Electronic Theses and Dissertation

Tanaman sawi samhong king (Brassica rapa L. subsp. chinensis var.) merupakan salah satu komoditas hortikultura yang pertumbuhan dan produksinya sangat dipengaruhi oleh kondisi iklim, terutama suhu, kelembaban, curah hujan, dan intensitas radiasi matahari. Suhu dan kelembaban tanah merupakan komponen iklim mikro yang penting dalam menciptakan kondisi lingkungan yang sesuai bagi tanaman. Namun, perubahan iklim yang terjadi dapat menyebabkan peningkatan suhu tanah serta ketidakstabilan curah hujan dapat mempengaruhi iklim mikro di sekitar tanaman, sehingga diperlukan upaya modifikasi iklim mikro melalui pemanfaatan biochar. Limbah kelapa muda yang melimpah memiliki potensi dimanfaatkan sebagai bahan baku biochar karena memiliki kandungan karbon sebesar 49,36%, nitrogen sebesar 1,23% dan struktur berpori yang mampu mempertahankan suhu dan kelembaban tanah. Penelitian ini bertujuan untuk mengetahui pengaruh biochar limbah kelapa muda terhadap iklim mikro pada tanaman sawi samhong king. Penelitian dilaksanakan di Biochar Research Station, Pusat Riset Biochar dan Hutan Tropis Lestari Universitas Syiah Kuala pada bulan Agustus 2025 hingga Februari 2026 menggunakan Rancangan Acak Kelompok (RAK) nonfaktorial dengan 7 perlakuan dan 3 ulangan, data dianalisis menggunakan analisis ragam (ANOVA) yang dilanjutkan dengan uji DMRT taraf 5% apabila terdapat pengaruh nyata. Parameter yang diamati meliputi suhu tanah, kelembaban tanah, suhu udara, kelembaban udara, intensitas radiasi matahari, curah hujan, bobot segar per tanaman, volume akar, dan panjang akar. Hasil penelitian menunjukkan bahwa aplikasi biochar limbah kelapa muda memberikan pengaruh sangat nyata terhadap kelembaban tanah pada kedalaman 7 cm pada 5 MSP, tetapi tidak memberikan pengaruh nyata terhadap kelembaban tanah pada kedalaman 14 cm maupun suhu tanah pada kedalaman 0, 7, dan 14 cm selama periode pengamatan. Perlakuan biochar embedded limbah kelapa muda 10 ton ha-1 menunjukkan pengaruh yang cenderung lebih baik untuk iklim mikro tanah. Biochar embedded limbah kelapa muda 10 ton ha-1 mampu menghasilkan suhu tanah yang cenderung lebih rendah pada kedalaman 7 cm baik sebelum maupun sesudah penanaman. Aplikasi biochar limbah kelapa muda tidak berpengaruh nyata terhadap bobot segar per tanaman, volume akar, dan panjang akar tanaman samhong king.

The Samhong King mustard plant (Brassica rapa L. subsp. chinensis var.) is a horticultural crop whose growth and production are significantly influenced by climatic conditions, particularly temperature, humidity, rainfall, and solar radiation intensity. Soil temperature and moisture are important microclimate components in creating suitable environmental conditions for the plant. However, ongoing climate change can lead to increased soil temperatures, and fluctuations in rainfall can affect the microclimate around the plants; therefore, efforts to modify the microclimate through the use of biochar are necessary. Abundant young coconut waste has the potential to be utilized as a raw material for biochar because it contains 49.36% carbon, 1.23% nitrogen, and a porous structure capable of maintaining soil temperature and moisture. This study aims to determine the effect of young coconut waste biochar on the microclimate of Samhong King mustard greens. The study was conducted at the Biochar Research Station, Center for Biochar and Sustainable Tropical Forest Research, Syiah Kuala University, from August 2025 to February 2026 using a non-factorial randomized block design (RBD) with 7 treatments and 3 replications. data were analyzed using analysis of variance (ANOVA), followed by the DMRT test at the 5% significance level when significant effects were found. The parameters observed included soil temperature, soil moisture, air temperature, air humidity, solar radiation intensity, rainfall, fresh weight per plant, root volume, and root length. The results showed that the application of young coconut waste biochar had a highly significant effect on soil moisture at a depth of 7 cm at 5 MSP, but had no significant effect on soil moisture at a depth of 14 cm or on soil temperature at depths of 0, 7, and 14 cm during the observation period. The treatment with 10 metric tons per hectare of young coconut waste-embedded biochar tended to have a more favorable effect on the soil microclimate. Young coconut waste-embedded biochar at a rate of 10 metric tons per hectare resulted in lower soil temperatures at a depth of 7 cm both before and after planting. The application of young coconut waste biochar had no significant effect on fresh weight per plant, root volume, or root length of the Samhong King variety.