Rasha Baddour *⁽¹⁾ , Jihad Ibrahim⁽¹⁾ and  Rabee Zainah⁽²⁾

(1). Department of soil sciences and water ,faculty of Agriculture, Tishreen University, Lattakia,Syria.

(2). General Commission for Scientific and Agricultural Research,Damascus,Syria

(*Corresponding author:  Rasha Baddour.Email: rasha.r.baddour@tishreen.edu.sy).

Received:  2/08/2023             Accepted:  27/10/2023

Abstract: 

The research was carried out during fall season on silty clay soil at the Center for Scientific Agricultural Research in Latakia (Stakhris Station) in 2019, where the study included four treatments (T0 control without mechanical disturbing of the subsoil layer, LT0 treatment of mechanical disturbing of the subsoil layer only, T1 addition of 1 kg/dunam of Potassium humate during mechanical disturbing, T2 (addition of 2 kg/donum of potassium humate during mechanical disturbing). The results showed a significant decrease in bulk density after mechanical disturbing by 0.14 g/cm³ compared to the control, and the addition of potassium humate in treatment T2 enhanced this decrease to reach 0.16 g/cm³. Mechanical disturbing of the subsurface soil layer improved the total porosity percentage, as it reached 50.51% in the LT0 treatment after it was 46.34% in the control treatment. Potassium humate contributed to improving the total porosity percentage in the subsurface soil layer, reaching 50.63% and 52.49% for the T1 and T2 treatments, respectively. Mechanical disintegration and the addition of potassium humate also improved the size of air pores larger than 10 microns, as their size increased significantly with mechanical disintegration by 5.9% and 6.68% in the LT0 and T2 treatments, respectively. While pores less than 0.2 microns decreased with mechanical disturbing and at addition levels T1 and T2, especially at addition level T2, bringing this decrease to 2.83% compared to the control. Adding potassium humate at a higher concentration enhanced both vegetative growth and production indicators, as the T2 treatment was significantly superior in terms of average plant height (48.43 cm) and average leaf surface index (2.18) compared to the control. Both the percentage of dry matter increased by (1.54%) and starch by (1.374%) significantly in treatment T2 compared to the control. The average production of treatment T2 was significantly higher than the rest of the treatments, as the average production increased with disassembly only by 5.9%, which is a non-significant increase. Adding potassium humate improved production, as it increased significantly by 13.7% and 32.4% in treatments T1 and T2, respectively. Therefore, we recommend adding potassium humate at a rate of 2 kg/dunum during mechanical disturbing of compressed subsurface soil layers, taking into account follow-up research to determine the optimal addition rate for crops and different types of soil.

Keywords: mechanical disintegration ,  potassium humic,   potato , bulk density,  productivity,  subsurface soil layer.

Full paper in Arabic: pdf