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All Journal Journal of Tropical Soils Akta Agrosia
Riwandi, Riwandi
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Agriculture, Biological Sciences & Forestry Environmental Science

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Pertumbuhan dan Hasil Tanaman Selada pada Tiga Jenis Tanah Mineral dengan Pemberian Dosis Pupuk Kandang Sapi yang Berbeda Putra, Dian Pramana; Handajaningsih, Merakati; Riwandi, Riwandi; Fahrurrozi, Fahrurrozi
Akta Agrosia Vol 19 No 2 (2016)
Publisher : Badan Penerbitan Fakultas Pertanian (BPFP), Fakultas Pertanian, Universitas Bengkkulu

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (346.136 KB)

Abstract

Growing lettuce on lowland mineral soil is an alternative to increase lettuce production. Mineral soil with less fertile soil property needs additional organic matter when it is used as growing medium for lettuce plants . The purpose of this study was to evaluate the growth and yield of lettuce on some mineral soil types and different doses of cow manure. The research was conducted in Surabaya village, Sungai Serut District, Bengkulu City. The experiment used a completely randomized design, two factors, five replications. The first factor was the three types of mineral soils, consisted of Inceptisol, Ultisol and Entisol. The second factor was dose of cow manure, consisted of 0 ton/ha, 5 ton/ha (7.065 g/polybag), 10 ton/ ha (14.13g/polybag), and 15 ton/ha (21.19 g/polybag ). Each combination was repeated 5 times in order to obtain 60 experimental units. The results showed that the mineral Ultisol generally resulted in better growth of lettuce plants than it was at Inceptisol and Entisols, which were indicated by the higher degree of the leaf greenness leaves, root fresh weight and shoot fresh weight. Dosage of fertilizer up to 15 tonnes/ha significantly increased shoot fresh weight and root fresh weight of plants. The interaction between soil types and doses of cow manure occured only on the variable of root fresh weight when it was grown on Ultisol with dose of cow manure at 8.07 tonnes/ha.
Improvement of Latex Quality Using Locally-Produced Organic Fertilizer from Rubber Processing Sewage Sludges Riwandi, Riwandi; Prasetyo, Prasetyo; Hasanudin, Hasanudin; Cahyadinata, Indra; Munawar, Ali; Doni, Rachma
JOURNAL OF TROPICAL SOILS Vol. 22 No. 3: September 2017
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2017.v22i3.155-165

Abstract

Most of rubber plants in Indonesia are cultivated in highly-weathered soils; therefore, their annual productions are relatively low with the low quality of latex. The aim of this reseach was to increase the latex quality from a rubber plantation grown on low fertility soils by applying a locally-produced organic fertilizer (LOF) to the soils. This research consisted of two steps, i.e. LOF production and a field fertilization experiment. The LOF was made mainly from waste of a latex processing industry. The field fertilization experiment was conducted to assess the effects of LOF additions to the soils on the latex quality. The field experiment was performed using a randomized complete block design with 6 LOF levels, 4 levels of land slopes, and 5 rubber trees in each block, resulting in 120 rubber trees. The LOF levels were 0, 10, 20, 30, 40, and 50 kg tree-1. The LOF contained 17.35% organic-C, 1.14% total-N, 0.53 ppm available-P, and 1.21 cmol (+)kg-1 exchangeable-K, with slightly alkaline pH (pH 8.0). The soil has low fertility status as indicated by the low amounts of total-N and exchangeable base cations (K, Na, and Mg), and very acid pH (pH 4.5). Indicators of latex quality comprising of blockage index, ash-, impurity- and dry rubber-content, and N, P, K contents in the rubber leaves were measured. Although there were no significant differences in most observed latex properties due to LOF addition, their values tended to be higher when the rubber trees were fertilized with LOF. Apparently N and K contents in the rubber leaves are better correlated to the latex properties compared to the P content. 
Soil Quality Engineering Using Vermicompost and its Effect on the Corn (Zea mays L.) Production in Coastal Area Riwandi, Riwandi; Hasanudin, Hasanudin; Gusmara, Herry; Anandyawati, Anandyawati
JOURNAL OF TROPICAL SOILS Vol. 25 No. 3: September 2020
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2020.v25i3.127-135

Abstract

The low quality of Entisol is caused by low availability of nitrogen, phosphorus, and potassium as well as low soil pH, so the addition of vermicompost is necessary. The purpose of this study was to determine the effect of vermicompost application on soil quality and to obtain the highest vermicompost dosage on the availability of nutrients such as N, P, K, and the yield of corn. The field experiment used a Randomized Completely Block Design (RCBD) with 7 dosages of vermicompost and three replications. The treatments were V0 = 0; V1 = 5; V2 = 10; V3 = 15; V4 = 20; V5 = 25; V6 = 30 Mg ha-1. Variables observed consisted of 1) initial soil and vermicompost characterization analysis, 2) soil analysis and N, P, and K content in leaves, and yield of corn. The results showed that Entisol was classified as low quality; however, vermicompost quality complied with the requirements of quality organic fertilizer. The experiment also indicated that the highest pH of Entisol (5.31) and K content in corn leaves (2.12%) were obtained at a dose of vermicompost 25 Mg ha-1. Meanwhile, the highest weight of husked corn cobs (415.55 g plant-1) and weight of unhusked corn cob (351.11 g plant-1) were obtained at a vermicompost dose of 15 Mg ha-1.
Co-Authors Ali Munawar Anandyawati, Anandyawati Doni, Rachma Gusmara, Herry Hasanudin Hasanudin Hery Widijanto Indra Cahyadinata, Indra Merakati Handajaningsih Prasetyo Prasetyo