Effect of acid soil and amendment on proximate and elemental composition of fluted pumpkin (Telfairia occidentalis) (Grinn)

Abstract

Soil degradation resulting from acidification poses a significant challenge to agriculture, impacting negatively on plant growth and nutrients accessibility. This study investigated the effects of acidic soil and substrate amendment on proximate and elemental composition of fluted pumpkin (Telfairia occidentalis). The evaluated crop was grown on acidic soil of pH 3.0 and 0 was used as the control. Growth on acidic soil was achieved by irrigating soil with acidified water, simulated by mixing sulphuric and nitric acids in a 2:1 ratio. Soils were subsequently amended with agricultural lime, organic manure, and a combination of both, with 50 g of each amendment mixed with 5 kg of each soil. The experiment was conducted in a completely randomized design (CRD) in three replicates, and data collected were analyzed using statistical package for social sciences (SPSS) version 20.0. Results of physico-chemical properties revealed that acidic soils treated with a combination of agricultural lime and organic manure improved the soil pH towards neutrality (from pH 3.0 to 7.37). Effective cation exchange capacity showed improvement in soils amended with organic manure and a combination treatment. Organic carbon (1.62), nitrogen (3.36) and phosphorus (389.62) concentrations were higher in soils amended with organic manure and agricultural lime compared to unamended soils (control) values of 1.18, 2.24 and 196.00 respectively. The mineral composition was comparable, calcium was significantly (P<0.05) higher in T. occidentalis grown on unamended acidic soils (pH 3.0) with values ranging from 2022.3 % to 5962.3 % compared to amended soils values of 1326.3 % to 1381.3 %. This study has revealed that these amendments not only enhanced growth, yield and the proximate composition of T. occidentalis but also positively impacted the soil physico-chemical properties and nutrients availability.