BIOCHAR FROM DIFFERENT FEEDSTOCKS AS A SUSTAINABLE APPROACH TO ALLEVIATE WATER DEFICIT EFFECTS ON ZUCCHINI

Rising temperatures and evapotranspiration (ETc) are causing drought in dryland regions, exacerbating water scarcity. Biochar has shown potential for water conservation and crop resilience under water deficit conditions. A study on zucchini plants grown under varying water regimes (100, 80, and 60% ETc) showed that date palm leaf midrib (DLMB) and maize bare cob (MBCB) biochar-amended media improved morpho-physio-biochemical traits. Zucchini plants grown in MBCBamended media exhibited 9%, 10%, 7%, and 16% increase in plant height, plant spread, fruit weight, and yield compared to those grown in DLMB media. However, these attributes declined 39%, 28%, 35%, and 52% in sandy loam (SL) control media compared to MBCB media. Comparing water deficit conditions (80% and 60%), plants irrigated at 100% ETc showed significantly positive effects. The combined effect of both factors indicated that plants are grown at 100% ETc in MBCBand DLMB-amended media surpass all other treatment combinations. However, impressively, zucchini plants grown in MBCB media at 80% and 60% ETc, and in DLMB media at 80% ETc, displayed growth, yield, and quality metrics comparable to those of plants grown in fully watered (100% ETc) SL soil. Water scarcity significantly suppressed plant growth, physiology, yield, and fruit quality in SL media at 80% and 60% ETc. This concludes that incorporating MBCB and DLMB biochar can conserve 20-40% of irrigation water while maintaining growth and production of zucchini crop under greenhouse conditions. The findings of this study can provide practical guidance for applying biochar derived from empty maize cobs and date palm leaf midribs to conserve water resources particularly in the water scarce regions. Further research is needed to comprehend the long-term impacts of biochar on crop production, soil fertility, water quality, soil biology, nutrient cycling, and greenhouse gas emissions across various soil types.