ABSTRACT
Labor intensive and periodical investigations are essentially required in the past for the evaluation of services and functions of ecosystem and its change, which resulted in much labor and time consumption with very limited frequencies. Currently, with rapid development of Information and Communication Technology (ICT), it has been applied in many different aspects. It can also be applied to ecological monitoring to replace the laborious investigation. In this study, it was applied to monitor the environment and biodiversity in the study site, Min-Jian Township. It is located on the landscape of Satoyama in eastern Taiwan, which the agriculture is highly developed. Some farmers have conducted the environmentally friendly practices, such as organic, natural farming or grass cultivation in tea gardens and orchards etc. The benefits of these practices need to be evaluated. The aim of this study is to compare the effect on environment, biodiversity and production between conventional and organic farming with grass cultivation. The results reveal organic farming can have benefits on the biodiversity and environment. However, the production of organic farming was much lower than that of conventional farming. It reveals the technologies for practices of environmentally friendly farming need to be developed to increase the income for farmers. The ecological subsidy might be necessary to promote the Satoyama initiative. The area near the mountains is vulnerable for environmental sustainability. To prevent contamination of groundwater with nitrogen caused by the heavy fertilization of conventional farming in this area, some strategies should be practiced to gradually reduce the environmental impact.
Keywords: Information and Communication Technology (ICT), Satoyama Initiative, Ecological monitoring
INTRODUCTION
The Satoyama Initiative is jointly sponsored by the United Nations University Institute of Advanced Studies (UNU-IAS) and the Ministry of the Environment. The goal is to foster local culture, increase biodiversity, and achieve sustainable use of the environment by collating the rural ecosystem of the mountainous landscapes similar in Japan around the world. The vision is to balance the maintenance of biodiversity with the sustainable use of resources (Zhao 2012, Li 2013).
In order to achieve the goal of the Satoyama Initiative, each region has different measures depending on its geographical location and social economic conditions. However, how to assess the effectiveness of its measures often takes time and effort. With the development of Information and Communication Technology (ICT), it has become common to use sensors to replace manual collection of environmental and ecological information in the wild (Chan et al. 2012, Chan et al. 2017). Many technologies have been applied to the monitoring of environmental and ecological information, such as images and soundscapes (Bridges & Dorcas 2000, Hsu et al. 2005, Corn et al. 2011, Vélez et al. 2017, Chiu et al. 2018), to save manpower and increasing the frequency of investigations, to more accurately assess the benefits of the practice implemented, and to understand the structure of the ecosystem for strategies study.
Min-Jian Township is located in highly developed agricultural area near the mountains with diverse landscape and crops. The newest study shows that smaller fields and diverse crops improve the biodiversity and resilience of farmed landscapes (Sirami et al. 2019). However, the impact of the environment and biodiversity become gradually serious due to the vigorous and quicl development of agriculture. In recent years, the government has promoted environmentally friendly practices, such as organic, natural farming and grass cultivation etc. Some local farmers have tried to change their methods of farming to meet the goal of the Satoyama Initiative to portect the natural ecological environment. In this study, we try to apply the ICTto evaluate the benefits of practice of the Satoyama Initiative.
MATERIALS AND METHODS
Research area
Description of study area
Min-Jian Township is located in the west part of Nantou County, Taiwan and the head area of Alluvial fan of the Zhuo-shui River. It is adjacent to Xin-jie Han River in the north, Zhuo-shui River in the south, Jiji Dashan in the west, Bagua Plateau as a boundary to the west (Figure 1). It is located in one kind of Satoyama’s landscape. The annual mean temperature and rainfall are around 22 to 25 °C and 1,200-2,800 mm. Although the fertility of red soil in this area is low, the physical property is good. Farmers are used to apply heavy fertilizers to assure high crop production. However, the soil layer is shallow and the geological layer is full of gravel without mud layer with higher permeability. The water groundwater quality is easily affected when over fertilization is practiced. This plateau is mainly planted with tea, pineapple, betel nut, etc. It is now an important low-altitude tea and agricultural production area in Taiwan.
According to the statistics of the Agricultural Survey of the Agriculture and Fisheries Department in 2018, the cultivated land of Min-Jian Township is about 4,343 ha, accounting for 52% of the total townships. The area of tea planting is the largest, about 2,003 ha, which accounts for 46.1% and 24.1% of farming and the township area (Table 1), followed by pineapple, betel nut, dragon fruit and banana etc.
Table 1. Crops cultivated area in Min-Jian Township in 2018.
|
Crop
|
Cultivated area (ha)
|
|
Tea
|
2,003
|
|
Pineapple
|
884
|
|
Betel nut
|
264
|
|
Dragon fruit
|
134
|
|
Banana
|
124
|
Note: Total area and cultivated of Min-Jian Township are 8,300 and 4,343 ha.
Table 2. Comparison on the annual yields of conventional and organic tea gardens.
|
Year
|
CF(kg/ha)a
|
OF(kg/ha) a
|
|
2010
|
24,000
|
7,704
|
|
2011
|
18,000
|
6,360
|
|
2012
|
-b
|
5,520
|
|
2013
|
-b
|
-c
|
|
2014
|
10,610
|
2,446
|
|
2015
|
8,019
|
-c
|
|
2016
|
23,690
|
3,455
|
|
2017
|
20,212
|
1,882
|
|
2018
|
22,057
|
-c
|
aCF = Conventional Farming, OF = Organic Farming.
bThe conventional tea garden has been replanted in 2012, there was no yield in 2012-2013.
cThe organic tea garden has been deeply cut in 2013 and the yields were quiet low in 2015 and 2018. There were no data collected in those years.
Monitoring sites of different farming
The monitoring was conducted in two tea gardens of the Long Term Ecological Research (LTER) sites at Min-Jian (Figure 1). One is conventional farming (CF) garden, the other is organic farming (OF) garden. The area of conventional farming tea garden is 0.2 ha, which is located on altitude of 308 m. It is practiced according to conventional management, such as application of organic fertilizers, chemical fertilizers and pesticides, and continuous regular irrigation. The planted varieties are Jinxuan and Qingxin Oolong. On the other hand, the area of organic farming garden is 0.2 ha, which is located on the altitude of 413m. It is practiced according to the principles of organic management, such as only applying slow-release organic fertilizer as basal fertilization every year. No pesticides and little irrigation are applied. The planted varieties are Sijichun and Assam. The annual production and prizes have been surveyed from 2010 to 2018 (Table 2).
Biodiversity monitoring
Biodiversity survey by laboring
The biodiversity investigation has been conducted on a crossing line survey every season in two tea gardens of conventional and organic farming since 2014, respectively. All inspected animals, including insects, birds, spiders, snails, etc., and plant species are recorded manually.
Ecological soundscape survey
A set of automatic tape recorder (SongMeter SM1, Wildlife acoustics, Inc.) was placed in each of two tea gardens of conventional and organic farming respectively. The automatic recording was set from 19:00 pm to 6:00 am next day from August, 2014 to 2015. The soundscape was recorded 3 minutes every 15 minutes. The total recording of soundscape was 132 minutes per day. The collected soundscape were analyzed by the automatic voice recognition software (Song Scope, Wildlife acoustics, Inc.). The known templates of Anurans sounds were obtained from the animal voiceprint database of the Taiwan Amphibian Conservation Association. The collected soundscape were matched with the known templates to identify the kind of Anurans and time period of its tweet in the recording. Since the soundscape were recorded automatically from the wild environment, the soundscape analysis is easily interfered by other sounds collected in the wild, such as the sounds of wind, rain and other animals. The results of matching by the soundscape analysis still need to be supplemented by manual inspection to confirm the results in this study.
Animal image survey
A set of automatic infrared video recorder was placed in each of the two tea gardens of conventional and organic farming from May 2015, respectively. They were placed in the animal trails that wild animals may pass through in the tea garden. The recorder will start up to take the video when the animals pass. The kind of animal recorded has been identified manually.
Environmental monitoring
Soil temperature, moisture, and electrical conductivity monitoring
Four soil sensors were installed in two tea gardens of conventional and organic farming respectively from 2018. The soil sensors were installed 10 cm away from the main stem of the tea tree and buried at 15 cm below soil surface. The frequency of monitoring was once every 30 minutes. Soil temperature, soil moisture, and soil conductivity were monitored by sensors. The real time data of monitoring sent back to server of database by 4G every half hour.
Soil nitrogen leaching monitoring
Two sets of soil non-destructed lysimeters were installed in two tea gardens of conventional and organic farming from 2011 to July, 2013. Nitrogen leaching was measured to estimate the nitrogen leaching to groundwater of tea gardens with different inputs. To avoid the agricultural practice to destroy the lysimeters, they were buried below 40 cm of the soil surface. The gauge is 20 cm in diameter and 60 cm in length, the amount of leaching is measured at 1 meter below soil surface. The soil profile in gauge was not disturbed when the gauge was installed to maintain the monitoring can be conducted in the natural situation of soil.
According to the design of the soil lysimeter, the amount of leaching is recorded in data collector (Datalog) when a certain amount of leaching is reached. The real time data of monitoring sent back to server of database by 4G every hour. After irrigation or raining, the leachate in the storage of lysimeter is extracted and taken to the laboratory for analysis of the inorganic nitrogen concentration. The amount of nitrogen is calculated based on the sum of the amounts of leachate and nitrogen contents in the leachate. This measure can also be applied to understand the groundwater subsidies by different farming management and evaluate its ecological function for groundwater conservation.
Data analysis
The statistics of all of the collected data, including the soil temperature, humidity, electrical conductivity, tailless tweet record and the number of species of animals and plants etc., were examined with the Pair-T test to recognize if there was a statistically significant difference between two conventional and organic farming.
RESULTS AND DISCUSSION
Tea production and output value survey
The comparison on the annual yields of conventional and organic tea gardens is shown in Table 2. Due to the higher fertilizers and irrigation were applied to the conventional tea garden, the yield was about 3 times than that of the organic tea garden. Although the price of organic tea is about 2.5 times than that of the conventional tea, the mean annual income of organic tea garden is still much lower than that of conventional tea gardens (Table 3). Even the income of organic tea garden is only 70% of that of conventional tea garden without serious pests and diseases under suitable climate. The results reveal it is quite difficult to maintain the income of farmer who conducts the environmentally friendly farming to reach the goal of the Satoyama initiative in Taiwan. Tea is the economic crop with higher prize in Taiwan, if it is difficult to maintain the income for farmer, the other crops will be more difficult for that. It reveals the technologies for practices of environmentally friendly farming need to be developed to increase the income for farmers. The ecological subsidy might be necessary to promote the satoyama initiative.
Table 3. Estimation of annual incomes of conventional and organic tea gardens.
|
Farming
|
Year
|
Average Unit Price (NTD/kg)
|
Income (NTD/ha)
|
|
CFa
|
2014
|
800
|
8,487,600
|
|
2016
|
1,000
|
23,690,000
|
|
2017
|
1,000
|
20,211,900
|
|
OFa
|
2014
|
2,500
|
6,116,000
|
|
2016
|
2,500
|
8,638,250
|
|
2017
|
2,500
|
4,705,000
|
aCF = Conventional Farming, OF = Organic Farming.
Biodiversity monitoring
Biodiversity general survey
The results of plants and animals investigation by laboring are showed in Table 4. There were statistically significant differences in the number of plant species between the convention and organic farming tea gardens (p<0.05), while there is marginally significant differences on the animal species between two kinds of farming (p=0.09). The numbers of plant and animal species in organic garden were significantly higher than that in conventional farming garden. It indicates that practices of organic farming, especially grass cultivation, can effectively enhance biodiversity.
Table 4. Comparison on environmental and biological factors between conventional and organic farming.
(1) Monitoring methods and periods of data collection
|
|
Methods
|
Data period
|
|
Biodiversity factors
|
|
|
|
Yearly animal species No.
|
laboring
|
2013, 2017
|
|
Yearly plant species No.
|
laboring
|
2013, 2017-2018
|
|
Monthly automatic record of Anuran
|
ICT
|
Aug, 2014-July, 2015
|
|
Environmental factors
|
|
|
|
Hourly average soil temperature (°C)
|
ICT
|
July, 2018-July, 2019
|
|
Hourly average soil moisture (m3/m3)
|
ICT
|
|
Hourly average soil EC (mS/cm)
|
ICT
|
(2) Results of statistics
|
|
CFa
|
OFa
|
p-valueb
|
|
Biodiversity factors
|
|
|
|
|
Yearly animal species No.
|
3.0 ± 3.0
|
6.8 ± 6.8
|
0.09
|
|
Yearly plant species No.
|
10.3 ± 2.9
|
27.3 ± 9.11
|
*
|
|
Monthly automatic record of Anuran
|
32.8 ± 43.2
|
26.1 ± 34.5
|
0.07
|
|
Environmental factors
|
|
|
|
|
Hourly average soil temperature (°C)
|
23.6 ± 2.9
|
23.5 ± 2.9
|
***
|
|
Hourly average soil moisture (m3/m3)
|
10. 8 ± 1.4
|
13.3 ± 3.54
|
***
|
|
Hourly average soil EC (mS/cm)
|
0.45 ± 0.08
|
0.40 ± 0.16
|
***
|
aCF = Conventional farming, OF = Organic farming.
bp-value: *p<0.05, **p<0.01, ***p<0.001.
Ecological soundscape survey
According to the results of tweets which were recorded analyzed by the automatic voice recognition software, 6 species of Anurans were detected in the two tea gardens with conventional and organic farming in Min-Jian, includes Polypedates braueri, Kurixalus idiootocus, Microhyla fissipes, Duttaphrynus melanosticus, Fejervarya limnocharis, and Hyla chinensis. Both of tea gardens have the most records of P. braueri (Figure 2). There is marginally significant differences) (p=0.07) in the numbers of tweet records in each month between conventional and organic gardens (Table 4). The results reveal that the population or activities of Anurans in the conventional garden might be higher than those in the organic garden. The heterogeneous environment around the conventional garden might be effective factors, include artificial lights close to the road, many containers for irrigation and near by the betel nut garden etc., which supple the food and suitable spawning environment to increase the population or activities of the male Anurans in the conventional tea garden.
Six species of Anurans were detected in Min-Jian tea garden, which were higher than the 5 species that could be investigated in the urban, but far lower the 18 species that could be investigated in the cultivate plain area (Yang 2010). Attributed to the skin of Anuran was sensitivity to environment (Hamer et al. 2004, Wojtaszek et al. 2004, Liu et al. 2011), the recovery of biodiversity were effected by pesticide, fertility, and high disturbance of farming. Furthermore, organic farms in Min-Jian Township were still few cultivated area and dispersed in the extensive conventional tea area leading to serious habitat fragmentation, it might also be one of the reasons for the slow recovery of the Anuran populations.
According to the comparison on the results of soundscape monitoring between by instruments and labor, it reveals that the automatic recording technology can be applied to the monitoring of amphibious species in the farmland ecosystem. The manpower of the survey can be reduced and monitoring efficiency can be increased. It is useful to get the integral information to understand the structure of ecosystem. The frequency of monitoring can also be adjusted to be increased or decreased according to the experimental requirements.
As a case of the traditional amphibious census by crossing lines, each sample requires about 2-4 investigators depending on the environmental heterogeneity. The survey to record all the species which are heard and seen across the line takes about 1-2 hours. It is labor and time consuming. However, it is possible to replace by the automatic recorders. According the results of this study, it reveals the integral ecological information with higher frequency of monitoring can be collected to evaluate the benefit of practice of Satoyama Initiative.
In addition, the amphibious species can be identified by the automatic identification software of the screaming analysis of soundscape to save the manpower required for analysis. Although the accuracy of identification by the software is high, the rate of detection is still low. However, the rate of detection is expected become higher and higher by the specific template produced and identification process enhanced in the future. The soundscape monitoring can also be applied to survey of birds.
Animal image survey
There is no animal which was captured by the infrared camera in the conventional tea garden. The masked palm civet (Paguma larvata taivana) and the domestic cat (Felis silvestris catus) have been inspected totally three times in the organic tea garden (Figure 3). However, the number of data was insufficient for statistical analysis.
Masked palm civet is the native omnivorous species which is occasionally seen in the suburban hills of Taiwan. The fruits and small seeds are their staple food, the rats, insects and mollusks are also their food. They are the medium and high level predator in the food web. As the role in the food web, they have greatly contributed to the strengthening of the top-down control of the ecosystem and the maintenance of the food web (Wu 1999). Their characteristics of the herbivore are also significant for the renewal of forests and seeds spread of wild plants (Hu et al. 2016). It is one of the important contributors to maintaining biodiversity in the low-altitude Satoyama area.
The domestic cat, which has been found in the organic tea gardens, is also a small invasive predator. It is native in central Asia and considered invasive worldwide. They cause serious impact on biodiversity in metropolitan areas, suburbs and shallow forests etc. all over the world showed by many studies (Churcher & Lawton 1987, Gillies & Clout 2003, Kuo 2006). They should be monitored imperatively to maintain biodiversity of ecosystem.
Environmental monitoring
Soil temperature, humidity and electrical conductivity
The results of monitoring reveals soil average temperature, humidity and conductivity were significantly different (p<0.001) between tea gardens of conventional and organic farming (Table 2). The average soil temperature of organic farming was slightly lower than that of conventional farming. The average soil moisture of organic farming was significantly higher than that of conventional farming. It showed soil moisture can be maintained and temperature can be reduced by the grass cultivation in tea garden of organic farming even with little irrigation. The average soil conductivity of conventional farming was significantly lower than that of organic farming due to the heavy fertilization of conventional farming (Wu 2004). However, the nutrient status is still suitable for the growth of tea trees by higher irrigation. Nevertheless, the higher irrigation leads to serious leaching to contaminate the groundwater, especially the soil layer is shallow in Min-Jian.
Soil nitrogen leaching
The applied rates of nitrogen with higher irrigation of conventional farming are much higher than those of organic farming. The results of monitoring also reveal the inorganic nitrogen leaching, especially nitrate, of conventional farming garden are more serious than that of organic farming garden (Table 5). It indicates that the conventional farming easily cause the groundwater contamination, rather organic farming is more environment friendly.
The results reveal high impact of nitrate contamination in groundwater in Min-Jian area due to the few mud layers in the geological profile under heavy rate of fertilization of conventional farming, even the soil texture is clay. According the investigation of groundwater quality in south-western Taiwan, it shows not only the nitrate content is higher in Min-Jian Township, those of most of the area of near mountain in south-western Taiwan are higher (Figure 4). It reveals most areas of near mountain in western Taiwan are vulnerable for environmental sustainability. It should be the critical issue to develop agriculture in landscape of satoyama.
To prevent groundwater nitrate contamination, some strategies should be practiced to reduce the environmental impact gradually, such as fertilization of more times with less amount each application, application of foliar fertilization and control release fertilizer and amount control irrigation etc. However, the higher expense and labor will be needed if these strategies are practiced. Farmers will not accept easily, unless the current crop was changed to the economical crop. It might be a long way to reach the goal of Satoyama Initiative in this area.
Table 5. Comparison on the nitrogen leaching between conventional and organic tea gardens.
|
Agricultural methods
|
Period
|
Leakage
|
Nitrogen input
Fertilizer / Rainfall / Irrigation
|
NH4+-
leaching
|
NO3--
leaching
|
|
mm
|
kg-N/ha
|
kg-N/ha
|
kg-N/ha
|
|
OFa
|
2011
|
425
|
0
|
10.4
|
0
|
0.9
|
40
|
|
CFa
|
2011
|
782
|
972.6
|
10.4
|
28.5
|
6.7
|
245
|
|
OFa
|
2012
|
671
|
0
|
42.6
|
0
|
6.0
|
95
|
|
CFa
|
2012
|
971
|
617
|
34.0
|
11
|
3.3
|
409
|
|
OFa
|
2013
|
-b
|
0
|
60.1
|
0
|
2.0
|
56
|
|
CFa
|
2013
|
-b
|
667
|
126.8
|
84.4
|
4.1
|
318
|
aCF = Conventional Farming, OF = Organic Farming.
bThe leakage data were incomplete in 2013.
CONCLUSIONS
The information and communication technology (ICT) has been successfully applied for environment and biodiversity monitoring in this study to reduce the labor and time consumption with higher frequency. The integral information of ecosystem has been collected to evaluate the benefit of practice of the Satoyama Initiative. The results reveal organic farming is helpful to increase the biodiversity and reduce impact of the groundwater contamination. However, the heterogeneous habitats seem more important for biodiversity than farming. Rather, the production of organic farming was much lower than that of conventional farming. It reveals the technologies for practices of environmentally friendly farming need to be developed to increase the income for farmers. The ecological subsidy might be necessary to promote the Satoyama Initiative. The area of near mountain is vulnerable for environmental sustainability. To prevent contamination of groundwater with nitrogen cause by the heavy fertilization of conventional farming in this area, some strategies should be practiced to gradually reduce its environmental impact.
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Evaluating the Benefit of Practice for Satoyama Initiative by Applying Information and Communication Technology (ICT)
ABSTRACT
Labor intensive and periodical investigations are essentially required in the past for the evaluation of services and functions of ecosystem and its change, which resulted in much labor and time consumption with very limited frequencies. Currently, with rapid development of Information and Communication Technology (ICT), it has been applied in many different aspects. It can also be applied to ecological monitoring to replace the laborious investigation. In this study, it was applied to monitor the environment and biodiversity in the study site, Min-Jian Township. It is located on the landscape of Satoyama in eastern Taiwan, which the agriculture is highly developed. Some farmers have conducted the environmentally friendly practices, such as organic, natural farming or grass cultivation in tea gardens and orchards etc. The benefits of these practices need to be evaluated. The aim of this study is to compare the effect on environment, biodiversity and production between conventional and organic farming with grass cultivation. The results reveal organic farming can have benefits on the biodiversity and environment. However, the production of organic farming was much lower than that of conventional farming. It reveals the technologies for practices of environmentally friendly farming need to be developed to increase the income for farmers. The ecological subsidy might be necessary to promote the Satoyama initiative. The area near the mountains is vulnerable for environmental sustainability. To prevent contamination of groundwater with nitrogen caused by the heavy fertilization of conventional farming in this area, some strategies should be practiced to gradually reduce the environmental impact.
Keywords: Information and Communication Technology (ICT), Satoyama Initiative, Ecological monitoring
INTRODUCTION
The Satoyama Initiative is jointly sponsored by the United Nations University Institute of Advanced Studies (UNU-IAS) and the Ministry of the Environment. The goal is to foster local culture, increase biodiversity, and achieve sustainable use of the environment by collating the rural ecosystem of the mountainous landscapes similar in Japan around the world. The vision is to balance the maintenance of biodiversity with the sustainable use of resources (Zhao 2012, Li 2013).
In order to achieve the goal of the Satoyama Initiative, each region has different measures depending on its geographical location and social economic conditions. However, how to assess the effectiveness of its measures often takes time and effort. With the development of Information and Communication Technology (ICT), it has become common to use sensors to replace manual collection of environmental and ecological information in the wild (Chan et al. 2012, Chan et al. 2017). Many technologies have been applied to the monitoring of environmental and ecological information, such as images and soundscapes (Bridges & Dorcas 2000, Hsu et al. 2005, Corn et al. 2011, Vélez et al. 2017, Chiu et al. 2018), to save manpower and increasing the frequency of investigations, to more accurately assess the benefits of the practice implemented, and to understand the structure of the ecosystem for strategies study.
Min-Jian Township is located in highly developed agricultural area near the mountains with diverse landscape and crops. The newest study shows that smaller fields and diverse crops improve the biodiversity and resilience of farmed landscapes (Sirami et al. 2019). However, the impact of the environment and biodiversity become gradually serious due to the vigorous and quicl development of agriculture. In recent years, the government has promoted environmentally friendly practices, such as organic, natural farming and grass cultivation etc. Some local farmers have tried to change their methods of farming to meet the goal of the Satoyama Initiative to portect the natural ecological environment. In this study, we try to apply the ICTto evaluate the benefits of practice of the Satoyama Initiative.
MATERIALS AND METHODS
Research area
Description of study area
Min-Jian Township is located in the west part of Nantou County, Taiwan and the head area of Alluvial fan of the Zhuo-shui River. It is adjacent to Xin-jie Han River in the north, Zhuo-shui River in the south, Jiji Dashan in the west, Bagua Plateau as a boundary to the west (Figure 1). It is located in one kind of Satoyama’s landscape. The annual mean temperature and rainfall are around 22 to 25 °C and 1,200-2,800 mm. Although the fertility of red soil in this area is low, the physical property is good. Farmers are used to apply heavy fertilizers to assure high crop production. However, the soil layer is shallow and the geological layer is full of gravel without mud layer with higher permeability. The water groundwater quality is easily affected when over fertilization is practiced. This plateau is mainly planted with tea, pineapple, betel nut, etc. It is now an important low-altitude tea and agricultural production area in Taiwan.
According to the statistics of the Agricultural Survey of the Agriculture and Fisheries Department in 2018, the cultivated land of Min-Jian Township is about 4,343 ha, accounting for 52% of the total townships. The area of tea planting is the largest, about 2,003 ha, which accounts for 46.1% and 24.1% of farming and the township area (Table 1), followed by pineapple, betel nut, dragon fruit and banana etc.
Table 1. Crops cultivated area in Min-Jian Township in 2018.
Crop
Cultivated area (ha)
Tea
2,003
Pineapple
884
Betel nut
264
Dragon fruit
134
Banana
124
Note: Total area and cultivated of Min-Jian Township are 8,300 and 4,343 ha.
Table 2. Comparison on the annual yields of conventional and organic tea gardens.
Year
CF(kg/ha)a
OF(kg/ha) a
2010
24,000
7,704
2011
18,000
6,360
2012
-b
5,520
2013
-b
-c
2014
10,610
2,446
2015
8,019
-c
2016
23,690
3,455
2017
20,212
1,882
2018
22,057
-c
aCF = Conventional Farming, OF = Organic Farming.
bThe conventional tea garden has been replanted in 2012, there was no yield in 2012-2013.
cThe organic tea garden has been deeply cut in 2013 and the yields were quiet low in 2015 and 2018. There were no data collected in those years.
Monitoring sites of different farming
The monitoring was conducted in two tea gardens of the Long Term Ecological Research (LTER) sites at Min-Jian (Figure 1). One is conventional farming (CF) garden, the other is organic farming (OF) garden. The area of conventional farming tea garden is 0.2 ha, which is located on altitude of 308 m. It is practiced according to conventional management, such as application of organic fertilizers, chemical fertilizers and pesticides, and continuous regular irrigation. The planted varieties are Jinxuan and Qingxin Oolong. On the other hand, the area of organic farming garden is 0.2 ha, which is located on the altitude of 413m. It is practiced according to the principles of organic management, such as only applying slow-release organic fertilizer as basal fertilization every year. No pesticides and little irrigation are applied. The planted varieties are Sijichun and Assam. The annual production and prizes have been surveyed from 2010 to 2018 (Table 2).
Biodiversity monitoring
Biodiversity survey by laboring
The biodiversity investigation has been conducted on a crossing line survey every season in two tea gardens of conventional and organic farming since 2014, respectively. All inspected animals, including insects, birds, spiders, snails, etc., and plant species are recorded manually.
Ecological soundscape survey
A set of automatic tape recorder (SongMeter SM1, Wildlife acoustics, Inc.) was placed in each of two tea gardens of conventional and organic farming respectively. The automatic recording was set from 19:00 pm to 6:00 am next day from August, 2014 to 2015. The soundscape was recorded 3 minutes every 15 minutes. The total recording of soundscape was 132 minutes per day. The collected soundscape were analyzed by the automatic voice recognition software (Song Scope, Wildlife acoustics, Inc.). The known templates of Anurans sounds were obtained from the animal voiceprint database of the Taiwan Amphibian Conservation Association. The collected soundscape were matched with the known templates to identify the kind of Anurans and time period of its tweet in the recording. Since the soundscape were recorded automatically from the wild environment, the soundscape analysis is easily interfered by other sounds collected in the wild, such as the sounds of wind, rain and other animals. The results of matching by the soundscape analysis still need to be supplemented by manual inspection to confirm the results in this study.
Animal image survey
A set of automatic infrared video recorder was placed in each of the two tea gardens of conventional and organic farming from May 2015, respectively. They were placed in the animal trails that wild animals may pass through in the tea garden. The recorder will start up to take the video when the animals pass. The kind of animal recorded has been identified manually.
Environmental monitoring
Soil temperature, moisture, and electrical conductivity monitoring
Four soil sensors were installed in two tea gardens of conventional and organic farming respectively from 2018. The soil sensors were installed 10 cm away from the main stem of the tea tree and buried at 15 cm below soil surface. The frequency of monitoring was once every 30 minutes. Soil temperature, soil moisture, and soil conductivity were monitored by sensors. The real time data of monitoring sent back to server of database by 4G every half hour.
Soil nitrogen leaching monitoring
Two sets of soil non-destructed lysimeters were installed in two tea gardens of conventional and organic farming from 2011 to July, 2013. Nitrogen leaching was measured to estimate the nitrogen leaching to groundwater of tea gardens with different inputs. To avoid the agricultural practice to destroy the lysimeters, they were buried below 40 cm of the soil surface. The gauge is 20 cm in diameter and 60 cm in length, the amount of leaching is measured at 1 meter below soil surface. The soil profile in gauge was not disturbed when the gauge was installed to maintain the monitoring can be conducted in the natural situation of soil.
According to the design of the soil lysimeter, the amount of leaching is recorded in data collector (Datalog) when a certain amount of leaching is reached. The real time data of monitoring sent back to server of database by 4G every hour. After irrigation or raining, the leachate in the storage of lysimeter is extracted and taken to the laboratory for analysis of the inorganic nitrogen concentration. The amount of nitrogen is calculated based on the sum of the amounts of leachate and nitrogen contents in the leachate. This measure can also be applied to understand the groundwater subsidies by different farming management and evaluate its ecological function for groundwater conservation.
Data analysis
The statistics of all of the collected data, including the soil temperature, humidity, electrical conductivity, tailless tweet record and the number of species of animals and plants etc., were examined with the Pair-T test to recognize if there was a statistically significant difference between two conventional and organic farming.
RESULTS AND DISCUSSION
Tea production and output value survey
The comparison on the annual yields of conventional and organic tea gardens is shown in Table 2. Due to the higher fertilizers and irrigation were applied to the conventional tea garden, the yield was about 3 times than that of the organic tea garden. Although the price of organic tea is about 2.5 times than that of the conventional tea, the mean annual income of organic tea garden is still much lower than that of conventional tea gardens (Table 3). Even the income of organic tea garden is only 70% of that of conventional tea garden without serious pests and diseases under suitable climate. The results reveal it is quite difficult to maintain the income of farmer who conducts the environmentally friendly farming to reach the goal of the Satoyama initiative in Taiwan. Tea is the economic crop with higher prize in Taiwan, if it is difficult to maintain the income for farmer, the other crops will be more difficult for that. It reveals the technologies for practices of environmentally friendly farming need to be developed to increase the income for farmers. The ecological subsidy might be necessary to promote the satoyama initiative.
Table 3. Estimation of annual incomes of conventional and organic tea gardens.
Farming
Year
Average Unit Price (NTD/kg)
Income (NTD/ha)
CFa
2014
800
8,487,600
2016
1,000
23,690,000
2017
1,000
20,211,900
OFa
2014
2,500
6,116,000
2016
2,500
8,638,250
2017
2,500
4,705,000
aCF = Conventional Farming, OF = Organic Farming.
Biodiversity monitoring
Biodiversity general survey
The results of plants and animals investigation by laboring are showed in Table 4. There were statistically significant differences in the number of plant species between the convention and organic farming tea gardens (p<0.05), while there is marginally significant differences on the animal species between two kinds of farming (p=0.09). The numbers of plant and animal species in organic garden were significantly higher than that in conventional farming garden. It indicates that practices of organic farming, especially grass cultivation, can effectively enhance biodiversity.
Table 4. Comparison on environmental and biological factors between conventional and organic farming.
(1) Monitoring methods and periods of data collection
Methods
Data period
Biodiversity factors
Yearly animal species No.
laboring
2013, 2017
Yearly plant species No.
laboring
2013, 2017-2018
Monthly automatic record of Anuran
ICT
Aug, 2014-July, 2015
Environmental factors
Hourly average soil temperature (°C)
ICT
July, 2018-July, 2019
Hourly average soil moisture (m3/m3)
ICT
Hourly average soil EC (mS/cm)
ICT
(2) Results of statistics
CFa
OFa
p-valueb
Biodiversity factors
Yearly animal species No.
3.0 ± 3.0
6.8 ± 6.8
0.09
Yearly plant species No.
10.3 ± 2.9
27.3 ± 9.11
*
Monthly automatic record of Anuran
32.8 ± 43.2
26.1 ± 34.5
0.07
Environmental factors
Hourly average soil temperature (°C)
23.6 ± 2.9
23.5 ± 2.9
***
Hourly average soil moisture (m3/m3)
10. 8 ± 1.4
13.3 ± 3.54
***
Hourly average soil EC (mS/cm)
0.45 ± 0.08
0.40 ± 0.16
***
aCF = Conventional farming, OF = Organic farming.
bp-value: *p<0.05, **p<0.01, ***p<0.001.
Ecological soundscape survey
According to the results of tweets which were recorded analyzed by the automatic voice recognition software, 6 species of Anurans were detected in the two tea gardens with conventional and organic farming in Min-Jian, includes Polypedates braueri, Kurixalus idiootocus, Microhyla fissipes, Duttaphrynus melanosticus, Fejervarya limnocharis, and Hyla chinensis. Both of tea gardens have the most records of P. braueri (Figure 2). There is marginally significant differences) (p=0.07) in the numbers of tweet records in each month between conventional and organic gardens (Table 4). The results reveal that the population or activities of Anurans in the conventional garden might be higher than those in the organic garden. The heterogeneous environment around the conventional garden might be effective factors, include artificial lights close to the road, many containers for irrigation and near by the betel nut garden etc., which supple the food and suitable spawning environment to increase the population or activities of the male Anurans in the conventional tea garden.
Six species of Anurans were detected in Min-Jian tea garden, which were higher than the 5 species that could be investigated in the urban, but far lower the 18 species that could be investigated in the cultivate plain area (Yang 2010). Attributed to the skin of Anuran was sensitivity to environment (Hamer et al. 2004, Wojtaszek et al. 2004, Liu et al. 2011), the recovery of biodiversity were effected by pesticide, fertility, and high disturbance of farming. Furthermore, organic farms in Min-Jian Township were still few cultivated area and dispersed in the extensive conventional tea area leading to serious habitat fragmentation, it might also be one of the reasons for the slow recovery of the Anuran populations.
According to the comparison on the results of soundscape monitoring between by instruments and labor, it reveals that the automatic recording technology can be applied to the monitoring of amphibious species in the farmland ecosystem. The manpower of the survey can be reduced and monitoring efficiency can be increased. It is useful to get the integral information to understand the structure of ecosystem. The frequency of monitoring can also be adjusted to be increased or decreased according to the experimental requirements.
As a case of the traditional amphibious census by crossing lines, each sample requires about 2-4 investigators depending on the environmental heterogeneity. The survey to record all the species which are heard and seen across the line takes about 1-2 hours. It is labor and time consuming. However, it is possible to replace by the automatic recorders. According the results of this study, it reveals the integral ecological information with higher frequency of monitoring can be collected to evaluate the benefit of practice of Satoyama Initiative.
In addition, the amphibious species can be identified by the automatic identification software of the screaming analysis of soundscape to save the manpower required for analysis. Although the accuracy of identification by the software is high, the rate of detection is still low. However, the rate of detection is expected become higher and higher by the specific template produced and identification process enhanced in the future. The soundscape monitoring can also be applied to survey of birds.
Animal image survey
There is no animal which was captured by the infrared camera in the conventional tea garden. The masked palm civet (Paguma larvata taivana) and the domestic cat (Felis silvestris catus) have been inspected totally three times in the organic tea garden (Figure 3). However, the number of data was insufficient for statistical analysis.
Masked palm civet is the native omnivorous species which is occasionally seen in the suburban hills of Taiwan. The fruits and small seeds are their staple food, the rats, insects and mollusks are also their food. They are the medium and high level predator in the food web. As the role in the food web, they have greatly contributed to the strengthening of the top-down control of the ecosystem and the maintenance of the food web (Wu 1999). Their characteristics of the herbivore are also significant for the renewal of forests and seeds spread of wild plants (Hu et al. 2016). It is one of the important contributors to maintaining biodiversity in the low-altitude Satoyama area.
The domestic cat, which has been found in the organic tea gardens, is also a small invasive predator. It is native in central Asia and considered invasive worldwide. They cause serious impact on biodiversity in metropolitan areas, suburbs and shallow forests etc. all over the world showed by many studies (Churcher & Lawton 1987, Gillies & Clout 2003, Kuo 2006). They should be monitored imperatively to maintain biodiversity of ecosystem.
Environmental monitoring
Soil temperature, humidity and electrical conductivity
The results of monitoring reveals soil average temperature, humidity and conductivity were significantly different (p<0.001) between tea gardens of conventional and organic farming (Table 2). The average soil temperature of organic farming was slightly lower than that of conventional farming. The average soil moisture of organic farming was significantly higher than that of conventional farming. It showed soil moisture can be maintained and temperature can be reduced by the grass cultivation in tea garden of organic farming even with little irrigation. The average soil conductivity of conventional farming was significantly lower than that of organic farming due to the heavy fertilization of conventional farming (Wu 2004). However, the nutrient status is still suitable for the growth of tea trees by higher irrigation. Nevertheless, the higher irrigation leads to serious leaching to contaminate the groundwater, especially the soil layer is shallow in Min-Jian.
Soil nitrogen leaching
The applied rates of nitrogen with higher irrigation of conventional farming are much higher than those of organic farming. The results of monitoring also reveal the inorganic nitrogen leaching, especially nitrate, of conventional farming garden are more serious than that of organic farming garden (Table 5). It indicates that the conventional farming easily cause the groundwater contamination, rather organic farming is more environment friendly.
The results reveal high impact of nitrate contamination in groundwater in Min-Jian area due to the few mud layers in the geological profile under heavy rate of fertilization of conventional farming, even the soil texture is clay. According the investigation of groundwater quality in south-western Taiwan, it shows not only the nitrate content is higher in Min-Jian Township, those of most of the area of near mountain in south-western Taiwan are higher (Figure 4). It reveals most areas of near mountain in western Taiwan are vulnerable for environmental sustainability. It should be the critical issue to develop agriculture in landscape of satoyama.
To prevent groundwater nitrate contamination, some strategies should be practiced to reduce the environmental impact gradually, such as fertilization of more times with less amount each application, application of foliar fertilization and control release fertilizer and amount control irrigation etc. However, the higher expense and labor will be needed if these strategies are practiced. Farmers will not accept easily, unless the current crop was changed to the economical crop. It might be a long way to reach the goal of Satoyama Initiative in this area.
Table 5. Comparison on the nitrogen leaching between conventional and organic tea gardens.
Agricultural methods
Period
Leakage
Nitrogen input
Fertilizer / Rainfall / Irrigation
NH4+-
leaching
NO3--
leaching
mm
kg-N/ha
kg-N/ha
kg-N/ha
OFa
2011
425
0
10.4
0
0.9
40
CFa
2011
782
972.6
10.4
28.5
6.7
245
OFa
2012
671
0
42.6
0
6.0
95
CFa
2012
971
617
34.0
11
3.3
409
OFa
2013
-b
0
60.1
0
2.0
56
CFa
2013
-b
667
126.8
84.4
4.1
318
aCF = Conventional Farming, OF = Organic Farming.
bThe leakage data were incomplete in 2013.
CONCLUSIONS
The information and communication technology (ICT) has been successfully applied for environment and biodiversity monitoring in this study to reduce the labor and time consumption with higher frequency. The integral information of ecosystem has been collected to evaluate the benefit of practice of the Satoyama Initiative. The results reveal organic farming is helpful to increase the biodiversity and reduce impact of the groundwater contamination. However, the heterogeneous habitats seem more important for biodiversity than farming. Rather, the production of organic farming was much lower than that of conventional farming. It reveals the technologies for practices of environmentally friendly farming need to be developed to increase the income for farmers. The ecological subsidy might be necessary to promote the Satoyama Initiative. The area of near mountain is vulnerable for environmental sustainability. To prevent contamination of groundwater with nitrogen cause by the heavy fertilization of conventional farming in this area, some strategies should be practiced to gradually reduce its environmental impact.
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