Utilization of locally available organic matter to improve chemical properties of pyroclastic materials from Mt. Kelud of East Java

Abstract

Pandansari village, Ngantang District was severely affected by Mt. Kelud eruption in 2014. Almost all soil surfaces were covered by the eruption product, leading to serious problems for cultivation. Pyroclastic materials potentially have high content of nutrients, but they are not readily available to plants. As an attempt to improve chemical properties of the pyroclastic materials, we applied locally available organic matters, from four different sources, i.e. leaves of sweet potatoes, Tithonia diversifolia, maize, and cow manure. The pyroclastic materials were sieved at 2 mm, placed inside pots (50 x 50 x 50 cm 3), until it reached 30 cm thick. The fresh leaves were chopped into 2 mm size and mixed with the pyroclastic materials at the dosage of 15 Mg/ha. They were incubated and kept at field condition. Selected chemical properties (pH, CEC, sum of basic cations, and the total contents of N, organic C, and available P) were measured before and after 90 days incubation. The results showed that after 90 days, organic matter application significantly increased pH, cation exchange capacity, organic C, and total exchangeable basic cations content. The increases of P-available and total N contents were only detected on cow manure treated materials.

Decomposition of Fine Roots and Aboveground Agroforestry Litter as Plant-soil Feedback After Volcanic Ash Deposition

“…The soil carbon accumulation rate of the volcanic ash from the Kelud has been high. The C org content in the Kelud volcanic ash in 2014 was very low, around 0.35% (Utami et al 2017). Six years later the topsoil (0-15 cm) in the +Ash sites had become 1.7%, still below the 2.12% in the -Ash site (Table 2).…”

“…Volcanic ash from the eruption of Mount Kelud changes the physical, chemical, and biological properties of the soil (Ishaq et al 2020a). The C org content in the Kelud volcanic ash was very low, around 0.35%, with an acidic pH of around 4.33 and a low cation exchange capacity (Utami et al 2017). One of the changes that occur after ash deposition is the compaction of the soil surface, decreasing in ltration rates.…”

“…On cropped lands, farmers hoe the soil surface after volcanic ash deposition and add organic matter from leaves and twigs left over from harvest (organic matter) found around their land as well as manure. The addition of organic matter in the form of Tithonia and Leucaena leaf litter on agricultural land affected by the eruption of Mount Kelud, increased pH, cation exchange capacity, C org content, total N, and neutralized toxic Al ions (Utami et al 2017). The recovery of soil conditions without external organic inputs and its dependence on tree root turnover has yet to be quanti ed for the speci c conditions of Mount Kelud and its vegetation.…”

Pengaruh Biochar Tempurung Kelapa Dan Pupuk Kandang Sapi Terhadap Sifat Kimia Tanah Dan Produksi Tanaman Sawi Pada Tanah Pasir Pantai

“…Rerata tinggi tanaman pada perlakuan biochar tempurung kelapa nyata dengan K2 (Tabel 6). Hal ini sejalan dengan penelitian Utami et al, (2017), melaporkan bahwa KPK dengan perlakuan bahan organik mengalami peningkatan lebih tinggi ibandingkan perlakuan kontrol, hal ini dikarenakan bahan organik berpotensi meningkatkan muatan negatif didalam tanah, sehingga dapat meningkatkan KPK. dan pupuk kandang sapi disajikan dalam Tabel 7.…”

Improving nutrient availability in pyroclastic materials from Mount Kelud using organic and inorganic amendment

“…The studied materials contained a considerable amount (45 ppm) of available P (Utami et al, 2017); however, it was potentially decreased by leaching process or plant uptake. Application of 100% inorganic fertilizers increased available P content, but tend to decrease with time (Table 1).…”