Abstract

Author:
Fidelis Vershima Aberagia, Chinyere Blessing Okebalamab, Charles Livinus Anija Asadub

Doi: 10.26480/jwbm.01.2024.15.20

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Soil microbial biomass is an important source of nutrients for crops. However, the response of microbial biomass- C (MBC) and -N (MBN) to various inorganic fertilizers in legume cultivation is lacking. A two-year impact of inorganic fertilizers [urea, single superphosphate (SSP), N15P15K15] addition on soil fertility and microbial biomass was determined in the rhizosphere of soybean (Glycine max) grown in an Ultisol. Treatments were laid out in randomized complete block design in triplicates. Rhizosphere soils from soybean plants was collected at 30, 60, and 90 days after sowing (DAS). Results showed that the soil had a sandy loam texture, moderately acid (pH 5.2), low in organic matter, total nitrogen, exchangeable bases and CEC, but moderate in available phosphorus. In both cropping years, the retention of these soil chemical parameters was significantly (p < 0.05) increased, apart from/expect total N in the second cropping year. Furthermore, there was improvement in soil MBC at 30, 60 and 90 DAS in both cropping years and an improvement in MBN at 60 and 90 DAS in the first year and at 90 DAS in the second year due to fertilizer treatment. This positive effect was highest with N15P15K15 compared to the individual addition of SSP and Urea. Study result showed that the contribution of rhizo-C to microbial biomass depends on the fertilizer-induced changes on soil pH, organic matter and NPK nutrients reserves in the study soil. These results will benefit farmers in the study area and similar study soils in selecting inorganic fertilizers to maintain soil biochemical fertility.