Santi Rosniawaty

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 phosphorus status of andisols as influenced by nanoparticles of volcanic ash and rock phosphate

Andisols need to be ameliorated to improve the phosphorus status. The objective of this research is to investigate the effect of nanoparticles of volcanic ash and rock phosphate as ameliorants in Andisols to P-retention, available P and potential P in Andisols. The research used a complete randomized experimental design in factorial with two factors. The first factor was nanoparticle of volcanic ash (a) and the second factor was rock phosphate (p). Both ameliorants consist of four doses on soil weight percentage (0%, 2.5%, 5.0% and 7.5%). The combined treatments were replicated three times. The soil and treatments were mixed and incubated for 4 months. Soil samples were taken after one month and four months of incubation to be analyzed the P-retention, available P and potential P. The results showed that there are interactions between the volcanic ash and rock phosphate on available P and potential P after one month of incubation. However, there were no interactions occurring between the volcanic ash and rock phosphate on P-retention after one and four months of incubation and no interactions on available P and potential P after four months. The best combined treatments in increasing available P and potential P after one month was obtained in 2.5% of volcanic ash and 5% of rock phosphate that increased available P to 405.75 ppm. The 2.5% of volcanic ash and 7.5% of rock phosphate increased potential P to 2190.26 mg/100 g. Independently, 7.5% of volcanic ash and rock phosphate decreased P-retention to 71.49% after one month and 89.74% after four months. Higher effect on the application of nanoparticle of volcanic ash and rock phosphate to the phosphorus status of Andisols recieved after one month of incubation is compared with four months of incubation.Andisols need to be ameliorated to improve the phosphorus status. The objective of this research is to investigate the effect of nanoparticles of volcanic ash and rock phosphate as ameliorants in Andisols to P-retention, available P and potential P in Andisols. The research used a complete randomized experimental design in factorial with two factors. The first factor was nanoparticle of volcanic ash (a) and the second factor was rock phosphate (p). Both ameliorants consist of four doses on soil weight percentage (0%, 2.5%, 5.0% and 7.5%). The combined treatments were replicated three times. The soil and treatments were mixed and incubated for 4 months. Soil samples were taken after one month and four months of incubation to be analyzed the P-retention, available P and potential P. The results showed that there are interactions between the volcanic ash and rock phosphate on available P and potential P after one month of incubation. However, there were no interactions occurring between the volcanic ash and ...