Improving Chemical and Microbial Properties of Calcareous Soil and its Productivity of Faba Bean (Vicia faba L.) Plants by using Compost Tea Enriched with Humic Acid and Azolla

This study evaluated the effect of compost teas enriched with humic acid and/or azolla on soil chemical and microbial properties as well as on yield and plant measurements of faba bean (Vicia faba L. c.v. 843) plants. A field experiment was carried out on calcareous soil of El Nobaria area, El-Beheira Governorate, Egypt during grown winter season of 2018/2019. The four compost teas treatments were: without any supplemental (NECT), enriched with humic acid (ECTH), enriched with azolla extract (ECTAz) and enriched with humic acid and azolla extract (ECTHAz). All treatments were applied to calcareous soils at two different rates (120 and 240 L.ha-1), through drip irrigation system. At 50 day of planting, nodules number, dehydrogenase activity (DHA) as well as fresh and dry weights of shoots were determined. Also, at harvest stage, straw and seeds yields of faba bean and soil chemical properties (pH, EC, CEC, CaCO3 and OM) and its content of macro-micronutrients (N, P, K, Fe, Mn, Zn and Cu) were determined. Generally, in most of the studied attributes in soil or plants, the greater effect was found with the treatment of ECTH, ECTAz and/or ECTHAz treatments. There is a superior increase effect of enriched compost teas (ECTH, ECTAz, ECTHAz) on nodules numbers, DHA, straw and seeds yield of faba bean plants compared to these of NECT and control treatments. The treatments of enriched compost teas significantly increased the seeds macro-micronutrients content compared to control. Also, enriched compost teas applications improved soil chemical and microbial properties and its content of available macro and micronutrients than those found with NECT treatments. Compost tea especially that enriched with humic acid and azolla extract can be used to improve calcareous soil and its productivity of faba bean plant.