RESPON PERTUMBUHAN DAN HASIL BAWANG MERAH (Allium ascalonicum L.) VARIETAS RUBARU TERHADAP BIOCHAR SEKAM PADI DAN MIKORIZA DI VERTISOL

Cultivating red onion on a Vertisol during rainny season could face to physical and chemical problems from the soil. Application of biochar and mycorrhiza can improve soil quality both physical and chemical properties of Vertisol. The objective of this study was to investigate the effect of rice husk biochar and arbuscular mycorrhizal fungus (AMF) on growth and yield of red onion grown on a vertisol. The research was carried out at the Agrotechnology Research Station, University of Trunojoyo Madura from December 2018 to February 2019. The experiments were arranged on Split Plot Design (SPD) with the main plots were the biochar treatments and the sub plots were AMF applications. Two rates of biochar applications namely B0 (no biochar) and B1 (10 ton/ha), and four rates of AMF applications involving M0 (no mycorrhiza), M1 (2.5 g/plant), M2 (5 g/plant) and M3 (10 g/plant), were employed. No P fertilizer was applied on three AMF treatments (M1, M2, and M3). There were 8 combination treatments, and each treatment was replicated four times to end up in 32 experimental units. The results showed that there was no interaction between biochar and AMF treatments on all observed parameters. Biochar increased the number of leaves at 4 and 6 WAP (week after planting), the number of roots, and the weight of fresh tubers, and dry tubers that were suitable for storage. Mycorrhizal (AMF) application significantly influenced the number of leaves at 2 and 6 WAP, number of roots, wet weight of tubers, dry weight of tubers, and percentage of AMF root colonization. The application of rice husk biochar and AMF increased tuber yields respectively up to 17.21% and 19.58% compared to that of control

Spesiasi Aluminium Terlarut dan Sifat Kimia Ultisol yang Diameliorasi dengan Dolomit dan Lignit-Teraktivasi

Phytotoxicity of soil aluminum (Al), both directly to the plant growth as well as indirectly through the increase of soil potential acidity, is closely related to the occurrence of various soil soluble-Al species. Amongst them, Al3+ and monomeric-Al species are the primary causes of Al phytotoxicity in soils with high Al content. This study was aimed to evaluate the effects of soil amelioration with dolomite and base-activated lignite (BAL) on changes in soluble-Al species and other soil chemical properties, and vegetative growth of soybean (Glycine max Merr) on Ultisol of Jasinga (Al-dd 16,03 cmol(+)/kg). A green house experiment was conducted by applying a Completely Randomized Design with dolomite and BAL amelioration as the treatments, each with three levels of repectively 0, 1, 1,5 x exchangeable-Al and 0, 2,5, 5 tons BAL ha-1, and three replications. The ameliorants were incubated at field capacity of soil moisture content for one week before planting soybean for one month. Soil soluble-Al speciation was carried out using colorimetric aluminon method to determine concentrations of total soluble-Al, monomeric-Al, and polymeric-Al species. Monomeric-Al were further speciated into inorganic monomeric-Al and organic monomeric-Al species. The results revealed that only dolomite amelioration that significantly increased soil pH-H2O, pH-KCl, Ca- dd, Na-dd, and decreased exchangeable-Al concentration, except for those of all soluble-Al species that only showed a decreasing trend. Soil exchangeable-Al that was negatively and significantly correlated with soybean measure parameters were plant height, root length, total roots and shoots wet and dry weights, as well as Ca concentration. These results indicated that soil Al phytotoxicity evaluation could be relied on the result of routine analysis on soil exchangeable-Al concentration.   Keywords: exchangeable-Al, inorganic monomeric-Al, organic monomeric-Al, polymeric-A

Pengaruh Biochar dan Bentonit-Teraktivasi Asam pada Karakteristik Kimia Tanah Lempung Liat Berpasir Bangkalan

Tanah lempung liat berpasir yang ada di Bangkalan merupakan tanah miskin hara dan bahan organik, rendah basa-basa, KTK, retensi air dan hara. Salah satu cara yang dapat digunakan untuk meningkatkan kualitas tanah berpasir adalah dengan menambahkan biochar dan bentonit-teraktivasi asam (BTA). Penelitian ini bertujuan untuk melihat efek peningkatan dosis (0, 5, 10 ton.ha-1) biochar, bentonit-teraktivasi asam dan kombinasi keduanya terhadap sifat kimia tanah lempung liat berpasir. Biochar dibuat dari limbah tongkol jagung dengan metode Kon-Tiki dan bentonit diaktivasi dengan metode fisik (200 oC) dan kimia (1N H2SO4). Percobaan rumah kaca dilakukan dengan Rancangan Acak Lengkap Faktorial. Biochar dan bentonit-teraktivasi asam sebagai perlakuan masing-masing tiga taraf (0, 5, 10 ton.ha-1) dan tiga ulangan. Analisis yang dilakukan adalah pH H2O dan KCl, C-Organik, KTK dan basa-basa. Selanjutnya data di analisis ragam dan uji lanjut dengan uji Tukey untuk perlakuan yang berpengaruh nyata. Hasil penelitian menunjukkan bahwa kombinasi biochar dan bentonit teraktivasi asam berpengaruh nyata meningkatkan pH H2O, K-dd dan Na-dd. Sedangkan pemberian biochar berpengaruh sangat nyata meningkatkan C-organik dan BTA berpengaruh nyata meningkatkan KTK tanah lempung liat berpasir di Bangkalan

Pengaruh Residu Biochar Sekam Padi dan Pupuk Kandang Sapi terhadap N Total dan Serapan N oleh Tanaman Jagung (Zea mays L.)

The objective of this study was to investigate the effects of soil conditioner of residue of rice husk biochar and cow manure, which was applied one year before this research conducted, on total N content in the soil and N uptake by maize (Zea mays L.). The research was carriet out at the Socah Horticultural Garden, Bangkalan Regency, East Java, which is located at 5-meter above sea level, from November 2020 to March 2021. The experiment was arranged on a completed randomized block design (CRBD), consisting of six treatments, namely P0 (control, without biochar or cow manure), P1 (10 ton biochar/ha), P2 (7.5 ton biochar/ha and 2.5 ton cow manure/ha), P3 (5 ton biochar/ha and 5 ton cow manure/ha), P4 (2.5 ton biochar/ha and 7.5 ton cow manure/ha), P5 (10 ton cow manure/ha). The results showed that Rice husk biochar residue and cow manure had a significant effect on total N in P4, organic carbon in P5, and CEC in P3 but that not significantly different with P2 and P4. While treatments that significantly affect N in plant tissues and N uptake by corn plants are P4