Rija Sudirja

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

The effect of Sinabung volcanic ash and rock phosphate nanoparticle on CEC (cation exchange capacity) base saturation exchange (K, Na, Ca, Mg) and base saturation at Andisol soils Ciater, West Java

Andisol, soil orders which covers an upland area dominantly. The aim of this research is to know the effect between the ameliorant of Sinabung volcanic ashes with the ameliorant of rock phosphatenanoparticle towards CEC and base saturation exchange (K, Na, Ca, Mg) and the base saturation on Ciater’s Andisols, West Java. A randomized complete block design (RCBD) factorial with two factors was used in this research. The first factor is the volcanic ash and the second factor is rock phosphate which consists of four levels each amount of 0%, 2.5%, 5%, 7.5% with three replications. The result showed that there was no interaction between volcanic ash and rock phosphate nanoparticle formed in first month and fourth month towards the improvement of CEC and saturation base exchange rate unless magnesium cation exchange increased in fourth month. There was independent effect of volcanic ash formed nanoparticles towards base saturation exchange increased for 5% dose. There was independent effect of rock phosphate formed nanoparticles towards base saturation exchange and increased for 5% dose. The dose combination of volcanic ashes 7.5% with phosphate rock, 5% increased the base saturation in the first month incubation.Andisol, soil orders which covers an upland area dominantly. The aim of this research is to know the effect between the ameliorant of Sinabung volcanic ashes with the ameliorant of rock phosphatenanoparticle towards CEC and base saturation exchange (K, Na, Ca, Mg) and the base saturation on Ciater’s Andisols, West Java. A randomized complete block design (RCBD) factorial with two factors was used in this research. The first factor is the volcanic ash and the second factor is rock phosphate which consists of four levels each amount of 0%, 2.5%, 5%, 7.5% with three replications. The result showed that there was no interaction between volcanic ash and rock phosphate nanoparticle formed in first month and fourth month towards the improvement of CEC and saturation base exchange rate unless magnesium cation exchange increased in fourth month. There was independent effect of volcanic ash formed nanoparticles towards base saturation exchange increased for 5% dose. There was independent effect of rock phosphate fo...

Remediation of Volcanic Ash Soil in Related to Soil Erodibility Against the Heavy Rainfall

Volcanic ash soil is a productive soil, but its P-retention has to be reduced to increase the available P. This research remedied the volcanic ash soil with steel slag and bokashi of husk to overcome the P-problem and to investigate their influence to soil physical aspects related to the soil erodibility. The treatments were arranged in randomized block designed in factorial pattern with two factors: steel slag and bokashi of husk, each consisted four levels: 0, 2.5, 5.0, and 7.5 % of soil weight (w/w), made the 4 × 4 or 16 combination treatments. The soil with each treatment was mixed thoroughly, filled into polybags, watered to the field capacity, closed tightly, incubated for four months, and sampled for chemical and physical analyses. The parameters were P-retention, available P, bulk density, organic carbon, permeability, and erodibility. Texture and structure was measured prior to the treatments to be calculated as erodibility factors. The results show that steel slag and bokashi of husk interact in increasing available P from 10.02 to 70.02 ppm. Steel slag and bokashi of husk do not interact in decreasing P-retention, decreasing bulk density and increasing permeability, but bokashi of husk individually shows the effect to such parameters. The soil erodibility is improved from 0.19 to 0.14. These results show that the remediation of volcanic ash soil to fix the P-status will also fix the soil erodibility against the heavy rainfall.