Inceptisol Soil Research Articles

Studies on potassium release in an inceptisol soil (Holambi Series) at the minimum level of exchangeable potassium

Ammonium acetate extractable potassium in the soil reached a minimum value of 6.8 mg K/100g soil after 14 crops of wheat and pearl millet in the field without applying any potassium fertilizer. At this level of ammonium acetate extractable K both wheat and pearl millet utilized about, 90 per cent of the total K from non-exchangeable sources. Wheat and pearl millet were grown in this soil in the greenhouse at different levels of K. At K0 level wheat utilized 86 per cent of the total K uptake from the non-exchangeable source and pearl millet, 95 per cent. At K1 level, wheat utilized only 19 per cent but at higher levels of K, there was build up in the K status of soils. In the case of pearl millet at K1, K2 and K3 levels 59, 13 and 22 per cent of total uptake were contributed by non-exchangeable forms. The total K uptake by pearl millet was more than double that by wheat. Plant analysis showed that 83 per cent of the total K in wheat was contained in the shoot portion and the rest in the roots. The corresponding figures for pearl millet were 94 and 6 per cent.

Endophytic Fungi in Cabbage Roots: Diversity and Antagonistic effects on Rhizoctonia solani

Root endophytic fungi that living inside the plant roots without causing any symptom, basically is part of microorganisms in the rhizosphere or soil. Considering that, the objective of this study was to examine the effect of growth media on the occurrence and variabilities of culturable endophytic fungi in cabbage roots. The growth media examined were soil from pine forest, rhizosphere of cogon grass and elephant grass, inceptisol soil mixed with goat manure, compost or vermicompost (1:1, v/v). Fungal isolates obtained were examined their effect on the growth of cabbage seedlings and their abilities to inhibit the growth of fungal pathogen Rhizoctonia solani in vitro. The results showed that the growth media influenced the colonization and variabilities of fungal endophytes isolated from cabbage roots. The media supporting better colonization and variabilities of fungal endophytes was soil mixed with goat manure (1:1, v/v). Among 12 isolates obtained, three isolates (PK-2, PK-4 and PK-5 isolates) tended to improve the growth of cabbage seedlings. There were also three isolates (PK-1, PK-2 and TH-1) inhibited the growth of R. solani in vitro by 56.7% -64.7%.