Emma Trinurani Sofyan

Pengaruh Organo-mineral Terhadap Beberapa Sifat Kimia Tanah dan Hasil Jagung pada Ultisol Jatinangor

The use of organic materials and minerals as fertilizer needs to be developed in order to increase agricultural productivity, especially in soils marginal that are widely distributed on the Indonesian. This study aims to determine the productivity of soil and corn plants by using various formulations of organo-mineral materials in the Ultisols Jatinangor. The experiment was conducted from April to November 2017 at Ciparanje Experimental Garden, Faculty of Agriculture, Universitas Padjadjaran, using a simple randomized block design consisting of 10 treatments and replicated 3 times. The organo-mineral ingredients used consist of a combination of Humic Acid (6; 8; 10 kg/ha); Dolomites (100; 150; 200 kg/ha); Natural Phosphates (250; 300; 350 kg/ha); also Zeolites (150; 200; 250 kg/ha). The results showed that ameliorant combination had significant effects on soil pH, P-available, and Mn Total, also the yield of maize. Dosage of 8 kg/ha of Humid Acids + 200 kg/ha of Dolomites + 350 kg/ha of Natural Phosphates + 250 kg/ha Zeolite, has indicated better result based on variable experiment. Keywords: maize, organo-mineral, Humic acid, dolomite, phosphate, ultisols

Pengaruh Dosis Konsorsium Pupuk Hayati dan Dosis Nutrisi terhadap Populasi Bakteri Pelarut Fosfat dan Hasil Tomat (Solanum lycopersicum L.) pada Sistem Hidroponik

Hydroponic system is an alternative agricultural cultivation technology that able to answer the problem of narrowing farmland, decline in soil fertility, and the need of healthy foods. Production of tomato with this system has its own market segment, but it needs a specific treatment, such as preparation of planting medium, usage of fertilizer and addition of nutrient, etc. This experiment aims to determine the effect of biofertilizer consortium dosage and nutrient dosage, as well as their interaction to the population of phosphate solubilizing bacteria and tomato yield. The experiment was conducted in a greenhouse of Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, in June to October 2015. Design of experiment was arranged in factorial randomized block design consisting of two factors. The first factor was biofertilizer consortium dosage (0 mL/polybag, 5 mL/polybag, and 10 mL/polybag), and the second factor was nutrient dosage (0 mL, 250 mL, and 500 mL). The result showed that there was no interaction between biofertilizer consortium dosage and nutrient dosage to the population of phosphate solubilizing bacteria and tomato yield. ywords: biofertilizer consortium, hydroponic, phosphate solubilizing bacteria, tomato

Manajemen Pemupukan N-P-K dengan Pupuk Hayati untuk Mempertahankan Kandungan N dan P Tanah serta Hasil Kedelai

One effort to increase the productivity of soybeans in Inceptisols Jatinangor is through utilize inoculant of soil microorganisms such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria in the form of specific biofertilizer (SB) for soybean plant without leaving inorganic fertilizer as a source of available nutrients to plants. This research aimed to determine fertilization management of N-P-K and specific biofertilizer in retaining N and P availability and yield of soybean. The Research was conducted from April to July 2016, arranged in Simple Randomized Block Design (RBD) and consisted of 10 treatments. The combination of biofertilizer and N-P-K were as follows; A = control (without fertilizer), B = Standard N-P-K, C = 0 N-P-K + 1 SB , D = 1/4 N-P-K + 1 SB, E = 1/2 N-P-K + 1 SB, F = 3/4 N-P-K + 1 SB, G = 1 N-P-K + 1 SB, H = 3/4 + 1/4 SB, I = 3/4 N-P-K + 1/2 SB dan J = 3/4 N-P-K + 3/4 SB. The results showed a dose of N-P-K and biofertilizer was recommended in the treatment E (250 kg ha -1 SB) and 1/2 N-P-K (37.5-50-50 kg ha -1 ). The dose was able to increase nitrogen and phosphor content in soil and plant, also on yield of soybean up to 0.4 t ha -1 or 32% of a standard N-P-K.

Application of Glomus sp. and Pseudomonas diminuta Reduce the Use of Chemical Fertilizers in Production of Potato Grown on Different Soil Types

The use of high chemical fertilizer rates in potato production has been applied on the farm in Indonesia. Application of biofertilizer consists of arbuscular mycorrhizal fungi has been tested to reduce the use of NPK rates in production of potato and to determine whether different soil types will have different response to this biofertilizer. A greenhouse experiment was conducted using mixtures of spores of Glomus sp. and inoculant of mycorrhizal helper bacteria Pseudomonas diminuta, applied at different rates of NPK fertilizer (0, 25, 50, 75 and 100% of recommended rates) and different soil types (Andisols and Inceptisols). Results of experiment showed that application of Glomus sp. and P. diminuta reduced the use of NPK up to 50%, where the growth (plant height and tuber number), N,P,K uptake and tuber yields of potato had similar effect to the highest recommendation rate of NPK fertilizer. Inceptisols in general had better response to the biofertiliser compared to Andisols. Findings from this experiment confirmed the evidences that biofertilizer could reduce the use of chemical fertilizer, and the widely distributed soil in Indonesia such as Inceptisols, is potential to be used as a medium for potato production.