Addition biochar to enhanced soil quality and sugar beet crop grown under water stress treatments in salt-affected soils

Abstract EN

Biochar amendment as agro-management technique could play an important role ingrowing crop for high profit, enhancing the availability of water and nutrients in the rootzone environment, and maintaining soil fertility.

The present study aims to evaluate the benefit effects of biochar applications on some soil properties and in mitigating the adverse effects induced by drought on sugar beet plants grown in salt-affected soils.

Therefore, field experiment was carried out in Demo farm, Faculty of Agriculture, Fayoum University, Fayoum, Egypt.

Three deficit irrigation regimes (i.

e.

I100= 100%, I80= 80% and I60=60% of crop evapotranspiration (ETc) and three application rates of biochar (i.

e.

B0=zero addition(control), B10 =10 (t ha-1) and B20 = 20 (t ha-1) were applied.

The experimental treatments were arranged in a complete randomized block design split-split plot with three replicates.

Sugar beet seeds (Beta vulgaris L., Baraca) was planted in two successive winter seasons along two years (2019/2020 and 2020/2021) in salt affected soils (ECe =10.94 dS/m).

The obtained results revealed that biochar amendment improved soil moisture retention characteristics.

Biochar addition by 20 t ha-1 caused significant reduction in soil bulk density, hydraulic conductivity, soil ECe by 2.94, 16.04 and 12.49% respectively.

Meanwhile under high level of biochar addition 20 (t ha-1), field capacity (FC), available water content (AW), cation exchangeable capacity and organic matter content were significantly increased by 18.03, 31.10and 11.76% respectively compared with control.

In addition, sugar beet growth parameters (root length, root diameter, leaves number, leaves area and dry matter) and physiological attributes (relative water content, membrane stability index and SPAD) were significantly affected by the applied deficit water regimes and biochar application levels.

However, sugar roots yield (t ha-1) and biomass yield (t ha-1) were reduced by 11.67 and15.01% at (I80) and by 33.78 and 33.22% at (I60), respectively, compared with full irrigation treatment.

However, harvest index (HI) and water productivity (WP) recorded their maximum values 0.68 and 18.18 (kgm-3), respectively, under moderate irrigation regime (I80).

Thus, the application of biochar treatments could be efficiently used to produce high productivity of sugar beet crop and reduce the hazardous effects induced by salinity and drought stresses on both growth and yield of sugar beet crop.

In addition, the use of irrigation regime (I80) in combination with biochar application rate (B20) could found to be a favorable agro-management strategy to save 20% of the applied irrigation water and slightly decrease in yield of sugar beet crop (11.67%) under Fayoum conditions.