Evaluation of Buffer Lime Requirement Methods without Hazardous Chemicals for Acid Soils of Assam, India

Liming is one of the most important and feasible management practices used to ameliorate soil
acidity. The amount of lime required to neutralize the soil acidity is called lime requirement. Generally
lime requirement (LR) for acidic soils are determined by buffer pH method because of their ease of
implementation, simplicity and rapidity (Wolf el al., 2008). The SMP buffer test is used to determine
lime requirement for Assam soils. Though this method is proven to work for Assam soils, it uses pnitrophenol,
which is very hazardous substance. Now-a-days soil-testing laboratories are under
increasing pressure to reduce hazardous waste. So goal of this study was to evaluate a buffer as
alternatives to the SMP buffer in determining the LR for Jorhat soils. In this study three buffer methods
were used, i.e., Shoemaker, McLean and Pratt buffer; Sikora-I buffer and Sikora-II buffer. Further,
Sikora-II based on the analysed parameters may be considered as an alternative to present SMP
buffer lime requirement method. These findings may overcome the use of hazardous chemicals used
for recommending lime rate during Soil Health Card (SHC) preparation as mandated by Govt. of India.