Soil macrofauna functional groups and their effects on soil structure, as related to agricultural management practices across agroecological zones of Sub-Saharan Africa

This study aimed at understanding the effects of crop management practices on soil macrofauna and the links with soil aggregation and soil organic matter dynamics, which is key to the improvement of infertile or degrading soils in Sub-Sahara Africa. Soil macrofauna, especially earthworms and termites, are important components of the soil ecosystem and, as ecosystem engineers, they influence the formation and maintenance of soil structure and regulate soil processes, such as organic matter decomposition and nutrient dynamics. In comparison with natural systems, earthworm and termite diversity and abundance were low in fallow, high soil-carbon (C) and low soil-C arable treatments in 12 long-term trial fields across the sub-humid to semi-arid tropical zones in Eastern and Western Africa. Continuous crop production had significant negative effects on earthworm diversity, but little effect on termite diversity, as compared to long-term fallow. Agricultural management resulting in high soil C increased earthworm and termite diversity as compared to low-C soil.Long-term application of manure in combination with fertilizer resulted in higher earthworm diversity and biomass, associated with improved soil aggregation and enhanced C and N stabilization within this more stable soil structure. These practices therefore result in the dual benefits of improving soil physical and chemical properties. A micromorphological study of undisturbed soil thin sections showed that fallowing, conservation tillage plus residue application (in East Africa) and hand-hoeing plus manure (in West Africa) enhanced biogenic soil structure formation, resulting in a well developed soil structure and a continuous pore system characterized by many faunal channels. In contrast,intensive tillage and absence of organic inputs resulted in soil with less biogenic soil structural features. Farmers in Nyabeda, West-Kenya, were aware of the activities and nesting habits of termites, but 90% percent of the farmers perceived termites as pests.This study has shown that the soil macrofauna, especially earthworms, and, to a lesser extent termites, are important drivers of stable soil aggregation in Sub-Saharan agroecosystems, with beneficial effects on soil physical and chemical properties. However, their beneficial impact on soil aggregation is reduced with increasing management intensity and associated soil disturbance due to cultivation. This knowledge is important in designing agricultural management systems aimed at increasing long-term soil fertility in Sub-Saharan Africa

Pengarauh Leverage, Profitabilitas, Ukuran Perusahaan dan Likuiditas Terhadap Nilai Perusahaan Pada Sektor Industri Barang Konsumsi Terdaftar Pada Bursa Efek Indonesia

This study aims to determine the effect of leverage, profitability, firm size and liquidity on firm value. The population in this study is the consumer goods industrial sector companies listed on the Indonesia Stock Exchange in 2016-2020. The sample in this study were 33 consumer goods industrial companies listed on the Indonesia Stock Exchange for the 2016-2020 period. This study uses purposive sampling method in determining the sample and multiple linear regression analysis to test the effect of independent variables on the dependent variable. Based on the results of this study indicate that leverage has a significant positive effect on firm value, profitability has a significant positive effect on firm value, firm size has a significant positive effect on firm value, and liquidity has no significant effect on firm value

Effects of soil management on aggregation and organic matter dynamics in sub-Saharan Africa

Maintenance of soil organic matter (SOM) is important for soil quality and agricultural productivity. However, little is known about the effects of management practices of different intensities on soil aggregation and SOM dynamics in tropical arable cropping systems of sub-Saharan Africa. We investigated the influence of land use practices and management intensity on soil aggregation and SOM dynamics across 12 long-term field experiments in eastern and western Africa. Aggregate size distribution and SOM were measured in arable systems under contrasting management intensities of high carbon, low carbon and a fallow. Aggregate stability indices and SOM were generally higher in the fallow compared to the arable systems. Fallowing and high carbon inputs in arable soils, significantly improved aggregate stability and carbon (C) and nitrogen (N) stabilization in whole soil, and in aggregate fractions. In contrast, no significant improvements in soil aggregation and C and N stabilization were found when organic inputs were either applied in low quantities or not applied at all, thus resulting in low carbon in soils. Our study showed that fallowing and long-term application of organic amendments alone or in combination with mineral fertilizers were the best among the practices tested in this study, for enhanced C and N stabilization in soils with the subsequent benefits of improving soil physical and chemical properties. These results emphasize the importance of management for sustaining soil quality. It is recommended that fallowing be an integral part of sustainable soil management strategies in these regions.Keywords: Soil aggregation, soil organic matter, carbon, nitrogen, managementintensit

Situational analysis of abiotic and biotic factors influencing abundance of tissue culture and non-tissue culture bananas in smallholder farms in Western Uganda

Bananas are, in Uganda primarily, grown for domestic consumption and regional trade. Production is constrained by several factors such as declining soil fertility, pests and disease, and erratic rainfall. Tissue culture banana were introduced partly to solve some of the challenges in banana production, though uptake of such technologies by smallholder farmers is still low. A survey on plant parasitic nematodes, banana weevils, and selected soil factors was done to analyse their effect on the abundance of tissue culture banana (TCB) and non-tissue culture banana (NTCB). Soil and banana root samples were collected from heterogeneous on-farm orchard conditions in smallholder farms. Composite banana root samples and composite soil samples were collected from banana orchards already established by farmers. A total of 1,280 genets from 20 orchards were obtained. Composite soil samples were analysed for pH, potassium, phosphorus, nitrogen, and organic matter. Endo-parasitic Helicotylenchus multinctus, Platylenchus goodeyi, Radopholous similis and Meloidogyne spp were isolated from the composite root samples. Banana weevils were captured using the disc-on-stamp and split-pseudo stem traps. Redundancy Analysis (RDA) and logistic regression were run to ascertain the relationship between variations in biotic [Nematodes and weevils] and abiotic [pH, K, Av.P, N, and OM] factors affecting the abundance of the banana type. Canonical eigenvalues showed that both biotic and abiotic variables significantly affected the abundance of TCB and NTCB banana types. Abundance of TCB was influenced by the banana weevil (P<0.05) than it was by nematodes in the same farmers’ fields. Infestation with nematodes for TCB and NTCB banana types was not different (P<0.05). The banana weevils were significantly (P<0.05) distributed within the districts. Relative abundances for the pH, phosphorus, potassium, nitrogen (%), organic matter (%) within districts were significant (P<0.05). Variations in soil pH and nitrogen availability resulted in significant interactions (P<0.05) that affected the abundance of the TCB types more than their contribution to the abundance of NTCB. The awareness that the interactions between nematodes, banana weevils, phosphorus, nitrogen, potassium and pH determine the abundance of banana types is important in shaping the adoption and production of the adopted banana technology. Mitigation of acidic pH, K, Av.P, N, and OM for soil fertility and reduction of the abundance of nematodes and weevils below the threshold will enhance banana production among small holder farmers in Uganda.&nbsp

PERAN EFEKTIVITAS SKAI DALAM MELAKSANAKAN FUNGSI AUDIT INTERNAL (STUDI KASUS : BANK ANDA PUSAT – BONGKARAN, SURABAYA )

This study aims to determine how the implementation of internal audit functions carried out by the Internal Audit Unit and is already carrying out its role effectively by reference to SPFAIB contained in Bank Indonesia Regulation number 1/6/PBI/1999 . This study used a qualitative approach using case studies in The Central Bank ANDA – Bongkaran, Surabaya with propositions to determine the effectiveness of the role of Internal Audit unit. Limitation in this study is the director of The Central Bank ANDA – Bongkaran, Surabaya, as well as employees in the Internal Audit Division which can provide information about the bank's Internal Audit. The unit of analysis in this study is an effective Internal Audit activity in the internal audit function. Criteria for determining the unit of analysis is the internal audit scope, duties and responsibilities of Internal Audit, Internal Audit minimal standards, and the Organization of Internal Audit. From this research, the results obtained that Internal Audit Unit of The Center Bank ANDA – Bongkaran, Surabaya has been effective in the measure of the propositions made researchers have been met. Key words: Internal Audit Unit, Internal Audit, SPFAIB, Bank Indonesia Regulation

Effects of biocontrol bacteria and earthworms on Aphanomyces euteiches root-rot and growth of peas (Pisum sativum) studied in a pot experiment

The role of below-ground interactions between microbial biocontrol agents and soil fauna for combatting soil-borne plant diseases have not been studied sufficiently. This study tested the hypothesis that the beneficial bacterium Bacillus velezensis UCMB5113 and the anecic earthworm Lumbricus terrestris positively influence health and growth of peas (Pisum sativum L.) infested with the pathogen Aphanomyces euteiches causing root-rot disease. A greenhouse fully factorial experiment studied the effects of A. euteches, B. velezensis and L. terrestris on the emergence, growth and health of pea plants. The factors B. velezensis and L. terrestris resulted in taller plants (p = .003 and p = .030). B. velezensis treatment resulted in a higher biomass of shoots and roots (p <= .001 and p = .005). The effects increased with the presence of both factors (p = .036). Earthworms reduced the disease symptoms significantly (p = .032). The decreased disease symptoms caused by the earthworms might be due to the consumption of A. euteiches (direct effect) as well as soil disturbance (indirect effect). Interactions between the microorganisms added and the earthworms were shown. B. velezensis and L. terrestris can be useful for enhancement of plant growth and for biological control of root-rot in peas

Influence des pratiques agricoles sur la macrofaune du sol : Cas de l’enfouissement de la paille et du fumier

La macrofaune du sol sur un essai agricole de longue durée a été inventoriée en 2008, huit semaines après les semis. Cet essai agricole implanté en 1980 est situé au Centre Ouest du Burkina Faso, et estreprésentatif de la production du sorgho avec utilisation de deux types de matières organiques exogènes avec ou sans fertilisation azotée. L’objectif était d’étudier l’influence de ces pratiques agricoles sur la macrofaunedes sols, représentée par les termites et les vers de terre. Les termites ont été échantillonnés par la méthode des monolithes et par transect ; les vers de terre ont été échantillonnés uniquement par monolithes. Sept espèces de termites de la famille des termitidae et trois espèces de vers de terre de la famille des Acanthodrilidae ont été identifiées. L’apport des matières organiques exogènes s’est traduit par une augmentation du nombre d’individus par unité de surface pour les deux groupes de macrofaune. L’incorporation de la paille a été beaucoup plus favorable aux termites par rapport au fumier qui a été plus favorable aux vers de terre. Pour les deux types de matières organiques, l’apport d’azote a entraîné une augmentation du nombre d’individus par unité de surface. La macrofaune dans la jachère bordant le site a été plus diversifiée que dans les sites de culture

Impact of Climate Change on Maize and Pigeonpea Yields in Semi-Arid Kenya

The objective of this study was to assess the impact of climate change on intercrops of maize and improved pigeonpea varieties developed. Future climate data for Katumani were downscaled from the National Meteorological Research Centre (CNRM) and Commonwealth Scientific and Industrial Research Organization (CSIRO) climate models using the Statistical Downscaling Model (SDSM) version 4.2. Both models predicted that Katumani will be warmer by 2°C and wetter by 11% by 2100. Agricultural Production Systems Simulator (APSIM) model version 7.3 was used to assess the impact of both increase in temperature and rainfall on maize and pigeonpea yield in Katumani. Maize crop will increase by 141–-150% and 10–-23 % in 2050 and 2100, respectively. Intercropping maize with pigeonpea will give mixed maize yield results. Pigeonpea yields will decline by 10–20 and 4–9% by 2100 under CSIRO and CNRM models, respectively. Intercropping short and medium duration pigeonpea varieties with maize will reduce pigeonpea yields by 60–80 and 70–90% under the CSIRO and CNRM model, respectively. There is a need to develop heat and waterlogging-tolerant pigeonpea varieties to help farmers adapt to climate change and to protect the huge pigeonpea export market currently enjoyed by Kenya

Exclusion of soil macrofauna did not affect soil quality but increased crop yields in a sub-humid tropical maize-based system

Soil macrofauna such as earthworms and termites are involved in key ecosystem functions and thus considered important for sustainable intensification of crop production. However, their contribution to tropical soil and crop performance, as well as relations with agricultural management (e.g. Conservation Agriculture), are not well understood. This study aimed to quantify soil macrofauna and its impact on soil aggregation, soil carbon and crop yields in a maize-soybean system under tropical sub-humid conditions. A field trial was established in Western Kenya in 2003 with tillage and residue retention as independent factors. A macrofauna exclusion experiment was superimposed in 2005 through regular insecticide applications, and measurements were taken from 2005 to 2012. Termites were the most abundant macrofauna group comprising 61% of total macrofauna numbers followed by ants (20%), while few earthworms were present (5%). Insecticide application significantly reduced termites (by 86 and 62%) and earthworms (by 100 and 88%) at 0-15 and 15-30 cm soil depth respectively. Termite diversity was low, with all species belonging to the family of Macrotermitinae which feed on wood, leaf litter and dead/dry grass. Seven years of macrofauna exclusion did not affect soil aggregation or carbon contents, which might be explained by the low residue retention and the nesting and feeding behavior of the dominant termites present. Macrofauna exclusion resulted in 34% higher maize grain yield and 22% higher soybean grain yield, indicating that pest damage – probably including termites - overruled any potentially beneficial impact of soil macrofauna. Results contrast with previous studies on the effects of termites on plant growth, which were mostly conducted in (semi-) arid regions. Future research should contribute to sustainable management strategies that reduce detrimental impact due to dominance of potential pest species while conserving soil macrofauna diversity and their beneficial functions in agroecosystems

Effects of Tillage Practices on Water Use Efficiency and Yield of Different Drought Tolerant Common Bean Varieties in Machakos County, Eastern Kenya

As world population increases, the need to feed this increasing population by the year 2050 is rising with marginal areas been cultivated to address these needs. This study seeks to compare effects of tillage on water use efficiencies (WUEs) and yields of drought tolerant bean varieties in Machakos County using three tillage systems: conventional tillage (CT) done with chisel mounted on oxen for ploughing while minimum tillage (MT) and no-till (NT) were done using hoes to dig directly  where seeds of four varieties were planted in 4 × 3 Split-plot randomized completely block design replicated four times. Erosion was negligible due to land slope flatness while actual ET crop was derived using meteorological data from 2016 and 2017 cropping seasons. Aboveground biomass and grain yield were harvested from the inner rows after discarding the outer two rows from all size of each experimental plot and weighed for total biomass and grain yield. Data were subjected to two-way analysis of variance (ANOVA) using Genstat 14th edition software statistical package at alpha 0.05. Duncan Multiple Range Test (DMRT) was used to separate means.Results indicate that interaction between tillage and seasons significantly influenced biomass and grain yield WUEs with GLPX92 yielding the highest in CT, MT and ZT though insignificant under the SR drought event, but under the LR favorable season GLPX92 yield decline with NT, CT and MT. These results, suggest interactions of conservation tillage and seasons the best option for production during favorable seasons and conventional tillage during drought events