Effect of Precision Nutrient Management and Humic Substances on Growth and Yield Attributes of Wheat (Triticum aestivum L.) in the Hyper-Arid Region of Rajasthan, India
Kiran Dhaka
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
R. C. Bairwa
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
Amit Kumawat
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
A. S. Godara
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
Ranjeet Singh
Department of Soil Science and Agricultural Chemistry, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
Rahul
*
Department of Agronomy, Rajasthan Agricultural Research Institute (RARI), Durgapura, Sri Karan Narendra Agriculture University (SKNAU), Jaipur 302018, Rajasthan, India.
Dilip Choudhary
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
Jigyasha Ninama
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
Avtar Singh
Department of Agronomy, College of Agriculture, Bikaner, Swami Keshwanand Rajasthan Agricultural University, Bikaner – 334 006, Rajasthan, India.
*Author to whom correspondence should be addressed.
Abstract
Background: Wheat cultivated on loamy sand soils in hyper-arid Rajasthan requires nutrient management suited to limited soil nutrient retention. This study assessed the effects of precision nutrient management and soil-applied humic substances on wheat growth and yield attributes.
Methods: A field experiment was conducted at Bikaner during the 2024–25 and 2025–26 rabi seasons using a split-plot design with three replications. Five nutrient treatments comprised an unfertilised control, the recommended dose of fertilisers (RDF), Nutrient Expert (NE), NE with leaf colour chart (LCC)-guided nitrogen application, and NE with chlorophyll meter (SPAD)-guided nitrogen application. Five humic-substance treatments comprised a control and combinations of humic acid (HA; 20 or 30 kg ha⁻¹) and fulvic acid (FA; 10 or 15 kg ha⁻¹). Results were pooled over two seasons.
Results: NE + SPAD produced the tallest plants (86.55 cm), the most total tillers (541 m⁻²) and effective tillers (407 m⁻²), and the longest (9.11 cm) and heaviest (2.27 g) spikes. These results were statistically comparable with NE + LCC. NE alone was comparable with RDF while applying 8.3% less nitrogen and 17.5% less P₂O₅. HA 30 + FA 15 kg ha⁻¹ gave the highest numerical responses but was statistically comparable with HA 30 + FA 10 kg ha⁻¹. No significant interaction between the two treatment factors was detected.
Conclusion: Sensor-guided NE and soil application of HA at 30 kg ha⁻¹ improved the measured growth and yield attributes under the experimental conditions.
Keywords: Triticum aestivum, site-specific nutrient management, Nutrient Expert, chlorophyll meter, leaf colour chart, humic acid, fulvic acid, arid zone