Housing crisis: Waste glass-stabilized clay for use as fired clay bricks

Scarce and expensive housing and consumer waste disposal are global challenges in today’s world. This study investigated the engineering properties of a clay stabilized with three waste glass sizes (less than 75 μm, greater than 150 μm but less than 75 μm, and less than 300 μm but greater than 150 μm) for the production of burnt clay bricks for earth building construction. Laboratory tests (sieve analysis, Atterberg limits, specific gravity, and compaction tests) were conducted on the clay soil sample, while firing shrinkage, water absorption, unit weight and compressive strength tests were conducted on the fired clay bricks. The unit weight, firing shrinkage and compressive strength decreased with an increasing particle size of the waste glass in the fired clay bricks, while the fired clay bricks absorbed more water as the particle size of its waste glass content decreased. The use of waste glass with particle sizes less than 75 μm for stabilizing the clay was found to produce fired clay bricks with the highest compressive strength. The compressive strength of the fired clay bricks containing less than 75 μm particle sizes of waste glass was increased by 43.9% when compared with the compressive strength of the fired clay bricks having no waste glass. Consequently, waste glass with particle sizes of less than 75 μm is recommended for use in the production of fired clay bricks. The use of waste glass, which could have been a nuisance to the environment, is a potential way of improving the strength of bricks and making them more affordable bricks and consequently, making housing more affordable

Changes in the Structure of a Nigerian Soil under Different Land Management Practices

Quantification of soil physical quality (SPQ) and pore size distribution (PSD) can assist understanding of how changes in land management practices influence dynamics of soil structure, and this understanding could greatly improve the predictability of soil physical behavior and crop yield. The objectives of this study were to measure the SPQ index under two different land management practices (the continuous arable cropping system and natural bush fallow system), and contrast the effects of these practices on the structure of PSD using soil water retention data. Soil water retention curves obtained from a pressure chamber were fitted to van Genuchten’s equation, setting m (= 1-1/n). Although values for soil bulk density were high, soils under the continuous arable cropping system had good SPQ, and maintained the capacity to support root development. However, soils under the natural bush fallow system had a worse structure than the continuous arable system, with restrictions in available water capacity. These two management systems had different PSDs. Results showed the inferiority of the natural bush fallow system with no traffic restriction (which is the common practice) in relation to the continuous arable cropping system in regard to physical quality and structure

CHANGES IN SOIL AGGREGATE STABILITY AND CARBON SEQUESTRATION MEDIATED BY LAND USE PRACTICES IN A DEGRADED DRY SAVANNA ALFISOL

Se investigaron los efectos de las prácticas de uso del suelo en la estabilidad de los agregados del suelo y se analizaron fracciones del carbono orgánico del uselo empleando procedimiento de fraccionamiento físico. Se muestreo el suelo a tres profundidades (0-5, 5-15 y 15-25 cm) en suelo cultivado, con vegetación nativa y en bosque. Los suelos fueron separados en agregados para calcular el diámetro medio (MWD) y carbono asociado al agregado. Los resultados mostraron que el MWD incrementó 61.4% en suelo del bosque en relación al suelo de áreas de cultivo. La fracción de macroagregados en los suelos de bosque fue 76.2% mayor que los suelos del área de cultivo. Carbono químicamente protegido fue mayor (39%) en suelos cultivados en comparación con los suelos de bosque. Se que concluye que los plantaciones forestales tienen el potencial de incrementar la estabilidad estructural de los suelos y su resistencia a la erosión. Las áreas de cultivo parecen favorecer el secuestro de carbono en relación a la vegetación nativa y los suelos de bosque de Eucalipto

Sole and Combined Application of Biodigestate, N, P, and K Fertilizers: Impacts on Soil Chemical Properties and Maize Performance

The fertilizing effects of biodigestate produced from biogas plants on crop and soil productivity are very scarce. Hence, a field study was conducted in 2022 at the Teaching and Research Farm of Bowen University, Iwo, Osun State, Nigeria. The study evaluated the effects of biodigestate fertilizer, applied alone or in combination with urea, single superphosphate, or muriate of potash fertilizers at low (N1, K1, and P1) and high (N2, P2, and K2) rates on soil chemical properties, growth, and yield of maize (Zea mays (L.)). The treatments were biodigestate alone (D), D + N fertilizer (urea) at 60 kg·ha−1 (DN1), D + N at 120 kg·ha−1 (DN2), D + P fertilizer (single superphosphate) at 30 kg·ha−1 (DP1), D + P at 60 kg·ha−1 (DP2), D + K fertilizer (muriate of potash) at 30 kg·ha−1 (DK1), D + K 60 kg·ha−1 (DK2), D + N1 + P1 + K1 (DN1P1K1), D + N2 + P2 + K2 (DN2P2K2) (10), and control. The 10 treatments were arranged in a randomized complete block design and replicated three times. Results showed that both low and high rates of fertilizer application improved soil chemical properties, growth parameters, and yield of maize compared with the control. High fertilizer rates (N2, P2, and K2) significantly enhanced soil chemical properties and growth parameters, but lower rates (N1, P1, and K1) resulted in higher maize yield. DN1 fertilizer significantly increased maize yield compared with DN2, DP1, DP2, DK1, and DK2. Overall, the treatment of DN1P1K1 demonstrated the highest grain yield, likely due to optimal nutrient supply from N, P, and K fertilizers, along with an improved soil environment facilitated by the biodigestate. The study recommends a balanced and sustainable fertilizer application strategy of 60 kg·N·ha−1, 30 kg·P2O5·ha−1, and 30 kg·K·ha−1 with 2500 L·ha−1 of biodigestate to enhance maize production while minimizing cost and environmental impact. However, for those aiming for maize fodder production, a higher fertilizer rate of 120 kg·N·ha−1, 60 kg·P2O5·ha−1, and 60 kg·K·ha−1 with 2500 L·ha−1 of biodigestate is advised

EFFECT OF ORGANIC AND INORGANIC SOIL AMENDMENTS ON SOIL PHYSICAL AND CHEMICAL PROPERTIES IN A WEST AFRICA SAVANNA AGROECOSYSTEM

Long-term agroecosystem productivity has stirred up the need to develop and implement nutrient management strategies that maintain and protect soil resources. In an attempt to address this, the current study involved the incorporation of residues of Centrosema pascuorum, Lablab purpureus and Parkia biglobosa. In addition, an inorganic fertilizer amended soil and, a maize/Lablab purpureus intercrop, along with the control (no amendment) was included. The treatments were replicated three times and the site had been under continuous cultivation for eight years in a savanna Alfisol. Soil quality (physical and chemical) indicators were examined for treatments effects. Dry macroaggregate turnover increased by 7% under C. pascuorum amended soils. This same treatment had more water-stable large microaggregates and a 40% increase in aggregated silt and clay content. Soil bulk density and saturated hydraulic conductivity reduced in nutrient management practices involving residue incorporation. However, soil organic carbon, total soil nitrogen, exchangeable Ca2+ and Mg2+ concentration were highest with soil receiving C. pascuorum. Crop residue management practices involving incorporation of C. pascuorum significantly improved soil physical and chemical properties of the study area