Soybean (Glycine max L.) Response to Lime and Vermicompost Amelioration of Acidic Nitisols of Assosa, North Western Ethiopia

Abstract

Acidic soils limit the production potential of crops because of low availability of basic cations and excess of hydrogen (H+) and aluminium (Al3+) in exchangeable forms. In the western part of the country such as Assosa and Wellega, soil acidity is a well-known problem limiting crop productivity. A field study was conducted to assess the effects of lime, vermicompost and their combinations on selected soil physico-chemical properties and responses of soybean grown on acidic Nitisols of Assosa area during 2016 and 2017 main cropping seasons. Soil samples were collected from the experimental site before planting and from plots after harvesting. The collected samples were analysed following the standard methods for soil physico-chemical analysis. The treatments were factorial combinations of four levels of lime (0, 1.62, 3.62 and 4.90 t ha-1) and four levels of vermicompost (0, 1.50, 3.00 and 4.50 t ha-1). The results revealed that soil pH increased from 5.31 – 5.86 pH while exchangeable acidity decreased from 5.46 - 2.85 cmol (+) kg-1 with levels of lime and vermicompost (3.26 with 3 and 4.90 with 4.5) t ha-1 respectively, which resulted in improved soil physico-chemical properties. The combined application of lime and vermicompost also significantly improved the yield related parameters of soybean. The maximum grain yield (1.95t ha-1) was obtained from the combined application of 4.90 ton lime and 3.00 ton vermicompost ha-1 followed by combined application of 3.26 ton lime with 3.00 ton vermicompost ha-1 with non-significant variation. Therefore, the combined application of 3.26 ton lime and 3.00 ton vermicompost ha-1 is a promising alternative amendment for amelioration of acidic Nitisols of Assosa (Amba-12 Kebele) and other similar agro-ecologies for the improvement of soybean production.

Responses of Acidic Soil to Lime and Vermicompost Application at Lalo Asabi District, Western Ethiopia

“…This might be due to combined application of lime with vermicompost, which resulted in improved soil conditions, such as soil pH, increased soil OM and reduction of exchangeable acidity. This result was supported by the finding of [48] who reported increment of soil CEC when lime and vermicompost amendments applied to acid soil. Cation exchange capacity of the soil was not significantly increased by the combined application of lime and VC.…”

“…Adsorption of organic anions on hydrous Fe and Al surfaces and the corresponding release of hydroxyl ions increased soil pH and reduced exchangeable acidity [44]. [48] also reported that addition of organic manures to acid soils increased soil pH, decreased Al saturation, and thereby improved soil conditions for plant growth. The lowest exchangeable acidity values were recorded for combined application of lime at 75% LR + 2.5 t VC ha -1 (0.31 cmol c kg -1 ) followed by 100% LR + 5 t VC ha -1 (0.33 cmol c kg -1 ) and 100% LR + 2.5 t VC ha -1 (0.35 cmol c kg -1 ) while the highest was recorded for the control (2.44 cmol c kg -1 ) (Table 6).…”

“…The increased exchangeable Ca 2+ concentration could be attributed to the release of Ca 2+ ions from lime through its dissolution and mineralization of VC, which are expected to be adsorbed on exchange sites. [48] reported increased exchangeable Ca 2+ for soils of western Ethiopia after application of lime alone and combined with vermicompost. [55] also found significant increase in soil exchangeable Ca 2+ when lime applied to acidic soils with manure.…”

Effect of Rhizobium Inoculation, NPS Fertilizer and Vermicompost on Nodulation and Yield of Soybean (<i>Glycine max</i> (l). Merrill) at Bako, Western Ethiopia

“…The possible reason for the greater number of nodules developed on the root of soybean after vermicompost application and NPS fertilization might be the importance P and S elements that found in NPS used in enhancing nodulation, symbiotic association between rhizobia and host plant and consequently improved N2 fixation. Likewise, application of vermicompost supply necessary nutrients (N, P, S, K and Fe) important for nodules formation and Rhizobia bacteria are sensitive to soil acidity and require P, adequate soil moisture for their multiplication [41,42]. In agreement with this result application of 16 t FYM ha -1 + 60 kg S ha -1 on soybean-wheat cropping system produced maximum mean number of nodules per 5 plant (231) across 3 years [43].…”

“…The possible reason of high number of effective nodules with vermicompost application might be due to the availability of calcium might enhance root development and root nodulation [51,52]. This might be due to combination of organic and inorganic nutrition provides better soil environment for root growth, nodule formation, availability and absorption of nutrient from soil [46,42]. Similarly application of 16 t FYM ha -1 + 60 kg S ha -1 on soybeanwheat cropping system produced maximum mean number of effective nodules per 5 plants (325) across 3 years, [43].…”