Electronic Theses and Dissertation

Entisol dikenal sebagai tanah yang masih muda atau belum berkembang sehingga tingkat kesuburannya sangat bervariasi tergantung bahan induk tanahnya. Entisol biasanya mempunyai kandungan bahan organik dan unsur hara di dalamnya relatif rendah terutama jika tekstur tanahnya didominasi oleh pasir. Salah satu metode untuk menilai status unsur hara di dalam tanah adalah dengan melakukan penelitian dengan mengkaji respons tanaman terhadap perlakuan hara lengkap dan perlakuan minus hara yang dikenal dengan teknis percobaan omisi (subtraksi). Penelitian ini bertujuan untuk mengetahui pengaruh percobaan hara pupuk dengan pemberian beberapa jenis pupuk anorganik terhadap pertumbuhan dan serapan nitrogen tanaman kedelai (Glycine max L. Merrill) varietas Anjasmoro pada Entisol Darussalam.
Penelitian ini dilaksanakan di Rumah Kasa Kebun Percobaan Fakultas Pertanian Universitas Syiah Kuala dimulai dari Juni hingga September 2024. Penelitian ini menggunakan rancangan acak kelompok (RAK) berpola non faktorial yang terdiri atas delapan perlakuan hara secara omisi dengan 3 ulangan. Susunan perlakuan dilakukan dengan tiga ulangan sehingga terdapat 24 unit percobaan. Untuk mengetahui pengaruh akibat dari perlakuan, dilakukan analisis ragam (ANOVA) pada taraf 5%, dan dilanjutkan dengan uji lanjut beda nyata jujur (BNJ) dengan taraf 5% untuk mengetahui perbedaan antar perlakuan. Parameter yang diamati meliputi pertumbuhan tanaman seperti tinggi tanaman dan jumlah daun umur 14, 28, 42, dan 56 hari setelah tanam (HST), berat berangkasan basah dan kering, serta serapan N tanaman.
Hasil penelitian menunjukkan bahwa perlakuan hara pupuk tidak memberikan pengaruh nyata terhadap tinggi tanaman, jumlah daun, dan bobot berangkasan basah maupun kering tanaman kedelai varietas Anjasmoro. Tinggi tanaman kedelai varietas Anjasmoro tidak menunjukkan perbedaan respon yang nyata akibat perlakuan pupuk secara omisi (substraksi) pada semua tahap pengamatan (14, 28, dan 42). Secara umum, pertumbuan tanaman berada di bawah perlakuan hara lengkap, meskipun terdapat beberapa perlakuan yang menunjukkan hasil di atas perlakuan hara lengkap. Perlakuan hara pupuk juga tidak berpengaruh nyata terhadap jumlah daun pada umur 14 dan 42 HST tetapi berbeda pada umur 28 HST. Pada tahap ini, perlakuan lengkap (CL) dan tanpa kalium (C-K) menghasilkan jumlah daun tertinggi, sedangkan perlakuan tanpa nitrogen (C-N) paling rendah. Berat berangkasan basah dan berat berangkasan kering tanaman bagian atas tidak dipengaruhi oleh perlakuan hara pupuk dan tidak ada perbedaan antar perlakuan. Namun, perlakuan yang diberi hara lengkap (CL) konsisten menghasilkan nilai tertinggi yang diikuti oleh perlakuan hara lengkap tanpa S. Konsentrasi N daun dan serapan nitrogen tertinggi diperoleh pada perlakuan hara lengkap (CL) yaitu sebesar (2,95%) dengan serapan N sebesar 0,24 mg N/tanaman atau setara (40 kg N/ha), sedangkan terendah pada perlakuan tanpa nitrogen (Co) sebesar 0,12 mg N/tanaman (20 kg N/ha), sehingga terjadi difisit N sebesar 6-26 kg N per hektar. Hal ini menunjukkan bahwa pentingnya penambahan nitrogen untuk pertumbuhan kedelai pada tanah Entisol Darussalam.

Entisols are known as young or undeveloped soils, with fertility levels that vary widely depending on their parent material. Entisols generally have low organic matter and nutrient content, especially when the soil texture is dominated by sand. One method for assessing soil nutrient status is through plant response experiments using complete nutrient treatments and nutrient omission treatments, a technique commonly referred to as nutrient omission or subtraction trials. This research aimed to determine the effects of nutrient omission trials using several types of inorganic fertilizers on the growth and nitrogen uptake of soybean plants (Glycine max L. Merrill) of the Anjasmoro variety grown on Entisol soil in Darussalam. The study was conducted in a greenhouse at the Experimental Farm of the Faculty of Agriculture, Syiah Kuala University, from June to September 2024. The experiment used a randomized complete block design (RCBD) with a non-factorial pattern consisting of eight nutrient omission treatments with three replications. The arrangement of treatments with three replications resulted in a total of 24 experimental units. To assess the effects of the treatments, analysis of variance (ANOVA) was conducted at the 5% significance level, followed by the Honestly Significant Difference (HSD) test at the 5% level to determine differences between treatments. The observed parameters included plant growth characteristics such as plant height and number of leaves at 14, 28, 42, and 56 days after planting (DAP), fresh and dry biomass weight, and plant nitrogen uptake. The results showed that nutrient treatments had no significant effect on plant height, number of leaves, and the fresh or dry biomass of Anjasmoro soybean plants. The height of Anjasmoro soybean plants did not show a significant response to the omission (subtraction) fertilizer treatments at any stage of observation (14, 28, and 42 DAP). In general, plant growth was lower in omission treatments compared to the complete nutrient treatment, although some omission treatments showed results higher than the complete nutrient treatment. Nutrient treatments also did not significantly affect the number of leaves at 14 and 42 DAP but did have a significant effect at 28 DAP. At this stage, the complete treatment (CL) and the treatment without potassium (C-K) produced the highest number of leaves, while the treatment without nitrogen (C-N) resulted in the lowest. Fresh and dry above-ground biomass was not affected by the nutrient treatments, and no differences were observed among treatments. However, the complete nutrient treatment (CL) consistently produced the highest values, followed by the treatment without sulfur. The highest leaf nitrogen concentration and nitrogen uptake were found in the complete nutrient treatment (CL), which reached 2.95% nitrogen concentration and 0.24 mg N/plant or the equivalent of 40 kg N/ha. The lowest was found in the nitrogen omission treatment (Co), with 0.12 mg N/plant (equivalent to 20 kg N/ha), resulting in a nitrogen deficit of 6–26 kg N per hectare. This indicates the importance of nitrogen addition for soybean growth on Entisol soils in Darussalam.