Effects of Urea Fertilizer Levels on Growth and Yield of Safflower (Carthamus tinctorius L.) Under Kabul Climatic Conditions

2026-06-20T07:09:55+00:00

Safflower (Carthamus tinctorius L.) is an important oil-bearing crop with significant economic and medicinal value, well adapted to arid and semi-arid climates. Despite its agronomic potential, systematic research on optimal nitrogen fertilization for safflower under the specific climatic conditions of Kabul, Afghanistan, remains limited. This study evaluated the effects of six urea levels (0, 40, 60, 80, 100, and 120 kg ha⁻¹) on the growth and yield of safflower using a Randomized Complete Block Design (RCBD) with three replications at the Kabul University research farm during the spring season of 2025. Data were analyzed by analysis of variance (ANOVA), and treatment means were compared using the least significant difference (LSD) test at the 5% probability level. Results demonstrated that urea application significantly influenced plant height, number of leaves, number of branches, days to 50% flowering, number of capitula plant⁻¹, number of seeds capitulum⁻¹, thousand-seed weight (TSW), seed yield, and straw yield. The highest seed yield (1,650 kg ha⁻¹) and TSW (41.50 g) were recorded at T5 (100 kg urea ha⁻¹), whereas the highest straw yield (3,300 kg ha⁻¹) was obtained at T6 (120 kg urea ha⁻¹), albeit with a slight decline in seed yield and TSW. These findings indicate that 100 kg urea ha⁻¹ represents the optimal nitrogen application rate for economically viable safflower production under Kabul conditions.

Rhizosphere Microbiome–Biofertilizer Nexus: Integrating Biological Inputs and Abiotic Stress Tolerance Mechanisms in Horticultural Crops

2026-07-16T07:18:05+00:00

Climate change is intensifying abiotic stresses such as drought and salinity, threatening horticultural productivity worldwide and creating an urgent need for sustainable, ecologically resilient production strategies. Using a structured narrative review approach, this study synthesizes peer-reviewed literature published between 2020 and 2026, retrieved from Scopus, Web of Science, PubMed, and Google Scholar; to evaluate how beneficial soil microorganisms and biological inputs enhance horticultural crop performance under stress. The objective is to examine the efficacy of Plant Growth-Promoting Rhizobacteria (PGPR), Arbuscular Mycorrhizal Fungi (AMF), and other microbial inoculants in improving growth and yield in tomato (Solanum lycopersicum), mediating drought tolerance in grapevine (Vitis vinifera) through osmotic adjustment and antioxidant defense, and mitigating salinity-induced ionic toxicity in date palm (Phoenix dactylifera) via halotolerant microbial mechanisms. Unlike previous reviews that typically examine a single crop, a single stress type, or a single microbial group in isolation, this review integrates rhizosphere microbial diversity, biofertilizer function, and multi-stress tolerance mechanisms within a single conceptual framework, the Rhizosphere Microbiome–Biofertilizer Nexus. Findings show that rhizosphere microbial diversity functions as a central mediator of nutrient cycling and stress signaling. Comparative evidence across studies further indicates that microbiome engineering and synthetic microbial consortia represent an emerging frontier in horticultural science, although consistent field performance remains constrained by formulation and site-specific limitations. The review concludes that the accumulated evidence positions microbial-based biological inputs as an increasingly indispensable, rather than merely supplementary, component of sustainable horticulture, with direct implications for climate-adaptive agricultural policy and food security.

Digital Agriculture and Innovation Journal

Effects of Urea Fertilizer Levels on Growth and Yield of Safflower (Carthamus tinctorius L.) Under Kabul Climatic Conditions

Rhizosphere Microbiome–Biofertilizer Nexus: Integrating Biological Inputs and Abiotic Stress Tolerance Mechanisms in Horticultural Crops