The adaptation to climate change of Bromo horticultural farmer to support the environmental and economic dimensions on sustainable agriculture

Climate change is a challenge for all humankind, generally caused by the El Nino and La Nina phenomenon. The impact of climate change affects production and income of people who depend on the agricultural sector, one of which is the horticulture sub-sector. This research aims to analyze forms of adaptation to climate change, support for adaptation to ecological/environmental and economic dimensions, as well as factors are taken into consideration by farmers in adapting to climate change. The research was conducted in the Bromo area, Probolinggo Regency, East Java Province, Indonesia. The data analysis used is descriptive analysis, difference test analysis, and logit analysis. The results show that there are 13 forms of climate change adaptation performed by horticultural farmers. Adaptation to climate change is proven to support the ecological/environmental and economic dimensions in realizing sustainable agriculture. Farmers with a high level of adaptation to climate change have higher productivity, income per hectare and cost efficiency than farmers with a low level of adaptation. Factors that influence the decision making of horticultural farmers to implement climate change adaptation include education, number of family, and land area of horticulture.


Introduction
Climate change caused by global warming is a challenge for all humankind.Global warming occurs due to human activities that produce gas emissions, causing the composition of gas emissions in the atmosphere to change through burning of fossil fuels and deforestation [1].Changes in the composition of gas emissions in the atmosphere can cause climate change.Climate change can lead an increase in the frequency and intensity of extreme weather events, such as floods and droughts, changes in rain patterns, and increases in temperature and sea levels [2][3][4].The Intergovernmental Panel on Climate Change-IPCC [5] shows that climate change has occurred with indications of an increase in the average global temperature for the period 1850-1899 to 2001-2005 of 0.76C.Global average sea level increased by 1.8 mm per year in the period from 1961 to 2003.Sea level in the 20th century had a total increase of 0.17 m.Indonesia is also inseparable from the impacts of climate change [6].
The cause of climate change is generally triggered by the El Nino and La Nina phenomenon [7,8].La Nina is a natural phenomenon which generally has an impact on increasing rainfall in Indonesia.The impact of La Nina is the increasing rainfall reaching more than 25% of the normal rainfall before the start of the rainy season [9].The process of La Nina is caused by the travel of hot sea water westward and will eventually reach Indonesian territory.As a result, Indonesia's territory will turn into a low pressured area (minimum) and all the winds around the South Pacific and Indian Ocean will move towards Indonesia [10].This wind carries a lot of water vapor, so that in Indonesia there will often be heavy rain and can cause flooding [11].According to Safitri [12] statement, the process of El Nino occurs at certain times of hot sea water from Indonesian waters with hot sea water from Central America on the west coast of Peru-Equador, and a large mass of hot sea water gathers and occupies wide area.As a result, the wind towards Indonesia carries only a small amount of water vapor, resulting in a long dry season.
Climate change has a significant impact on the agricultural sector [13][14][15].The impact of climate change affects production and income of people who depend on this sector.One of the agricultural subsectors affected by climate change is the horticultural subsector where horticultural crops, which are generally annual crops, are vulnerable to stress (excess and lack) of water.In general, there are two forms of efforts to deal with climate change which are efforts through mitigation and adaptation.Mitigation to climate change includes the use of low-emission rice varieties, ZA fertilizer as a source of N fertilizer, application of zero tillage, and intermittent irrigation technology.Meanwhile forms of adaptation to climate change include adjustments to planting times and patterns, rain water harvesting, irrigation, and the use of improved varieties tolerant to drought, soaking, and salinity [6].Choosing a planting pattern can be used as a strategy in dealing with climate change.Agriculture uses various systems to increase efficiency and crop productivity to support the income that farmers earn.Land efficiency can be increased with technology and farming systems.Polyculture (intercropping) is a farming system to increase crop productivity [16][17][18], besides reducing the operational costs during production process [19].Climate change can cause damage to agricultural crops, including horticultural crops, which can cause crop failure.Land destruction as a result of climate change will disrupt the ecological or environmental dimension, while a decrease in production will disrupt the existence of the economic dimension in achieving sustainable agriculture.Climate changes that have occurred recently, such as rainfall which has become more extreme in the season, drought situations that hit agriculture, hurricane seasons, extreme temperature conditions in certain months have caused young plants to experience damage in the form of dead and withered plants, as well as climate conditions that increasingly difficult to be predicted by highland farmers [20].
Horticultural crop farmers in the highlands have adaptation strategies in maintaining their horticultural crops in facing climate change, one of which is Tengger tribe farmers.Tengger tribe farmers have a generational anticipatory strategy in dealing with climate change.Tengger tribe farmers apply the use of water savings, intensive use of manure, cultivating land against contours, use of good irrigation and drainage systems, increasing the intensity of weeding, better and more careful preparation of seeds/seedlings, planting at the start of the rainy season, planting terrace reinforcing plants, changing planting times, applying recommended planting distances, seeking information about climate change, and handling harvests by minimizing yield losses.Those adaptation strategies are activities which are oftenly conducted.How often the Tengger tribe farmers using those adaptation strategies can be seen in the percentage which is 80-100% [21].Based on the background and phenomena of climate change in Indonesia, especially in the Bromo area, this study aims to analyze: 1) forms of adaptation to climate change of Bromo horticultural farmers, 2) support for adaptation to climate change of Bromo horticultural farmer to environmental dimension, 3) support for adaptation to climate change of Bromo horticultural farmer to economic dimension, and 4) factors that influence the implementation of adaptation to climate change by Bromo horticultural farmers.

Methods
The location of the research was deliberately chosen in Ngadisari Village, Sukapura District, Probolinggo Regency on the basis that the village is part of the Bromo mountain area and has great potential for horticultural farming (potato, cabbage, leek, and tomato farming).The research focuses on farmer population units who operate potato farming, which in their farming can be monoculture or intercropping with cabbage or leeks.Samples were taken purposively as many as 30 farmers with the consideration that farmers with the main crop of potatoes, were willing to be interviewed, the location was affordable considering the location of horticultural planting in the Bromo area, up to the hills and even the forests around Ngadisari village.
Forms of adaptation to climate change for horticultural farmers in the Bromo area were identified through interviews with farmers which is about what forms of adaptation that had been carried out when climate change occurred (drought or high and prolonged rainfall.)Based on previous research, Fermansah and Mamilianti [21] state that there were 26 types adaptation to climate change.Each form of adaptation is identified through a form of farmer adaptation, then the percentage of farmers who implement it is calculated.To answer the second problem formulation related to climate change support in the environmental/ecological dimension, the percentage of implementation of each form of adaptation is calculated in detail and also calculates the contribution of each aspect in this dimension.Based on Wahyudi et al., [22] that states the ecological/environmental dimension is divided into aspects of fertilization, water quality, fig fulfillment, water efficiency, biodiversity, and land management.
The support of climate change on the economic dimension was analyzed using a test of the difference in average productivity, net income, and cost efficiency between farmers in the high adaptation and low adaptation categories.The analysis used is the t statistical test for two independent groups.
Data analysis used to determine the factors that influence decision making by farmers to implement climate change adaptation uses logistic regression analysis (logit model) with the following equation formulation:

Forms of adaptation to climate change of Bromo horticulture farmer
Horticultural farmers in the Bromo area implement 13 forms of climate change adaptation as presented in Table 1.Most farmers do not only carry out one form of adaptation, but they implement a combination of several forms of climate change adaptation.Based on farmer information, one of the climate changes that have occurred in Bromo area in the last 3 years is prolonged drought as a result of El Nino or La Nina.There are 7 forms of adaptation that all horticultural companies follow, and one type of adaptation to change that is less popular by farmers is rotate crop types on the same land.The use of manure is chosen by horticultural farmers (100%) in Bromo area as a suitable fertilizer choice when climate change occurs, such as during a prolonged dry season.Farmers believe that organic manure is more easily absorbed even during times of drought.Application of manure can improve soil fertility and soil organic matter [23].
Selection of varieties that are resistant to disease is a way of adapting to climate change carried out by farmers (100%), where horticultural plant diseases such as bacterial ring rot is caused by Clavibacter michiganensis.Bacterial ring rot often occurs when climate change occurs, especially when there is high extreme rainfall.Apart from being disease resistant, farmers also choose improved varieties that are tolerant to flood and drought.In line with previous study stated that new crop varieties such as the flood and/or drought-tolerant varieties, the pest and disease-resistant varieties play in supporting adaptation to climate change [23,24].The interview result shows that all farmers are accustomed to anticipating climate change by preparing improved varieties.This condition will support the preservation of horticultural biodiversity in the Bromo area.
All horticultural farmers (100%) also use strategies for selecting varieties that are suitable for certain conditions, including drought-tolerant and/or high flood-tolerant varieties.The importance of flood and drought tolerant varieties is to produce the result that farmers expect.The variety used by farmers that is tolerant to flood and drought is BL variety.The combination of improved varieties and soil fertilization can effectively minimize climate change risks [25].
Paying attention to the contours of cultivated land for horticultural crops is one form of adaptation carried out by farmers (66.67%).Climate change has the potential to impact agricultural land where mountain slopes and highlands are more vulnerable to landslides and erosion due to high rainfall.Therefore, it is necessary to cultivate the land appropriately.
Planting at the beginning of the rainy season is carried out by horticultural farmers (100%).It aims to ensure sufficient water availability.The people of Ngadisari Village have local wisdom, a special way to determine the start of the rainy season.Generally, the people of Ngadisari Village mark the beginning of the rainy season with the arrival of "geluduk" or "genta" which originates from Mount Lingga.Several other farmers also stated that the start of the rainy season will arrive if there is fog cloud, which is low fog that blows towards the southeast.Early planting is carried out as an effort by farmers to maintain water availability during the growth of horticultural plants.Errors in managing planting time risk water shortages.
Maximizing the use of agricultural land can be done by one of the methods is intercropping (50%).It is one of the farmers' adaptation strategies to climate change.With intercropping system, farmers hope that the use of limited inputs will be able to reduce farming costs when climate change occurs with drought.Intercropping is able to increase the efficiency of utilizing limited resources [23], contribute to higher farmer income from different crop yields and reduce farming costs [19].
Horticultural farmers (100%) have changed planting times because the rainy season comes earlier than it should.Improper planting time causes plants to not grow well, which can affect plant productivity.Therefore, anticipating planting time is very necessary to maintain sufficient water during plant growth.Changing planting times combined with irrigation management can be considered as an adaptation strategy and it can provide benefits to reduce the negative impacts of climate change [26].
All horticultural farmers (100%) adapt to climate change in the form of implementing recommended planting distances.Farmers implement the recommended planting distance of 60 to 80 cm between plant bunds.The aim of the planting distance is to optimize plant growth, so that no plants compete for nutrients, and maintains land management.
Successive plantings on the same land can increase the risk of pests and disease.Horticultural farmers stated that climate change is causing more pests and diseases to attack plants.Climate change in the form of rain that comes earlier, and high intensity rain causes more pests and diseases to attack, so farmers need to use pesticides more intensively.Horticultural farmers (40%) also rotate crops to reduce pest and disease attacks.Rotate crops also aim to improve the quality of soil structure and soil fertility [23], and preserve biodiversity [27].

Support for Adaptation to Climate Change of Bromo Horticultural Farmer to Environmental Dimension
Sustainable development as an interaction between three dimensions, which are ecological, social, and economic [21,28].Dale and Beyeler [29] put forward the criteria for indicators of agricultural sustainability in developing countries clearly from each environmental/ecological, social, and economic dimension.It is explained that environmental or ecological indicators consist of: aspects of the amount of fertilizer, amount of irrigation water, nutrient levels, water availability, water use efficiency, added with biodiversity and agricultural land or environment management [30,31].In a complete form of adaptation to climate change, horticultural farmers in the Bromo area have considered the environmental or ecological dimensions and their supporting aspects.Based on Tabel 1, it is explained that the climate change adaptation behavior of horticultural farmers in the Bromo area is most supportive to the aspects of land management (23.71%),successively aspects of fulfilling nutrients (17.14%), preserving biodiversity (16.90%), and then related to aspects of fertilization and water (14.08%).Typical land or environmental management in horticultural areas is terraces in the direction of the contour, terraces should be against the contour, but in the Bromo area this cannot be done because the land is sandy, so it is not possible to make this type of terrace.Farmers' adaptation is also carried out by considering preserving biodiversity, so that Bromo's typical types of vegetable crops (potatoes, cabbage, leeks, and tomatoes) remain to become central products in the area.Setting the planting period, selecting improved varieties, and intercropping farming system carried out by farmers intend to maintain the nutrient availability during the growth as well as for adapting in the climate change.It indicates that climate change adaptation by farmers in the Bromo area has noticed to indicators of the ecological dimension on sustainable agriculture.Apart from that, the adaptation to climate change by farmers is able to improving environmental quality to support sustainable agriculture.

Support for Adaptation to Climate Change of Bromo Horticultural Farmers to the Economic Dimension
Meanwhile, the economic aspects to assess sustainable agriculture are measured through income, land productivity [30], and production cost ratio [32].Adaptation to climate change does not only impact the environmental dimension, but economic dimension does.By differentiating farmers' adaptation levels in the high and low categories, and carrying out analysis of differences in average productivity, net income and R/C ratio, the results are as shown in Table 2. Table 2 provides an explanation that farmers who adapt (with high level of adaptation) have the consequence of achieving higher productivity, net income per hectare, and level of cost efficiency.It proves that the adaptation to climate change of horticultural farmers in the Bromo area have an impact on the economic dimension of sustainable agriculture.There was an increase in productivity of around 13.20%, an increase in revenue of 14.53%, and an increase in cost efficiency of 10.09%.Statistical testing based on economic dimensions, productivity, and cost efficiency has a significant effect at alpha 5%, while income has a significant effect at alpha 10%.In line with the previous research stated that adaptation strategies significantly increase productivity [33].These results show that climate change adaptation contributes to increasing agricultural productivity and farmer welfare to support sustainable agriculture.

Factors influencing decision making on implementing adaptation to climate change for horticultural farmers in the Bromo area
Analysis of factors that influence farmers' decision making to adapt to climate change uses logistic regression analysis (logit model).Independent variables that are thought to influence the implementation of adaptation to climate change include farmer age, formal education, farming experience, number of family members, and land area.The dependent variable is variable in the category of adaptation level include high level (value = 1) and low level (value = 0).The results of the logit model analysis are presented in Table 3.
Based on Table 3, it can be explained that there are 2 variables that have a negative influence on farmers' decision making to adapt, which are the farming experience (not significant) and the area of horticultural crops (significant at an alpha error level of 10%).This means that the longer the experience in farming and the larger the area owned by farmers, the more they will actually reduce the level of adaptation of farmers.Farmers will only choose a few combinations of forms of adaptation.The variables of farmer age (not significant), farmer education, and number of family members have a positive effect, meaning that the higher these three variables, the more they will increase the farmer's opportunity to combine several forms of climate change adaptation in horticultural farming.
Farmer age has a significance value of 0.384 > 0.05, it means that the age variable has an insignificant influence on the implementation of climate change adaptation.The younger the farmer, the easier it is to adopt innovation so that the opportunity to implement adaptation to climate change is higher.In line with the results of previous research stated that young and old farmers have the same ability to adopt new innovations in farming activities [34].Farmer education has a significance value of 0.043 > 0.05, it means that education has a significant and positive effect on the implementation of climate change adaptation by farmers.The coefficient value of 2.193 indicates that if farmer education increases by 1 year, it will increase the odds ratio of the farmer's chances to implement a higher level of adaptation by 2.193.High formal education provides broad and useful insight for improving farmers' farming businesses [33,35].The farming experience variable shows a significance value of 0.160 > 0.05, which means that the farming experience has an insignificant effect on the implementation of climate change adaptation.It is because the longer farmers carry out farming, the easier it is to accept and apply innovations in farming [35,36].The number of family members has a significance value of 0.075 < 0.1, it means this variable has a significant and positive influence on the implementation of climate change adaptation.The coefficient value of 2.929 can be interpreted that if the number of farmer family members increases by 1 person, it will increase the odds ratio of the farmer's chances of implementing a higher level of adaptation by 2.929.The increasing number of family dependents tends to make farmers become more active in farming.The land area variable has a significance value of 0.065 < 0.1.This value means that land area has a significant and negative influence on the implementation of climate change adaptation by farmers.The coefficient value of 2.318 can be interpreted that if the farmer's land area increases by 1 Ha, it will reduce the odds ratio of farmer's chances to implement the adaptation level by 2.318.It is because farmers with larger land areas are less likely to combine forms of climate change adaptation.

Conclusions
There are 13 adaptation forms of Bromo horticulture farmers, namely: 1) intensifying the use of drum fertilizer, 2) using pest and disease resistant varieties, 3) using flood or drought tolerant varieties, 4) cultivating land against the contour, 5) using chemical pesticides, 6) increasing the intensity of control weeds, 7) improving accuracy in preparing seeds or seedlings, 8) planting early in the rainy season, 9) planting terrace reinforcing plants, 10) applying an intercropping system, 11) changing planting times, 12) applying recommended planting distance, and 13) crop rotation.
The adaptation to climate change by Bromo horticulture farmers was able to support the economic dimension through aspects of land productivity, farming income per hectare, and cost efficiency.The results of the analysis show that farmers with a high level of adaptation have higher land productivity per hectare, income per hectare, and cost efficiency than farmers with a low level of adaptation.

Table 1 .
Forms of Adaptation to Climate Change, Level of Implementation, and Contribution to the Environmental Dimension of Bromo Horticulture Farmers

Table 2 .
Differences in Productivity, Income, and Cost Efficiency in Climate Change Adaptation Level Categories Bromo Horticulture Farmers

Table 3 .
Results of logit analysis model of determinant factors in decision making for implementing climate change adaptation for horticulture farmers in the Bromo Area