrigation is implemented throughout the growth period. Shallow water is
retained from transplanting to the tillering stage to protect seedlings and
promote tillering, and moderate field drying is conducted at the late tillering
stage. Intermittent shallow-wet irrigation and deep water
irrigation under low temperature are adopted from
young panicle differentiation to the milky ripe stage for panicle protection.
Alternating dry and wet conditions with nighttime irrigation are maintained from
the milky ripe stage to pre-harvest, and water supply is cut off one week
before harvesting, so as to ensure the stable growth of rice in the whole
growth cycle.
5.3.6 Pest, Disease and Weed Control
The prevention and control of diseases, pests and weeds follows the principle of prioritizing agricultural, physical
and biological control, with scientific chemical control as auxiliary measures,
and strictly abides by pesticide application specifications.
Agricultural control mainly includes seed replacement, strong
seedling cultivation, rational close planting and field sanitation. Biological
control adopts Trichogramma, sex pheromone traps and biological agents.
Physical control relies on insecticidal lamps to trap and kill pests. Targeted
pesticides are selected for chemical control to prevent and treat rice blast,
rice false smut, chilo suppressalis
and field weeds, with strict compliance with the safety interval period and
pesticide application regulations.
5.4 Current Status of
Industrial Development
In
recent years, Liuhe County has developed 35 rice brands, represented by Liuhe
Rice, Watian, Sheji Shangpin and Damajie. A total of
19 locally produced agricultural products have obtained green certification,
and Liuhe Rice has been granted the China Geographical Indication Certification
Trademark. The volcanic ash‑derived rice of Liuhe has received many prestigious
honors, such as China Top Brand Agricultural Product, Gold Award Rice of China
Rice Expo and Jilin Provincial Famous Brand Product. Academician Yuan Longping
inscribed an inscription for Liuhe Rice and spoke highly of its quality.
In
terms of industrial development, Liuhe County has greatly improved the brand
value and market competitiveness of volcanic ash substrate rice through
multiple modes, including the “company + farmer” model, standardized
cultivation, ecological management and scientific and technological cooperation[9]. Leading enterprises such as Guoxin Sheji Shangpin and Watian Rice Industry have introduced advanced processing
equipment, promoted organic certification, and expanded online and offline
sales channels. These efforts not only raise product added value, but also
increase local farmers’ income, forming a virtuous interaction between
ecological protection and economic development.
5.5 Construction of Ground Real-time
Observation Stations and Traceability System
To realize effective traceability of rice growth
environment and production process, automatic observation stations for rice
habitats have been constructed. Adopting a low‑power IoT sensing system, the
stations can automatically monitor and record 10 targeted observation
parameters in real time, including landscape video, air temperature, air
humidity, air quality, wind speed and wind direction (Figure 9).
Figure 9 Real-time
Habitat Monitoring System in Liuhe County