Effects of Lime, Mineral P, Farmyard Manure and Compost on Selected Chemical Properties of Acid Soils in Lay Gayint District, Northwestern Highlands of Ethiopia

Aim: to evaluate the effects of sole and combined applications of lime, mineral P, Farmyard manure, and compost on selected chemical properties of acid soils of Lay Gayint District after 20, 40, and 60 days of incubation under greenhouse conditions.

Study Design: the treatment consisted of fifteen treatments (lime, mineral P, FYM, compost, and their combinations) arranged in a completely randomized design (CRD) in three replications.

Place and Duration of the Study: the study was conducted in Amhara Agricultural Research Institute greenhouse in 2015 cropping season.

Methodology: Treatments (lime, mineral P, FYM, and compost) were applied in sole and combination to acid soils collected from cultivated lands. After application, the soils were incubated for 20, 40, and 60 days to evaluate the effects of the applied treatments on selected soil chemical properties.

Results: The treatment combinations raised the soil pH significantly (P < 0.001) at the 40 days of incubation. All the treatments showed increased P availability with increasing time of incubation. Maximum available P was observed at the 60 days of incubation due to application of 8 t FYM ha-1 + 30 kg P ha-1 + 5 t lime ha-1 followed by 8 t compost ha-1 + 30 kg P ha-1 + 5 t lime ha-1. Exchangeable acidity and Al3+ were reduced significantly (P < 0.001) at the 40 and 60 days of incubation with the application of 30 kg P ha-1 + 10 t lime ha-1 followed by 4 t FYM or compost ha-1 + 15 kg P ha-1 + 10 t lime ha-1. The highest exchangeable Ca2+ was obtained at 20 days of incubation with the application of 30 kg P ha-1 + 10 t lime ha-1 followed by 4 t ha-1FYM + 15 kg P ha-1 + 10 t lime ha-1. Sole addition of 10 t lime ha-1 increased effective cation exchange capacity (ECEC) from 17.59 to 22.09 cmolc kg-1 at the 40 days of incubation. Likewise, combined applications of 30 kg P ha-1 + 10 t lime ha-1 followed by 4 t FYM ha-1 + 15 kg P ha-1 + 10 t lime ha-1 improved ECEC of the soil from 17.59 to 23.95 and 22.97 cmolc kg-1, respectively at the 40 days of incubation.

Conclusion: Integrated applications of organic and inorganic amendments were found to be more effective in reducing soil acidity and Al3+ concentration while increasing the fertility of the soil.