Thesis (Ph.D)-Cairo University, 2025.

Bibliography: pages 92-111.

Cocopeat is among the most frequently utilized substrates in soilless farming.
Nonetheless, the extraction of Cocopeat generates a detrimental carbon footprint,
highlighting the necessity for alternative, sustainable substrate options. To tackle
this issue, we examined the effects of substituting Cocopeat with a blend of various
Rice straw, Sawdust, and compost on cucumber growth and yield over two growing
seasons, 2021–2022 and 2022–2023. The treatments included Cocopeat 100%
(control), sawdust 100%, rice straw 100%, compost 100%, combinations of
Cocopeat and sawdust (1:1, v/v), combinations of Cocopeat and sawdust (3:1, v/v),
combinations of Cocopeat and rice straw (1:1, v/v), combinations of Cocopeat and
rice straw (3:1, v/v), combinations of Cocopeat and compost (1:1, v/v), and
combinations of Cocopeat and compost (3:1, v/v). The highest yield was recorded
with rice straw at 100.55 ton ha-1, followed by the Coco 50%: Compost 50%
treatment yielding 74.32 ton ha-1 and 69.26 ton ha-1, respectively, while the lowest
yield was noted for sawdust at 22.23 ton ha-1. Across both growth seasons, rice
straw achieved the highest irrigation water productivity (IWP) of 51.56 and 51.91
kg m− 3, respectively, followed by Coco 50%: Rice straw 50% at 38.08 and 38.37
kg m− 3, whereas sawdust resulted in the lowest IWPs of 6.93 and 11.48 kg m− 3. In
both growing seasons, the rice straw showed the greatest rate of photosynthesis,
with readings of 23.34 µmol m–2 s–1 and 22.14 µmol m–2 s–1, respectively.
Conversely, the lowest photosynthesis rates during both growing seasons were
observed with the Coco 75%: Compost 25% treatment, at 3.23 µmol m–2 s–1 and
3.03 µmol m–2 s–1, respectively. The treated rice straw substrate media ranked as
the most profitable and resilient option in terms of net present value (NPV) and
benefit-cost (B/C) ratio metrics, followed closely by the compost treatment. It
seems that treated rice straw-based media is a promising substrate in soilless culture
systems as a viable alternative substrate for cucumber cultivation instead of
Cocopeat substrate.

يُعدّ الكوكوبيت من أكثر البيئات استخدامًا في الزراعة بدون تربة، إلا أن استخراجه يسبب بصمة كربونية مرتفعة، مما يستدعي البحث عن بدائل مستدامة. هدفت الدراسة إلى تقييم تأثير استبدال الكوكوبيت بخليط من قش الأرز، ونشارة الخشب، والكمبوست على نمو وإنتاجية الخيار خلال موسمي 2021–2022 و2022–2023. أظهرت النتائج أن قش الأرز حقق أعلى إنتاجية (100.55 طن/هكتار) وأعلى كفاءة لاستخدام مياه الري (51.91 كجم/م³). كما تميز قش الأرز بأعلى معدل للتمثيل الضوئي مقارنة بباقي المعاملات. في المقابل، سجلت نشارة الخشب أقل القيم في جميع الصفات المدروسة. أظهرت التحليلات الاقتصادية تفوق قش الأرز من حيث الربحية وفقًا لمؤشري NPV وB/C، مما يجعله بديلاً واعدًا للكوكوبيت في أنظمة الزراعة بدون تربة.

Issues also as CD.

Text in English and abstract in Arabic & English.