A field experiment was carried out to study the conditioning effect of composted rice straw biochar (RSB) and synthetic cellulose polymer like carboxymethyl cellulose (CMC) on soil moisture distribution patterns, some plant growth parameters, yield and water use efficiency of squash plant (Cucurbita pepo L. var. Hybrid Revera). So, a complete randomized field experiment with three replications was conducted during the summer season of 2018 on a loamy sand soil at the Animal Production farm, Faculty of Agriculture, Al-Azhar University, Nasr City, Cairo, Egypt. The treatments were applying RSB by two rates (i.e. 840 and 1680 ) and CMC by two rates (i.e. 16.8 and 33.6 ) with 100% and 80% of squash water requirements. The obtained results indicated a positive effect on soil moisture distribution patterns, some plant growth parameters, yield and water use efficiency due to application of RSB with 100 and 80  of squash water requirements. Whereas, the soil was retained by the highest moisture content (18.8-15.0 ) and (15.4-10.6 ) with 100  and 80  at (0-40cm), respectively. The highest productivity was 7576.69 and 6436.69  when adding 100  and 80  of squash water requirements, respectively. Also, the highest irrigation water use efficiency was 9.33 and 9.91 of irrigation water when adding 100  and 80  squash water requirements, respectively. Finally, the obtained results indicate that adding rice straw biochar (RSB) to the planting medium at a low water irrigation rate of 80  increases the efficiency of water use by preventing applied moisture from infiltrating beyond plant root zones and maximizing the amount of applied water available for plant uptake.
A field experiment was carried out to study the conditioning effect of composted rice straw biochar (RSB) and synthetic cellulose polymer like carboxymethyl cellulose (CMC) on soil moisture distribution patterns, some plant growth parameters, yield and water use efficiency of squash plant (Cucurbita pepo L. var. Hybrid Revera). So, a complete randomized field experiment with three replications was conducted during the summer season of 2018 on a loamy sand soil at the Animal Production farm, Faculty of Agriculture, Al-Azhar University, Nasr City, Cairo, Egypt. The treatments were applying RSB by two rates (i.e. 840 and 1680 ) and CMC by two rates (i.e. 16.8 and 33.6 ) with 100% and 80% of squash water requirements. The obtained results indicated a positive effect on soil moisture distribution patterns, some plant growth parameters, yield and water use efficiency due to application of RSB with 100 and 80  of squash water requirements. Whereas, the soil was retained by the highest moisture content (18.8-15.0 ) and (15.4-10.6 ) with 100  and 80  at (0-40cm), respectively. The highest productivity was 7576.69 and 6436.69  when adding 100  and 80  of squash water requirements, respectively. Also, the highest irrigation water use efficiency was 9.33 and 9.91 of irrigation water when adding 100  and 80  squash water requirements, respectively. Finally, the obtained results indicate that adding rice straw biochar (RSB) to the planting medium at a low water irrigation rate of 80  increases the efficiency of water use by preventing applied moisture from infiltrating beyond plant root zones and maximizing the amount of applied water available for plant uptake.