Effect of Banana-based soil management routines on soil chemical properties in Nyaruzinga, Bushenyi district

Abstract

Banana, indigenously the East African Highland Banana (Musa Acuminata AAA-EA) is grown in many parts of the country and contributes significantly to food and economic security. However, the sustainability of its production is threatened by soil degradation as influenced by poor soil fertility management. In Bushenyi at the Presidential Initiative on Banana Industrial Development (PIBID) center, Banana production has been ongoing for the last 15-18 years under different soil fertility management routines, which had a far-reaching impact on soil fertility, however, the extent of their effect on soil fertility was less studied. This study aimed to investigate the effect of banana-based soil management routines on soil chemical properties. The soils had been under two contrasting long-term soil fertility management routines, where banana fields have been managed for over 15 years (routines). These were intensive management routine (>15 years), moderate management routine (<7 years), and undisturbed routine (as reference), from where composite soils were sampled in triplicate based on slope of each routine at a depth of 20 cm. 15 samples from the intensive routine, 12 from the moderate routine, and 3 from the undisturbed routine, totaling to 30 samples. These were taken to the Soil and Plant Analysis Laboratory at Makerere University for the analysis of soil chemical properties, soil pH, EC, SOC, Total N, Available P, Exchangeable K and Na, and soil texture as an additional physical property. Statistical Analysis was done using Genstat 14th edition for ANOVA at p < 0.05 and Least Significant Difference (LSD) at 5% for mean comparisons. The results indicated that Soil pH, EC, Available P, Exchangeable Na and K were not significantly affected by management routines and slope (p > 0.05), whereas Total N and SOC significantly varied (p < 0.05), however, slope only influenced textural distribution with sand varying significantly whereas clay was not affected (p = 0.055). The pH across all soil management routines ranged between moderate acidity to low alkalinity (4.7-7.1). Total N and SOC ranged from moderate to high concentration for intensive management; moderate to low for moderate management, and very low for the undisturbed. This study concluded that management routines had significant contributions to soil fertility, as evidenced by significant variations across management routines on SOC and total N. The intensive management routine registered high proportions of soil chemical parameters. Therefore, stakeholders should continue ensuring proper use of the already established soil fertility management patterns, and adopt ISFM as measures to improve nitrogen stocks, routine soil testing and targeted fertilization, and extend the knowledge to smallholder farmers across Bushenyi and Uganda at large, whose soils contain inherently low soil fertility due to intensive cultivation.