Articles

Soybean Growth and Yield Response to Fertilizers: A Comparative Review of Organic and Inorganic Inputs under Kabul Semi‑Arid Conditions

Soybean (Glycine max L.) is a globally important crop valued for its high protein and oil content, yet its productivity in Afghanistan remains constrained by poor soil fertility and reliance on chemical fertilizers. This review article synthesizes experimental evidence on the comparative effects of organic inputs (night soil, farm manure) and inorganic fertilizers (diammonium phosphate, urea) on soybean growth and yield under Kabul’s semi‑arid conditions. The purpose of this study is to evaluate sustainable nutrient management strategies that enhance crop productivity while maintaining soil health.

Field trials conducted at Kabul University employed a randomized complete block design with five treatments: control, night soil, farm manure, DAP, and urea. Growth parameters such as plant height, branches per plant, leaf number, and pods per plant were measured alongside yield attributes including 100‑seed weight and grain yield. Results demonstrated that organic amendments significantly improved soybean performance compared to chemical fertilizers. Farm manure produced the tallest plants, highest branching, and maximum pods per plant, with grain yield reaching 1725 kg/ha. Night soil accelerated flowering and pod formation while also improving yield (1616 kg/ha). In contrast, urea resulted in the lowest yield (1262 kg/ha), highlighting the limitations of sole reliance on chemical inputs.

The findings confirm that organic fertilizers enhance soil structure, microbial activity, and long‑term fertility, making them vital for sustainable soybean production in semi‑arid Kabul. Integrating organic inputs into nutrient management strategies can reduce dependence on chemical fertilizers, improve food security, and support climate‑resilient agriculture in Afghanistan.

Effect of Different Levels of Diammonium Phosphate (DAP) Fertilizer on Growth and Yield of Chickpea (Cicer arietinum L.) Variety Flip 94

Chickpea (Cicer arietinum L.) is an important pulse crop valued for its nutritional quality and role in sustainable agriculture. However, productivity is often constrained by low soil fertility and poor nutrient management, particularly phosphorus deficiency. A field experiment was conducted during the 2025 growing season at the Research Farm of the Faculty of Agriculture, Kabul University, Afghanistan, to evaluate the effect of different levels of diammonium phosphate (DAP) fertilizer on growth and yield of chickpea variety Flip 94. The experiment was arranged in a Randomized Complete Block Design (RCBD) with five DAP levels (0, 50, 100, 150, and 200 kg ha⁻¹) and three replications. Results showed that DAP application significantly influenced all growth and yield parameters, while replication effects were non-significant. Treatment 3 (100 kg ha⁻¹ DAP) consistently performed best, recording the highest plant height (34.23 cm), number of branches per plant (4.92), number of pods per plant (37.47), grains per pod (1.93), and grain yield (5.52 t ha⁻¹). In contrast, the control treatment recorded the lowest values for all studied traits. The improved performance under optimal DAP application is attributed to enhanced nutrient availability, better root development, increased nodulation, and improved photosynthetic efficiency, which collectively supported stronger vegetative growth and reproductive development. In conclusion, application of DAP fertilizer significantly improves chickpea growth and yield under Kabul agro-climatic conditions. Treatment 3 (100 kg ha⁻¹ DAP) was identified as the most effective dose for maximizing productivity of chickpea variety Flip 94.

Effects of Different Levels of DAP on Agronomical Characteristics and Yield of Mung bean

Phosphorus deficiency is one of the main factors restricting mung bean (Vigna radiata L.) production in many parts of the world, including Afghanistan. Therefore, a field experiment was carried out in the 2025 growing season at the Research Farm of the Faculty of Agriculture, Kabul University, to determine the influence of different diammonium phosphate (DAP) fertilizer levels on mung bean growth and yield. The experiment was arranged in a randomized complete block design (RCBD) with three replications, consisting of four DAP rates: 0, 30, 60, and 90 kg ha⁻¹. The collected growth and yield data were analyzed using analysis of variance (ANOVA), and mean comparisons were performed using the Least Significant Difference (LSD) test at a 5% probability level. The application of DAP fertilizer significantly improved plant height, shoot dry matter, number of branches, pods per plant, pod length, seeds per pod, and 100-seed weight. However, leaf number, grain weight per square meter, seed yield, and harvest index did not show significant differences among fertilizer treatments, although higher values were generally observed compared with the control treatment. The maximum seed yield (870.83 kg ha⁻¹) was obtained from the application of 60 kg DAP ha⁻¹, while the highest performance for most growth and yield-related traits was recorded under 90 kg DAP ha⁻¹. The findings suggest that DAP fertilizer application enhances mung bean growth and yield performance under the environmental conditions of Kabul. Among the tested fertilizer levels, 60 kg DAP ha⁻¹ was found to be the most effective rate for achieving higher grain yield.