PJB-2024-236
Interactive effect of humic acid and farmyard manure on soil health and microbial activity in calcareous soil
Shahzad Afzal, Dost Muhammad, Rafi Ullah, Muhammad Adnan, Beena Saeed, Rasha M. Alzayed, Sondos A. Alhajouj, Meaad F. Alaida, Manzoor Ahmad, A. Altalhi and Madeha O. I. Ghobashy
Abstract
Humic acid (HA) improves soil solids surface chemistry and thereby optimizes biological activity and fertility of soil. However, its interactive effect with farmyard manure (FYM) under calcareous soil is not fully explored. Therefore, a laboratory incubation experiment (1st) was conducted to investigate effect of various levels of lignitic coal derived humic acid (0, 100 and 200 mg kg-1 soil) applied alone or in conjunction with 10 g FYM kg-1 on soil microbial activity and nutrients availability for 79 days. In the 2nd experiment, the same soil was remoistened and treated with lower levels of HA ( 0, 2, 4, 6, 8 and 10 mg kg-1) for 14 days to further verify its effect on soil microbial activity. The combine application of HA and FYM significantly increased CO2 release except at 2nd day, however, application of 100 and 200 mg HA produced non-consistent supremacy over each other at different incubation intervals. Combine use of HA and FYM consistently accelerated the rate of CO2 production over all incubation intervals as compared to the sole application of HA or control. Cumulative release of CO2 also showed that application of HA either as 100 or 200 mg produced higher (1014 and 1035 mg CO2 kg-1 respectively) as compared to control (918 mg kg-1) at 79th day. Integrated use of HA+FYM further amplified cumulative CO2 releases as compared to control or alone HA at both levels. In the second experiment, application of HA increased CO2 release with increasing doses up to 6 mg HA kg-1 only at day 4 of incubation while its effect was non-significant for the rest of incubation interval. The integrated application of HA and FYM significantly improved post incubated soil pH, Organic matter and NPK content compared to their sole application. Therefore, it can be concluded that the application of FYM further amplify the positive effect of humic acid on soil health and shall be adopted
To Cite this article:
Afzal, S., D. Muhammad, R. Ullah, M. Adnan, B. Saeed, R.M. Alzayed, S.A. Alhajouj, M.F. Alaida, M. Ahmad, A. Altalhi and M.O.I. Ghobashy. 2025. Interactive effect of humic acid and farmyard manure on soil health and microbial activity in calcareous soil. Pak. J. Bot., 57(3): DOI: http://dx.doi.org/10.30848/PJB2025-3(17)
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