Andisols of the Kitakami mountain range were derived from a mixture of tephras and long range eolian dust deposited during the Quaternary. Thus, the relative proportions of the components of the mixture determined the unique properties of the soils. Soils of the northern and central parts of the mountain range were derived mainly from tephras and had been classified, generally, as Typic Kuroboku soils by the Group of Japanese Pedologists. Soils of the southern part showed a strong influence of long range eolian dust and had been classified, generally, as Typic Para Kuroboku soils. We studied the Andic soil properties of 35 pedons covering the mountain range in order to classify them under the Andisols order. All the soils showed a bulk density (BD) < 0.90 Mg m-3 and Pretention >85% in the Andisol diagnostic horizon. The soils of the northern and central parts of the mountain range had a pH(H 2 0) range of 5.1-6.7 and acid oxalate-extractable Al plus half Fe (Alo+0.5Feo) level was >2%. They were therefore classified under criterion one of the Andic soils requirements. The soils of the southern part of the mountain range had a pH(H 2 0) range of 4.3-5_7 and the majority of them contained <2.0% of Al o +0.5Fe o . The pedons with Alo +0.5Fe o level < 2.0%, however, had a sufficient amount of volcanic glass in their sand fraction to satisfy the criterion two of the Andic soil requirements. The soils of the northern part contained moderate amounts of organic C and were mainly Typic Hapludands. The soils of the southern part contained large amounts of KCI-extractable Al and organic C and also showed a wider spectrum of Andisols. However, Alic and Typic Fulvudands, and Alic and Typic Melanudands tended to occur in higher frequencies. The classification of the pedons of the central part bridged that of the pedons of the northern and the southern parts.Key Words: Andisols, Kitakami mountain range, long-range eolian dust, tephra, USDA Soil Taxonomy.Soils derived from tephras and others with similar properties, perhaps more than any other group of soils, have been subjected to continuous changes in their terminology. Apart from numerous local names, these soils have been classified variously; Ando soils (Thorp and Smith 1949), Andosols (FAa/UNESCO 1974), Andepts (Soil Survey Staff 1975) and, presently, Andisols (Soil Survey Staff 1990. The extent of the changes is a measure of the advances in the knowledge of their pedogenesis. Although these soils have originally been associated solely with tephra, with the creation of the Andisols order and its subsequent revisions, Andisols derived from parent materials other than tephra have been reported. The reports cover tephric nonallophanic Andisols (Baham and Simonson 1985;Hunter et al. 1987;Shoji and Otowa 1988), nontephric nonallophanic Andisols (Garcfa-Rodeja et al. 1987;Clayden 1989;Leamy et al. 1990;Baumler and Zech 1994) and non-tephric allophanic Andisols (Whitton et al. 1985). Thus, the central concept of Andisols has expanded from soils dominated by allophane, imogolite...

The efficacy of a natural soil conditioner, Coco-Peat (C-P), and synthetic soil conditioners, Terawet (T-200) and Teraflow (T-F), in improving soil moisture content were examined on five Ghanaian soil series (Akroso, Akuse, Amo, Hake and Oyarifa). In general, the water retention of T-200 and C-P treated soils were similar but significantly higher (p < 0.001) than that of T-F and the control (C-T) treated soils, which were also similar on all the test soils. The dry matter yields of the test crop (maize) were 5.4, 5.2, 4.5 t ha -1 on T-200, C-P and T-F treated soils, respectively, on Akroso series. These yields were 36%, 31% and 5%, respectively, more than those of the control treatment. On Akuse series even though T-200 and T-F gave higher dry matter yields than the control, the differences were not significant, only C-P treatment gave significantly higher (p < 0.001) yield than the control. On Amo series, dry matter yields of 6.1, 5.8 and 4.9 t ha -1 on T-200, C-P and T-F treated soils, respectively, were 38%, 31% and 10% more than the control treatment. On Hake series, T-200, C-P and T-F treatments improved dry matter yields by 45%, 32% and 12%, respectively, over that of the control. The greatest effect of the polymeric absorbents was observed on the sandy/clay/loam Oyarifa series. The treatments T-200, C-P and T-F improved dry matter yields by 92%, 81% and 4%, respectively, over the control treatment. The results indicate that the differences in yields over the control were due to the improved water retention ability of the soils amended with the polymeric absorbents.

Background: Application of biochar has been suggested as a carbon (C) management strategy to sequester C and enhance soil quality. An incubation study was carried out to investigate the interactive effect of biochar and cattle manure application on mineralization of carbon (C) in a tropical coastal savanna sandy soil. Methods: The soils were amended with three sole levels of cattle manure (0, 13 and 26 tons ha −1) or biochar (0, 20 and 40 tons ha −1) and four combined manure-biochar levels (20 or 40 tons ha −1 biochar plus 13 or 26 tons ha −1 manure) and CO 2 evolution was measured over 56 days incubation period. The soils were analyzed for mineral N (NH 4 +-N and NO 3 −-N) and water extractable organic C, and net N mineralization, and priming effect (PE) values calculated. Results: The cumulative C mineralized increased in the sole manure and biochar amended soils, resulting in 45-125% positive PE. However, co-application of biochar and manure decelerated decomposition of C, probably through adsorption of labile C and net N immobilization, subsequently leading up to negative 35% PE. Conclusions: The results suggest that co-application of biochar and cattle manure can potentially stabilize C in manure amended sandy soils, albeit with a temporary mineral N limitation to plants.

Infestation of fruits by native and invasive fruit flies causes significant economic losses. In most cases, incidence of ‘regulated’ dangerous fruit flies in orchards results in restrictions on export of fruits from such places to international markets. Unfortunately, use of insecticides applied on foliage and fruits does not kill the fruit‐to‐soil stages of fruit flies. However, diverse biological control agents (BCAs) do so. Thus, prevalence of native and invasive fruit flies in orchards will require that a combination of BCAs is included in integrated pest management (IPM) programmes. In the case of Bactrocera dorsalis Hendel and other economically important fruit flies found in sub‐Saharan Africa (SSA), use of classical biocontrol approach involves concomitant releases of two exotic parasitoids (Fopius arisanus Sonan and Diachasmimorpha longicaudata Ashmead). These non‐native wasps may have complemented the indigenous parasitoids in combination with application of entomopathogenic fungi (EPFs) and conservation of predatory ants (Oecophylla longinoda Latreille, with O. smaragdina) in fruit fly IPM plans. Consequently, some levels of decline in fruit infestation have been observed. Although interspecific interactions between BCAs against several insect pests have produced varying results, including threatening the survival of other BCAs, the prevalence of B. dorsalis in orchards across SSA requires further research to investigate effects of coalescing biocontrol approaches in IPM strategies. Therefore, future research into combining parasitoids, EPFs and entomopathogenic nematodes, in addition to conservation of predatory ants (O. longinoda, O. smaragdina and others) in IPM plans may improve the effectiveness of currently used strategies for the management of fruit‐infesting tephritids. © 2021 Society of Chemical Industry.

Hydroponic barley (Hordeum vulgare L. cv. minorimugi) was treated with 10 µM arsenic (As) together with 500, 250, 50 and 0 µM phosphorus (P) for 14 days to observe the response of the seedlings. The plants were also treated with 0 µM As + 0 µM P. Iron (Fe)-plaque was visible in the roots under As-treated and P-depleted conditions. The intensity of reddish coloration in the roots decreased with increasing P in the media. However, reddish coloration was not found in the absence of both As and P. The results show that both As and P played a vital role in the formation of Fe-plaque. Additionally, Fe-plaque formation was dependent on the concentration of P in the media. Iron concentration in the roots of the As treated plants without P was higher than that observed in the roots treated with 0 µM As + 0 µM P which suggests that As may have been adsorbed with Fe on the surface of roots, forming Fe-plaque. Arsenic concentration in the shoots and the roots was low under 500 and 250 µM P conditions while high under 50 and 0 µM P conditions. It was found that a higher concentration of P (50 µM; 5 times of As level) was required in the medium to reduce As concentration in the plant tissues.