STIPER Amuntai College of Agricultural Sciences Entrance Exam Set

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer implementing a new crop rotation system. To determine the most beneficial practice for long-term soil fertility and structure, we need to consider the principles of nutrient cycling, organic matter decomposition, and pest/disease management. A crop rotation that includes legumes (like soybeans) is crucial because legumes fix atmospheric nitrogen through a symbiotic relationship with Rhizobium bacteria in their root nodules. This process enriches the soil with nitrogen, a vital nutrient for plant growth, thereby reducing the need for synthetic nitrogen fertilizers. Furthermore, incorporating cover crops, such as grasses or brassicas, between main crop cycles helps to prevent soil erosion, suppress weeds, and add organic matter when tilled back into the soil. This organic matter improves soil structure, water retention, and microbial activity, all of which are fundamental to sustainable agriculture and are emphasized in STIPER Amuntai’s curriculum. The combination of nitrogen-fixing legumes and cover crops that enhance organic matter and soil structure provides a holistic approach to soil management. This integrated strategy directly addresses the challenges of maintaining soil productivity in the face of environmental pressures and aligns with the college’s commitment to sustainable agricultural development in the region. Therefore, a rotation incorporating nitrogen-fixing legumes and cover crops is the most advantageous for long-term soil health and productivity.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer transitioning from conventional monoculture to a more diversified system. The key to answering lies in identifying the practice that most directly enhances soil organic matter and nutrient cycling, which are foundational to long-term soil fertility and reduced reliance on synthetic inputs. Crop rotation with legumes, cover cropping, and reduced tillage are all beneficial practices. However, the integration of agroforestry, which involves planting trees and shrubs within or around agricultural fields, offers a more comprehensive and synergistic approach. Agroforestry systems contribute significantly to soil organic matter through leaf litter decomposition, improve soil structure and water infiltration due to root systems, enhance nutrient cycling by accessing deeper soil nutrients and fixing atmospheric nitrogen (if legumes are incorporated), and provide habitat for beneficial insects and pollinators. These combined effects lead to a more resilient and productive agroecosystem, aligning with the principles of sustainable agriculture emphasized at STIPER Amuntai. While other practices contribute, agroforestry’s multi-faceted benefits make it the most impactful in this context for fostering a robust, self-sustaining agricultural environment.

The question probes the understanding of integrated pest management (IPM) principles within the context of tropical agriculture, specifically relevant to STIPER Amuntai College of Agricultural Sciences’ focus on sustainable farming practices. The scenario describes a farmer facing a significant infestation of rice stem borers, a common pest in the region. The farmer is considering various control methods. The core concept being tested is the prioritization of control strategies within an IPM framework, which emphasizes ecological balance and long-term pest suppression over immediate, broad-spectrum chemical application. An IPM approach begins with monitoring and identification, followed by cultural controls (e.g., crop rotation, sanitation), biological controls (e.g., introducing natural predators or parasitoids), and finally, judicious use of selective chemical pesticides only when thresholds are exceeded and other methods are insufficient. The scenario highlights the farmer’s immediate inclination towards a broad-spectrum insecticide. However, a robust IPM strategy would first involve assessing the economic threshold of the pest, exploring biological control agents known to target stem borers in rice paddies (such as specific parasitic wasps or predatory insects), and implementing cultural practices that disrupt the pest’s life cycle or habitat. Only after these steps, and if the infestation warrants it, would chemical intervention be considered, and even then, a selective pesticide that targets the stem borer without harming beneficial insects would be preferred. Therefore, the most appropriate initial step in an IPM strategy, given the options, is to investigate and implement biological control measures, as this aligns with the foundational principles of ecological pest management taught at institutions like STIPER Amuntai College of Agricultural Sciences. This approach aims to establish a sustainable balance, reducing reliance on synthetic chemicals and their associated environmental and economic costs, which is a key tenet of modern agricultural science.

The question assesses understanding of soil nutrient management principles within the context of tropical agriculture, a core focus at STIPER Amuntai College of Agricultural Sciences. Specifically, it probes the concept of nutrient cycling and the potential for nutrient loss in a humid tropical environment. In such climates, high rainfall and temperatures accelerate organic matter decomposition, but also increase the risk of nutrient leaching and volatilization. Consider a scenario where a farmer in a tropical region, aiming to improve rice yields, applies a nitrogen-rich organic fertilizer. Without proper soil management techniques, particularly in the context of STIPER Amuntai’s emphasis on sustainable agricultural practices, several nutrient loss pathways can become significant. Leaching, the process where water-soluble nutrients are washed down through the soil profile, is exacerbated by heavy rainfall common in tropical areas. Volatilization, the loss of nitrogen as a gas (e.g., ammonia) into the atmosphere, can occur, especially with surface application of certain organic materials under warm conditions. Runoff, the movement of nutrients across the soil surface with water flow, is also a major concern, particularly on sloped land or after intense precipitation events. Immobilization, where soil microbes temporarily tie up nutrients, is a natural process but can be influenced by the carbon-to-nitrogen ratio of the applied organic matter. However, the most pervasive and significant losses in a humid tropical setting, directly impacting the efficiency of fertilizer application and contributing to environmental pollution, are typically leaching and volatilization, often compounded by surface runoff. Therefore, understanding these primary loss mechanisms is crucial for optimizing nutrient use efficiency and promoting environmentally sound agricultural practices, aligning with STIPER Amuntai’s commitment to sustainable development.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. Specifically, it probes the nuanced benefits of intercropping legumes with cereal crops in the context of nutrient cycling and soil structure. Legumes, through their symbiotic relationship with rhizobia bacteria, fix atmospheric nitrogen, enriching the soil. This biological nitrogen fixation reduces the need for synthetic nitrogen fertilizers, which can have detrimental environmental effects, including eutrophication and greenhouse gas emissions. Furthermore, the diverse root systems of intercropped species contribute to improved soil aggregation, enhancing water infiltration and aeration, and reducing erosion. This contrasts with monocultures, which can deplete specific nutrients and degrade soil structure over time. The question requires candidates to synthesize knowledge of plant physiology, soil science, and ecological principles to identify the most comprehensive benefit. The correct answer highlights the synergistic effects on both nutrient availability and soil physical properties, reflecting a holistic approach to agricultural sustainability that is central to STIPER Amuntai’s curriculum.

The question assesses understanding of soil nutrient management principles in the context of tropical agriculture, a core area for STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in South Kalimantan facing declining yields in a rice paddy system. The key issue is the potential for nutrient depletion and imbalance due to continuous cropping without adequate replenishment. Let’s analyze the options based on agricultural science principles relevant to STIPER Amuntai: * **Option a) Implementing a crop rotation system that includes legumes and incorporating organic matter amendments.** This is the most comprehensive and sustainable solution. Legumes fix atmospheric nitrogen, enriching the soil. Organic matter improves soil structure, water retention, and nutrient availability, while also providing a slow-release source of essential elements. This approach directly addresses potential nutrient deficiencies and improves overall soil health, aligning with STIPER’s focus on sustainable agricultural practices. * **Option b) Increasing the application of synthetic nitrogen fertilizers to compensate for perceived deficiencies.** While nitrogen is crucial for rice, relying solely on synthetic nitrogen can lead to nutrient imbalances, soil acidification, and environmental pollution (e.g., eutrophication). It doesn’t address other potential nutrient limitations or improve soil structure, making it a short-term, less sustainable fix. * **Option c) Conducting detailed soil analysis to identify specific nutrient deficiencies and then applying targeted micronutrient fertilizers.** Soil analysis is a vital first step, but focusing *only* on micronutrients might overlook macro-nutrient limitations (like phosphorus or potassium) or the fundamental issue of organic matter depletion. While targeted application is good, it’s often part of a broader strategy. * **Option d) Shifting to a monoculture of a high-yielding rice variety to maximize immediate output.** Monoculture exacerbates nutrient depletion and increases susceptibility to pests and diseases, leading to a downward spiral in productivity and soil health. This is contrary to the principles of sustainable agriculture that STIPER emphasizes. Therefore, the most effective and scientifically sound approach, reflecting STIPER’s commitment to sustainable and integrated farming, is the combination of crop rotation with legumes and organic matter incorporation.

The question assesses understanding of soil nutrient management principles in the context of tropical agriculture, specifically focusing on phosphorus (P) availability in acidic soils, a common characteristic of many Indonesian agricultural lands, including those around Amuntai. In acidic soils, free aluminum (Al) and iron (Fe) oxides are abundant. These oxides have a high capacity to adsorb phosphate ions (\(P O_4^{3-}\)), a process known as phosphorus fixation. This fixation renders the phosphorus unavailable for plant uptake, even if it is present in the soil. The core concept here is the relationship between soil pH and phosphorus availability. As soil pH decreases (becomes more acidic), the concentration of soluble Al and Fe increases, leading to greater P adsorption. Conversely, as soil pH increases (becomes more alkaline), P availability generally improves up to a certain point, after which calcium (Ca) fixation can occur. However, for typical tropical acidic soils, the primary limiting factor for P availability is fixation by Al and Fe. Therefore, to enhance phosphorus availability in such conditions, strategies that reduce the activity of Al and Fe or compete for P adsorption sites are employed. Liming (application of calcium carbonate or calcium oxide) is a fundamental practice to raise soil pH. By increasing the pH, liming reduces the solubility and activity of Al and Fe, thereby decreasing P fixation. Additionally, liming can precipitate Al and Fe as hydroxides, which are less reactive with phosphate. Organic matter also plays a crucial role by forming complexes with Al and Fe, thereby reducing their ability to adsorb P. The application of phosphorus fertilizers in smaller, more frequent doses, or the use of less soluble P fertilizers, can also help manage fixation. However, the most direct and widely recognized method to combat P fixation in acidic soils is through pH adjustment via liming.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in Hulu Sungai Utara, North Kalimantan, implementing a new crop rotation system. The goal is to enhance soil fertility and reduce reliance on synthetic inputs, aligning with STIPER’s emphasis on ecological principles in agriculture. The farmer is transitioning from a monoculture of rice (paddy) to a rotation that includes legumes and cover crops. Rice cultivation, especially in flooded paddies, can lead to depletion of certain soil nutrients and affect soil structure over time. Legumes, such as soybeans or peanuts, are known for their ability to fix atmospheric nitrogen through symbiotic relationships with rhizobia bacteria in their root nodules. This process converts atmospheric nitrogen (\(N_2\)) into a form usable by plants (ammonia, \(NH_3\), which is then converted to ammonium, \(NH_4^+\)), thereby enriching the soil with a vital nutrient. Cover crops, like cowpea or mung bean, planted between main crop seasons or intercropped, further contribute by preventing soil erosion, suppressing weeds, improving soil structure through root activity, and adding organic matter when incorporated into the soil. Therefore, the most significant direct benefit of incorporating legumes into the rotation, particularly in the context of improving soil fertility for subsequent crops like rice, is the natural enrichment of soil nitrogen levels. This reduces the need for nitrogenous fertilizers, which can have environmental drawbacks and increase production costs. While improved soil structure and increased organic matter are also crucial benefits of crop rotation and cover cropping, the direct and most immediate impact on nutrient availability, specifically nitrogen, is the primary advantage of including legumes. The question asks for the *most significant direct benefit* of the legume component in the rotation.

The question assesses understanding of soil science principles relevant to tropical agriculture, specifically focusing on the impact of continuous monoculture on soil nutrient cycling and structure, a key concern for institutions like STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in Hulu Sungai Utara Regency, known for its agricultural activities, who has been cultivating rice continuously for a decade without significant soil amendment. This practice leads to a depletion of essential macronutrients, particularly nitrogen and phosphorus, which are heavily utilized by rice and are not adequately replenished through natural processes or crop residue decomposition in a monoculture system. Furthermore, continuous rice cultivation can lead to soil compaction and a reduction in soil organic matter, impacting soil aeration, water infiltration, and the activity of beneficial soil microorganisms. The decline in soil fertility and physical properties necessitates intervention. The most effective long-term strategy to mitigate these issues, aligning with sustainable agricultural practices emphasized at STIPER Amuntai, involves a multi-pronged approach. Introducing crop rotation with legumes, such as soybeans or peanuts, is crucial. Legumes fix atmospheric nitrogen, enriching the soil with this vital nutrient and breaking the cycle of nitrogen depletion. Additionally, incorporating organic amendments like compost or animal manure enhances soil organic matter content, improves soil structure, increases water-holding capacity, and provides a slow-release source of various nutrients. Cover cropping during fallow periods can further protect the soil from erosion, suppress weeds, and contribute to organic matter accumulation. While inorganic fertilizers can provide a quick nutrient boost, they do not address the underlying issues of soil structure degradation and organic matter depletion, making them a less sustainable primary solution. Therefore, a combination of crop rotation with legumes and the application of organic amendments represents the most comprehensive and sustainable approach to restoring and maintaining soil health in this context.

The question assesses understanding of sustainable agricultural practices, specifically in the context of soil health and nutrient management, which are core to the curriculum at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer aiming to improve soil fertility in a region prone to nutrient depletion. The core concept here is the role of cover crops in nutrient cycling and soil structure improvement. Leguminous cover crops, such as *Centrosema pubescens* (Centro) or *Mucuna pruriens* (Velvet bean), are particularly effective because they fix atmospheric nitrogen through symbiosis with rhizobia bacteria in their root nodules. This biological nitrogen fixation directly enriches the soil with a crucial nutrient, reducing the need for synthetic nitrogen fertilizers. Furthermore, the biomass produced by cover crops, when incorporated into the soil as green manure, adds organic matter. Increased soil organic matter enhances soil structure, improves water retention, promotes beneficial microbial activity, and facilitates nutrient availability. Considering the options: * **Option a)** focuses on the dual benefits of nitrogen fixation by legumes and the addition of organic matter through biomass incorporation. This directly addresses the problem of nutrient depletion and soil degradation. * **Option b)** suggests using only inorganic fertilizers. While this can provide nutrients, it does not address the underlying issues of soil structure degradation and the depletion of organic matter, which are critical for long-term sustainability and are emphasized at STIPER Amuntai. It can also lead to environmental issues like nutrient runoff. * **Option c)** proposes crop rotation without specifying the inclusion of cover crops or organic amendments. While crop rotation is beneficial, it might not be sufficient on its own to rapidly rebuild depleted soil fertility and organic matter compared to a system that actively incorporates nutrient-fixing cover crops. * **Option d)** advocates for intensive tillage. This practice is generally detrimental to soil health, leading to increased erosion, loss of organic matter, and disruption of soil structure, directly contradicting the principles of sustainable agriculture taught at STIPER Amuntai. Therefore, the most comprehensive and sustainable approach for the farmer, aligning with STIPER Amuntai’s focus on ecological principles in agriculture, is the integration of leguminous cover crops.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer implementing a new crop rotation system. To determine the most likely positive impact on soil organic matter, we need to consider the characteristics of the crops involved. Legumes, such as soybeans or peanuts, are known for their ability to fix atmospheric nitrogen through symbiotic relationships with rhizobia bacteria in their root nodules. This process enriches the soil with nitrogen, a crucial nutrient for plant growth. Furthermore, legumes often have extensive root systems that contribute significant biomass to the soil upon decomposition, directly increasing soil organic matter. Cover crops, especially those with fibrous root systems or those that are tilled back into the soil (green manure), also contribute substantially to soil organic matter. However, the question specifically asks about the *most significant* positive impact on soil organic matter in the context of a rotation that includes a grain crop and a root crop. While grain crops contribute some organic matter through their residues, and root crops add organic matter from their root systems, the nitrogen-fixing capability and substantial biomass production of legumes, when integrated into a rotation, typically lead to the most pronounced increase in soil organic matter and overall soil fertility. Therefore, the inclusion of a legume in the rotation is the most critical factor for enhancing soil organic matter.

The question assesses understanding of soil nutrient management principles in the context of tropical agriculture, a core area for STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in South Kalimantan aiming to improve rice yields on a soil with known deficiencies. The key is to identify the most appropriate strategy that balances immediate nutrient needs with long-term soil health and sustainability, aligning with the college’s emphasis on responsible agricultural practices. The soil analysis indicates low levels of available phosphorus (P) and potassium (K), and a slightly acidic pH. Rice cultivation, especially in paddy systems, is known to have high nutrient demands, particularly for nitrogen (N) and P. Low P availability can severely limit root development and tillering, while low K can affect water regulation and disease resistance. An acidic pH can further reduce the availability of essential nutrients like P and micronutrients, while increasing the solubility of potentially toxic elements like aluminum. Considering these factors, a comprehensive approach is needed. Applying a balanced fertilizer that addresses the identified deficiencies is crucial. Organic matter amendment, such as compost or manure, is vital for improving soil structure, water retention, and nutrient cycling, particularly in tropical soils which can degrade rapidly. Organic matter also helps buffer soil pH, making nutrients more available. Crop rotation or intercropping with legumes can further enhance soil fertility by fixing atmospheric nitrogen and improving soil structure. Option A, focusing solely on nitrogenous fertilizers, would neglect the critical P and K deficiencies and the pH issue, leading to unbalanced growth and limited yield improvement. Option B, recommending liming without addressing the P and K deficiencies, would improve pH but not directly supply the missing macronutrients, thus not fully resolving the yield constraint. Option D, suggesting a single application of a high-potassium fertilizer, would overlook the phosphorus deficiency and the benefits of organic matter for overall soil health. Therefore, the most effective strategy, as outlined in the correct option, involves a combination of targeted mineral fertilization to correct the immediate P and K deficiencies, organic matter incorporation to improve soil physical and chemical properties and pH buffering, and potentially a legume integration for nitrogen fixation and soil improvement. This holistic approach aligns with sustainable agricultural principles taught at STIPER Amuntai College of Agricultural Sciences, promoting both immediate productivity and long-term soil resilience.

The question assesses understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) and its ecological underpinnings relevant to the STIPER Amuntai College of Agricultural Sciences’ curriculum. The scenario describes a farmer in Hulu Sungai Utara facing challenges with rice blast disease. Rice blast, caused by the fungus *Magnaporthe oryzae*, is a significant threat to rice production. Effective management requires a multi-faceted approach that minimizes reliance on broad-spectrum chemical pesticides, which can harm beneficial insects and disrupt ecological balance. Option A, promoting the use of resistant rice varieties, biological control agents (like specific fungi or bacteria that parasitize the pathogen), and cultural practices (such as proper water management and crop rotation), directly aligns with the principles of IPM. These methods aim to prevent pest outbreaks by maintaining a healthy agroecosystem, reducing the need for chemical interventions. This approach is central to sustainable agriculture, a key focus at STIPER Amuntai. Option B, advocating for the immediate application of a novel broad-spectrum fungicide, is a short-term solution that ignores the long-term ecological consequences and the potential for resistance development. This is contrary to the sustainable principles taught at STIPER Amuntai. Option C, suggesting a complete cessation of all farming activities until the disease naturally subsides, is impractical and economically unviable. While natural cycles can influence disease prevalence, active management is usually required. Option D, recommending the introduction of an invasive predatory insect species to control the disease vector, is a risky strategy. Introducing non-native species can have unpredictable and detrimental impacts on the local ecosystem, potentially creating new pest problems, which is a critical consideration in ecological studies at STIPER Amuntai. Therefore, the most appropriate and sustainable strategy, reflecting the educational philosophy of STIPER Amuntai College of Agricultural Sciences, is the integrated approach described in Option A.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer implementing a new crop rotation system designed to improve soil fertility and reduce reliance on synthetic inputs. The key to answering correctly lies in identifying which practice most directly contributes to enhanced soil microbial activity and nutrient cycling, which are fundamental to long-term soil health. Cover cropping, particularly with legumes, fixes atmospheric nitrogen, providing a natural source of fertility. It also adds organic matter when incorporated into the soil, which fuels microbial populations. This increased microbial activity leads to better nutrient availability for subsequent cash crops and improved soil structure. Crop diversification itself is beneficial, but the specific mechanism of nitrogen fixation and organic matter addition from legumes in a cover crop is the most potent driver of the described improvements. Intercropping can also enhance biodiversity and nutrient use efficiency, but the direct impact on microbial biomass and nitrogen availability is often more pronounced with well-managed legume cover crops. Reduced tillage minimizes soil disturbance, preserving soil structure and microbial habitats, but its primary benefit is not the direct addition of nutrients or stimulation of microbial populations in the same way as legume cover crops. Organic fertilization, while beneficial, is a direct input rather than a system-level practice that intrinsically enhances soil biological processes over time through ecological interactions. Therefore, the integration of legume cover crops within the rotation is the most impactful element for the observed soil improvements.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer implementing a new crop rotation system. To determine the most beneficial outcome for soil organic matter (SOM) content, one must consider the biological processes involved in decomposition and nutrient cycling. Leguminous crops, such as soybeans or peanuts, are known for their ability to fix atmospheric nitrogen through a symbiotic relationship with rhizobia bacteria in their root nodules. This process enriches the soil with nitrogen, a crucial nutrient for plant growth. Furthermore, the residue from these crops, when incorporated back into the soil, contributes significantly to the soil organic matter pool. Cover crops, particularly those with extensive root systems and high biomass production, also play a vital role in increasing SOM by adding organic material and improving soil structure. Continuous monoculture, on the other hand, tends to deplete soil nutrients and reduce SOM over time due to consistent nutrient removal by the same crop and potentially less diverse root structures and residue inputs. Intercropping, while beneficial for biodiversity and pest management, might have a less direct or pronounced impact on SOM accumulation compared to a well-designed rotation that specifically includes nitrogen-fixing and high-biomass cover crops. Therefore, a rotation incorporating nitrogen-fixing legumes and cover crops is the most effective strategy for enhancing soil organic matter content.

The question assesses understanding of soil nutrient management principles relevant to tropical agriculture, a core focus at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in Hulu Sungai Utara, a region characterized by specific soil types and cropping systems. The farmer is observing reduced yields in rice paddies, a common staple crop. The explanation focuses on identifying the most likely limiting nutrient based on the symptoms described and the typical soil conditions in the area. In the context of rice cultivation in tropical regions like those surrounding Amuntai, nitrogen (N) is frequently the most limiting nutrient. This is due to several factors: high rainfall can lead to leaching of nitrates, organic matter decomposition rates are high, and rice plants have a high demand for nitrogen throughout their growth cycle, particularly during vegetative and reproductive stages. Symptoms of nitrogen deficiency typically include general yellowing (chlorosis) of older leaves, stunted growth, and reduced tillering, all of which are alluded to in the scenario. Phosphorus (P) deficiency usually manifests as purplish discoloration, especially on lower leaves and stems, and delayed maturity. Potassium (K) deficiency often appears as yellowing or necrosis along the leaf margins, starting with older leaves. Sulfur (S) deficiency can resemble nitrogen deficiency but often affects younger leaves first and can lead to a more uniform pale green or yellowish appearance across the entire plant. Given the widespread nature of nitrogen limitation in rice and the general symptoms described, nitrogen is the most probable primary limiting nutrient. Therefore, a balanced fertilizer program that prioritizes nitrogen supplementation would be the most effective initial strategy for the farmer to consider. This aligns with the practical agricultural science training at STIPER Amuntai, emphasizing evidence-based nutrient management for improved crop productivity.

The question revolves around understanding the principles of integrated pest management (IPM) and its application in a specific agricultural context relevant to STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in Hulu Sungai Utara facing a recurring infestation of rice stem borers in their paddy fields. The farmer has been relying heavily on broad-spectrum synthetic insecticides, which are proving less effective over time and are also impacting beneficial insect populations. The core concept to evaluate is the most appropriate next step for this farmer, considering the principles of sustainable agriculture and effective pest control as taught at STIPER Amuntai. Integrated Pest Management (IPM) emphasizes a multi-faceted approach that prioritizes prevention and the use of biological and cultural controls before resorting to chemical interventions. Let’s analyze the options in the context of IPM: * **Option A (Focus on scouting and monitoring, followed by targeted biological controls):** This aligns perfectly with IPM principles. Regular scouting allows for early detection of pest populations and their life stages, enabling timely and precise interventions. Introducing or conserving natural enemies (biological controls) like parasitic wasps or predatory insects is a cornerstone of IPM, reducing reliance on chemicals and preserving biodiversity. This approach addresses the diminishing effectiveness of insecticides and the impact on beneficials. * **Option B (Increase the frequency and dosage of synthetic insecticides):** This is the opposite of IPM. It exacerbates the problem of insecticide resistance, harms beneficial organisms, and can lead to environmental contamination, all of which are discouraged in modern agricultural practices promoted by institutions like STIPER Amuntai. * **Option C (Switch to a different brand of synthetic insecticide with a similar mode of action):** While a change in insecticide might offer temporary relief, it doesn’t address the underlying issue of resistance development or the negative impacts on the ecosystem. It’s a superficial solution that doesn’t embrace a holistic IPM strategy. * **Option D (Implement crop rotation with non-host crops and introduce a new variety of rice resistant to stem borers):** While crop rotation and resistant varieties are important cultural control methods within IPM, they are typically long-term strategies. The immediate problem described is the current infestation and the ineffectiveness of existing methods. While these are valuable components of a broader IPM plan, the most immediate and impactful next step for managing the *current* recurring problem, given the farmer’s current practices, is to shift towards monitoring and biological control, which directly tackles the resistance and beneficial insect issues. The question asks for the *most appropriate next step* to address the farmer’s current predicament, which is the declining efficacy of insecticides and the need for a more sustainable approach. Therefore, focusing on monitoring and biological control is the most direct and effective immediate response within an IPM framework. The calculation, in this conceptual context, is about weighing the effectiveness and sustainability of different pest management strategies. The best strategy is the one that most closely adheres to the principles of IPM, which are foundational to agricultural science education at STIPER Amuntai. The most effective approach is to move away from sole reliance on synthetic pesticides and integrate other methods.

The question probes understanding of soil amendment strategies for improving water retention in tropical agricultural settings, a core concern for STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in a region experiencing intermittent heavy rainfall followed by dry spells, a common challenge in Indonesia. The goal is to enhance the soil’s capacity to hold moisture. To determine the most effective amendment, we consider the properties of various organic materials. Compost, derived from decomposed organic matter, significantly improves soil structure by increasing aggregation. This aggregation creates larger pore spaces that can hold more water, while also improving aeration. Furthermore, the humic substances within compost contribute to cation exchange capacity, which helps retain essential nutrients and water. Biochar, produced from the pyrolysis of organic materials, also enhances water retention due to its porous structure and high surface area, which can adsorb water. However, the long-term benefits and integration into existing soil microbial communities are still areas of active research, and its immediate impact on soil structure might be less pronounced than well-established compost. Manure, while a valuable fertilizer, often has a higher nutrient content and can lead to nutrient imbalances or runoff if not properly composted. Its water-holding capacity improvement is generally less significant than mature compost or biochar. Synthetic fertilizers, on the other hand, primarily provide nutrients and do not directly improve soil structure or water retention; in fact, some can degrade soil structure over time. Considering the need for immediate and sustained improvement in water retention, alongside soil health, compost offers a balanced and proven solution. Its ability to bind soil particles, increase pore volume, and contribute to the formation of stable organic matter makes it the most suitable choice for the described conditions. The explanation focuses on the mechanisms by which each amendment affects soil physical properties, particularly water-holding capacity, aligning with the scientific principles taught at STIPER Amuntai College of Agricultural Sciences.

The question probes understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) in the context of rice cultivation, a staple crop in Indonesia and a key area of study at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer facing a significant outbreak of brown planthoppers. The core of IPM is to utilize a combination of methods to control pests while minimizing environmental impact and reliance on synthetic pesticides. This involves biological control (natural enemies), cultural practices (crop rotation, resistant varieties), and judicious use of chemical controls only when necessary and targeted. The correct answer emphasizes a holistic approach that aligns with the principles of ecological farming and the curriculum at STIPER Amuntai, which often integrates modern scientific advancements with traditional knowledge for sustainable resource management. Biological control agents, such as predatory insects or parasitic wasps, are a cornerstone of IPM, offering a natural and environmentally sound method to suppress pest populations. Cultural practices, like adjusting planting dates or using specific rice varieties known for their resistance, also play a crucial role in preventing or mitigating pest damage. The judicious and targeted application of selective pesticides, as a last resort, is also part of a well-designed IPM strategy. This multi-faceted approach aims to maintain pest populations below economically damaging levels without causing significant harm to the ecosystem or human health, reflecting the broader goals of agricultural sustainability promoted at STIPER Amuntai. The incorrect options represent less effective or unsustainable approaches. Relying solely on broad-spectrum chemical pesticides, for instance, can lead to resistance development in pests, harm beneficial insects, and pose environmental risks, contradicting the principles of IPM and sustainable agriculture. Similarly, focusing only on cultural practices without considering biological or chemical interventions might not be sufficient to manage a severe outbreak. A purely biological approach, while valuable, might also require specific conditions or a sufficient population of natural enemies to be effective against a severe infestation, making a combined strategy more robust.

The question assesses understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) within the context of rice cultivation, a staple crop in Indonesia and a key area of study at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer facing a significant outbreak of brown planthoppers (BPH) in their paddy fields. The core of IPM is to manage pests in an economically and environmentally sound manner, prioritizing biological and cultural controls before resorting to chemical interventions. The farmer’s current approach involves a broad-spectrum insecticide applied indiscriminately at the first sign of infestation. This method, while potentially offering immediate relief, is detrimental to the long-term sustainability of the farm and the surrounding ecosystem. Broad-spectrum insecticides kill not only the target pest (BPH) but also beneficial insects, such as natural predators (e.g., ladybugs, lacewings) and parasitoids, which are crucial for keeping pest populations in check naturally. This disruption of the natural ecosystem can lead to secondary pest outbreaks or the development of pesticide resistance in the target pest, making future control efforts more difficult and costly. A more effective and sustainable approach, aligned with the principles taught at STIPER Amuntai College of Agricultural Sciences, would involve a multi-pronged strategy. This would include: 1. **Monitoring and Thresholds:** Regularly scouting fields to assess pest populations and identify the economic threshold (the point at which pest damage is likely to cause more economic loss than the cost of control). This prevents unnecessary pesticide applications. 2. **Cultural Practices:** Implementing practices like crop rotation, adjusting planting dates, using resistant rice varieties, and maintaining field sanitation to disrupt pest life cycles and reduce habitat suitability. 3. **Biological Control:** Encouraging and conserving natural enemies of BPH by avoiding broad-spectrum pesticides, planting flowering plants that attract beneficial insects, and potentially introducing specific biological control agents. 4. **Targeted Chemical Control:** If pest populations exceed the economic threshold and other methods are insufficient, using selective insecticides that target the pest with minimal harm to beneficial organisms. Considering these principles, the most appropriate response for the farmer, reflecting a deep understanding of sustainable agriculture as emphasized at STIPER Amuntai College of Agricultural Sciences, is to shift towards an integrated pest management strategy. This involves a combination of monitoring, cultural practices, and biological control methods to manage the brown planthopper infestation, reserving chemical interventions as a last resort and using them judiciously. This approach fosters a resilient agroecosystem, reduces reliance on synthetic pesticides, and promotes long-term farm productivity and environmental health, which are core tenets of agricultural education at STIPER Amuntai College of Agricultural Sciences.

The question assesses understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) and its ecological implications within the context of Indonesian agriculture, a key area of study at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in Hulu Sungai Utara Regency, North Kalimantan, facing a common challenge with rice pests. The core of IPM involves a multi-faceted approach that prioritizes ecological balance over sole reliance on synthetic pesticides. This includes biological control agents (like predatory insects or parasitic wasps), cultural practices (crop rotation, intercropping), physical controls (traps), and judicious use of selective chemical pesticides only when absolutely necessary and as a last resort. The explanation emphasizes that the most effective and sustainable strategy, aligning with STIPER Amuntai’s commitment to environmental stewardship and agricultural innovation, would be to implement a comprehensive IPM program. This program would involve monitoring pest populations, identifying beneficial insects, and employing a combination of non-chemical methods before resorting to chemical interventions. The rationale is that over-reliance on broad-spectrum pesticides can disrupt natural predator-prey relationships, lead to pest resistance, and harm non-target organisms, including pollinators crucial for agricultural productivity. Therefore, a strategy that fosters biodiversity and utilizes natural pest regulation mechanisms is paramount for long-term agricultural sustainability and resilience, which are central tenets of the curriculum at STIPER Amuntai College of Agricultural Sciences.

The question assesses understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) and its alignment with the principles of ecological balance and resource conservation, core tenets at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in Hulu Sungai Utara facing pest resistance to synthetic pesticides. The most effective long-term strategy, aligning with STIPER’s emphasis on environmentally sound agriculture, involves a multi-pronged approach that minimizes reliance on chemical inputs. This includes promoting natural predators (biological control), employing crop rotation to disrupt pest life cycles, using resistant varieties, and applying targeted, less persistent chemical treatments only when absolutely necessary and in conjunction with other methods. This holistic approach fosters biodiversity, reduces environmental contamination, and builds resilience in the farming system, directly reflecting the college’s commitment to sustainable development and agricultural innovation. The other options, while potentially offering short-term relief, do not address the root cause of resistance or promote the long-term ecological health and economic viability that STIPER Amuntai College of Agricultural Sciences champions. For instance, solely increasing pesticide concentration can exacerbate resistance and harm beneficial organisms. Relying exclusively on resistant varieties might not be feasible for all crops or may eventually face its own resistance issues. A complete shift to organic farming, while laudable, might not be immediately practical or economically viable for all farmers in the region without significant transitional support and may not be the *most* effective *initial* step in addressing existing resistance.

The question assesses understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) and its ecological implications within the context of Indonesian agriculture, a core area of study at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in Hulu Sungai Utara Regency, North Kalimantan, facing challenges with rice blast disease. The goal is to identify the most ecologically sound and sustainable approach that aligns with the principles taught at STIPER Amuntai. Option a) represents a holistic IPM strategy that emphasizes biological control agents (e.g., predatory insects, parasitic wasps), cultural practices (e.g., crop rotation, resistant varieties), and judicious use of biopesticides. This approach minimizes reliance on synthetic pesticides, thereby protecting beneficial organisms, reducing environmental contamination, and promoting long-term soil health and biodiversity, all key tenets of sustainable agriculture promoted by STIPER Amuntai. Option b) suggests a broad-spectrum chemical pesticide application. While it might offer immediate control, it is detrimental to beneficial insects, can lead to pesticide resistance, and poses risks to the environment and human health, contradicting sustainable principles. Option c) proposes a sole reliance on genetically modified (GM) resistant rice varieties. While GM technology can be a tool, focusing solely on it neglects other crucial aspects of IPM and can lead to the evolution of new disease strains that overcome the resistance, demonstrating a lack of a comprehensive, adaptive strategy. Option d) advocates for organic farming practices that exclude all synthetic inputs, including biopesticides. While organic farming is sustainable, a complete exclusion of all interventions, even those derived from natural sources and used judiciously, might not be the most effective or practical approach for immediate disease management in a specific outbreak scenario, especially if it means foregoing proven biological control agents or biopesticides that are part of a broader IPM framework. Therefore, the integrated approach that incorporates biological and cultural methods with minimal, targeted chemical intervention (biopesticides) is the most aligned with advanced sustainable agricultural principles taught at STIPER Amuntai.

The question probes understanding of sustainable agricultural practices, specifically focusing on integrated pest management (IPM) in the context of rice cultivation, a staple crop in Indonesia and a key area of study at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer facing a significant outbreak of brown planthoppers. The core of IPM is to prevent pest populations from reaching economically damaging levels through a combination of methods, prioritizing biological and cultural controls before resorting to chemical interventions. In this scenario, the farmer has observed a high density of brown planthoppers. The most effective IPM strategy would involve a multi-pronged approach. Firstly, introducing natural enemies of the brown planthoppers, such as predatory insects like ladybugs or parasitic wasps, is a crucial biological control measure. These natural predators can significantly reduce the pest population without the negative environmental impacts of broad-spectrum insecticides. Secondly, employing cultural practices like maintaining optimal water levels in the paddy fields can disrupt the planthopper’s life cycle and reduce their survival and reproduction. For instance, fluctuating water levels can drown eggs or larvae. Finally, if these methods are insufficient, targeted application of selective insecticides that are less harmful to beneficial insects and the environment would be considered as a last resort. Therefore, the most appropriate and sustainable approach for the STIPER Amuntai College of Agricultural Sciences context, which emphasizes ecological balance and efficient resource management, is to first implement biological control agents and adjust water management practices. This aligns with the college’s commitment to research and education in environmentally sound agricultural techniques. The other options are less effective or sustainable. Relying solely on chemical pesticides, even if selective, can lead to resistance and harm beneficial organisms. Ignoring the outbreak is not a viable option. Implementing only cultural practices without biological support might not be sufficient for a severe outbreak.

The question assesses understanding of sustainable agricultural practices in the context of Indonesian tropical agriculture, specifically focusing on soil health and nutrient cycling, which are core to STIPER Amuntai College of Agricultural Sciences’ curriculum. The scenario involves a farmer in South Kalimantan aiming to improve rice paddy yields while minimizing environmental impact. The core concept is the integration of organic matter and biological nitrogen fixation to reduce reliance on synthetic fertilizers. Let’s consider the nitrogen cycle in a paddy field. Rice plants require nitrogen for growth. Synthetic nitrogen fertilizers provide readily available nitrogen but can lead to environmental issues like eutrophication and greenhouse gas emissions (N₂O). Organic amendments, such as compost or green manure, release nitrogen slowly as they decompose, improving soil structure and water retention. Leguminous cover crops, like Sesbania rostrata, are particularly valuable because they can fix atmospheric nitrogen through symbiotic bacteria in their root nodules. This biological nitrogen fixation (BNF) directly enriches the soil with nitrogen, reducing the need for external inputs. If a farmer uses 100 kg of compost per hectare, and assuming it contains 1% available nitrogen that is released over a growing season, this contributes \(100 \text{ kg} \times 0.01 = 1 \text{ kg}\) of available nitrogen. If they incorporate a leguminous cover crop that fixes an average of 50 kg of nitrogen per hectare, the total biologically available nitrogen from these organic sources is \(1 \text{ kg} + 50 \text{ kg} = 51 \text{ kg}\). If the target nitrogen requirement for the rice crop is 100 kg/ha, and the farmer has supplied 51 kg/ha through organic means, the deficit that might still require synthetic input is \(100 \text{ kg} – 51 \text{ kg} = 49 \text{ kg}\). However, the question asks for the *most effective* strategy for long-term soil fertility and reduced chemical input. While compost provides some nutrients, the direct atmospheric nitrogen fixation by legumes offers a more substantial and sustainable source of nitrogen, directly addressing the core challenge of nutrient depletion in tropical soils without the environmental drawbacks of synthetic fertilizers. Therefore, prioritizing the integration of nitrogen-fixing cover crops alongside organic matter management represents the most holistic and sustainable approach for improving soil fertility and reducing chemical dependency, aligning with STIPER Amuntai’s commitment to sustainable agriculture. The calculation demonstrates the contribution of organic matter and BNF, highlighting the significant impact of legumes. The key is understanding that BNF is a direct input of atmospheric nitrogen, a crucial element for plant growth, making it a cornerstone of sustainable nutrient management in rice cultivation.

The question assesses understanding of sustainable agricultural practices and their economic implications within the context of Indonesian agriculture, a core focus at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in Hulu Sungai Utara Regency, a region relevant to the college’s operational area, facing challenges with soil degradation and fluctuating market prices for rice. The farmer is considering adopting a new farming technique that promises higher yields but requires significant upfront investment in specialized equipment and organic inputs. To determine the most appropriate strategy, one must analyze the long-term sustainability and economic viability of different approaches. The core issue is balancing immediate profitability with ecological health and resilience. * **Option 1 (Focus on immediate yield increase with chemical inputs):** While this might offer a short-term boost in income, it exacerbates soil degradation, increases reliance on external inputs, and is unsustainable in the long run, contradicting the principles of ecological agriculture taught at STIPER Amuntai. This approach also makes the farmer vulnerable to price volatility and potential environmental regulations. * **Option 2 (Adopting the new technique with significant investment):** This option presents a higher risk due to the upfront cost and the unproven nature of the technique in the local context. Without a thorough cost-benefit analysis and risk assessment, it might lead to financial distress if yields don’t materialize as expected or if market prices remain unfavorable. This requires careful consideration of capital availability and return on investment. * **Option 3 (Integrated Pest Management and crop rotation with organic fertilizers):** This approach aligns with the principles of agroecology and sustainable farming, which are central to the curriculum at STIPER Amuntai. Integrated Pest Management (IPM) reduces reliance on synthetic pesticides, thereby lowering costs and environmental impact. Crop rotation improves soil health, nutrient cycling, and pest control naturally. Utilizing organic fertilizers, such as compost or manure, enhances soil structure and fertility over time, reducing the need for expensive chemical inputs and building long-term resilience. This strategy fosters a more stable and less input-dependent farming system, making it more economically viable and environmentally sound in the face of market fluctuations and soil degradation. It promotes a circular economy within the farm. * **Option 4 (Diversifying into non-rice crops without soil improvement):** While diversification can spread risk, doing so without addressing the underlying soil degradation issues will likely lead to poor performance across all crops and perpetuate the cycle of low productivity and environmental damage. Therefore, the most prudent and sustainable strategy, reflecting the educational ethos of STIPER Amuntai College of Agricultural Sciences, is the adoption of integrated pest management, crop rotation, and organic fertilization. This approach addresses both the immediate challenges of soil health and pest control while building a resilient and economically viable farming system for the future.

The question assesses understanding of soil nutrient management strategies, specifically focusing on the role of organic matter in improving soil fertility and plant growth, a core concept in agricultural sciences at STIPER Amuntai College of Agricultural Sciences. The scenario describes a farmer in Hulu Sungai Utara facing challenges with low crop yields due to depleted soil nutrients. The farmer is considering adopting a new practice. The core principle at play is the long-term impact of soil amendments on soil health. While synthetic fertilizers provide immediate nutrient boosts, they can degrade soil structure and microbial activity over time. Organic matter, conversely, improves soil aggregation, water retention, nutrient cycling, and supports beneficial soil organisms. This leads to more sustainable and resilient agricultural systems, aligning with STIPER Amuntai’s focus on sustainable agriculture. The question asks to identify the most beneficial long-term strategy for enhancing soil fertility and crop productivity in the given context. * **Option a) Incorporating compost derived from local agricultural waste:** This directly addresses the depletion of soil nutrients and organic matter. Compost is a rich source of slow-release nutrients and improves soil physical properties. It is a sustainable practice that aligns with the principles of circular economy in agriculture, often emphasized at institutions like STIPER Amuntai. The decomposition process enriches the soil with humus, which is crucial for long-term fertility. * **Option b) Relying solely on high-nitrogen synthetic fertilizers:** While this might provide a quick yield increase, it neglects the underlying issue of soil degradation. Over-reliance on synthetic fertilizers can lead to nutrient imbalances, soil acidification, and reduced microbial diversity, ultimately harming long-term soil health and productivity. This is contrary to sustainable agricultural practices. * **Option c) Implementing a strict crop rotation without any soil amendments:** Crop rotation is beneficial for nutrient cycling and pest management, but without replenishing the soil’s organic matter content, nutrient depletion will eventually limit yields. This approach alone does not address the fundamental issue of low organic matter and nutrient reserves. * **Option d) Practicing no-till farming exclusively:** No-till farming is excellent for soil structure and reducing erosion, but if the soil is already severely depleted of nutrients and organic matter, simply not disturbing it will not inherently improve fertility. It needs to be combined with other practices that actively build soil health, such as adding organic amendments. Therefore, incorporating compost is the most comprehensive and sustainable strategy for addressing the farmer’s challenges and improving long-term soil fertility and productivity, reflecting the educational philosophy of STIPER Amuntai College of Agricultural Sciences.

The question assesses understanding of sustainable agricultural practices and their impact on soil health, a core concern at STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in Hulu Sungai Utara implementing a new crop rotation system. The key to answering this question lies in identifying which practice most directly contributes to long-term soil fertility and structure, aligning with the principles of sustainable agriculture taught at STIPER. Consider a farmer in Hulu Sungai Utara who is transitioning from a monoculture rice paddy system to a more diversified agricultural approach to improve soil health and resilience. They are considering several new practices. To determine the most beneficial practice for long-term soil health and fertility in this context, we must analyze the potential impacts of each option on soil structure, nutrient cycling, and organic matter content. * **Option 1: Introducing a legume cover crop (e.g., cowpea) during the fallow period between rice seasons.** Legumes are known for their nitrogen-fixing capabilities, directly enriching the soil with essential nutrients. Furthermore, cover crops protect the soil from erosion, suppress weeds, and add organic matter when tilled back into the soil, significantly enhancing soil structure and microbial activity. This practice directly addresses nutrient depletion and improves the soil’s physical properties. * **Option 2: Increasing the frequency of synthetic fertilizer application to the rice crop.** While synthetic fertilizers can provide immediate nutrient boosts, their overuse can lead to soil acidification, reduced microbial diversity, and potential nutrient runoff, negatively impacting long-term soil health. This approach is generally counter to sustainable principles. * **Option 3: Expanding the area dedicated solely to rice cultivation.** Monoculture, especially of a water-intensive crop like rice, can deplete specific soil nutrients, disrupt natural soil ecosystems, and increase susceptibility to pests and diseases over time, leading to soil degradation. * **Option 4: Implementing a strict no-till farming method without incorporating organic amendments.** While no-till farming can reduce soil disturbance and erosion, its effectiveness in improving soil health is significantly enhanced when combined with practices that build organic matter, such as cover cropping or the addition of compost. Without these complementary practices, soil fertility may not improve substantially, and in some cases, could even decline due to the lack of organic matter replenishment. Therefore, the introduction of a legume cover crop during the fallow period is the most effective practice for enhancing long-term soil health and fertility in the context of transitioning from monoculture rice farming. This aligns with STIPER Amuntai College of Agricultural Sciences’ emphasis on agroecological principles and sustainable land management.

The question probes understanding of soil fertility management in the context of tropical agriculture, a core area for STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in Hulu Sungai Utara regency aiming to improve rice yields on a soil with naturally low cation exchange capacity (CEC) and high phosphorus fixation. Low CEC soils, common in tropical regions due to lower organic matter and clay content, have a limited ability to retain essential positively charged nutrients like potassium (\(K^+\)), calcium (\(Ca^{2+}\)), and magnesium (\(Mg^{2+}\)). This means these nutrients are more prone to leaching, especially with heavy rainfall. High phosphorus fixation, a phenomenon where applied phosphorus becomes unavailable to plants due to strong binding with soil minerals (particularly iron and aluminum oxides in acidic soils), is another significant challenge. To address these issues effectively and sustainably, a multi-pronged approach is necessary. Organic matter addition is crucial. Decomposed organic matter not only improves soil structure and water retention but also significantly increases CEC, providing more binding sites for cations. Furthermore, organic matter can chelate (bind) phosphorus, keeping it in a more soluble and plant-available form, thereby reducing fixation. The strategic use of liming (application of calcium carbonate or calcium oxide) is vital for two primary reasons: it neutralizes soil acidity, which is often associated with high phosphorus fixation, and it provides calcium, a key nutrient, while also increasing the soil’s CEC. However, excessive liming can lead to nutrient imbalances, so precise application based on soil testing is paramount. The choice of fertilizers is also critical. For phosphorus, using readily available forms like single superphosphate (SSP) or triple superphosphate (TSP) is important, but their effectiveness is enhanced by the improved soil conditions from liming and organic matter. For potassium, split applications of potassium chloride or potassium sulfate are recommended to minimize leaching losses due to the low CEC. Considering these factors, the most comprehensive and sustainable strategy involves a combination of organic matter enhancement and appropriate liming. Organic matter directly addresses both low CEC and phosphorus availability, while liming tackles acidity and contributes to CEC. While specific fertilizer types are important, their efficacy is maximized by the foundational improvements to soil health. Therefore, prioritizing the increase of soil organic matter and judicious liming provides the most robust solution for the farmer’s challenges at STIPER Amuntai College of Agricultural Sciences.

The question assesses understanding of sustainable agricultural practices and their economic implications in the context of Indonesian agriculture, specifically relevant to STIPER Amuntai College of Agricultural Sciences. The scenario involves a farmer in South Kalimantan considering a shift from conventional rice cultivation to an integrated farming system incorporating aquaculture and agroforestry. The core concept being tested is the long-term viability and resilience of agricultural systems. Integrated farming systems, by diversifying income streams and reducing reliance on single crops, enhance economic stability and environmental sustainability. Aquaculture provides an additional protein source and potential market, while agroforestry can improve soil health, biodiversity, and provide supplementary income from timber or non-timber forest products. These elements contribute to a more robust and adaptable farming model, aligning with the principles of sustainable development that STIPER Amuntai emphasizes. The economic benefit of such a system, while not requiring direct calculation, is understood through the diversification of revenue and the reduction of input costs associated with chemical fertilizers and pesticides, which are often high in conventional monocultures. The improved soil fertility from agroforestry practices can lead to higher yields in the long run, and the reduced environmental impact can mitigate risks associated with climate change and market volatility. Therefore, the most appropriate strategy for the farmer at STIPER Amuntai College of Agricultural Sciences to adopt, considering the long-term economic and ecological benefits, is the implementation of an integrated farming system that synergizes rice cultivation with aquaculture and agroforestry. This approach fosters resilience, reduces environmental degradation, and creates multiple avenues for income generation, reflecting a holistic and sustainable agricultural philosophy.