Chemical and Biological Properties of Paddy Soil Treated with Herbicides and Pyroligneous Acid

In this study, the effect of different herbicide x pyroligenous acid mixtures on soil chemical and biological properties was evaluated in order to elucidate its potential impacts on nutrient availability and soil quality. The experiment was conducted under greenhouse conditions consisted of 100-fold diluted wood vinegar (100 WV), 50% BCB (Bentazone cyhalofop-butyl), 100% BCB, 50% BCB+100 WV, 50% BCB+250 WV and 50% BCB+500 WV applied against Echinochloa crusgalli. Ten days after herbicide application, the chemical properties were altered and the changes were influenced by the amount of WV dilutions. The soil pH was near neutral to slightly alkaline coupled with decreased electrical conductivity (EC). The total carbon, available phosphorous, exchangeable magnesium, exchangeable sodium, exchangeable calcium, exchangeable potassium and cation exchange capacity (CEC) were relatively lower compared to the control. BiologTM assay showed that different treatments resulted to variable microbial activity, Shannon-Weaver index and richness of carbon utilization potential. Principal component analysis showed segregation of samples based on extracted principal components indicating variable carbon utilization potential due to different treatments combination. Correlation analysis between soil and microbial properties revealed that Principal Component 2 has negative correlation with pH and available P. On the other hand, Principal Component 3 was positively correlated with total C, exch. Ca, Mg, Na, and CEC (0.475, 0.490, 0.555, 0.489, and 0.517, respectively). Application of pyroligneous acid combined with herbicides resulted to changes in soil chemical and biological characteristics which may have unique implications on nutrient availability and overall soil quality.