Browsing by Author "Maitra, Sagar"

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    Review of Scientific Advances and Importance of Biochar for Agricultural and Industrial Uses
    (International Journal of Bioresource Science, 2024-12-07) Mwadalu, Riziki; Ndufa, James; Maitra, Sagar; Gweyi-Onyango, Joseph; Gitari, Harun
    Biochar has been known as an effective soil amendment with capabilities of boosting soil moisture storage, increasing soil fertility, and enhancing crop productivity. Biochar also has the potential for industrial use for wastewater treatment, water purification, steel making, building insulation, and air pollution control. The current metadata analysis evaluated the importance of biochar for agricultural and industrial uses and its relevance for use in Kenya. A total of 120 reference materials comprising journal papers, conference proceedings, and book chapters were used. Numerous studies conducted across the globe have documented the positive effects of biochar in increasing available soil nutrients (increased by 28.6% and phosphorus by 2 folds), lowering bulk density by 3-31%, enhancing soil moisture storage by 18-108%, and boosting microbial activities in the soil thus enhancing nutrient cycling. The metadata analysis also showed that biochar can reduce CO2 emissions by up to 33% thereby mitigating climate change. Biochar equally increased maize yield by 32-135% and rice yield by 8.5-10.7%. The review also showed that biochar can play a crucial role in different industrial uses such as wastewater treatment, steel making, and water purification. Some of the main impediments to the adoption of biochar were; the lack of a regulatory framework to govern the sector and the lack of a decision support system for use by end users.
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    Revisiting Intercropping Indices with Respect to Potato-legume Intercropping Systems
    (Elsevier, 2020) Gitari, Harun I.; Nyawade, Shadrack O.; Kamau, Solomon; Karanja, Nancy N.; Gachene, Charles K. K.; Raza, Muhammad A.; Maitra, Sagar; Schulte-Geldermann, Elmar
    Intercropping is gaining popularity in developing countries as a viable strategy for diversifying cropping systems to ease food insecurity, given that arable land is shrinking, and demand for food crops is increasing due to rapid population growth. A field experiment was conducted in 2015 and 2016, to examine the biological and economic viability of two intercropping systems (potato-dolichos and potato-bean planted in two potatoes to legume population density ratios: 1.1:2 and 1: 2.4) and their corresponding pure stands. Intercropping systems were also evaluated based on five competition indices: relative crowding coefficient (K), aggressivity (A), competitive ratio (CR), intercropping advantage (IA) and actual yield loss (AYL). Although biological feasibility revealed that intercropping decreased the yield of intercrops compared with respective monocultures; the economic assessment of different cropping systems indicated that intercropping resulted in a higher remuneration (gross and net income) than pure stands. Intercropping potato with a high population of legume (in 1: 2.4 patterns), resulted in not only higher system productivity but also potato equivalent yield compared to 1.1:2. Intercropping proved to be advantageous with AYL decreasing with increasing proportion of the legumes, whereas IA increased as the population of legumes increased. With regard to competition between the intercrops, the potato was more aggressive (A of potato was positive, and its CR > 1) in all cropping systems, and it dominated over legume (that had negative A values and CR < 1). Aggressivity and dominance capacity was higher in 1: 2.4 than 1.1:2 series. These results suggest that potato-legume intercropping may provide viable intensification options, especially for smallholder farmers.
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    Spatial Distribution of Soil Organic Carbon Stocks, and Soil Total Nitrogen in Central Equatorial State, South Sudan
    (International Journal of Bioresource Science, 2024-12-06) Malo, Meshack Oguna; Ladu, John Leju Celestino; Mukeka, Joseph; Maitra, Sagar; Gitari, Harun; Onyango, Joseph Gweyi
    The composition of soil organic carbon (SOC) and soil organic nitrogen (SON) is imperative to soil health in different agroecological zones globally. The proliferation of anthropogenic activities triggers the nitrogen and carbon stocks in soils. This study presents the spatial distribution of SOC and SON in six counties in Central Equatoria State, South Sudan counties. This study sought to determine the effect of pastoral activities on SOC and SON. We collected the soil samples within a 12-14 km radius from specific areas including congregation, grazing, degraded, water points, and agricultural land. The soil was collected at depths of 0–10 cm, 10–20 cm, and 20–30 cm respectively. The results indicate that land use activities had varied impacts on SOC and SON at different depths. The results showed that the interactive effects of the three sites and land uses differed in soil organic carbon (SOC) under different soil depths, which varied from 0.3 to 5.3%. The grazing area also recorded a higher SOC than the other land use types under 0-10 cm soil depth. The means showed that the SOC in the deep soils (20-30 cm) was lower than the surface soils in all the areas and land uses. The interactive effects of the districts and land uses differed in soil organic carbon (SOC) under different soil depths, which varied from 0.3 to 5.3%. The highest mean SOC of 5.73% was recorded in 0-10 depth in Kajokeji in the grazing area. The grazing area also recorded a higher SOC than the other land use types under 0-10 cm soil depth. The means showed that the SOC in the deep soils 20-30 cm was lower than the surface soils in all the areas and land uses. The results thus underscore that study areas and land use activity could impact the SOC and SON directly or indirectly.