INTRODUCTION
Background and rationale
Indonesia, the world's largest archipelago with 17,000 islands, is situated across two bio-geographic regions—Indonesia and Australia—boasting remarkable biodiversity in its pristine rainforests and rich coastal and marine environments It is recognized as home to the planet's richest biological diversity of plant and animal life, with the highest marine diversity globally and the second largest rainforest area.
Indonesia boasts a strategic geographical location and rich natural resources; however, recent climate changes have significantly impacted agriculture, forestry, public health, biodiversity, and natural resources These climatic shifts not only affect the environment but also have profound effects on the population and national development Daily weather phenomena, including temperature, precipitation, light intensity, wind direction, and humidity, directly influence local communities Despite these challenges, Indonesia's economy has experienced rapid growth over the past two decades, driven by effective economic policies and political stability.
Indonesia is currently facing significant challenges due to climate change, experiencing severe droughts, heat waves, and floods These climatic phenomena pose major obstacles to the country's development in the near future Each location in Indonesia exhibits a unique climate pattern that evolves daily, weekly, monthly, and seasonally, with these patterns repeating annually This long-term climate data, which encompasses decades of weather observations, helps in predicting seasonal weather trends Additionally, the microclimate refers to the specific climate characteristics of smaller areas, particularly those close to the ground surface Understanding these patterns is crucial, as each plant species thrives in particular habitats influenced by the local climate.
For optimal growth, it is essential to meet the specific requirements of each crop variety, as the success or failure of the crop largely depends on how well these needs are addressed (Sakata et al., 2008).
Indonesia ranks as the fourth most populous country globally and stands as the tenth-largest agricultural producer Agriculture plays a vital role in the nation's economy, supported by its fertile land and tropical climate, which fosters diverse agricultural activities.
3 agricultural products, especially rice Around 49 million people work in agriculture (42% of the country's population) and contribute 13.5% of the country's total GDP (FAO-2013)
Weeds play a crucial role in managing land and water resources, significantly impacting agriculture by competing with crops for essential nutrients, soil moisture, and sunlight The extent of weed competition is influenced by various factors, including the species of weeds present, the severity and duration of the infestation, the competitive ability of the crops, and specific climatic conditions that affect the growth of both weeds and crops (Kropff et al 1991).
Weeds in tropical regions significantly reduce crop yields and create challenges for agriculture Favorable conditions such as high temperatures and abundant moisture lead to rapid weed growth, resulting in multiple generations per year and dense populations Many annual weed species behave like perennials in these environments, complicating control efforts Effective modern weed management requires advanced techniques and the development of tailored control programs Commonly found weeds are typically easier to manage, as they are widespread but not overly aggressive.
Research objective
This study aims to assess the diversity of weeds across various habitats and crops in Palembang and Indralaya, Indonesia Additionally, it will evaluate the influence of climate factors, including temperature and precipitation, as well as the impact of chemical usage, such as fertilizers, herbicides, and pesticides, on weed diversity.
Research’s question
This study is designed to address the following question:
How is the habitats and different crop varieties determining weed species composition and diversities in Palembang and Indralaya, Indonesia?
Hypothesis
The hypothesis posits that weed communities often exist in a nonequilibrium state, where periodic population reductions and environmental fluctuations disrupt competitive equilibrium This disruption can lead to a dynamic balance between competitive displacement and population reduction frequency, ultimately maintaining a stable level of diversity Additionally, varying crop varieties and habitats can lead to increased population growth rates among competitors, which typically results in a decline in weed diversity.
The requirements
- Data collection to be honest, objective and accurate
- Assessing the impact of is the habitats and different crop varieties determining weed species composition and diversitie in Palembang and Indralaya.
Limitations
Lack of experience in the classification of grass species by families and genera
LITERATURE REVIEW
Introduction about weeds
2.1.1 The origins and definitions of weeds
Weeds have existed in nature long before the advent of agriculture, posing challenges to early civilizations (Kumar et al., 2016) In ancient Near Eastern cultures, while individual weeds were recognized, there is little evidence of a collective term for them Weeds are defined as undesirable plants that grow where they are not wanted, often hindering the growth of cultivated crops and disrupting human activities They can be harmful and considered useless, as they thrive in modified habitats, competing with beneficial plants (Singh et al., 1996) There are four categories of plants: wild plants, which grow uncontrollably in nature; crop plants, which are cultivated for their benefits; rouge plants, which can be economically advantageous; and weeds, which threaten agricultural productivity by increasing labor costs and reducing yields (David Kruft, 2001).
Table 1: The Origin of Important Weeds
Cirsium arvense Europe, North Africa & Eastern Asia
Eupatorium odoratum West Indies and Tropical America
Eichhornia crassipes Tropical America, Brazil
Lantana camara Central America/Tropical America
Opuntia spp Western Hemisphere/South America
Sorghum halepense Southern Europe and Asia
Tribulus terrestris Southern Europe/Africa/Medeterrian region
There are over 350,000 plant species globally, with 30,000 identified as weeds Weeds are classified in various ways to develop effective management strategies for both crop and non-crop situations They are categorized into three main life cycle groups: annual, biennial, and perennial, which can be further subdivided Additionally, weeds can be classified based on their relationship with crops as seasonal/season-bound, crop-bound, or crop-associated (Joan Lee Faust, 1991).
Figure.1: Classification of weeds based on association with crops
Grasslands and shrubs play a vital role in the ecosystem, offering numerous benefits for agriculture, forestry, and the environment These areas enhance air quality, retain soil moisture, and act as natural filters for clean air Additionally, they help mitigate flooding caused by heavy rainfall and reduce soil erosion Furthermore, certain types of weeds can be utilized in culinary dishes and traditional medicine, highlighting their versatility and importance.
Weeds pose significant disadvantages to agricultural productivity by competing with crops for essential resources such as nutrients, light, and water Their well-developed root systems, primarily concentrated in the topsoil, allow them to absorb nutrients more effectively, leading to suboptimal growth of desired plants Additionally, weeds can serve as hosts for pests, further threatening the health of crops.
Weed classification based on association with crops
Root parasites Holo-root parasites Hemi-root parasites Summer
Holo-shoot parasites Hemi-shoot parasites
Seasonal weeds Crop-bound weeds
Pests thrive in environments with high host availability, leading to increased production costs due to necessary measures like weeding and chemical herbicides Additionally, the production of plant growth inhibitors can disrupt water movement, adversely affecting aquatic life, particularly fish.
Impact of habitat on diversity of weeds
Indonesia, located along the equator, is a vast archipelago comprising major islands like Sumatra, Java, and Borneo, along with numerous smaller ones The country features significant volcanic and mountainous terrain, with peaks rising over 10,000 feet Its climate exhibits sharp local variations, with cooler temperatures in the hills and differing rainfall patterns influenced by two primary monsoon systems The north monsoon, active from November to March, brings moisture from the Indian Ocean, while transition months in April and October experience lighter, variable winds Indonesia's tropical climate ensures heavy rainfall year-round, with the south monsoon making southern coasts wetter and the north monsoon affecting northern regions Despite abundant rainfall, sunshine persists, averaging four to five hours daily during wet months and eight to nine hours during dry periods Temperatures remain consistently high, with minor variations, while coastal areas experience a small daily temperature range that increases inland and in mountainous regions Additionally, the extreme southern islands, like Timor, may encounter strong winds and tropical cyclones from November to March, along with occasional thunderstorms that can cause local wind squalls Nights inland are cooler, providing some relief from coastal heat and humidity.
Indonesia's crop plant distribution is significantly influenced by climatic factors, including air movement, rainfall, temperature, and light To optimize growth, plants are typically spaced to maximize leaf area exposure to sunlight While some plants thrive in full light, others can successfully grow in shaded conditions Plants that develop in low light conditions tend to have reduced respiration rates, leading to lower photosynthesis levels and consequently a decrease in available carbohydrates for respiration.
Air circulation patterns in the atmosphere are primarily influenced by the sun's radiation, which heats the tropical regions more directly than the polar areas Warm air rises at the equator and moves toward the poles, where it cools and sinks, creating a cycle of air movement This ground flow is affected by various factors, including the Earth's rotation, axial tilt, and differences in heating between land and water, as well as elevation changes and local weather phenomena These interactions lead to the formation of diverse climatic regions, sometimes in close proximity to one another Strong winds can significantly impact crop yields, particularly during critical growth stages like blooming, when pollination is reliant on bee activity Young plants are vulnerable to damage from high winds, which can cause injury or dehydration To mitigate wind effects and enhance crop viability, tall trees are often strategically planted, such as Norfolk Island pines in Hawaii, which provide protection for macadamia nut crops.
Canifornia tall eucalyptus trees (Eucalytus spp.) serve as windbreaks in the central coastal valleys (Republic of Indonesia, 2016)
Topography and air circulation significantly impact rainfall patterns and distribution, with valley areas often receiving up to 100 cm of precipitation Mountain ranges act as barriers, forcing clouds to rise and cool, resulting in condensation and rainfall on the windward side, while leaving the leeward side drier Adequate rainfall during two-thirds of the growing season supports crop growth, but areas with insufficient water require irrigation through dams, aqueducts, canals, or groundwater wells Water is crucial for plant growth, comprising 75 to 95 percent of a plant's mass and playing a vital role in biological reactions, structural components, and temperature regulation Additionally, moisture influences climate by regulating temperature and filtering solar radiation, while also preventing heat loss, making atmospheric water an essential climatic insulator that mitigates extreme temperature variations.
Temperature significantly influences all chemical, physiological, and biological processes in plants While different plant species exhibit varying degrees of temperature adaptability, individuals within a species typically thrive within specific temperature ranges For instance, some algae can endure extreme heat up to 90 °C (195 °F) in hot springs, while certain plants in arctic regions are adapted to survive frigid conditions.
Most plant species thrive within a temperature range of 0°C to 50°C (32°F to 120°F), as extreme temperatures, such as 65°C (-85°F), are rare Biological activities are constrained by the freezing point of water at lower temperatures and protein denaturation at higher temperatures Even slight temperature variations can significantly affect the quality of harvested products (Republic of Indonesia, 2016).
Fertilizers and pesticides play a crucial role in enhancing agricultural yields, significantly impacting food production, especially in famine-prone regions However, their use raises environmental concerns, as these chemicals can contribute to water pollution through erosion, which carries them into waterways Additionally, there are worries regarding the potential risks pesticides pose to non-target plant and animal species, as well as to human health.
Palembang and Indralaya
Palembang, the capital of South Sumatera province, is the second-largest city in Sumatra and the sixth-largest in Indonesia, following Jakarta, Surabaya, Bandung, Medan, and Semarang Approximately 25% of its 1.4 million residents live in areas above the tidal marsh and along the Musi River, which significantly influences the city's geography Characterized by its flat terrain, Palembang spans 400.61 km² in the expansive lowland region east of the Bukid Barisan Mountains in southern Sumatra.
Sumatra, with an average elevation of just 8 meters and located approximately 105 kilometers from the Bangka Strait, is home to the Musi River, one of the largest rivers in the region This river divides the city into two main areas: Seberang Ilir in the north and Seberang Ulu in the south During the rainy season, many parts of the city experience flooding due to the river's tides The rivers are crucial for the livelihoods of the people in Palembang, serving as a means for transportation, rice cultivation, and daily activities such as bathing and washing Given the swampy area's unstable soil and high water table, it is essential to implement sanitation facilities that align with the unique characteristics of Palembang.
Indralaya, located in Ogan Ilir, South Sumatra, Indonesia, serves as a satellite city of Palembang, situated approximately 31 km away The construction of the Palembang-Indralaya highway between 2005 and 2010 significantly reduced travel time between the two cities Covering a total area of 77.65 km², Indralaya has a population density of about 42,498 residents and is divided into 20 villages Tanjung is the largest village, spanning 38.20 km², while Ulak Segelum is the smallest, at just 0.15 km² Additionally, the city is intersected by the Trans-Sumatra highway, enhancing its connectivity.
Software
SPSS (Statistical Package for the Social Sciences) is a powerful software tool designed for processing, data mining, and analyzing data related to weed species and their geographical relationships.
METHODS
Time and Place
This experiment was conducted in period for 4 months from March 2017 to June
2017 at the field in Graduate school-Sriwijaya University; Talang keramat Banyuasin and Kebun Bunga belong to Palembang; Indralaya in Indonesia.
Materials
The equipments used in the study as follow:
- 5 plastics bags for setting up observation subplots
- 4 sticks (To set a stick in the ground)
Methodology
3.3.1 Methods of investigation and Sampling methods
To accurately assess vegetation in the research area, standard plots must be randomly selected to ensure they are representative of various habitats Before field activities commence, it's essential to map out these locations to maintain randomness and representation To analyze species composition and identify dominant species, all plant species within the research plots must be sampled, prioritizing those with flowers and fruits While many species are critical for understanding vegetation structure, not all may meet the sampling criteria Collected samples should be documented with relevant details, including location and plant characteristics, to facilitate thorough analysis.
14 identification, as well as temporary recognition for possible species In the each plot, set up the plot with small size (size approximately 1m x 1m) to indentify the land vegetation grass region
The growth of weed species is influenced by various external factors, leading to differences in their composition and prevalence across different regions To effectively investigate these factors, it is essential to assess soil conditions, plant growth conditions, irrigation, drainage, and the cultivated area Identifying the leading and trailing points in each area is crucial, and each field should involve sampling and surveying approximately five plots to gather comprehensive data.
This crucial step involves conducting an inquiry focused on specific weed species and their current climatic conditions, assessing the impact of climate and other factors on weed diversity and growth In each survey field, five plots are selected and divided diagonally The next step is to identify the names and species of weeds in each plot, followed by counting the number of each weed species, particularly through a 1m x 1m area investigation within each plot Finally, individual weed samples are collected, photographed, and documented with details such as location, sampling date, species name, and numbers.
Figure 2: Sample plots for measurement of taking samples
Samples were collected from the field were made specimen Samples after processing pre-treatment wet in the field and then bring to be processing of drying and flat pressing
Identify and examine the scientific name
During the specimen processing, we classified each family name into specific limbs The identification of scientific names involved analyzing samples based on characteristics such as branches, trunks, leaf shapes, roots, flowers, and fruits Key documents utilized for this identification included "Vietnam Vegetation" by Pham Hoang Ho (1991-1993, 1999-2000), the "List of Vietnamese Flora Species" (2001-2003), and "Weeds of Rice in Indonesia" by Soerjani and Tjitrosoepomo (1987).
The determination of transection relies on the various types of vegetations and land forms, utilizing purposive sampling to effectively represent the diverse land types and weeds found in the agricultural regions of Indralaya and Palembang.
Figure 3: The transect locations in Indralaya and Palembang Sources: Image
Landsat from Google Earth (free version)
Table 2: Co-ordinate point of transects
Transect Co-ordinate point Location
Graduate school in Sriwijaya university
Cluster analysis, also known as segmentation or taxonomy analysis, is an exploratory technique aimed at uncovering structures within data This method identifies homogeneous groups of cases, observations, or participants when prior groupings are unknown, without differentiating between dependent and independent variables.
In SPSS, cluster analyses can be accessed through Analyze/Classify, offering three methods: K-Means Cluster, Hierarchical Cluster, and Two-step Cluster This research utilized the Two-step Cluster method for data analysis, which serves as a versatile tool rather than a standalone analysis It identifies groupings by initially performing pre-clustering and then applying a cluster algorithm, efficiently managing large datasets that would be time-consuming with hierarchical methods (Everitt et al., 2011).
Hierarchical cluster analysis involves three essential steps: calculating distances, linking clusters, and selecting the optimal number of clusters Before initiating the process, it is crucial to choose the variables that will form the basis of the clusters In our case, we added the names of various weed types to the list of variables while keeping the default settings for the remaining options, as our focus was on clustering the cases effectively.
In the Statistics dialog box, we have the option to output the proximity matrix, which contains the distances calculated during the initial analysis, along with the predicted cluster membership for our observations For this analysis, we will keep all settings at their default values.
In the Plots dialog box, we incorporate the Dendrogram, which visually illustrates the merging of clusters and helps determine the optimal number of clusters.
The dialog box Method is crucial for specifying both the distance measure and the clustering method in SPSS It is essential to select the appropriate distance measure, as SPSS provides three main categories: interval (scale), counts (ordinal), and binary (nominal) data.
RESULTS AND DISCUSSION
Results
4.1.1 Herbarium preparation and the relationship between places
In single-linkage clustering, we begin with a matrix of similarity coefficients to analyze the data This research aims to assess the similarity of locations where weed samples were collected using light traps across various fields.
Table 3: Hypothetical matrix of similarity coeffiicients for different fields at two places in
Indralaya and three places in Palembang-Indonesia
1 Find greastest similarity less than unity
3 already joined to cluster containing 4
2 already joined to cluster containing 3
5 Find next-highest similarity More than 25
Therefore, place 5 ignore join to cluster containing 2 These same data were used to produce the dendrogram of community similarity shown in Figure 1
Dendrogram using Average Linkage (Between Groups)
Figure 4: A single-linkage cluster dendrogram showing the similarity place found at five light-trap sites in 5 reseach places
In the analysis of the matrix, the most similar pair of samples identified is between Indralaya 1 and Talang-Keramat, with a similarity score of 1 Following this, the second most similar pair is between Graduate School and Indralaya 1, which has a similarity score of 7, indicating a connection between these locations The investigation continues to reveal additional similarities among the remaining sites.
In the cluster analysis, place 3 is associated with places 1 and 4, forming a three-community group Additionally, place 3 shows a significant similarity with place 2 (Indralaya 2) at a distance of 17, indicating a connection between these two locations Place 2 is also linked to the clusters of places 3, 4, and 1, resulting in a four-community structure Ultimately, all five places—1, 2, 3, 4, and 5—are combined into a single cluster at a similarity distance of 25 This relationship is visually summarized in Figure 1, which illustrates the five-tree structure of the cluster analysis.
Following the collection of weeds from the crop fields, the specimens were identified by comparing them to certified reference specimens These identifications were subsequently verified using floras to ensure accurate naming for each plant.
Table 4: The species of each field types in the study site
The number of species is directly influenced by the population of individuals, meaning that any factor affecting individual numbers will subsequently alter species counts In natural cropping systems, the population of individuals fluctuates across different areas over the course of a month, reflecting the typical emergence patterns of annual weeds.
Table 5: Weed families of Indralaya and Palembang, Indonesia
Scientific names Species Genera Families
Paspalum virgatum P.virgatum Paspalum Poeceae
Mimosa pudica M.pudica Mimosa Fabaceae
Richardia brasiliensies R.brasiliensis Richardia Rubiaceae
Ageratum conyzoides A.conyzoides Ageratum Asteraceae
Achillea millefolium L Millefolium Achillea Asteraceae
Imperata cylindrica I.cylindrica Imperata Poaceae
Melastoma affine M.affine Melastoma Melastomataceae
Borreria alata S.alata Spermacoce Rubiaceae
Torenia violacea Violacea Torenia Linderniaceae
Dichrocephala integrifolia D.integrifolia Dichrocephala Asteraceae
Panicum repens P.repens Panicum Poaceae
Borerria laevis S.laevis Spermacoce Rubiaceae
Ipomoea triloba I.triloba Ipomoea Convolvulaceae
Brachiaria reptans B reptans Brachiaria Poaceae
Eleusine indica E indica Eleusine Poaceae
Uraria lagopodioides U.lagopodoides Uraria Fabaceae
Hyptis capitata H.capitata Hyptis Lamiaceae
Cyperus iria C.iria Cyperus Cyperaceae
Spigelia anthelmia S.anthelmia Spigelia Loganiaceae
Amaranthus gracilis A.hybridus Amaranthus Amaranthus
Portulaca oleracea P.oleracea Portulaca Portulacaceae
Stenotaphrum secundatum S.cecundatum Stenotaphrum Poaceae
Cyperus imbricatus C.imbricatus Cyperus Cyperaceae
Phyllanthus debilis P.debilis Phylanthus Phyllanthaceae
Cyperus kyllingia C.rotundus Cyperus Cyperaceae
Phyllanthus niruri P.niruri Phylanthus Phyllanthaceae
Cyperus distans C.distans Cyperus Cyperaceae
Centrosema molle C.molle Centrosema Fabaceae
Achyranthes aspera A.aspera Achyranthes Amaranthaceae
Stachytarpheta jamaicensis S.jamaicensis Stachytarpheta Verbenaceae
Cleome rutidosperma C.rutidosperma Cleome Cleomaceae
Elatine triandra E.triandra Elatine Elatinaceae
Phyllanthus urinaria P.urinaria 5 Phylanthus Phyllanthaceae
Scoparia dulcis S.dulcis Scoparia Plantaginaceae
Blumea lacera B.lacera Blumea Asteraceae
Mitracarpus villosus M.polycladus Mitracarpus Rubiaceae
Delonix regia D.regia Delonix Fabaceae
Physalis angulata P.angulata Physalis Solanaceae
Eclipta prostrata E.prostrata Eclipta Asteraceae
Boerhavia erecta B.erecta Boerhavia Nyctaginaceae
Manihot esculenta M.esculenta Manihot Euphorbiaceae
Peperomia pellucida P.pellucida Peperomia Piperaceae
Hypericum japonicum Hypericum Hypericoideae Hypericaceae
Solanum melongena S.melongena Solanum Solanaceae
Croton lobatus Lobatus Croton Euphorbiaceae
Hedyotis corymbosa O.corymbosa Oldenlandia Rubiaceae
Fimbristylis alboviridi F.alboviridis Fimbristylis Cyperaceae
Bacopa rotundifolia B.rotundifolia Bacopa Plantaginaceae
Echinochloa colona E.colona Echinochloa Poeceae
Lindernia hyssopioides Hyssopioides Lindernia Linderniaceae
Ipomoea aquatica I.aquatica Ipomoea Convolvulaceae
Sauropus androgynus S Androgynus Sauropus Phyllanthaceae
Cleome viscosa C Viscosa Cleome Cleomaceae
Hydrolea spinosa Spinosa Hydrolea Hydroleaceae
Eragrostis tenella E amabilis Eragrostis Poeceae
Ludwigia hyssopifolia L.hyssopifolia Ludwigia Onagraceae
Setaria palmifolia S.palmifolia Setaria Poaceae
Eriochloa polystachya E.polystachya Eriochloa Poaceae
Ischaemum rugosum I rugosum Ischaemum Poeceae
Digitaria ciliaris D.ciliaris Digitaria Poeceae
Brassica juncea B.juncea Brassica Brassicaceae
Digitaria setigera D.setigera Digitaria Poeceae
Figure 5: Taxa of Weed Plants
In the present investigation, a total of 63 plant species, belonging to 55 genera and
In Palembang and Indralaya, Indonesia, 32 families of crop land weeds were identified, specifically found in cultivated crop fields This study also examined plants located at the edges of these fields, with Borreria alata (Rubiaceae) and Eleusine indica (Poaceae) being the predominant weed species observed.
Portulaca oleracea (Portulacaceae) and Cyperus kyllingia (Cyperaceae)
Climate variability significantly influences crop production, with increases in sunlight and temperature leading to notable changes in plant growth and long-term agricultural impacts (Goudriaan et al, 1990) Temperature affects herbicide efficacy both directly and indirectly, showcasing its complex role in plant development Additionally, air and soil temperatures influence growth rates and leaf characteristics, determining the periods when plants are most vulnerable to herbicides (Jamal R Qasem, 2011) Data from a weather station in Indralaya and Palembang provides insights into air temperature and precipitation patterns (Table 3).
Table 6: Monthly total precipitation and average temperatures in Indralaya and
(Source: Meteorological, Climatological and Geophysical Agency,PalembangIndonesia)
Almost those weeds that were established in the rainy season (from November to
Timely germination of weeds, particularly in low-lying areas that retain moisture, can enhance their competitiveness by reducing competition for resources Additionally, dry conditions can influence the diversity of weed species in a field, as some species thrive better than others in arid environments.
Weed communities on compacted heavy soils exhibited the highest average biodiversity index values, while those on light sands or slightly loamy sands showed the greatest dominance index values The biodiversity index for weed communities on semi-compacted and compacted soils was influenced by the study area's proximity to the river, where traditional grassland and small farming practices thrive Annual water supply from the Musi River tributaries supports agriculture in Indonesia, and effective irrigation by farmers creates favorable conditions for both plant and weed growth Moreover, herbicides can significantly impact soil organisms and processes, such as decomposition and mycorrhizal functioning, highlighting the need to quantify these effects within agroecosystems.
Table 7 : Presents the factor in planting areas in the Palembang and Indralaya
The number of crop per field changed Not changed changed changed Not changed
4.1.5 Effects of fertilisers, herbicides and pesticides on weed communities
Changes in cropping practices and herbicide use significantly impact weed communities, but other factors also play a role Eutrophication, for instance, greatly affects community structure and biodiversity in various habitats (Marrs, 1993) The "hump-back" model illustrates the relationship between increasing fertility, productivity, and species richness, showing that diversity initially rises to a peak before declining Recent studies indicate that the application of fertilizers, particularly nitrogen, has a substantial effect on plant species composition in agroecosystems.
Changes in weed susceptibility due to varying herbicide and fertilizer use only partially reflect the overall impact of weed management on arable field flora Herbicides can either completely eliminate or promote plant growth, influenced by factors such as dosage and plant susceptibility Reduced herbicide doses may subtly alter plant morphology and phenology Additionally, environmental conditions surrounding herbicide applications significantly affect their performance and environmental impact In Indonesia, where temperatures are consistently high and drought is prevalent throughout the year, these factors play a crucial role in specific weed management practices.
Understanding the effects of sunlight and drought on plants is crucial, particularly regarding how these dry conditions influence weeds and the effectiveness of herbicides in both the plants and the soil.
The application of herbicides in agriculture has evolved from earlier practices based on intensive farming experiences As labor shortages and high costs become more prevalent, producers increasingly turn to herbicides to manage weeds effectively Herbicides are particularly beneficial during the early development stages of forest nursery plants, where weed competition can significantly impact growth This method not only enhances economic efficiency but also minimizes mechanical damage to young plants, which is often unavoidable due to high soil moisture that restricts mechanical treatments Furthermore, herbicide use reduces weed control costs, as reapplications are typically unnecessary and require less labor Weed control strategies can be executed through broadcast application, targeted row treatments, or localized application around nursery plants, with the primary goal being to prevent competition rather than complete eradication of weeds.
Pesticides are chemicals designed to eliminate harmful insects and weeds that threaten plant health A survey revealed that farmers in Talang-Keramat and the Unsri campus in Indralaya typically refrain from using herbicides during plant growth In contrast, farmers in Kebun-bunga apply herbicides and insecticides approximately three times throughout the crop cycle—before planting, during growth, and post-harvest—to combat infectious weeds that damage their crops This practice contributes to a notable difference in weed species and diversity in Kebun-bunga compared to other regions Additionally, farmers in Talang-Keramat and the Unsri campus utilize both organic and inorganic fertilizers, such as chicken manure, cow manure, and urea, to supply essential nutrients for optimal plant growth and development.
Many farmers are turning to tools like the mattock or grass extractor for weed control, as they recognize the harmful effects of herbicides on both the environment and human health Additionally, the high cost of herbicides and pesticides discourages their use, prompting farmers to seek more sustainable and cost-effective solutions for their crops.
Organic fertilizers: chicken manure, cow manure, goat shit,…
Figure 6: Some pictures of pesticides and herbicides used in fields
Discussion
Weeds possess a unique ability to thrive amidst habitat changes, granting them a competitive edge over less aggressive species The relationship between habitats, crop varieties, and individual species, as well as ecosystems, is inherently complex Climate change, coupled with other factors like land use alterations and shifts in fire regimes, has the potential to transform currently benign species, both native and non-native, into invasive threats, while also activating sleeper weeds Those weeds that effectively adapt to habitat changes may not only occupy the voids left by vulnerable native plants but could also significantly disrupt ecosystem composition and integrity.
In fact, some factors like climate, fertilizers, quality of soils may favour certain native plants to such an extent that they then become weeds
High temperatures and dry soil conditions can extend the lifespan of weeds, while importing fodder and grain into drought-stricken areas may introduce new weed problems Elevated temperatures diminish the competitiveness of native plants, creating opportunities for weed invasions, which can be exacerbated by rainfall that spreads weeds along watercourses and disturbs existing vegetation This study found that even a brief period of organic cropping can enhance weed species diversity, although the differences in species numbers between organic and conventional fields were less pronounced than in previous research, likely due to the comparison being based on the same number of weed individuals Earlier studies may have overestimated the advantages of organic cropping for species diversity, as the higher species richness in organic systems is partially attributed to a greater number of individuals Some evidence supports the idea that herbicide-susceptible species are more prevalent in organic cropping, but there is limited support for the expectation of fewer nitrophilous species in the species pool.
The study of 39 organic fields revealed that the minor differences in species composition were likely due to the low intensity of conventional cropping and the brief duration of organic farming practices in these fields A significant shift in the species pool necessitates a longer period of organic cropping These changes influence the proliferation of specific weed species, leading to their expanded range and increased population size and density in new habitats (Pal R 2004).
CONCLUSION
Current findings indicate that short-term surveys (over 4 months) cannot effectively predict long-term changes in the species richness of arable weed communities due to varying farming practices While no single factor was pinpointed as a determinant of weed density and diversity, crop rotation was linked to higher weed diversity, whereas maize monoculture resulted in reduced diversity My research found a correlation between higher weed diversity and increased species richness However, the specific factors influencing weed species diversity remain unclear, highlighting the necessity for larger-scale analyses that can reveal differences in farming practices, particularly in regions with varying soil fertility and monoculture prevalence Additionally, data from weed surveys in South Sumatra, Indonesia, suggest that the application of fertilizers and herbicides significantly impacts species diversity and density in this region.
Further research is essential to understand the impact of rainfall and temperature on weed diversity, which is positively correlated with weed density A comprehensive understanding of how climate factors, fertilizers, and herbicides influence arable species is crucial for maintaining weed diversity Currently, there is a lack of original research on the niche and trait shifts of arable weeds concerning crop varieties Future studies should adopt a systemic approach that combines process-oriented and spatially explicit investigations to accurately reflect the functional interrelations within arable ecosystems Relying solely on individual weed species is insufficient to capture habitat effects in a short timeframe To effectively assess the influence of climate on weed growth, research should span at least three seasons.
Alberto, A M P., Ziska, L H., Cervancia, C R and P A Manalo 1996 The influence of increasing carbon dioxide and temperature on competitive interactions between a C3 crop, rice (Oryza sativa) and a C4 weed (Echinochloa glabrescens) Aust.J.Pl Physiol 23: 795-802
Australian Module, 2008 Climate change impacts on weeds and pests, An initiative of The national Agricultural and climatic change Action plan
Auld, B A 2004 The persistence of weeds and their social impact Int J Social Eco., 31 : 879- 86
Ahn, Y.J., Kim, K.J., & Yoo, J.K (2001) Toxicity of the herbicide glufosinateammonium to predatory insects and mites of Tetranychus urticae (Acari : Tetranychidae) under laboratory conditions Journal of Economic Entomology, 94, 157-161
Archambault D J X Li, D Robinson, J T O’Donovan Kurt, K Klein, 2001 The Effects of Elevated CO2 and Temperature on Herbicide Efficacy and Weed/Crop Competition, Agriculture and Agri-Food Canada
Beegle, D B and D D Lingenfelter 1996 Soil Acidity and Aglime, Agronomy Facts
3, College of Agric Sci., Penn State Univ., Univ Park
Bunce, J A 2001 Weeds in a changing climate BCPC Symp Proc No 77: The World’s
Bhumesh Kumar, India; Dr M.S Bhullar, India; Dr Sushil Kumar, India- Weed Science
Societies of Asian-Pacific Region 2015 In Commemoration of Silver Jubilee APWSS Conference, Hyderabad, India Asian-Pacific Weed Science Society and Indian Society of Weed Science, Jabalpur, India, 50
Boatman, N.D (1992) Effects of herbicide use, fungicide use and position in the field on the yield and yield components of spring barley Journal of Agricultural Science, Cambridge, 118, 17-28
Chandrasena, N., 2009 How will weed management change under climate change, some perspective Journal of crop and weed; 5 (2) 95-105
Chancellor R J The long-term effects of herbicides on weed populations Journal of
Carvalho, S J P de.; Nicolai, M.; Ferreira Rodrigues, R.; De Oliveira Figueira, A.V & Christoffoleti, P.J (2009) Herbicide selectivity by differential metabolism: considerations for reducing crop damages Scientia Agricola, Vol.66, No.1, 136-
142 Cole, D J (1994) Detoxification and activation of agrochemicals in plants
Pesticide Science, Vol.42, 209 - 222 Cudney, D W (1996) Why Herbicides Are Selective California Exotic Pest Plant Council, Symposium Proceedings
CRC Australian Weed Management 2008 Briefing Notes Invasive Pl Climate Change David Kruft, Legal Research Assistant November 2001 Impacts of Genetically-Modified
Crops and Seeds on Farmers
Djonoputro, E R Blackett, I.Weitz, A., Lambertus, A., Siregar, R., Arianto, I., Supangkat, J (2011) Opsi Sanitasi yang Terjangkau Untuk Daerah Spesifik, Water and Sanitation Program East Asia & the Pacific (WSP-EAP), Indonesia
Everitt, Brian (2011) Cluster analysis Chichester, West Sussex, U.K: Wiley ISBN 9780470749913
Hulme Pe, 2009 Relative roles of life-form, land use and climate in recent dynamics of alien plant distributions in the British, Weed Research 49, 19–28
Holm LG, DL Plucknett, JV Pancho & JP Herberger The World’s Worst Weeds University Press of Hawai, Hawai, 1977
Hyvửnen T., Ketoja E., Salonen J., Jalli H., Tianinen J Weed species diversity and community composition in cropping of spring cereals Agriculture, Ecosystems and
Goudriaan and Unsworth, 1990 Impact of carbon dioxide, trace gases and climate changes on global agriculture, No.353, WI, pp 111-130
Gupta OP Weed Management: Principles and Practices Agrobotanical Publishers, Bikaner, India, 1993
Jamal R Qasem (2011) Herbicides Applications: Problems and Considerations,
Joan lee faust, 1991 Gardening; 10 stubborn plants that bedevil American
Kumar, rakesh; chatterjee, dibyendu; deka, bidyut c.; kuotsu, manoj kumar rukuosietuo; ao, merasenla; ngachan, s V Research on crops Jun2016, vol 17 issue 2, p199-
Kropff, M.J and C.J.S Spitters 1991) A simple model of crop yield loss by weed competition from early observations on relative leaf area of the weeds Weed Res 31:97-105
Marshall E J P., Brown V K., Boatman N D., Lutman P J W., Squire G R., Ward L
K The role of weeds in supporting biological diversity within crop fields Weed Research – 2003, vol 43, p 77–89
Michael Case, Fitrian Ardiansyah, Emily Spector Climate change in Indonesia-
Implications for Humans and Nature
Pal R Invasive plants threaten segetal weed vegetation of south Hungary Weed Technol 2004;18:1314–1318
Patterson, D T (1995): Weeds in a Changing Climate Weed Science 43: 685–701
Petersen, J., 1999 Placement of fertilizer in cereal crops DJF Rapport 11, 1–64
Py ek P., Lep J Response of a weed community to nitrogenfertilization – a multivariate- analysis.Journal of Vegetation Science – 1991, vol 2, p 237–244
Redwitz C., de Mol F., Gerowitt B 2011 Multivariate analysis of maize field survey in Germany Proceedings if the 4th EWRS Workshop on Weeds and Biodiversity 28.02 – 02.03.2011, Dijon, France Pp.21
Rao VS Principles of Weed Science Oxford and I.B.H.Pub.Co, New Delhi, 1986
Sans F.X., Rotches-Ribalta R., Dubois D., Mader P 2011 Long term effects of farming on weed seed bank size and diversity in arable fields Proceedings if the 4th EWRS
Workshop on Weeds and Biodiversity 28.02 – 02.03.2011, Dijon, France Pp 17
Smith RJ, Hill JE 1990 Weed control technology in U.S rice In: Grayson BT, Green
MB, Copping LG, editors Pest management in rice London and New York: Elsevier p 314-327
Salonen, J., Laitinen, P., Saastamoinen, M & Salopelto, J 2011 The main weed species and their control in oilseed crops in Finland Agricultural and Food Science 20: 262-268
Sakata T., Higashitani A (2008) Male sterility accompanied with abnormal anther development in plants–genes and environmental stresses with special reference to high temperature injury Int J Plant Dev Biol 2 42–51
Singh, NN Angiras, S Kumar - 1996 Weed Management
Soerjani, Tjitrosoepomo,1987 Weeds of rice in Indonesia
Wagner, R G.; Newton, M.; Cole, E C.; Miller, J H & Shiver, B D (2004) The role of herbicides for enhancing forest productivity and conserving land for biodiversity in North America Wildlife Society Bulletin, Vol.32, No.4, 1028-1041
Williamson, Lucy (2007) “Climate Change Lessons in Indonesia” (Jakarta: BBC News, 2 May)
World Bank (2009) Indonesia Rising: Mainstreaming Climate Change for Sustainability (Jakarta, Indonesia: World Bank Office Jakarta)
Research indicates that rising atmospheric carbon dioxide levels could enhance glyphosate tolerance in plants, as discussed by Ziska et al (1999) in Weed Science Additionally, Zinn et al (2010) explored the impact of temperature stress on plant sexual reproduction, identifying critical vulnerabilities in the process These studies highlight the complex interactions between environmental factors and plant resilience.