Pengaruh Cekaman Air dan Konsentrasi Silika pada POC terhadap Pertumbuhan Tanaman Sawi (Brassica juncea L.)

The Effect of Water Stress and Silica Concentration in LOF on The Growth of Mustard Greens (Brassica juncea L.)

Indonesia tercatat mengimpor sawi, sehingga upaya peningkatan produktivitas sawi diperlukan. Di antaranya memanfaatkan lahan kering yang mengalami keterbatasan air dan rendah unsur hara dengan pemberian silika dan Pupuk Organik Cair (POC). Penelitian ini bertujuan mengetahui kadar hara N, P, K POC kulit pisang-eceng gondok, dan mengetahui pengaruh tingkat cekaman air, konsentrasi penambahan silika pada POC, dan interaksinya terhadap pertumbuhan sawi. Penelitian dibagi dua tahap. Tahap I, penelitian deskriptif yaitu pembuatan POC dan pengujian kandungan hara. Tahap II, penelitian eksperimental yaitu implementasi POC-Si terhadap tanaman sawi pada berbagai tingkat cekaman air. Penelitian menggunakan Rancangan Acak Kelompok (RAK) dua faktor yaitu konsentrasi penambahan silika pada POC ([0, 1, 2] gram/L) dan tingkat cekaman air ([75%, 50%, 25%] KL) dengan 3 kali pengulangan sehingga terdapat 27 unit percobaan. Data kualitas POC dianalisis deskriptif, sedangkan data pertumbuhan dianalisis menggunakan ANOVA dua arah dilanjut uji Duncan. Hasil menunjukkan POC mengandung N 1,24%; P 1,03%; K 1,22%; dan rasio C/N 10. Tingkat cekaman air berpengaruh signifikan terhadap biomassa basah, panjang akar, kerapatan stomata, kadar klorofil, dan kadar air relatif daun (KARD), sedangkan konsentrasi silika pada POC berpengaruh signifikan terhadap tinggi tanaman, biomassa basah, panjang akar, kerapatan stomata, kadar klorofil total, dan KARD. Interaksi antara tingkat cekaman air dan konsentrasi silika pada POC berpengaruh signifikan terhadap biomassa basah sebesar 20,67 gram, panjang akar sebesar 14,53 cm, kerapatan stomata sebesar 314,07/mm2, dan kadar klorofil sebesar 21,865 mg/L. Namun, tidak berpengaruh signifikan terhadap tinggi tanaman, jumlah daun, dan KARD. Hasil tertinggi ditunjukkan pada perlakuan konsentrasi silika 2 gram/L pada tingkat cekaman 75% KL.

Kata kunci: hara, cekaman air, pupuk organik cair, sawi (Brassica juncea L.), silika

Indonesia was recorded imports mustard greens, efforts to increase mustard greens productivity are required. One of them is utilizing dry land with limited water and low nutrients by applying silica and liquid organic fertilizer (LOF). This study aimed to determine the N, P, K nutrient quality of banana peels-water hyacinth LOF and the effect of water stress levels, silica concentrations in LOF, and its interaction on the growth of mustard greens. There are two stages of the research. Stage I, descriptive research, which is the process of making LOF and analyzing the nutrient content. Stage II, experimental research by implementing the LOF-Si on mustard greens at various levels of water stress. The study used a randomized block design (RBD) with two factors, which are the concentration of silica addition ([0, 1, 2] gram/L) and the level of water stress ([75%, 50%, 25%] field capacity) with 3 repetitions to obtain 27 treatment units. Data of LOF's nutrient quality were analyzed descriptively, while data of mustard's growth were analyzed using two-way ANOVA continued by the Duncan test. The results showed that LOF contained 1.24% N, 1.03% P, 1.22% K, and a C/N ratio of 10. Water stress had a significant effect on wet biomass, root length, stomatal density, chlorophyll content, and relative water content (RWC), while silica concentration in LOF had a significant effect on plant height, wet biomass, root length, stomata density, chlorophyll content, and RWC. The interaction between water stress level and silica concentration in LOF had a significant effect on the wet biomass of 20.67 grams, root length of 14.53 cm, stomatal density of 314.07/mm2, and chlorophyll content of 21.865 mg/L. However, there was no significant effect on the plant height, leaf number, and RWC. The highest result was obtained in the treatment of 2 gram/L silica at 75% feld capacity.

Keywords: nutrient, water stress, liquid organic fertilizer, mustard greens (Brassica juncea L.), silica