Evaluation of sawdust used as soil amendment on the performance of Groundnut (Arachis hypogaea L.)

Abstract

In this study, the effect of rates of sawdust (0g, 80g, 120g and 160g) on soil chemical properties and the performance of Groundnut (Arachis hypogaea L.) was investigated for a period of 15 weeks. The experiment was laid out in a Randomized Complete Block Design (RCBD) and replicated 3 times. 48
polybags of sandy topsoil were prepared and 0g (control), 80g, 120g and 160g of sawdust were incorporated into the 10kg soil contained in each of the polythene bags. Then, 3 groundnut seeds were sown on the same day and the seedlings were thinned to one exactly 2 weeks after planting (2WAP), while data were collected weekly on parameters such as germination percentage, plant height, number of leaves, leaf area, number of pods, number of seeds, weight of pods and of the seeds. The data collected were subjected to analysis of variance (ANOVA) using the personal computer software packages SPSS version 20.1. Significant treatment means were compared using the Duncan multiple range test ((DMRT)) at P≤0.05. Results showed that increasing rates of sawdust increased the germination percentage and plant height of groundnut except at 6WAP. Leaf area increased from 8.918mm2 to 9.477mm2 at 120g, number of leaves was not significantly (P≤0.05) increased, number of seeds increased from 19 at 0g to 21 at 160g of sawdust application, seed weight increased from 20.0g at control to 22.3g at 160g but the number of pod and weight of pod was not significantly (P≤0.05)
increased when compared to control. The sawdust rates (80g, 120g and 160g) incorporated in the soil significantly decreased the soil pH range but still within a pH range of 6 and 7, required for groundnut cultivation. It also decreased the available phosphorus and potassium content in the soil which
resulted in the reduced number of pods and weight of pods of the groundnut plant. In conclusion, sawdust as a soil amendment significantly increased vegetative growth, the number and weight of the groundnut seed but did not significantly increase the number and weight of pods of the groundnut
plant.