Pedological characterization and soil fertility assessment of the selected rice irrigation schemes, Tanzania
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Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
Frontiers
Abstract
Rice (Oryza sativa L.) is the second cereal food crop grown in Tanzania after
maize (Zea mays L.) and covers approximately 18% of the agricultural land. Soil
degradation due to intensive cultivation along with low organic matter input and
nutrient imbalance has led to a decline in rice crop yields. This study was
conducted to characterize, classify, and assess the fertility status of soils in two
rice irrigation schemes of Morogoro region in Tanzania. The data obtained
through this study will contribute significantly to land use planning and will
facilitate the transfer of agro-technology and other development of the regions
with similar ecological conditions. The studied pedons were named MKU-P1 and
MKD-P1 for Mkula and Mkindo irrigation schemes, respectively. A total of seven
composite soil samples (0–20 cm) were collected for soil fertility assessments.
Landform, soil morphological features, parent material, natural vegetation,
drainage, erosion, and laboratory data were used to classify the soils in their
respective order as per the United States Department of Agriculture (USDA) Soil
Taxonomy and the World Reference Base (WRB) soil classification systems.
Results showed that the pedons were sandy clay loam in the topsoil and sandy
clay to clay in the subsoil; soil reaction ranged from medium acid (pH 5.7) to
strongly alkaline (pH 8.6). The topsoil and subsoil nutrients of the studied pedons
including available K+, total N, soil organic matter, and organic carbon are low.
Based on the USDA Soil Taxonomy, MKU-P1 is classified as Inceptisols cumulic
humaquepts and MKD-P1 as Vertisols Fluvaquentic endoaquerts corresponding
to Subaquatic fluvisols (loamic, oxyaquic) and Irragric vertisols (gleyic) in the
WRB, respectively. The pedons were ranked as suitable for rice production.
However, the chemical fertility of the soil is ranked as low fertile associated with
deficient in total N; available P, K+, and Ca2+ with excessive iron and manganese;
and likely to pose toxicity to crops. The application of organic and mineral
amendments in recommended rates and timing for N and P is therefore essential
to increase the nutrient content of these soils and minimize losses. Salinity in the
subsurface pedon MKD-P1 needs to be taken into future consideration.
Description
Journal Article
Keywords
Soil fertility, Soil classification, Paddy soils, Pedons, Soil health
Citation
Marzouk SH, Tindwa HJ, Massawe BHJ, Amuri NA and Semoka JM (2023) Pedological characterization and soil fertility assessment of the selected rice irrigation schemes, Tanzania