Amending Sandy Soil with Biochar or/and Superabsorbent Polymer Mitigates the Adverse Effects of Drought Stress on Green Pea

Abstract

Faced with the scarceness of water resources and climate changes, drought is undoubtedly one of the most important abiotic stresses limiting the growth and productivity of plants including green pea, especially in the arid and semi-arid areas. The uses of soil amendments like biochar and superabsorbent polymer, which characterized by enhancing water holding capacity and improving soil physical properties, become more important in these areas. A lysimeter experiment with sandy soil in a completely randomized design was carried out in three replicates to study the effect of biochar or/and superabsorbent polymer on the growth and productivity of green pea (Pisum sativum L.) cv. Master B under full irrigation (100% of water requirement) and water deficit regime (75% of water requirement) conditions during 2015/2016 and 2016/2017 seasons at the Experimental Research Farm of the Horticulture Department, Faculty of Agriculture, Ain Shams University, Qalyubia Governorate, Egypt. Results revealed that lowering irrigation level to 75% of water requirements led to significant decreases in vegetative growth parameters, SPAD readings, leaf relative water content, leaf nutrients (N, P, and K) and pod yield components compared with the full irrigation. Adding biochar or/and superabsorbent polymer significantly increased the aforementioned characters under both full irrigation and water deficit conditions. Application of biochar with superabsorbent polymer was the most efficient treatment to alleviate the deleterious effects of water deficit on green pea cultivation in sandy soils. In conclusion, applying biochar (1% w/w) with superabsorbent polymer (0.7% w/w) might be a promising novel approach to improve sandy soils characteristics and help green pea cultivation in these soils which are characterized by a low water holding capacity and low fertility.