Sistem Modular Mesin Tanam Padi Jajar Legowo Untuk Meningkatkan Adaptabilitas Mekanisasi Pertanian Pada Lahan Terasering

Abstract

Mekanisasi pertanian merupakan salah satu strategi utama dalam meningkatkan efisiensi, produktivitas, dan keberlanjutan sistem produksi padi di Indonesia. Penggunaan mesin tanam padi (rice transplanter) jajar legowo telah terbukti mampu meningkatkan kapasitas tanam, menekan kebutuhan tenaga kerja, memperbaiki keseragaman jarak dan kedalaman tanam, serta mendukung peningkatan produktivitas usahatani. Namun demikian, pemanfaatan teknologi tersebut masih terbatas pada lahan sawah datar, sedangkan implementasinya pada lahan sawah terasering masih menghadapi berbagai kendala akibat karakteristik topografi, aksesibilitas, dan ukuran petakan lahan yang sempit. Bobot mesin yang mencapai sekitar 168–180 kg menyebabkan mobilisasi antarpetakan menjadi sulit sehingga tingkat utilisasi alsintan pada lahan terasering masih rendah. Permasalahan tersebut menunjukkan bahwa pengembangan mekanisasi pertanian tidak cukup hanya berorientasi pada peningkatan kapasitas kerja mesin, tetapi juga harus mempertimbangkan kemampuan teknologi beradaptasi terhadap karakteristik agroekosistem. Penelitian ini bertujuan mengembangkan sistem modular pada mesin rice transplanter jajar legowo untuk meningkatkan mobilitas dan adaptabilitas mesin pada agroekosistem sawah terasering. Secara khusus penelitian meliputi analisis pembagian modul, perancangan dan simulasi interface modular menggunakan Finite Element Analysis (FEA), prediksi perilaku dinamis melalui analisis frekuensi alami dan metode Experimental Modal Analysis, validasi eksperimental melalui pengujian statis dan dinamis, serta evaluasi kinerja bongkar-pasang dan pengangkutan modul berdasarkan pendekatan ergonomi. Hasil analisis fungsi, hubungan antarkomponen, distribusi massa, dan kompleksitas sistem menghasilkan konfigurasi modular yang membagi mesin berbobot sekitar 166,7 kg menjadi empat modul utama, yaitu main transmission (62,90 kg), wheel transmission (32,70 kg), feeding transmission (59,65 kg), dan floating skid (11,45 kg). Konfigurasi ini mempertahankan fungsi tanam, transmisi, dan kendali mesin, sekaligus memungkinkan mobilisasi antarpetak sawah yang sebelumnya sulit dilakukan pada mesin utuh. Sistem antarmuka modular menggunakan mekanisme toggle clamp dan guide plate sehingga proses bongkar-pasang dapat dilakukan tanpa peralatan khusus. Hasil analisis modal menunjukkan bahwa modularisasi menurunkan frekuensi alami mode pertama struktur tunggal dari 160,39 Hz menjadi 131,24 Hz (18,18%), namun masih berada di luar rentang frekuensi eksitasi mesin (28–95 Hz) sehingga struktur tunggal tidak berpotensi mengalami resonansi. Pada konfigurasi mesin lengkap, hasil Experimental Modal Analysis menunjukkan frekuensi alami pertama sebesar 51,69 Hz, yang berada dalam rentang eksitasi mesin sehingga mengindikasikan potensi resonansi pada sistem lengkap. Meskipun terdapat deviasi kuantitatif antara simulasi dan eksperimen pada beberapa mode akibat idealisasi sambungan dan kondisi batas, hasil eksperimen memvalidasi kecenderungan perubahan karakteristik dinamis yang diprediksi model numerik. Selain karakteristik dinamis, keamanan struktur modular juga dievaluasi melalui simulasi numerik dan pengujian eksperimental. Hasil simulasi dan pengujian eksperimental menunjukkan bahwa seluruh komponen antarmuka memiliki faktor keamanan (FoS) lebih besar dari 1,5 pada kondisi pembebanan kritis. Guide plate aman menerima beban horizontal hingga 1000 N, sedangkan sistem toggle clamp mampu mempertahankan integritas sambungan tanpa deformasi permanen. Pengujian regangan menunjukkan seluruh tegangan masih berada pada daerah elastis sehingga struktur modular memenuhi persyaratan keamanan operasional. Setelah aspek struktural dan dinamis terpenuhi, penelitian dilanjutkan dengan evaluasi adaptabilitas sistem melalui pengujian bongkar-pasang dan pengangkutan modul. Evaluasi adaptabilitas menunjukkan bahwa modularisasi memungkinkan mesin dimobilisasi antarpetak sawah melalui pembagian menjadi empat modul dengan waktu bongkar-pasang sekitar 337–432 detik (5–7 menit) dan kebutuhan ruang kerja minimum sekitar 2,0 × 2,5 m. Evaluasi fisiologis berdasarkan HR, VO2, dan Energy Expenditure (EE) menunjukkan beban kerja operator masih berada dalam kategori yang dapat diterima sehingga proses pengangkutan dan perakitan layak dilakukan di lahan terasering. Hasil ini membuktikan bahwa modularisasi meningkatkan mobilitas mesin tanpa melampaui kapasitas fisiologis operator.. Secara keseluruhan, penelitian ini membuktikan bahwa modularisasi mampu mempertahankan integritas struktural, keandalan dinamis, serta kesesuaian ergonomis sekaligus meningkatkan mobilitas operasional sehingga menghasilkan sistem mekanisasi yang lebih adaptif terhadap agroekosistem sawah terasering. Berdasarkan sintesis seluruh hasil penelitian tersebut dirumuskan konsep Adaptive Modular Rice Transplanter yang menjadi dasar paradigma agroecosystem-adaptive mechanization, yaitu pendekatan rekayasa yang menempatkan karakteristik agroekosistem sebagai dasar dalam pengembangan alat dan mesin pertanian melalui integrasi mesin, manusia, dan lingkungan dalam satu sistem rekayasa yang utuh.

Agricultural mechanization has become one of the principal strategies for improving the efficiency, productivity, and sustainability of rice production systems in Indonesia. The application of the jajar legowo rice transplanter has been demonstrated to increase planting capacity, reduce labor requirements, improve the uniformity of planting spacing and depth, and enhance rice production. Nevertheless, its utilization remains largely confined to flat paddy fields, while its application in terraced paddy fields is constrained by complex topography, limited accessibility, and narrow field plots. The machine weight, ranging from approximately 168 to 180 kg, restricts its mobility between terraces, resulting in a low utilization rate of agricultural machinery in terraced agroecosystems. These limitations indicate that agricultural mechanization should not solely focus on improving machine performance but should also emphasize the ability of agricultural machinery to adapt to the characteristics of the target agroecosystem. This study aimed to develop a modular jajar legowo rice transplanter to improve machine mobility and adaptability for terraced paddy field agroecosystems. The research comprised functional modular decomposition, modular interface design and simulation using Finite Element Analysis (FEA), prediction of structural dynamic behavior through natural frequency analysis and Experimental Modal Analysis (EMA), experimental validation through static and dynamic testing, and evaluation of module assembly, disassembly, transportation, and ergonomic performance. Functional analysis, component interaction, mass distribution, and system complexity assessment resulted in a modular configuration that divided the approximately 166.7 kg rice transplanter into four primary modules: the main transmission (62.90 kg), wheel transmission (32.70 kg), feeding transmission (59.65 kg), and floating skid (11.45 kg). This configuration preserved the planting, transmission, and control functions of the original machine while enabling inter-terrace transportation that was previously impractical with the monolithic configuration. The modular interface employed a toggle clamp locking mechanism and guide plates, allowing assembly and disassembly without specialized tools. Modal analysis demonstrated that modularization reduced the first natural frequency of the standalone transmission neck structure from 160.39 Hz to 131.24 Hz (18.18%). However, the resulting frequency remained outside the engine excitation range (28–95 Hz), indicating no resonance risk for the standalone structure. In contrast, Experimental Modal Analysis of the complete machine identified a first natural frequency of 51.69 Hz, which falls within the engine excitation range, indicating a potential resonance condition in the fully assembled configuration. Although quantitative deviations were observed between numerical predictions and experimental measurements in several vibration modes due to joint idealization and boundary condition assumptions, the experimental results confirmed the predicted trend of structural dynamic behavior obtained from the numerical model. In addition to dynamic performance, the structural integrity of the modular system was evaluated through numerical simulation and experimental testing. The results demonstrated that all modular interface components achieved safety factors (FoS) greater than 1.5 under critical loading conditions. The guide plate safely sustained horizontal loads of up to 1000 N, while the toggle clamp system maintained joint integrity without permanent deformation. Strain measurements confirmed that all stresses remained within the elastic region, indicating that the modular structure satisfied the operational structural safety requirements. Following the structural and dynamic evaluations, the adaptability of the modular system was assessed through assembly, disassembly, and module transportation tests. The modular configuration enabled machine transportation between terraced plots by dividing the machine into four transportable modules, with assembly and disassembly times ranging from 337 to 432 seconds (approximately 5–7 minutes) and requiring a minimum working area of approximately 2.0 × 2.5 m. Physiological evaluation based on heart rate (HR), oxygen consumption (VO2), and energy expenditure (EE) indicated that operator workload remained within acceptable physiological limits, demonstrating that module transportation and reassembly can be performed safely under terraced field conditions. These findings confirm that the modular concept significantly improves machine mobility without exceeding the physiological capacity of the operator. Overall, the study demonstrates that modularization successfully preserves structural integrity, maintains dynamic reliability, and ensures ergonomic suitability while substantially improving the operational mobility of the rice transplanter in terraced paddy field agroecosystems. The integration of these findings led to the formulation of the Adaptive Modular Rice Transplanter concept, which establishes the foundation of the agroecosystem-adaptive mechanization paradigm. This paradigm places agroecosystem characteristics at the center of agricultural machinery design by integrating engineering design, human factors, and environmental considerations into a unified engineering framework for developing adaptive agricultural mechanization systems.