The impact of biochar, lime and fertilizer on soil acidity and microbiological properties and their relationship with yield of rice and cowpea in an acidic soil of Southern India

Abstract

A field experiment was conducted at Zonal Agricultural Research Station, Mandya to evaluate the effect of biochar, lime and fertilizer on soil acidity and microbiological properties in an acidic soil. The experiment was laid out in randomized complete block design with seven treatments and three replications. The results revealed that application of fertilizer based on the soil test value (STV) either in combination with biochar or lime influenced soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), dehydrogenase, urease and phosphatase activities significantly. Similarly, application of STV-based fertilizer along with biochar + FYM (Farm Yard Manure) + ZnSO₄ significantly decreased exchangeable aluminum, exchangeable acidity and total acidity as compared with recommended dose of fertilizer (RDF) + FYM + ZnSO₄ treatment. The grain yield of rice was increased by 37.90% in STV + biochar + FYM + ZnSO₄ and by 22.87% in STV + lime + FYM + ZnSO₄ plots than RDF + FYM + ZnSO₄ plot. Seed and haulm yield of cowpea increased by 33.57% and 18.53% in STV + biochar + FYM + ZnSO₄ treatments as compared with RDF + FYM + ZnSO₄ treatment. Exchangeable aluminum and exchangeable acidity were found to be negatively correlated with yield of rice (r = −0.179) and cowpea (r = −0.266). However, yield of rice and cowpea showed the significantly and positively correlated with microbiological properties. The exchangeable Al and exchangeable acidity were found to be negatively correlated with SMBC, SMBN, dehydrogenase activity, urease activity and phosphatase activity.

Keywords:

• biochar
• lime
• soil test value-based fertilizer application
• soil acidity
• microbiological properties
• correlation
• yield of rice and cowpea

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are thankful to the University of Agricultural Sciences, Bengaluru (India), for providing financial support to this study.